User login
Helicobacter pylori (HP) eradication reduced the risk of gastric noncardia adenocarcinoma in five Scandinavian countries, a population-based study in Gastroenterology reported. Risk became virtually similar to the background population from 11 years after treatment onward.
HP infection of the stomach is the main established risk factor for this tumor, but not much was known about the impact of eradication on long-term risk, particularly in Western populations, noted investigators led by Jesper Lagengren, MD, a gastrointestinal surgeon and professor at the Karolinksa Institutet in Stockholm, Sweden. Research with longer follow-up has reported contradictory results.
The study cohort included all adults treated for HP from 1995 to 2019 in Denmark, Finland, Iceland, Norway, and Sweden. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by comparing the gastric noncardia adenocarcinoma incidence in the study cohort with the incidence in the background population of the same age, sex, calendar period, and country.
The 659,592 treated participants were 54.3% women, 61.5% age 50 or younger, and had no serious comorbidities. They contributed to 5,480,873 person-years at risk with a mean follow-up of 8.3 years. Treatment consisted of a minimum one-week antibiotic regimen with two of amoxicillin, clarithromycin, or metronidazole, in combination with a proton pump inhibitor. This is the recommended regimen in the Nordic countries, where it achieves successful eradication in 90% of infected individuals.
Among these patients, 1311 developed gastric noncardia adenocarcinoma. Over as many as 24 years of follow-up, the SIR in treated HP patients was initially significantly higher than in the background population at 2.27 (95% confidence interval [CI], 2.10-2.44) at 1 to 5 years after treatment. By 6 to 10 years the SIR had dropped to 1.34 (1.21-1.48) and by 11 to 24 years it further fell to 1.11 (.98-1.27). In terms of observed vs expected cases, that translated to 702 vs 310 at 1 to 5 years, 374 vs 270 at 6 to 10 years, and 235 vs 211 from 11 to 24 years.
The results of the Nordic study align with systematic reviews from Asian populations indicating that eradication reduces the risk of gastric cancer, the authors said.
They noted gastric HP infection is the most prevalent bacterial infection worldwide, found in approximately 50% of the global population but with striking geographical variations in prevalence and virulence. The highest prevalence (>80%) and virulence are found in countries with low socioeconomic status and sanitation standards such as regions in Africa and Western Asia.
Gastric adenocarcinoma is the fourth-commonest cause of cancer-related death globally, leading to 660,000 deaths in 2022.
Lagergren and colleagues cited the need for research to delineate high-risk individuals who would benefit rom HP screening and eradication.
This study was supported by the Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, and Stockholm Cancer Society. The authors had no conflicts of interest to disclose.
Helicobacter pylori (HP) eradication reduced the risk of gastric noncardia adenocarcinoma in five Scandinavian countries, a population-based study in Gastroenterology reported. Risk became virtually similar to the background population from 11 years after treatment onward.
HP infection of the stomach is the main established risk factor for this tumor, but not much was known about the impact of eradication on long-term risk, particularly in Western populations, noted investigators led by Jesper Lagengren, MD, a gastrointestinal surgeon and professor at the Karolinksa Institutet in Stockholm, Sweden. Research with longer follow-up has reported contradictory results.
The study cohort included all adults treated for HP from 1995 to 2019 in Denmark, Finland, Iceland, Norway, and Sweden. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by comparing the gastric noncardia adenocarcinoma incidence in the study cohort with the incidence in the background population of the same age, sex, calendar period, and country.
The 659,592 treated participants were 54.3% women, 61.5% age 50 or younger, and had no serious comorbidities. They contributed to 5,480,873 person-years at risk with a mean follow-up of 8.3 years. Treatment consisted of a minimum one-week antibiotic regimen with two of amoxicillin, clarithromycin, or metronidazole, in combination with a proton pump inhibitor. This is the recommended regimen in the Nordic countries, where it achieves successful eradication in 90% of infected individuals.
Among these patients, 1311 developed gastric noncardia adenocarcinoma. Over as many as 24 years of follow-up, the SIR in treated HP patients was initially significantly higher than in the background population at 2.27 (95% confidence interval [CI], 2.10-2.44) at 1 to 5 years after treatment. By 6 to 10 years the SIR had dropped to 1.34 (1.21-1.48) and by 11 to 24 years it further fell to 1.11 (.98-1.27). In terms of observed vs expected cases, that translated to 702 vs 310 at 1 to 5 years, 374 vs 270 at 6 to 10 years, and 235 vs 211 from 11 to 24 years.
The results of the Nordic study align with systematic reviews from Asian populations indicating that eradication reduces the risk of gastric cancer, the authors said.
They noted gastric HP infection is the most prevalent bacterial infection worldwide, found in approximately 50% of the global population but with striking geographical variations in prevalence and virulence. The highest prevalence (>80%) and virulence are found in countries with low socioeconomic status and sanitation standards such as regions in Africa and Western Asia.
Gastric adenocarcinoma is the fourth-commonest cause of cancer-related death globally, leading to 660,000 deaths in 2022.
Lagergren and colleagues cited the need for research to delineate high-risk individuals who would benefit rom HP screening and eradication.
This study was supported by the Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, and Stockholm Cancer Society. The authors had no conflicts of interest to disclose.
Helicobacter pylori (HP) eradication reduced the risk of gastric noncardia adenocarcinoma in five Scandinavian countries, a population-based study in Gastroenterology reported. Risk became virtually similar to the background population from 11 years after treatment onward.
HP infection of the stomach is the main established risk factor for this tumor, but not much was known about the impact of eradication on long-term risk, particularly in Western populations, noted investigators led by Jesper Lagengren, MD, a gastrointestinal surgeon and professor at the Karolinksa Institutet in Stockholm, Sweden. Research with longer follow-up has reported contradictory results.
The study cohort included all adults treated for HP from 1995 to 2019 in Denmark, Finland, Iceland, Norway, and Sweden. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated by comparing the gastric noncardia adenocarcinoma incidence in the study cohort with the incidence in the background population of the same age, sex, calendar period, and country.
The 659,592 treated participants were 54.3% women, 61.5% age 50 or younger, and had no serious comorbidities. They contributed to 5,480,873 person-years at risk with a mean follow-up of 8.3 years. Treatment consisted of a minimum one-week antibiotic regimen with two of amoxicillin, clarithromycin, or metronidazole, in combination with a proton pump inhibitor. This is the recommended regimen in the Nordic countries, where it achieves successful eradication in 90% of infected individuals.
Among these patients, 1311 developed gastric noncardia adenocarcinoma. Over as many as 24 years of follow-up, the SIR in treated HP patients was initially significantly higher than in the background population at 2.27 (95% confidence interval [CI], 2.10-2.44) at 1 to 5 years after treatment. By 6 to 10 years the SIR had dropped to 1.34 (1.21-1.48) and by 11 to 24 years it further fell to 1.11 (.98-1.27). In terms of observed vs expected cases, that translated to 702 vs 310 at 1 to 5 years, 374 vs 270 at 6 to 10 years, and 235 vs 211 from 11 to 24 years.
The results of the Nordic study align with systematic reviews from Asian populations indicating that eradication reduces the risk of gastric cancer, the authors said.
They noted gastric HP infection is the most prevalent bacterial infection worldwide, found in approximately 50% of the global population but with striking geographical variations in prevalence and virulence. The highest prevalence (>80%) and virulence are found in countries with low socioeconomic status and sanitation standards such as regions in Africa and Western Asia.
Gastric adenocarcinoma is the fourth-commonest cause of cancer-related death globally, leading to 660,000 deaths in 2022.
Lagergren and colleagues cited the need for research to delineate high-risk individuals who would benefit rom HP screening and eradication.
This study was supported by the Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, and Stockholm Cancer Society. The authors had no conflicts of interest to disclose.
FROM GASTROENTEROLOGY