Sheena Meredith, MBBS, MPhil

Infertile men may be twice as likely to develop invasive breast cancer as those without fertility issues, according to new research funded by the charity Breast Cancer Now and published in Breast Cancer Research. The study is one of the largest ever into male breast cancer, enabling the team to show a highly statistically significant association.  

A link with infertility had been suspected, since parity markedly reduces the risk of female breast cancer; there are known genetic links in both sexes, and a high risk of both breast cancer and infertility among men with Klinefelter syndrome, suggesting some sex hormone-related involvement. However, the rarity of breast cancer in men – with an annual incidence of about 370 cases and 80 deaths per year in the United Kingdom – meant that past studies were necessarily small and yielded mixed results.

“Compared with previous studies, our study of male breast cancer is large,” said study coauthor Michael Jones, PhD, of the division of genetics and epidemiology at the Institute of Cancer Research (ICR) in London. “It was carried out nationwide across England and Wales and was set in motion more than 15 years ago. Because of how rare male breast cancer is, it took us over 12 years to identify and interview the nearly 2,000 men with breast cancer who were part of this study.”

The latest research is part of the wider Breast Cancer Now Male Breast Cancer Study, launched by the charity in 2007. For the new study, the ICR team interviewed 1,998 males living in England and Wales who had been diagnosed with breast cancer between 2005 and 2017. All were aged under 80 but most 60 or older at diagnosis; 92% of their tumors were invasive, and almost all were estrogen receptor positive (98.5% of those with known status).

Their responses were compared with those of a control group of 1,597 men without breast cancer, matched by age at diagnosis and geographic region, recruited from male non-blood relatives of cases and from husbands of women participating in the Generations cohort study of breast cancer etiology.
 

Raised risk with history of male infertility

Overall, 112 cases (5.6%) and 80 controls (5.0%) reported that they had had infertility problems for which they or their partner had consulted a doctor or infertility clinic. This represented a raised odds ratio of 1.29 (95% confidence interval, 0.94-1.77), which was statistically not significant. However, when analyzed by outcome of the infertility consultation, there was a significant and more than doubled risk of breast cancer among men who were diagnosed as the source of the couple’s infertility (OR = 2.03 [1.18-3.49]), whereas this was not the case among men whose partner was the source (OR = 0.86 [0.51-1.45]) or for whom no source was identified (OR = 1.26 [0.71-2.24]).

In addition, proportionately fewer cases (1,615, or 80.8%) compared with controls (1,423, or 89.1%) had fathered any children, also giving a statistically significantly raised risk of breast cancer for men with no biological children (OR = 1.50 [1.21-1.86], P < .001), “congruent with infertility as a risk factor,” the authors said. The risk was statistically significant for invasive tumors but not for the much smaller number of in situ tumors.

Analysis by number of children showed a decreasing risk with increasing numbers of children, with a highly significant (P < .001) inverse trend where zero was included as a value, but a borderline significant trend (P = .04) if it was not. The team noted that number of children beyond one is difficult to interpret as an indicator of male fertility, since it may more reflect social and cultural factors than fertility per se.

Baseline demographic factors were adjusted for in the risk analyses, and results were not materially changed by sensitivity analyses adjusting additionally for alcohol consumption, smoking, liver disease, and family history of breast cancer. The association also largely remained after exclusion of patients with other preexisting potential confounders including severe obesity and testicular abnormalities, and was consistent irrespective of HER-2 status (there were too few ER-negative tumors to analyze results by ER status).
 

Potential underlying factors

“The causes of breast cancer in men are largely unknown, partly because it is rare and partly because previous studies have been small,” Dr. Jones said. “The evidence presented in our study suggests that the association of infertility and breast cancer should be confirmed with further research, and future investigations are needed into the potential underlying factors, such as hormone imbalances.”

Commenting on the study, Fiona Osgun, senior health information manager at Cancer Research UK, told this news organization: “Overall, there isn’t strong evidence that infertility is a risk factor for male breast cancer. This study helps to shed light onto a cancer type that is sadly still not very well understood, but much more research is needed to say that infertility is a risk factor for male breast cancer.”

She added that although male breast cancer is a rare condition, it’s still important for men to be aware of what looks and feels normal for them, and to be encouraged to seek medical advice if something is not quite right.

A spokesperson for Breast Cancer UK told this news organization: “[We] believe it’s important to understand what leads to breast cancer in men as well as women and that high quality, long-term studies such as this will help with this understanding.

The findings are consistent with an earlier study that found that U.S. men who have never fathered children are at higher risk of breast cancer. This new long-term U.K. study provides strong evidence, which supports this finding.  

“As the authors note, the biological reasons are unclear, but may be associated with altered hormone levels. The ratio of circulating levels of estrogen and androgens (e.g. testosterone) is crucial in healthy functioning of breast tissue. Disruption to this, for example as a result of damage to testes, may affect both fertility and breast cancer risk.

“It is also possible that external factors, such as exposure to certain endocrine (hormone) disrupting chemicals (EDCs), which affect sex hormones, may also affect both fertility and breast cancer risk.

“More studies into breast cancer in men are needed to help us understand better all the risk factors associated with this disease including both hormonal factors and chemical exposures.”

Simon Vincent, PhD, director of research, support, and influencing at Breast Cancer Now, said: “Research has discovered different treatments directed at some features of breast cancer in women; however, breast cancer is not as well understood for men. This is why Breast Cancer Now funds the Male Breast Cancer Study, which looks at what might cause the disease in men. Discovering a link between infertility and male breast cancer is a step towards us understanding male breast cancer and how we could find more ways to diagnose and treat men – and possibly women – with this devastating disease.”

A version of this article first appeared on Medscape UK.

Infertile men may be twice as likely to develop invasive breast cancer as those without fertility issues, according to new research funded by the charity Breast Cancer Now and published in Breast Cancer Research. The study is one of the largest ever into male breast cancer, enabling the team to show a highly statistically significant association.  

A link with infertility had been suspected, since parity markedly reduces the risk of female breast cancer; there are known genetic links in both sexes, and a high risk of both breast cancer and infertility among men with Klinefelter syndrome, suggesting some sex hormone-related involvement. However, the rarity of breast cancer in men – with an annual incidence of about 370 cases and 80 deaths per year in the United Kingdom – meant that past studies were necessarily small and yielded mixed results.

“Compared with previous studies, our study of male breast cancer is large,” said study coauthor Michael Jones, PhD, of the division of genetics and epidemiology at the Institute of Cancer Research (ICR) in London. “It was carried out nationwide across England and Wales and was set in motion more than 15 years ago. Because of how rare male breast cancer is, it took us over 12 years to identify and interview the nearly 2,000 men with breast cancer who were part of this study.”

The latest research is part of the wider Breast Cancer Now Male Breast Cancer Study, launched by the charity in 2007. For the new study, the ICR team interviewed 1,998 males living in England and Wales who had been diagnosed with breast cancer between 2005 and 2017. All were aged under 80 but most 60 or older at diagnosis; 92% of their tumors were invasive, and almost all were estrogen receptor positive (98.5% of those with known status).

Their responses were compared with those of a control group of 1,597 men without breast cancer, matched by age at diagnosis and geographic region, recruited from male non-blood relatives of cases and from husbands of women participating in the Generations cohort study of breast cancer etiology.
 

Raised risk with history of male infertility

Overall, 112 cases (5.6%) and 80 controls (5.0%) reported that they had had infertility problems for which they or their partner had consulted a doctor or infertility clinic. This represented a raised odds ratio of 1.29 (95% confidence interval, 0.94-1.77), which was statistically not significant. However, when analyzed by outcome of the infertility consultation, there was a significant and more than doubled risk of breast cancer among men who were diagnosed as the source of the couple’s infertility (OR = 2.03 [1.18-3.49]), whereas this was not the case among men whose partner was the source (OR = 0.86 [0.51-1.45]) or for whom no source was identified (OR = 1.26 [0.71-2.24]).

In addition, proportionately fewer cases (1,615, or 80.8%) compared with controls (1,423, or 89.1%) had fathered any children, also giving a statistically significantly raised risk of breast cancer for men with no biological children (OR = 1.50 [1.21-1.86], P < .001), “congruent with infertility as a risk factor,” the authors said. The risk was statistically significant for invasive tumors but not for the much smaller number of in situ tumors.

Analysis by number of children showed a decreasing risk with increasing numbers of children, with a highly significant (P < .001) inverse trend where zero was included as a value, but a borderline significant trend (P = .04) if it was not. The team noted that number of children beyond one is difficult to interpret as an indicator of male fertility, since it may more reflect social and cultural factors than fertility per se.

Baseline demographic factors were adjusted for in the risk analyses, and results were not materially changed by sensitivity analyses adjusting additionally for alcohol consumption, smoking, liver disease, and family history of breast cancer. The association also largely remained after exclusion of patients with other preexisting potential confounders including severe obesity and testicular abnormalities, and was consistent irrespective of HER-2 status (there were too few ER-negative tumors to analyze results by ER status).
 

Potential underlying factors

“The causes of breast cancer in men are largely unknown, partly because it is rare and partly because previous studies have been small,” Dr. Jones said. “The evidence presented in our study suggests that the association of infertility and breast cancer should be confirmed with further research, and future investigations are needed into the potential underlying factors, such as hormone imbalances.”

Commenting on the study, Fiona Osgun, senior health information manager at Cancer Research UK, told this news organization: “Overall, there isn’t strong evidence that infertility is a risk factor for male breast cancer. This study helps to shed light onto a cancer type that is sadly still not very well understood, but much more research is needed to say that infertility is a risk factor for male breast cancer.”

She added that although male breast cancer is a rare condition, it’s still important for men to be aware of what looks and feels normal for them, and to be encouraged to seek medical advice if something is not quite right.

A spokesperson for Breast Cancer UK told this news organization: “[We] believe it’s important to understand what leads to breast cancer in men as well as women and that high quality, long-term studies such as this will help with this understanding.

The findings are consistent with an earlier study that found that U.S. men who have never fathered children are at higher risk of breast cancer. This new long-term U.K. study provides strong evidence, which supports this finding.  

“As the authors note, the biological reasons are unclear, but may be associated with altered hormone levels. The ratio of circulating levels of estrogen and androgens (e.g. testosterone) is crucial in healthy functioning of breast tissue. Disruption to this, for example as a result of damage to testes, may affect both fertility and breast cancer risk.

“It is also possible that external factors, such as exposure to certain endocrine (hormone) disrupting chemicals (EDCs), which affect sex hormones, may also affect both fertility and breast cancer risk.

“More studies into breast cancer in men are needed to help us understand better all the risk factors associated with this disease including both hormonal factors and chemical exposures.”

Simon Vincent, PhD, director of research, support, and influencing at Breast Cancer Now, said: “Research has discovered different treatments directed at some features of breast cancer in women; however, breast cancer is not as well understood for men. This is why Breast Cancer Now funds the Male Breast Cancer Study, which looks at what might cause the disease in men. Discovering a link between infertility and male breast cancer is a step towards us understanding male breast cancer and how we could find more ways to diagnose and treat men – and possibly women – with this devastating disease.”

A version of this article first appeared on Medscape UK.

Infertile men may be twice as likely to develop invasive breast cancer as those without fertility issues, according to new research funded by the charity Breast Cancer Now and published in Breast Cancer Research. The study is one of the largest ever into male breast cancer, enabling the team to show a highly statistically significant association.  

A link with infertility had been suspected, since parity markedly reduces the risk of female breast cancer; there are known genetic links in both sexes, and a high risk of both breast cancer and infertility among men with Klinefelter syndrome, suggesting some sex hormone-related involvement. However, the rarity of breast cancer in men – with an annual incidence of about 370 cases and 80 deaths per year in the United Kingdom – meant that past studies were necessarily small and yielded mixed results.

“Compared with previous studies, our study of male breast cancer is large,” said study coauthor Michael Jones, PhD, of the division of genetics and epidemiology at the Institute of Cancer Research (ICR) in London. “It was carried out nationwide across England and Wales and was set in motion more than 15 years ago. Because of how rare male breast cancer is, it took us over 12 years to identify and interview the nearly 2,000 men with breast cancer who were part of this study.”

The latest research is part of the wider Breast Cancer Now Male Breast Cancer Study, launched by the charity in 2007. For the new study, the ICR team interviewed 1,998 males living in England and Wales who had been diagnosed with breast cancer between 2005 and 2017. All were aged under 80 but most 60 or older at diagnosis; 92% of their tumors were invasive, and almost all were estrogen receptor positive (98.5% of those with known status).

Their responses were compared with those of a control group of 1,597 men without breast cancer, matched by age at diagnosis and geographic region, recruited from male non-blood relatives of cases and from husbands of women participating in the Generations cohort study of breast cancer etiology.
 

Raised risk with history of male infertility

Overall, 112 cases (5.6%) and 80 controls (5.0%) reported that they had had infertility problems for which they or their partner had consulted a doctor or infertility clinic. This represented a raised odds ratio of 1.29 (95% confidence interval, 0.94-1.77), which was statistically not significant. However, when analyzed by outcome of the infertility consultation, there was a significant and more than doubled risk of breast cancer among men who were diagnosed as the source of the couple’s infertility (OR = 2.03 [1.18-3.49]), whereas this was not the case among men whose partner was the source (OR = 0.86 [0.51-1.45]) or for whom no source was identified (OR = 1.26 [0.71-2.24]).

In addition, proportionately fewer cases (1,615, or 80.8%) compared with controls (1,423, or 89.1%) had fathered any children, also giving a statistically significantly raised risk of breast cancer for men with no biological children (OR = 1.50 [1.21-1.86], P < .001), “congruent with infertility as a risk factor,” the authors said. The risk was statistically significant for invasive tumors but not for the much smaller number of in situ tumors.

Analysis by number of children showed a decreasing risk with increasing numbers of children, with a highly significant (P < .001) inverse trend where zero was included as a value, but a borderline significant trend (P = .04) if it was not. The team noted that number of children beyond one is difficult to interpret as an indicator of male fertility, since it may more reflect social and cultural factors than fertility per se.

Baseline demographic factors were adjusted for in the risk analyses, and results were not materially changed by sensitivity analyses adjusting additionally for alcohol consumption, smoking, liver disease, and family history of breast cancer. The association also largely remained after exclusion of patients with other preexisting potential confounders including severe obesity and testicular abnormalities, and was consistent irrespective of HER-2 status (there were too few ER-negative tumors to analyze results by ER status).
 

Potential underlying factors

“The causes of breast cancer in men are largely unknown, partly because it is rare and partly because previous studies have been small,” Dr. Jones said. “The evidence presented in our study suggests that the association of infertility and breast cancer should be confirmed with further research, and future investigations are needed into the potential underlying factors, such as hormone imbalances.”

Commenting on the study, Fiona Osgun, senior health information manager at Cancer Research UK, told this news organization: “Overall, there isn’t strong evidence that infertility is a risk factor for male breast cancer. This study helps to shed light onto a cancer type that is sadly still not very well understood, but much more research is needed to say that infertility is a risk factor for male breast cancer.”

She added that although male breast cancer is a rare condition, it’s still important for men to be aware of what looks and feels normal for them, and to be encouraged to seek medical advice if something is not quite right.

A spokesperson for Breast Cancer UK told this news organization: “[We] believe it’s important to understand what leads to breast cancer in men as well as women and that high quality, long-term studies such as this will help with this understanding.

The findings are consistent with an earlier study that found that U.S. men who have never fathered children are at higher risk of breast cancer. This new long-term U.K. study provides strong evidence, which supports this finding.  

“As the authors note, the biological reasons are unclear, but may be associated with altered hormone levels. The ratio of circulating levels of estrogen and androgens (e.g. testosterone) is crucial in healthy functioning of breast tissue. Disruption to this, for example as a result of damage to testes, may affect both fertility and breast cancer risk.

“It is also possible that external factors, such as exposure to certain endocrine (hormone) disrupting chemicals (EDCs), which affect sex hormones, may also affect both fertility and breast cancer risk.

“More studies into breast cancer in men are needed to help us understand better all the risk factors associated with this disease including both hormonal factors and chemical exposures.”

Simon Vincent, PhD, director of research, support, and influencing at Breast Cancer Now, said: “Research has discovered different treatments directed at some features of breast cancer in women; however, breast cancer is not as well understood for men. This is why Breast Cancer Now funds the Male Breast Cancer Study, which looks at what might cause the disease in men. Discovering a link between infertility and male breast cancer is a step towards us understanding male breast cancer and how we could find more ways to diagnose and treat men – and possibly women – with this devastating disease.”

A version of this article first appeared on Medscape UK.

A relationship between consumption of dairy products and risk of various cancers has been intensively investigated in the past but yielded inconclusive or conflicting results. Now a large new study comparing Chinese dairy consumption with that in the United Kingdom, shows that increased dairy consumption was linked to higher risks of liver cancer and female breast cancer.

The study, by researchers from Oxford University’s department of population health, and Peking University and the Chinese Academy of Medical Sciences in Beijing, used data from the China Kadoorie Biobank Study, a long-term prospective study involving more than over 510,000 participants recruited from 10 geographically diverse areas across China, including both rural and urban regions. They compared this to data from the UK biobank.

Subjects were 59% female, 41% male, aged 30-79 years, and had no history of cancer at recruitment between 2004 and 2008. Food questionnaires were completed at the outset and participants followed for an average of 11 years, using national cancer and death registries and health insurance records to identify new cancer diagnoses, including both fatal and nonfatal events.

Participants were categorized into three groups according to how often they consumed dairy products (primarily milk):

• Regular consumers (at least once a week): 20.4% of the cohort.
• Monthly consumers: 11.1%.
• Nonconsumers who never or rarely consumed dairy products: 68.5%.

Average dairy consumption was 37.9 g/day overall and 80.8 g/day among regular consumers. This compares with an average consumption of around 300 g/day in participants in the UK Biobank cohort.

Over the course of the study, 29,277 new cancer cases were recorded, including 6,282 lung, 2,582 female breast, 3,577 stomach, 3,350 colorectal, and 3,191 liver cancer cases.

Analyses correlating cases with consumption took into account a range of other factors potentially affecting cancer risk, including age, sex, region, family history of cancer, socioeconomic status (education and income), lifestyle factors (alcohol intake, smoking, physical activity, soy consumption, and fresh fruit intake), body mass index, chronic hepatitis B virus infection, and female reproductive factors.

Higher dairy intakes linked with risk of liver and breast cancers

Results revealed that higher regular dairy intake was associated with significantly higher risks of liver cancer and female breast cancer, both common types of cancer in China. Analyses indicated that for each 50-g/day intake, the risks increased by 12% and 17%, respectively.

There was also an increase in total cancer diagnoses, and an increased risk of lymphoma, though this was not statistically significant after correction for confounders. No association was found between dairy products and colorectal cancer, prostate cancer, or any other site-specific cancer.

The research, published in BMC Medicine, is the first major study to investigate dairy consumption and cancer risk in Chinese adults. The results conflict with previous studies on Western populations, which have suggested that dairy products may be associated with a lower risk of colorectal cancer and a higher risk of prostate cancer but have found no clear link for breast or other types of cancer.

Lead researchers Maria Kakkoura, PhD, MSc, and associate professor Huaidong Du, MD, PhD, told this news organization that, although they don’t know the reason for the difference, “there is clear evidence that colorectal cancer has a different incidence pattern in China, compared with Western countries. Other risk factors, like adiposity, may have a stronger effect on the risk of colorectal cancer in Western countries than in China.” Notably, the mean body mass index in the study population was around 23 kg/m², they said – by contrast in the United Kingdom it is 27.6 kg/m2.

Effects not necessarily causal

Ian Givens, PhD, professor of food chain nutrition at the University of Reading (England), said the study was “potentially very important for Chinese people, if it can be confirmed that dairy products affect the risk of breast and/or liver cancer differently in Chinese subjects to those in Western Societies, especially as dairy consumption in China is much lower than in most Western diets.”

He added: “As always it needs to be kept in mind that this type of study can only establish associations with disease risk, not cause.”

Dr. Kakkoura, nutritional epidemiologist at Oxford (England) University’s department of population health, said: “This was the first major study to investigate the link between dairy products and cancer risk in a Chinese population. Further studies are needed to validate these current findings, establish if these associations are causal, and investigate the potential underlying mechanisms involved.”

The researchers said that, while the results do not prove causation, “there are several plausible biological mechanisms that may explain these associations.” They pointed to higher dairy consumption potentially increasing levels of insulinlike growth factor-I, known to promote cell proliferation and associated with higher risks of several types of cancer.

In addition, estrogen and progesterone present in cows’ milk may play a role in increasing breast cancer risk, whilst saturated and trans-fatty acids from dairy products may increase the risk of liver cancer. As many Chinese people are lactase deficient, dairy products may also be broken down into products that affect cancer risk.

No justification for dietary change

Confounding factors may also have influenced the results, commented Duane Mellor, PhD, RD, RNutr, registered dietitian and senior teaching fellow at Aston University, Birmingham, England. “Those in the study who consumed dairy were more likely to live in cities and have other health conditions, including cardiovascular disease and diabetes – although some of these factors were considered in the analysis, not all of these covariates were, which could influence the findings.

“In my view this study alone does not provide strong evidence that reducing dairy intake would reduce cancer risk.”

He added: “Although the paper suggests a 12% increased relative risk for female breast cancer, this does not equate to 12 more cases per 100 individuals – in absolute terms this would be more like 1 or 2 cases per 1,000 people.”

Similarly, Kevin McConway, PhD, emeritus professor of applied statistics at the Open University, Milton Keynes, England, said: “An issue is that there were many differences between the people that consumed different amounts of dairy products, apart from their difference in dairy consumption. For instance, of those who never or rarely consumed dairy products, fewer than a third lived in urban areas, but of regular dairy consumers (at least once a week), 83% lived in urban areas. Regular consumers were considerably more likely to be well educated than those who never or rarely consumed dairy products, and there were other differences too. 

“So if, as the researchers found, a greater proportion of the regular consumers than of the never or rare consumers had a cancer diagnosis, that could have been because of their different dairy consumption, or it could have been (in part or entirely) because of the different places they lived, or their different education levels, or any of the other factors on which the groups differed.

“One can never be sure that all the relevant factors have been adjusted for. That’s why the researchers rightly say that these results can’t establish whether the associations between dairy consumption and the risks of some cancers, that they found, are there because the dairy consumption differences change the cancer risks in a cause-and-effect way. They might, or they might not.”

He cautioned: “I don’t think anyone should decide to change their individual diet solely because of the results of this new study.”

Commenting on the study, Fiona Osgun, senior health information manager at Cancer Research UK, London, told this news organization: “This early-stage study found an association between dairy consumption and the risks of certain cancers, but that doesn’t mean that they’re causing them or that people need to avoid dairy. Dairy products can be part of a healthy balanced diet and, in the U.K., the Food Standards Agency regulates them to make sure they’re safe. There’s good evidence that dairy reduces the risk of bowel cancer, but no clear evidence for other cancer types, and this is no different for people who are lactose intolerant.”

A version of this article first appeared on Medscape UK.

A relationship between consumption of dairy products and risk of various cancers has been intensively investigated in the past but yielded inconclusive or conflicting results. Now a large new study comparing Chinese dairy consumption with that in the United Kingdom, shows that increased dairy consumption was linked to higher risks of liver cancer and female breast cancer.

The study, by researchers from Oxford University’s department of population health, and Peking University and the Chinese Academy of Medical Sciences in Beijing, used data from the China Kadoorie Biobank Study, a long-term prospective study involving more than over 510,000 participants recruited from 10 geographically diverse areas across China, including both rural and urban regions. They compared this to data from the UK biobank.

Subjects were 59% female, 41% male, aged 30-79 years, and had no history of cancer at recruitment between 2004 and 2008. Food questionnaires were completed at the outset and participants followed for an average of 11 years, using national cancer and death registries and health insurance records to identify new cancer diagnoses, including both fatal and nonfatal events.

Participants were categorized into three groups according to how often they consumed dairy products (primarily milk):

• Regular consumers (at least once a week): 20.4% of the cohort.
• Monthly consumers: 11.1%.
• Nonconsumers who never or rarely consumed dairy products: 68.5%.

Average dairy consumption was 37.9 g/day overall and 80.8 g/day among regular consumers. This compares with an average consumption of around 300 g/day in participants in the UK Biobank cohort.

Over the course of the study, 29,277 new cancer cases were recorded, including 6,282 lung, 2,582 female breast, 3,577 stomach, 3,350 colorectal, and 3,191 liver cancer cases.

Analyses correlating cases with consumption took into account a range of other factors potentially affecting cancer risk, including age, sex, region, family history of cancer, socioeconomic status (education and income), lifestyle factors (alcohol intake, smoking, physical activity, soy consumption, and fresh fruit intake), body mass index, chronic hepatitis B virus infection, and female reproductive factors.

Higher dairy intakes linked with risk of liver and breast cancers

Results revealed that higher regular dairy intake was associated with significantly higher risks of liver cancer and female breast cancer, both common types of cancer in China. Analyses indicated that for each 50-g/day intake, the risks increased by 12% and 17%, respectively.

There was also an increase in total cancer diagnoses, and an increased risk of lymphoma, though this was not statistically significant after correction for confounders. No association was found between dairy products and colorectal cancer, prostate cancer, or any other site-specific cancer.

The research, published in BMC Medicine, is the first major study to investigate dairy consumption and cancer risk in Chinese adults. The results conflict with previous studies on Western populations, which have suggested that dairy products may be associated with a lower risk of colorectal cancer and a higher risk of prostate cancer but have found no clear link for breast or other types of cancer.

Lead researchers Maria Kakkoura, PhD, MSc, and associate professor Huaidong Du, MD, PhD, told this news organization that, although they don’t know the reason for the difference, “there is clear evidence that colorectal cancer has a different incidence pattern in China, compared with Western countries. Other risk factors, like adiposity, may have a stronger effect on the risk of colorectal cancer in Western countries than in China.” Notably, the mean body mass index in the study population was around 23 kg/m², they said – by contrast in the United Kingdom it is 27.6 kg/m2.

Effects not necessarily causal

Ian Givens, PhD, professor of food chain nutrition at the University of Reading (England), said the study was “potentially very important for Chinese people, if it can be confirmed that dairy products affect the risk of breast and/or liver cancer differently in Chinese subjects to those in Western Societies, especially as dairy consumption in China is much lower than in most Western diets.”

He added: “As always it needs to be kept in mind that this type of study can only establish associations with disease risk, not cause.”

Dr. Kakkoura, nutritional epidemiologist at Oxford (England) University’s department of population health, said: “This was the first major study to investigate the link between dairy products and cancer risk in a Chinese population. Further studies are needed to validate these current findings, establish if these associations are causal, and investigate the potential underlying mechanisms involved.”

The researchers said that, while the results do not prove causation, “there are several plausible biological mechanisms that may explain these associations.” They pointed to higher dairy consumption potentially increasing levels of insulinlike growth factor-I, known to promote cell proliferation and associated with higher risks of several types of cancer.

In addition, estrogen and progesterone present in cows’ milk may play a role in increasing breast cancer risk, whilst saturated and trans-fatty acids from dairy products may increase the risk of liver cancer. As many Chinese people are lactase deficient, dairy products may also be broken down into products that affect cancer risk.

No justification for dietary change

Confounding factors may also have influenced the results, commented Duane Mellor, PhD, RD, RNutr, registered dietitian and senior teaching fellow at Aston University, Birmingham, England. “Those in the study who consumed dairy were more likely to live in cities and have other health conditions, including cardiovascular disease and diabetes – although some of these factors were considered in the analysis, not all of these covariates were, which could influence the findings.

“In my view this study alone does not provide strong evidence that reducing dairy intake would reduce cancer risk.”

He added: “Although the paper suggests a 12% increased relative risk for female breast cancer, this does not equate to 12 more cases per 100 individuals – in absolute terms this would be more like 1 or 2 cases per 1,000 people.”

Similarly, Kevin McConway, PhD, emeritus professor of applied statistics at the Open University, Milton Keynes, England, said: “An issue is that there were many differences between the people that consumed different amounts of dairy products, apart from their difference in dairy consumption. For instance, of those who never or rarely consumed dairy products, fewer than a third lived in urban areas, but of regular dairy consumers (at least once a week), 83% lived in urban areas. Regular consumers were considerably more likely to be well educated than those who never or rarely consumed dairy products, and there were other differences too. 

“So if, as the researchers found, a greater proportion of the regular consumers than of the never or rare consumers had a cancer diagnosis, that could have been because of their different dairy consumption, or it could have been (in part or entirely) because of the different places they lived, or their different education levels, or any of the other factors on which the groups differed.

“One can never be sure that all the relevant factors have been adjusted for. That’s why the researchers rightly say that these results can’t establish whether the associations between dairy consumption and the risks of some cancers, that they found, are there because the dairy consumption differences change the cancer risks in a cause-and-effect way. They might, or they might not.”

He cautioned: “I don’t think anyone should decide to change their individual diet solely because of the results of this new study.”

Commenting on the study, Fiona Osgun, senior health information manager at Cancer Research UK, London, told this news organization: “This early-stage study found an association between dairy consumption and the risks of certain cancers, but that doesn’t mean that they’re causing them or that people need to avoid dairy. Dairy products can be part of a healthy balanced diet and, in the U.K., the Food Standards Agency regulates them to make sure they’re safe. There’s good evidence that dairy reduces the risk of bowel cancer, but no clear evidence for other cancer types, and this is no different for people who are lactose intolerant.”

A version of this article first appeared on Medscape UK.

A relationship between consumption of dairy products and risk of various cancers has been intensively investigated in the past but yielded inconclusive or conflicting results. Now a large new study comparing Chinese dairy consumption with that in the United Kingdom, shows that increased dairy consumption was linked to higher risks of liver cancer and female breast cancer.

The study, by researchers from Oxford University’s department of population health, and Peking University and the Chinese Academy of Medical Sciences in Beijing, used data from the China Kadoorie Biobank Study, a long-term prospective study involving more than over 510,000 participants recruited from 10 geographically diverse areas across China, including both rural and urban regions. They compared this to data from the UK biobank.

Subjects were 59% female, 41% male, aged 30-79 years, and had no history of cancer at recruitment between 2004 and 2008. Food questionnaires were completed at the outset and participants followed for an average of 11 years, using national cancer and death registries and health insurance records to identify new cancer diagnoses, including both fatal and nonfatal events.

Participants were categorized into three groups according to how often they consumed dairy products (primarily milk):

• Regular consumers (at least once a week): 20.4% of the cohort.
• Monthly consumers: 11.1%.
• Nonconsumers who never or rarely consumed dairy products: 68.5%.

Average dairy consumption was 37.9 g/day overall and 80.8 g/day among regular consumers. This compares with an average consumption of around 300 g/day in participants in the UK Biobank cohort.

Over the course of the study, 29,277 new cancer cases were recorded, including 6,282 lung, 2,582 female breast, 3,577 stomach, 3,350 colorectal, and 3,191 liver cancer cases.

Analyses correlating cases with consumption took into account a range of other factors potentially affecting cancer risk, including age, sex, region, family history of cancer, socioeconomic status (education and income), lifestyle factors (alcohol intake, smoking, physical activity, soy consumption, and fresh fruit intake), body mass index, chronic hepatitis B virus infection, and female reproductive factors.

Higher dairy intakes linked with risk of liver and breast cancers

Results revealed that higher regular dairy intake was associated with significantly higher risks of liver cancer and female breast cancer, both common types of cancer in China. Analyses indicated that for each 50-g/day intake, the risks increased by 12% and 17%, respectively.

There was also an increase in total cancer diagnoses, and an increased risk of lymphoma, though this was not statistically significant after correction for confounders. No association was found between dairy products and colorectal cancer, prostate cancer, or any other site-specific cancer.

The research, published in BMC Medicine, is the first major study to investigate dairy consumption and cancer risk in Chinese adults. The results conflict with previous studies on Western populations, which have suggested that dairy products may be associated with a lower risk of colorectal cancer and a higher risk of prostate cancer but have found no clear link for breast or other types of cancer.

Lead researchers Maria Kakkoura, PhD, MSc, and associate professor Huaidong Du, MD, PhD, told this news organization that, although they don’t know the reason for the difference, “there is clear evidence that colorectal cancer has a different incidence pattern in China, compared with Western countries. Other risk factors, like adiposity, may have a stronger effect on the risk of colorectal cancer in Western countries than in China.” Notably, the mean body mass index in the study population was around 23 kg/m², they said – by contrast in the United Kingdom it is 27.6 kg/m2.

Effects not necessarily causal

Ian Givens, PhD, professor of food chain nutrition at the University of Reading (England), said the study was “potentially very important for Chinese people, if it can be confirmed that dairy products affect the risk of breast and/or liver cancer differently in Chinese subjects to those in Western Societies, especially as dairy consumption in China is much lower than in most Western diets.”

He added: “As always it needs to be kept in mind that this type of study can only establish associations with disease risk, not cause.”

Dr. Kakkoura, nutritional epidemiologist at Oxford (England) University’s department of population health, said: “This was the first major study to investigate the link between dairy products and cancer risk in a Chinese population. Further studies are needed to validate these current findings, establish if these associations are causal, and investigate the potential underlying mechanisms involved.”

The researchers said that, while the results do not prove causation, “there are several plausible biological mechanisms that may explain these associations.” They pointed to higher dairy consumption potentially increasing levels of insulinlike growth factor-I, known to promote cell proliferation and associated with higher risks of several types of cancer.

In addition, estrogen and progesterone present in cows’ milk may play a role in increasing breast cancer risk, whilst saturated and trans-fatty acids from dairy products may increase the risk of liver cancer. As many Chinese people are lactase deficient, dairy products may also be broken down into products that affect cancer risk.

No justification for dietary change

Confounding factors may also have influenced the results, commented Duane Mellor, PhD, RD, RNutr, registered dietitian and senior teaching fellow at Aston University, Birmingham, England. “Those in the study who consumed dairy were more likely to live in cities and have other health conditions, including cardiovascular disease and diabetes – although some of these factors were considered in the analysis, not all of these covariates were, which could influence the findings.

“In my view this study alone does not provide strong evidence that reducing dairy intake would reduce cancer risk.”

He added: “Although the paper suggests a 12% increased relative risk for female breast cancer, this does not equate to 12 more cases per 100 individuals – in absolute terms this would be more like 1 or 2 cases per 1,000 people.”

Similarly, Kevin McConway, PhD, emeritus professor of applied statistics at the Open University, Milton Keynes, England, said: “An issue is that there were many differences between the people that consumed different amounts of dairy products, apart from their difference in dairy consumption. For instance, of those who never or rarely consumed dairy products, fewer than a third lived in urban areas, but of regular dairy consumers (at least once a week), 83% lived in urban areas. Regular consumers were considerably more likely to be well educated than those who never or rarely consumed dairy products, and there were other differences too. 

“So if, as the researchers found, a greater proportion of the regular consumers than of the never or rare consumers had a cancer diagnosis, that could have been because of their different dairy consumption, or it could have been (in part or entirely) because of the different places they lived, or their different education levels, or any of the other factors on which the groups differed.

“One can never be sure that all the relevant factors have been adjusted for. That’s why the researchers rightly say that these results can’t establish whether the associations between dairy consumption and the risks of some cancers, that they found, are there because the dairy consumption differences change the cancer risks in a cause-and-effect way. They might, or they might not.”

He cautioned: “I don’t think anyone should decide to change their individual diet solely because of the results of this new study.”

Commenting on the study, Fiona Osgun, senior health information manager at Cancer Research UK, London, told this news organization: “This early-stage study found an association between dairy consumption and the risks of certain cancers, but that doesn’t mean that they’re causing them or that people need to avoid dairy. Dairy products can be part of a healthy balanced diet and, in the U.K., the Food Standards Agency regulates them to make sure they’re safe. There’s good evidence that dairy reduces the risk of bowel cancer, but no clear evidence for other cancer types, and this is no different for people who are lactose intolerant.”

A version of this article first appeared on Medscape UK.

Pregnant women with HIV can be reassured that protease inhibitors are safer than previously thought in terms of risk to the fetus, according to research from the National Perinatal Epidemiology Unit (NPEU) at Oxford Population Health, a research institute based at the University of Oxford (England).

Antiretroviral therapy (ART) is recommended for all pregnant women living with HIV and plays a crucial role both in improving maternal health and in reducing transmission of HIV from mother to child. However, there has been a critical lack of evidence about the effects of ART on the risk of adverse pregnancy outcomes, with particular concern about protease inhibitors.

Current guidelines recommend that protease inhibitor-based therapies should be used in pregnancy only if first-line treatments (such as integrase and reverse-transcriptase based treatments) are either unsuitable or unavailable. These guidelines also often advise against the use of a specific protease inhibitor, lopinavir/ritonavir, citing an increased risk of preterm birth. However, such advice may restrict treatment options for pregnant women with HIV on the basis of limited evidence.
 

Largest review to date

The NPEU researchers, therefore, conducted the largest systematic review to date of adverse perinatal outcomes after a range of antiretroviral therapies. It included 34 cohort studies published between 1980 and 2020 and involving over 57,000 pregnant women with HIV in 22 different countries. The review, published in eClinicalMedicine, looked for evidence of 11 perinatal outcomes:

• Preterm birth, very preterm birth, and spontaneous preterm birth
• Low birth weight, very low birth weight, term low birth weight, and preterm low birth weight
• Small for gestational age and very small for gestational age
• Stillbirth, and neonatal death

Using pairwise random-effects meta-analyses, researchers compared protease inhibitor versus non-protease inhibitor-based ART, as well as specifically looking at the comparative risks associated with different protease inhibitor regimens.

They found that protease inhibitor-based ART significantly increased the risk of small or very small for gestational age babies, with relative risks of 1.24 (95% confidence interval, 1.08-1.43; I2 = 66.7%) and 1.40 (95% CI, 1.09-1.81; I2 = 0.0%), respectively. However there were no significant differences in other adverse pregnancy outcomes for protease inhibitors, compared with other therapies.

In addition, researchers found no significant differences in perinatal outcomes between ART regimens containing lopinavir/ritonavir, atazanavir/ritonavir, or darunavir/ritonavir, which are the most frequently used protease inhibitors.
 

No increased risk of preterm birth

Senior author Dr. Joris Hemelaar, senior clinical research fellow at the NPEU and honorary consultant in obstetrics at the John Radcliffe Hospital, Oxford (England), said: “Antiretroviral therapy in pregnancy has clear benefits for maternal health and prevention of HIV transmission to the child, but our study has shown for the first time that protease inhibitors are associated with babies being small or very small for their gestational age.”

“However, there was no increased risk of preterm birth, or any other adverse pregnancy outcomes. This means protease inhibitors remain an important option for pregnant women living with HIV if other treatments are unsuitable, for example due to drug resistance, or unavailable. The evidence presented here indicates that the commonly used protease inhibitors atazanavir, lopinavir, and darunavir are comparable with regard to perinatal outcomes, which should inform international treatment guidelines.”

Over 70% of the studies assessed were conducted in high-income countries, and Dr. Hemelaar added that there is an urgent need for more research on pregnancy outcomes after different ART in low- to middle-income countries, where the burden of HIV is highest.

Professor Yvonne Gilleece, a spokesperson for the British HIV Association (BHIVA) and immediate past chair of the BHIVA guidelines on the management of HIV in pregnancy and the postpartum period commented: “Pregnancy is a unique life situation in which we must consider the safety of both the birthing parent and the baby. Due to ongoing under-representation of all women in clinical trials, but particularly pregnant women, we do not have enough evidence on which to base all our management decisions. This systematic review includes large numbers of pregnant women living with HIV and can, therefore, improve an informed discussion regarding the safety of the use of protease inhibitors during pregnancy.”

Dr. Hemelaar told Medscape UK: “Many international treatment guidelines cite adverse pregnancy outcomes, in particular preterm birth, associated with protease inhibitor (PI)-drugs as a reason for caution for their use in pregnancy. However, PI drugs are not associated with preterm birth in our analysis. This suggests that PI drugs may not be as detrimental as previously thought (and we found no differences between different PI drugs used), and, hence, these drugs may have a more favourable profile for use in pregnancy.

“However, many other aspects of treatment, including the extent to which the virus can be suppressed, adverse drug effects, adherence to drug prescriptions, antiretroviral drug resistance, drug interactions, drug cost, and availability, should also be taken into account by clinicians and guideline development committees.”

A version of this article first appeared on Medscape UK.

Pregnant women with HIV can be reassured that protease inhibitors are safer than previously thought in terms of risk to the fetus, according to research from the National Perinatal Epidemiology Unit (NPEU) at Oxford Population Health, a research institute based at the University of Oxford (England).

Antiretroviral therapy (ART) is recommended for all pregnant women living with HIV and plays a crucial role both in improving maternal health and in reducing transmission of HIV from mother to child. However, there has been a critical lack of evidence about the effects of ART on the risk of adverse pregnancy outcomes, with particular concern about protease inhibitors.

Current guidelines recommend that protease inhibitor-based therapies should be used in pregnancy only if first-line treatments (such as integrase and reverse-transcriptase based treatments) are either unsuitable or unavailable. These guidelines also often advise against the use of a specific protease inhibitor, lopinavir/ritonavir, citing an increased risk of preterm birth. However, such advice may restrict treatment options for pregnant women with HIV on the basis of limited evidence.
 

Largest review to date

The NPEU researchers, therefore, conducted the largest systematic review to date of adverse perinatal outcomes after a range of antiretroviral therapies. It included 34 cohort studies published between 1980 and 2020 and involving over 57,000 pregnant women with HIV in 22 different countries. The review, published in eClinicalMedicine, looked for evidence of 11 perinatal outcomes:

• Preterm birth, very preterm birth, and spontaneous preterm birth
• Low birth weight, very low birth weight, term low birth weight, and preterm low birth weight
• Small for gestational age and very small for gestational age
• Stillbirth, and neonatal death

Using pairwise random-effects meta-analyses, researchers compared protease inhibitor versus non-protease inhibitor-based ART, as well as specifically looking at the comparative risks associated with different protease inhibitor regimens.

They found that protease inhibitor-based ART significantly increased the risk of small or very small for gestational age babies, with relative risks of 1.24 (95% confidence interval, 1.08-1.43; I2 = 66.7%) and 1.40 (95% CI, 1.09-1.81; I2 = 0.0%), respectively. However there were no significant differences in other adverse pregnancy outcomes for protease inhibitors, compared with other therapies.

In addition, researchers found no significant differences in perinatal outcomes between ART regimens containing lopinavir/ritonavir, atazanavir/ritonavir, or darunavir/ritonavir, which are the most frequently used protease inhibitors.
 

No increased risk of preterm birth

Senior author Dr. Joris Hemelaar, senior clinical research fellow at the NPEU and honorary consultant in obstetrics at the John Radcliffe Hospital, Oxford (England), said: “Antiretroviral therapy in pregnancy has clear benefits for maternal health and prevention of HIV transmission to the child, but our study has shown for the first time that protease inhibitors are associated with babies being small or very small for their gestational age.”

“However, there was no increased risk of preterm birth, or any other adverse pregnancy outcomes. This means protease inhibitors remain an important option for pregnant women living with HIV if other treatments are unsuitable, for example due to drug resistance, or unavailable. The evidence presented here indicates that the commonly used protease inhibitors atazanavir, lopinavir, and darunavir are comparable with regard to perinatal outcomes, which should inform international treatment guidelines.”

Over 70% of the studies assessed were conducted in high-income countries, and Dr. Hemelaar added that there is an urgent need for more research on pregnancy outcomes after different ART in low- to middle-income countries, where the burden of HIV is highest.

Professor Yvonne Gilleece, a spokesperson for the British HIV Association (BHIVA) and immediate past chair of the BHIVA guidelines on the management of HIV in pregnancy and the postpartum period commented: “Pregnancy is a unique life situation in which we must consider the safety of both the birthing parent and the baby. Due to ongoing under-representation of all women in clinical trials, but particularly pregnant women, we do not have enough evidence on which to base all our management decisions. This systematic review includes large numbers of pregnant women living with HIV and can, therefore, improve an informed discussion regarding the safety of the use of protease inhibitors during pregnancy.”

Dr. Hemelaar told Medscape UK: “Many international treatment guidelines cite adverse pregnancy outcomes, in particular preterm birth, associated with protease inhibitor (PI)-drugs as a reason for caution for their use in pregnancy. However, PI drugs are not associated with preterm birth in our analysis. This suggests that PI drugs may not be as detrimental as previously thought (and we found no differences between different PI drugs used), and, hence, these drugs may have a more favourable profile for use in pregnancy.

“However, many other aspects of treatment, including the extent to which the virus can be suppressed, adverse drug effects, adherence to drug prescriptions, antiretroviral drug resistance, drug interactions, drug cost, and availability, should also be taken into account by clinicians and guideline development committees.”

A version of this article first appeared on Medscape UK.

Pregnant women with HIV can be reassured that protease inhibitors are safer than previously thought in terms of risk to the fetus, according to research from the National Perinatal Epidemiology Unit (NPEU) at Oxford Population Health, a research institute based at the University of Oxford (England).

Antiretroviral therapy (ART) is recommended for all pregnant women living with HIV and plays a crucial role both in improving maternal health and in reducing transmission of HIV from mother to child. However, there has been a critical lack of evidence about the effects of ART on the risk of adverse pregnancy outcomes, with particular concern about protease inhibitors.

Current guidelines recommend that protease inhibitor-based therapies should be used in pregnancy only if first-line treatments (such as integrase and reverse-transcriptase based treatments) are either unsuitable or unavailable. These guidelines also often advise against the use of a specific protease inhibitor, lopinavir/ritonavir, citing an increased risk of preterm birth. However, such advice may restrict treatment options for pregnant women with HIV on the basis of limited evidence.
 

Largest review to date

The NPEU researchers, therefore, conducted the largest systematic review to date of adverse perinatal outcomes after a range of antiretroviral therapies. It included 34 cohort studies published between 1980 and 2020 and involving over 57,000 pregnant women with HIV in 22 different countries. The review, published in eClinicalMedicine, looked for evidence of 11 perinatal outcomes:

• Preterm birth, very preterm birth, and spontaneous preterm birth
• Low birth weight, very low birth weight, term low birth weight, and preterm low birth weight
• Small for gestational age and very small for gestational age
• Stillbirth, and neonatal death

Using pairwise random-effects meta-analyses, researchers compared protease inhibitor versus non-protease inhibitor-based ART, as well as specifically looking at the comparative risks associated with different protease inhibitor regimens.

They found that protease inhibitor-based ART significantly increased the risk of small or very small for gestational age babies, with relative risks of 1.24 (95% confidence interval, 1.08-1.43; I2 = 66.7%) and 1.40 (95% CI, 1.09-1.81; I2 = 0.0%), respectively. However there were no significant differences in other adverse pregnancy outcomes for protease inhibitors, compared with other therapies.

In addition, researchers found no significant differences in perinatal outcomes between ART regimens containing lopinavir/ritonavir, atazanavir/ritonavir, or darunavir/ritonavir, which are the most frequently used protease inhibitors.
 

No increased risk of preterm birth

Senior author Dr. Joris Hemelaar, senior clinical research fellow at the NPEU and honorary consultant in obstetrics at the John Radcliffe Hospital, Oxford (England), said: “Antiretroviral therapy in pregnancy has clear benefits for maternal health and prevention of HIV transmission to the child, but our study has shown for the first time that protease inhibitors are associated with babies being small or very small for their gestational age.”

“However, there was no increased risk of preterm birth, or any other adverse pregnancy outcomes. This means protease inhibitors remain an important option for pregnant women living with HIV if other treatments are unsuitable, for example due to drug resistance, or unavailable. The evidence presented here indicates that the commonly used protease inhibitors atazanavir, lopinavir, and darunavir are comparable with regard to perinatal outcomes, which should inform international treatment guidelines.”

Over 70% of the studies assessed were conducted in high-income countries, and Dr. Hemelaar added that there is an urgent need for more research on pregnancy outcomes after different ART in low- to middle-income countries, where the burden of HIV is highest.

Professor Yvonne Gilleece, a spokesperson for the British HIV Association (BHIVA) and immediate past chair of the BHIVA guidelines on the management of HIV in pregnancy and the postpartum period commented: “Pregnancy is a unique life situation in which we must consider the safety of both the birthing parent and the baby. Due to ongoing under-representation of all women in clinical trials, but particularly pregnant women, we do not have enough evidence on which to base all our management decisions. This systematic review includes large numbers of pregnant women living with HIV and can, therefore, improve an informed discussion regarding the safety of the use of protease inhibitors during pregnancy.”

Dr. Hemelaar told Medscape UK: “Many international treatment guidelines cite adverse pregnancy outcomes, in particular preterm birth, associated with protease inhibitor (PI)-drugs as a reason for caution for their use in pregnancy. However, PI drugs are not associated with preterm birth in our analysis. This suggests that PI drugs may not be as detrimental as previously thought (and we found no differences between different PI drugs used), and, hence, these drugs may have a more favourable profile for use in pregnancy.

“However, many other aspects of treatment, including the extent to which the virus can be suppressed, adverse drug effects, adherence to drug prescriptions, antiretroviral drug resistance, drug interactions, drug cost, and availability, should also be taken into account by clinicians and guideline development committees.”

A version of this article first appeared on Medscape UK.

The SARS-CoV-2 pandemic has given added impetus for metagenomic testing using nanopore sequencing to progress from a research tool to routine clinical application. A study led by researchers from Guy’s and St. Thomas’ NHS Foundation Trust has shown the potential for clinical metagenomics to become a same-day test for identifying secondary infection in ventilated ICU patients. Getting results in hours rather than days would help to ensure rapid treatment with the correct antibiotic, minimize unnecessary prescriptions, and thus reduce the growing menace of antimicrobial resistance.

‘SARS-CoV-2 has put considerable strain on ICUs’

The researchers point out that the setting of an intensive care unit involves frequent staff-patient contact that imparts a risk of secondary or nosocomial infection. In addition, invasive ventilation may introduce organisms into the lungs and lead to ventilator-acquired pneumonia. This carries a high mortality and is responsible for up to 70% of antimicrobial prescribing, with current guidelines requiring empiric antibiotics pending culture results, which typically takes 2-4 days.

Many of these infection problems worsened during SARS-CoV-2. Expanded critical care capacity raised the risk of nosocomial infections, with attendant increased antimicrobial prescriptions and the threat of antimicrobial resistance. In addition, treatment of COVID-19 patients with steroid therapy potentially exacerbates bacterial or fungal infections.

The researchers, from the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy’s and St. Thomas’ NHS Foundation Trust and King’s College London, in collaboration with the Quadram Institute in Norwich, Oxford Nanopore Technologies, and Viapath, the U.K.’s largest independent pathology service provider, noted that the pandemic thus reinforced “a need for rapid comprehensive diagnostics to improve antimicrobial stewardship and help prevent emergence and transmission of multi-drug-resistant organisms.”

“As soon as the pandemic started, our scientists realized there would be a benefit to sequencing genomes of all bacteria and fungi causing infection in COVID-19 patients while on ICU,” said Professor Jonathan Edgeworth, who led the research team.

“Within a few weeks we showed it can diagnose secondary infection, target antibiotic treatment, and detect outbreaks much earlier than current technologies – all from a single sample.”
 

Proof-of-concept study

The team performed a proof-of-concept study of nanopore metagenomics sequencing – a type of DNA sequencing that allows direct rapid unbiased detection of all organisms present in a clinical sample – on 43 surplus respiratory samples from 34 intubated COVID-19 patients with suspected secondary bacterial or fungal pneumonia. Patients were drawn from seven ICUs at St. Thomas’ Hospital, London over a 9-week period between April 11 and June 15 2020, during the first wave of COVID-19.

Their median age was 52, 70% were male, 47% White, and 44% Black or minority ethnicities. Median length of stay was 32 days and mortality 24%. Samples sent for metagenomic analysis and culture included 10 bronchoalveolar lavages, 6 tracheal aspirates, and 27 non-direct bronchoalveolar lavages.

The study, published in Genome Medicine, showed that an 8-hour metagenomics workflow was 92% sensitive (95% CI, 75% to 99%) and 82% specific (95% CI, 57% to 96%) for bacterial identification, based on culture-positive and culture-negative samples, respectively.

The main Gram-negative bacteria identified were Klebsiella spp. (53%), Citrobacter spp. (15%), and E coli (9%). The main Gram-positive bacteria were S aureus (9%), C striatum (24%) and Enterococcus spp. (12%). In addition, C albicans, other Candida spp. and Aspergillus spp. were cultured from 38%, 15%, and 9% of patients, respectively.

In every case, the initial antibiotics prescribed according to prevailing guideline recommendations would have been modified by metagenomic sequencing demonstrating the presence or absence of β-lactam-resistant genes carried by Enterobacterales.

Next day results of sequencing also detected Aspergillus fumigatus in four samples, with results 100% concordant with quantitative PCR for both the four positive and 39 negative samples. It identified two multi-drug–resistant outbreaks, one involving K pneumoniae ST307 affecting four patients and one a C striatum outbreak involving 14 patients across three ICUs.

Thus, a single sample can provide enough genetic sequence data to compare pathogen genomes with a database and accurately identify patients carrying the same strain, enabling early detection of outbreaks. This is the first time this combined benefit of a single test has been demonstrated, the team say.

Gordon Sanghera, CEO of Oxford Nanopore commented that “rapidly characterizing co-infections for precision prescribing is a vital next step for both COVID-19 patients and respiratory disease in general.”

Dr. Andrew Page of the Quadram Institute said: “We have been working on metagenomics technology for the last 7 years. It is great to see it applied to patient care during the COVID-19 pandemic.”

He said in an interview: “The pandemic has accelerated the transition from using sequencing purely in research labs to using it in the clinic to rapidly provide clinicians with information they can use to improve outcomes for patients.”
 

Potential to inform antimicrobial prescribing and infection control

“Clinical metagenomic testing provides accurate pathogen detection and antibiotic resistance prediction in a same-day laboratory workflow, with assembled genomes available the next day for genomic surveillance,” the researchers say.

The technology “could fundamentally change the multi-disciplinary team approach to managing ICU infections.” It has the potential to improve initial targeted antimicrobial treatment and infection control decisions, as well as help rapidly detect unsuspected outbreaks of multi-drug–resistant pathogens.

Professor Edgeworth told this news organization that since the study, “secondary bacterial and fungal infections have increased, perhaps due to immunomodulatory treatments or just the length of time patients spend on ICU recovering from COVID-19. This makes rapid diagnosis even more important to ensure patients get more targeted antibiotics earlier, rather than relying on generic guidelines.”

The team “are planning to move respiratory metagenomics into pilot service under our Trust’s quality improvement framework,” he revealed. This will enable them to gather data on patient benefits.  

“We also need to see how clinicians use these tests to improve antibiotic treatment, to stop antibiotics when not needed or to identify outbreaks earlier, and then how that translates into tangible benefits for individual patients and the wider NHS.”

He predicts that the technique will revolutionize the approach to prevention and treatment of serious infection in ICUs, and it is now planned to offer it as a clinical service for COVID-19 and influenza patients during the coming winter.

In addition, he said: “It can be equally applied to other samples such as tissue fluids and biopsies, including those removed at operation. It therefore has potential to impact on diagnostics for many clinical services, particularly if the progress is maintained at the current pace.”

This article first appeared on Medscape UK/Univadis.

The SARS-CoV-2 pandemic has given added impetus for metagenomic testing using nanopore sequencing to progress from a research tool to routine clinical application. A study led by researchers from Guy’s and St. Thomas’ NHS Foundation Trust has shown the potential for clinical metagenomics to become a same-day test for identifying secondary infection in ventilated ICU patients. Getting results in hours rather than days would help to ensure rapid treatment with the correct antibiotic, minimize unnecessary prescriptions, and thus reduce the growing menace of antimicrobial resistance.

‘SARS-CoV-2 has put considerable strain on ICUs’

The researchers point out that the setting of an intensive care unit involves frequent staff-patient contact that imparts a risk of secondary or nosocomial infection. In addition, invasive ventilation may introduce organisms into the lungs and lead to ventilator-acquired pneumonia. This carries a high mortality and is responsible for up to 70% of antimicrobial prescribing, with current guidelines requiring empiric antibiotics pending culture results, which typically takes 2-4 days.

Many of these infection problems worsened during SARS-CoV-2. Expanded critical care capacity raised the risk of nosocomial infections, with attendant increased antimicrobial prescriptions and the threat of antimicrobial resistance. In addition, treatment of COVID-19 patients with steroid therapy potentially exacerbates bacterial or fungal infections.

The researchers, from the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy’s and St. Thomas’ NHS Foundation Trust and King’s College London, in collaboration with the Quadram Institute in Norwich, Oxford Nanopore Technologies, and Viapath, the U.K.’s largest independent pathology service provider, noted that the pandemic thus reinforced “a need for rapid comprehensive diagnostics to improve antimicrobial stewardship and help prevent emergence and transmission of multi-drug-resistant organisms.”

“As soon as the pandemic started, our scientists realized there would be a benefit to sequencing genomes of all bacteria and fungi causing infection in COVID-19 patients while on ICU,” said Professor Jonathan Edgeworth, who led the research team.

“Within a few weeks we showed it can diagnose secondary infection, target antibiotic treatment, and detect outbreaks much earlier than current technologies – all from a single sample.”
 

Proof-of-concept study

The team performed a proof-of-concept study of nanopore metagenomics sequencing – a type of DNA sequencing that allows direct rapid unbiased detection of all organisms present in a clinical sample – on 43 surplus respiratory samples from 34 intubated COVID-19 patients with suspected secondary bacterial or fungal pneumonia. Patients were drawn from seven ICUs at St. Thomas’ Hospital, London over a 9-week period between April 11 and June 15 2020, during the first wave of COVID-19.

Their median age was 52, 70% were male, 47% White, and 44% Black or minority ethnicities. Median length of stay was 32 days and mortality 24%. Samples sent for metagenomic analysis and culture included 10 bronchoalveolar lavages, 6 tracheal aspirates, and 27 non-direct bronchoalveolar lavages.

The study, published in Genome Medicine, showed that an 8-hour metagenomics workflow was 92% sensitive (95% CI, 75% to 99%) and 82% specific (95% CI, 57% to 96%) for bacterial identification, based on culture-positive and culture-negative samples, respectively.

The main Gram-negative bacteria identified were Klebsiella spp. (53%), Citrobacter spp. (15%), and E coli (9%). The main Gram-positive bacteria were S aureus (9%), C striatum (24%) and Enterococcus spp. (12%). In addition, C albicans, other Candida spp. and Aspergillus spp. were cultured from 38%, 15%, and 9% of patients, respectively.

In every case, the initial antibiotics prescribed according to prevailing guideline recommendations would have been modified by metagenomic sequencing demonstrating the presence or absence of β-lactam-resistant genes carried by Enterobacterales.

Next day results of sequencing also detected Aspergillus fumigatus in four samples, with results 100% concordant with quantitative PCR for both the four positive and 39 negative samples. It identified two multi-drug–resistant outbreaks, one involving K pneumoniae ST307 affecting four patients and one a C striatum outbreak involving 14 patients across three ICUs.

Thus, a single sample can provide enough genetic sequence data to compare pathogen genomes with a database and accurately identify patients carrying the same strain, enabling early detection of outbreaks. This is the first time this combined benefit of a single test has been demonstrated, the team say.

Gordon Sanghera, CEO of Oxford Nanopore commented that “rapidly characterizing co-infections for precision prescribing is a vital next step for both COVID-19 patients and respiratory disease in general.”

Dr. Andrew Page of the Quadram Institute said: “We have been working on metagenomics technology for the last 7 years. It is great to see it applied to patient care during the COVID-19 pandemic.”

He said in an interview: “The pandemic has accelerated the transition from using sequencing purely in research labs to using it in the clinic to rapidly provide clinicians with information they can use to improve outcomes for patients.”
 

Potential to inform antimicrobial prescribing and infection control

“Clinical metagenomic testing provides accurate pathogen detection and antibiotic resistance prediction in a same-day laboratory workflow, with assembled genomes available the next day for genomic surveillance,” the researchers say.

The technology “could fundamentally change the multi-disciplinary team approach to managing ICU infections.” It has the potential to improve initial targeted antimicrobial treatment and infection control decisions, as well as help rapidly detect unsuspected outbreaks of multi-drug–resistant pathogens.

Professor Edgeworth told this news organization that since the study, “secondary bacterial and fungal infections have increased, perhaps due to immunomodulatory treatments or just the length of time patients spend on ICU recovering from COVID-19. This makes rapid diagnosis even more important to ensure patients get more targeted antibiotics earlier, rather than relying on generic guidelines.”

The team “are planning to move respiratory metagenomics into pilot service under our Trust’s quality improvement framework,” he revealed. This will enable them to gather data on patient benefits.  

“We also need to see how clinicians use these tests to improve antibiotic treatment, to stop antibiotics when not needed or to identify outbreaks earlier, and then how that translates into tangible benefits for individual patients and the wider NHS.”

He predicts that the technique will revolutionize the approach to prevention and treatment of serious infection in ICUs, and it is now planned to offer it as a clinical service for COVID-19 and influenza patients during the coming winter.

In addition, he said: “It can be equally applied to other samples such as tissue fluids and biopsies, including those removed at operation. It therefore has potential to impact on diagnostics for many clinical services, particularly if the progress is maintained at the current pace.”

This article first appeared on Medscape UK/Univadis.

The SARS-CoV-2 pandemic has given added impetus for metagenomic testing using nanopore sequencing to progress from a research tool to routine clinical application. A study led by researchers from Guy’s and St. Thomas’ NHS Foundation Trust has shown the potential for clinical metagenomics to become a same-day test for identifying secondary infection in ventilated ICU patients. Getting results in hours rather than days would help to ensure rapid treatment with the correct antibiotic, minimize unnecessary prescriptions, and thus reduce the growing menace of antimicrobial resistance.

‘SARS-CoV-2 has put considerable strain on ICUs’

The researchers point out that the setting of an intensive care unit involves frequent staff-patient contact that imparts a risk of secondary or nosocomial infection. In addition, invasive ventilation may introduce organisms into the lungs and lead to ventilator-acquired pneumonia. This carries a high mortality and is responsible for up to 70% of antimicrobial prescribing, with current guidelines requiring empiric antibiotics pending culture results, which typically takes 2-4 days.

Many of these infection problems worsened during SARS-CoV-2. Expanded critical care capacity raised the risk of nosocomial infections, with attendant increased antimicrobial prescriptions and the threat of antimicrobial resistance. In addition, treatment of COVID-19 patients with steroid therapy potentially exacerbates bacterial or fungal infections.

The researchers, from the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy’s and St. Thomas’ NHS Foundation Trust and King’s College London, in collaboration with the Quadram Institute in Norwich, Oxford Nanopore Technologies, and Viapath, the U.K.’s largest independent pathology service provider, noted that the pandemic thus reinforced “a need for rapid comprehensive diagnostics to improve antimicrobial stewardship and help prevent emergence and transmission of multi-drug-resistant organisms.”

“As soon as the pandemic started, our scientists realized there would be a benefit to sequencing genomes of all bacteria and fungi causing infection in COVID-19 patients while on ICU,” said Professor Jonathan Edgeworth, who led the research team.

“Within a few weeks we showed it can diagnose secondary infection, target antibiotic treatment, and detect outbreaks much earlier than current technologies – all from a single sample.”
 

Proof-of-concept study

The team performed a proof-of-concept study of nanopore metagenomics sequencing – a type of DNA sequencing that allows direct rapid unbiased detection of all organisms present in a clinical sample – on 43 surplus respiratory samples from 34 intubated COVID-19 patients with suspected secondary bacterial or fungal pneumonia. Patients were drawn from seven ICUs at St. Thomas’ Hospital, London over a 9-week period between April 11 and June 15 2020, during the first wave of COVID-19.

Their median age was 52, 70% were male, 47% White, and 44% Black or minority ethnicities. Median length of stay was 32 days and mortality 24%. Samples sent for metagenomic analysis and culture included 10 bronchoalveolar lavages, 6 tracheal aspirates, and 27 non-direct bronchoalveolar lavages.

The study, published in Genome Medicine, showed that an 8-hour metagenomics workflow was 92% sensitive (95% CI, 75% to 99%) and 82% specific (95% CI, 57% to 96%) for bacterial identification, based on culture-positive and culture-negative samples, respectively.

The main Gram-negative bacteria identified were Klebsiella spp. (53%), Citrobacter spp. (15%), and E coli (9%). The main Gram-positive bacteria were S aureus (9%), C striatum (24%) and Enterococcus spp. (12%). In addition, C albicans, other Candida spp. and Aspergillus spp. were cultured from 38%, 15%, and 9% of patients, respectively.

In every case, the initial antibiotics prescribed according to prevailing guideline recommendations would have been modified by metagenomic sequencing demonstrating the presence or absence of β-lactam-resistant genes carried by Enterobacterales.

Next day results of sequencing also detected Aspergillus fumigatus in four samples, with results 100% concordant with quantitative PCR for both the four positive and 39 negative samples. It identified two multi-drug–resistant outbreaks, one involving K pneumoniae ST307 affecting four patients and one a C striatum outbreak involving 14 patients across three ICUs.

Thus, a single sample can provide enough genetic sequence data to compare pathogen genomes with a database and accurately identify patients carrying the same strain, enabling early detection of outbreaks. This is the first time this combined benefit of a single test has been demonstrated, the team say.

Gordon Sanghera, CEO of Oxford Nanopore commented that “rapidly characterizing co-infections for precision prescribing is a vital next step for both COVID-19 patients and respiratory disease in general.”

Dr. Andrew Page of the Quadram Institute said: “We have been working on metagenomics technology for the last 7 years. It is great to see it applied to patient care during the COVID-19 pandemic.”

He said in an interview: “The pandemic has accelerated the transition from using sequencing purely in research labs to using it in the clinic to rapidly provide clinicians with information they can use to improve outcomes for patients.”
 

Potential to inform antimicrobial prescribing and infection control

“Clinical metagenomic testing provides accurate pathogen detection and antibiotic resistance prediction in a same-day laboratory workflow, with assembled genomes available the next day for genomic surveillance,” the researchers say.

The technology “could fundamentally change the multi-disciplinary team approach to managing ICU infections.” It has the potential to improve initial targeted antimicrobial treatment and infection control decisions, as well as help rapidly detect unsuspected outbreaks of multi-drug–resistant pathogens.

Professor Edgeworth told this news organization that since the study, “secondary bacterial and fungal infections have increased, perhaps due to immunomodulatory treatments or just the length of time patients spend on ICU recovering from COVID-19. This makes rapid diagnosis even more important to ensure patients get more targeted antibiotics earlier, rather than relying on generic guidelines.”

The team “are planning to move respiratory metagenomics into pilot service under our Trust’s quality improvement framework,” he revealed. This will enable them to gather data on patient benefits.  

“We also need to see how clinicians use these tests to improve antibiotic treatment, to stop antibiotics when not needed or to identify outbreaks earlier, and then how that translates into tangible benefits for individual patients and the wider NHS.”

He predicts that the technique will revolutionize the approach to prevention and treatment of serious infection in ICUs, and it is now planned to offer it as a clinical service for COVID-19 and influenza patients during the coming winter.

In addition, he said: “It can be equally applied to other samples such as tissue fluids and biopsies, including those removed at operation. It therefore has potential to impact on diagnostics for many clinical services, particularly if the progress is maintained at the current pace.”

This article first appeared on Medscape UK/Univadis.