AVAHO

Introduction

Hematologists and oncologists (HO) face mortality daily. “Death Cafe” (DC) is a safe space set aside for open dialogue about death and dying. Despite origins outside the healthcare setting, DC has been used as a framework to help health care students and workers process death and dying. We aim to assess if DC sessions are perceived to have value by HO trainees and faculty.

Methods

HO fellows from Baylor College of Medicine (BCM) and HO Faculty from BCM, mostly those at the Houston Michael E. DeBakey Veterans Affairs Hospital (VA), were offered the opportunity to participate in the DC sessions. Our VA Cancer Center Chaplain was present for all sessions and helped facilitate the conversation. HO fellows who were invited to a DC and attended were emailed a survey questionnaire after the activity via survey monkey. The sessions and the surveys were not compulsory. Their participation in the session and completion of surveys implied informed consent. After IRB approval, we reviewed responses for the study groups. Sessions were held in person pre-pandemic in 2019 and virtually during the COVID-19 pandemic in 2022.

Results

Five fellows responded to our survey in 2019 and 7 in 2022 for a total of 12 respondents. 100% of respondents had been emotionally affected by a patient’s death. 82% had been emotionally affected by a patient’s death during the preceding 3 months. 90% had previously discussed their emotions relating to patient death with others. 83% would participate in DC again and 92% would recommend DC to a colleague. One 2019 participant commented that they thought attendings needed the session more than fellows, 2 2022 participants commented that they believe the meeting would be better in person. One 2022 participant commented they thought DC “is a good platform to vent emotions, identify self-destructive thoughts and better coping mechanisms.”

Conclusions 

DC provides a framework for HC to share personal and professional experience with mortality from a human perspective and support each other. This approach may be useful for HO departments or fellowships to offer as an opportunity to process end-of-life matters experienced as providers and finite humans.

Introduction

Hematologists and oncologists (HO) face mortality daily. “Death Cafe” (DC) is a safe space set aside for open dialogue about death and dying. Despite origins outside the healthcare setting, DC has been used as a framework to help health care students and workers process death and dying. We aim to assess if DC sessions are perceived to have value by HO trainees and faculty.

Methods

HO fellows from Baylor College of Medicine (BCM) and HO Faculty from BCM, mostly those at the Houston Michael E. DeBakey Veterans Affairs Hospital (VA), were offered the opportunity to participate in the DC sessions. Our VA Cancer Center Chaplain was present for all sessions and helped facilitate the conversation. HO fellows who were invited to a DC and attended were emailed a survey questionnaire after the activity via survey monkey. The sessions and the surveys were not compulsory. Their participation in the session and completion of surveys implied informed consent. After IRB approval, we reviewed responses for the study groups. Sessions were held in person pre-pandemic in 2019 and virtually during the COVID-19 pandemic in 2022.

Results

Five fellows responded to our survey in 2019 and 7 in 2022 for a total of 12 respondents. 100% of respondents had been emotionally affected by a patient’s death. 82% had been emotionally affected by a patient’s death during the preceding 3 months. 90% had previously discussed their emotions relating to patient death with others. 83% would participate in DC again and 92% would recommend DC to a colleague. One 2019 participant commented that they thought attendings needed the session more than fellows, 2 2022 participants commented that they believe the meeting would be better in person. One 2022 participant commented they thought DC “is a good platform to vent emotions, identify self-destructive thoughts and better coping mechanisms.”

Conclusions 

DC provides a framework for HC to share personal and professional experience with mortality from a human perspective and support each other. This approach may be useful for HO departments or fellowships to offer as an opportunity to process end-of-life matters experienced as providers and finite humans.

Introduction

Hematologists and oncologists (HO) face mortality daily. “Death Cafe” (DC) is a safe space set aside for open dialogue about death and dying. Despite origins outside the healthcare setting, DC has been used as a framework to help health care students and workers process death and dying. We aim to assess if DC sessions are perceived to have value by HO trainees and faculty.

Methods

HO fellows from Baylor College of Medicine (BCM) and HO Faculty from BCM, mostly those at the Houston Michael E. DeBakey Veterans Affairs Hospital (VA), were offered the opportunity to participate in the DC sessions. Our VA Cancer Center Chaplain was present for all sessions and helped facilitate the conversation. HO fellows who were invited to a DC and attended were emailed a survey questionnaire after the activity via survey monkey. The sessions and the surveys were not compulsory. Their participation in the session and completion of surveys implied informed consent. After IRB approval, we reviewed responses for the study groups. Sessions were held in person pre-pandemic in 2019 and virtually during the COVID-19 pandemic in 2022.

Results

Five fellows responded to our survey in 2019 and 7 in 2022 for a total of 12 respondents. 100% of respondents had been emotionally affected by a patient’s death. 82% had been emotionally affected by a patient’s death during the preceding 3 months. 90% had previously discussed their emotions relating to patient death with others. 83% would participate in DC again and 92% would recommend DC to a colleague. One 2019 participant commented that they thought attendings needed the session more than fellows, 2 2022 participants commented that they believe the meeting would be better in person. One 2022 participant commented they thought DC “is a good platform to vent emotions, identify self-destructive thoughts and better coping mechanisms.”

Conclusions 

DC provides a framework for HC to share personal and professional experience with mortality from a human perspective and support each other. This approach may be useful for HO departments or fellowships to offer as an opportunity to process end-of-life matters experienced as providers and finite humans.

PARIS – Adding pembrolizumab (Keytruda) to chemoradiotherapy did not significantly improve event-free survival, compared with CRT plus placebo as first-line therapy for patients with locally advanced head and neck squamous cell cancers (HNSCC), reported investigators of the KEYNOTE-412 trial.

Among 804 patients with newly diagnosed, pathologically proven, unresected locally advanced head and neck squamous cell carcinomas who were followed for a median of 47.7 months, the event-free survival (EFS) rate with the pembrolizumab/CRT combination followed by maintenance pembrolizumab was 63.2%, compared with 56.2% for CRT plus placebo. This translated into a nonsignificant hazard ratio of 0.83, said Jean-Pascal Machiels, MD, PhD, at the annual meeting of the European Society for Medical Oncology.

Despite the trial failing to meet its primary endpoint, Dr. Machiels expressed optimism about the results.

“Pembrolizumab with chemoradiation was associated with a favorable trend toward improved event-free survival versus placebo plus chemoradiation in patients with locally advanced head and neck cancer,” he said.

He noted that the 2-year EFS rate was 63% with pembrolizumab, compared with 56% with placebo.

The data also support the hypothesis that programmed death–ligand 1 (PD-L1) expression as measured by a combined positive score (CPS) could be a predictive biomarker for identifying those patients most likely to respond to the immune checkpoint inhibitor, he added.

KEYNOTE-412 details

The rationale for combining the checkpoint inhibitors pembrolizumab with chemoradiotherapy comes from the KEYNOTE-048 trial results of which showed a survival improvement for the use of pembrolizumab plus a platinum-containing regimen as a first-line therapy for recurrent or metastatic HNSCC, as well as pembrolizumab monotherapy for patients with PD-L1 CPS of 1 or greater.

In the current study, Dr. Machiels and colleagues studied whether adding pembrolizumab to CRT could benefit patients with treatment-naive unresected, locally advanced HNSCC.

Eligible patients included those with stage T3 or T4, N0-N3 or any N2a-3 (T1-T4) cancers of the larynx, hypopharynx, or oral cavity, and either p16-negative oropharynx cancers or T4 or N3 p16-positive oropharynx cancer. Patients were required to be eligible for high-dose cisplatin-based CRT.

A total of 804 patients were randomized, 402 in each arm, to receive either pembrolizumab 200 mg intravenously every 3 weeks for 3 cycles plus CRT followed by maintenance pembrolizumab for 14 cycles, or to placebo plus CRT followed by placebo maintenance.

As noted before, there was no significant difference between the study arms for the primary endpoint of EFS. The 24-month EFS rate was 63.2% for the pembrolizumab group, compared with 56.2% for controls. The respective 6-month EFS rates were 57.4% versus 52.1%.­

In a post hoc analysis, both EFS and overall survival were numerically with pembrolizumab among patients with PD-L1 CPS of 20 or greater. The respective 2- and 3-year EFS rates were 71.2% versus 62.6%, and 66.7% versus 57.2%.

The 24-months overall survival rates were 83.3% with pembrolizumab and 79.9% with placebo, and 36-month rates were 79.1% and 73%, respectively.

Neither EFS rates nor OS rates among patients in this subgroup differed significantly; however, there were no new safety signals with the combination, Dr. Machiels said. The incidence of grade 3 or greater adverse events was 92.2% in the pembrolizumab arm versus 88.4% in the placebo arm. Four patients in the pembrolizumab arm and six in the control arm died from treatment-related causes.
 

Benefit still to be proven

In a media briefing held prior to his presentation, Dr. Machiels was asked how he could justify his conclusions about a benefit for adding pembrolizumab given that there was no difference between the treatment groups for the primary endpoint.

He said that when the investigators designed the trial 7 years ago, the CPS score for PD-L1 expression had not yet been developed, and that if it had been they might have designed the trial to explore the effect of the pembrolizumab chemoradiation combination according to CPS subgroups.

He also pointed to the numerically superior 2-year EFS and overall rates.

In the presidential symposium, James Larkin, MD, PhD, an invited discussant from the Royal Marsden Hospital, London, said that chemotherapy and anti–PD-1 therapies are known to offer benefit in advanced cancers despite the trial’s failure.

“There is a signal, particularly as we’ve seen in the high PD-L1 group,” he said, noting that the signal was consistent with that seen in the JAVELIN 100 study, which was also a negative trial. He cautioned against relying too heavily on the comparison, however, as JAVELIN 100 was conducted with avelumab, a PD-L1 inhibitor, whereas pembrolizumab is a PD-1 inhibitor.

“Could there be an issue here with treatment schedule? An example and a comparison might be the PACIFIC study in non–small cell lung cancer, which is a positive trial, where actually the checkpoint inhibit with durvalumab was given immediately after the chemoradiotherapy, leading to benefit, rather than being concurrent,” he said.

Dr. Larkin also questioned whether, as codiscussant Sherene Loi, MD, PhD, from the Peter MacCallum Cancer Center, Melbourne, suggested radiotherapy to lymph nodes might alter the immune response to checkpoint inhibitors.

“Clearly radiotherapy is the central component of treatment in this setting, so it would be quite difficult to scale too much on that, but the question is: ‘Could it be modified?’ For example, just to irradiate the primary tumor and involved lymph nodes and potentially spare noninvolved lymph nodes,” he said.

The KEYNOTE-412 study was funded by Merck Sharp & Dohme. Dr. Machiels reported uncompensated consulting to the company. Dr. Larkin reported consulting for and receiving honoraria from Merck and others. Dr. Loi reported uncompensated advisory board activity for Merck and others.

PARIS – Adding pembrolizumab (Keytruda) to chemoradiotherapy did not significantly improve event-free survival, compared with CRT plus placebo as first-line therapy for patients with locally advanced head and neck squamous cell cancers (HNSCC), reported investigators of the KEYNOTE-412 trial.

Among 804 patients with newly diagnosed, pathologically proven, unresected locally advanced head and neck squamous cell carcinomas who were followed for a median of 47.7 months, the event-free survival (EFS) rate with the pembrolizumab/CRT combination followed by maintenance pembrolizumab was 63.2%, compared with 56.2% for CRT plus placebo. This translated into a nonsignificant hazard ratio of 0.83, said Jean-Pascal Machiels, MD, PhD, at the annual meeting of the European Society for Medical Oncology.

Despite the trial failing to meet its primary endpoint, Dr. Machiels expressed optimism about the results.

“Pembrolizumab with chemoradiation was associated with a favorable trend toward improved event-free survival versus placebo plus chemoradiation in patients with locally advanced head and neck cancer,” he said.

He noted that the 2-year EFS rate was 63% with pembrolizumab, compared with 56% with placebo.

The data also support the hypothesis that programmed death–ligand 1 (PD-L1) expression as measured by a combined positive score (CPS) could be a predictive biomarker for identifying those patients most likely to respond to the immune checkpoint inhibitor, he added.

KEYNOTE-412 details

The rationale for combining the checkpoint inhibitors pembrolizumab with chemoradiotherapy comes from the KEYNOTE-048 trial results of which showed a survival improvement for the use of pembrolizumab plus a platinum-containing regimen as a first-line therapy for recurrent or metastatic HNSCC, as well as pembrolizumab monotherapy for patients with PD-L1 CPS of 1 or greater.

In the current study, Dr. Machiels and colleagues studied whether adding pembrolizumab to CRT could benefit patients with treatment-naive unresected, locally advanced HNSCC.

Eligible patients included those with stage T3 or T4, N0-N3 or any N2a-3 (T1-T4) cancers of the larynx, hypopharynx, or oral cavity, and either p16-negative oropharynx cancers or T4 or N3 p16-positive oropharynx cancer. Patients were required to be eligible for high-dose cisplatin-based CRT.

A total of 804 patients were randomized, 402 in each arm, to receive either pembrolizumab 200 mg intravenously every 3 weeks for 3 cycles plus CRT followed by maintenance pembrolizumab for 14 cycles, or to placebo plus CRT followed by placebo maintenance.

As noted before, there was no significant difference between the study arms for the primary endpoint of EFS. The 24-month EFS rate was 63.2% for the pembrolizumab group, compared with 56.2% for controls. The respective 6-month EFS rates were 57.4% versus 52.1%.­

In a post hoc analysis, both EFS and overall survival were numerically with pembrolizumab among patients with PD-L1 CPS of 20 or greater. The respective 2- and 3-year EFS rates were 71.2% versus 62.6%, and 66.7% versus 57.2%.

The 24-months overall survival rates were 83.3% with pembrolizumab and 79.9% with placebo, and 36-month rates were 79.1% and 73%, respectively.

Neither EFS rates nor OS rates among patients in this subgroup differed significantly; however, there were no new safety signals with the combination, Dr. Machiels said. The incidence of grade 3 or greater adverse events was 92.2% in the pembrolizumab arm versus 88.4% in the placebo arm. Four patients in the pembrolizumab arm and six in the control arm died from treatment-related causes.
 

Benefit still to be proven

In a media briefing held prior to his presentation, Dr. Machiels was asked how he could justify his conclusions about a benefit for adding pembrolizumab given that there was no difference between the treatment groups for the primary endpoint.

He said that when the investigators designed the trial 7 years ago, the CPS score for PD-L1 expression had not yet been developed, and that if it had been they might have designed the trial to explore the effect of the pembrolizumab chemoradiation combination according to CPS subgroups.

He also pointed to the numerically superior 2-year EFS and overall rates.

In the presidential symposium, James Larkin, MD, PhD, an invited discussant from the Royal Marsden Hospital, London, said that chemotherapy and anti–PD-1 therapies are known to offer benefit in advanced cancers despite the trial’s failure.

“There is a signal, particularly as we’ve seen in the high PD-L1 group,” he said, noting that the signal was consistent with that seen in the JAVELIN 100 study, which was also a negative trial. He cautioned against relying too heavily on the comparison, however, as JAVELIN 100 was conducted with avelumab, a PD-L1 inhibitor, whereas pembrolizumab is a PD-1 inhibitor.

“Could there be an issue here with treatment schedule? An example and a comparison might be the PACIFIC study in non–small cell lung cancer, which is a positive trial, where actually the checkpoint inhibit with durvalumab was given immediately after the chemoradiotherapy, leading to benefit, rather than being concurrent,” he said.

Dr. Larkin also questioned whether, as codiscussant Sherene Loi, MD, PhD, from the Peter MacCallum Cancer Center, Melbourne, suggested radiotherapy to lymph nodes might alter the immune response to checkpoint inhibitors.

“Clearly radiotherapy is the central component of treatment in this setting, so it would be quite difficult to scale too much on that, but the question is: ‘Could it be modified?’ For example, just to irradiate the primary tumor and involved lymph nodes and potentially spare noninvolved lymph nodes,” he said.

The KEYNOTE-412 study was funded by Merck Sharp & Dohme. Dr. Machiels reported uncompensated consulting to the company. Dr. Larkin reported consulting for and receiving honoraria from Merck and others. Dr. Loi reported uncompensated advisory board activity for Merck and others.

PARIS – Adding pembrolizumab (Keytruda) to chemoradiotherapy did not significantly improve event-free survival, compared with CRT plus placebo as first-line therapy for patients with locally advanced head and neck squamous cell cancers (HNSCC), reported investigators of the KEYNOTE-412 trial.

Among 804 patients with newly diagnosed, pathologically proven, unresected locally advanced head and neck squamous cell carcinomas who were followed for a median of 47.7 months, the event-free survival (EFS) rate with the pembrolizumab/CRT combination followed by maintenance pembrolizumab was 63.2%, compared with 56.2% for CRT plus placebo. This translated into a nonsignificant hazard ratio of 0.83, said Jean-Pascal Machiels, MD, PhD, at the annual meeting of the European Society for Medical Oncology.

Despite the trial failing to meet its primary endpoint, Dr. Machiels expressed optimism about the results.

“Pembrolizumab with chemoradiation was associated with a favorable trend toward improved event-free survival versus placebo plus chemoradiation in patients with locally advanced head and neck cancer,” he said.

He noted that the 2-year EFS rate was 63% with pembrolizumab, compared with 56% with placebo.

The data also support the hypothesis that programmed death–ligand 1 (PD-L1) expression as measured by a combined positive score (CPS) could be a predictive biomarker for identifying those patients most likely to respond to the immune checkpoint inhibitor, he added.

KEYNOTE-412 details

The rationale for combining the checkpoint inhibitors pembrolizumab with chemoradiotherapy comes from the KEYNOTE-048 trial results of which showed a survival improvement for the use of pembrolizumab plus a platinum-containing regimen as a first-line therapy for recurrent or metastatic HNSCC, as well as pembrolizumab monotherapy for patients with PD-L1 CPS of 1 or greater.

In the current study, Dr. Machiels and colleagues studied whether adding pembrolizumab to CRT could benefit patients with treatment-naive unresected, locally advanced HNSCC.

Eligible patients included those with stage T3 or T4, N0-N3 or any N2a-3 (T1-T4) cancers of the larynx, hypopharynx, or oral cavity, and either p16-negative oropharynx cancers or T4 or N3 p16-positive oropharynx cancer. Patients were required to be eligible for high-dose cisplatin-based CRT.

A total of 804 patients were randomized, 402 in each arm, to receive either pembrolizumab 200 mg intravenously every 3 weeks for 3 cycles plus CRT followed by maintenance pembrolizumab for 14 cycles, or to placebo plus CRT followed by placebo maintenance.

As noted before, there was no significant difference between the study arms for the primary endpoint of EFS. The 24-month EFS rate was 63.2% for the pembrolizumab group, compared with 56.2% for controls. The respective 6-month EFS rates were 57.4% versus 52.1%.­

In a post hoc analysis, both EFS and overall survival were numerically with pembrolizumab among patients with PD-L1 CPS of 20 or greater. The respective 2- and 3-year EFS rates were 71.2% versus 62.6%, and 66.7% versus 57.2%.

The 24-months overall survival rates were 83.3% with pembrolizumab and 79.9% with placebo, and 36-month rates were 79.1% and 73%, respectively.

Neither EFS rates nor OS rates among patients in this subgroup differed significantly; however, there were no new safety signals with the combination, Dr. Machiels said. The incidence of grade 3 or greater adverse events was 92.2% in the pembrolizumab arm versus 88.4% in the placebo arm. Four patients in the pembrolizumab arm and six in the control arm died from treatment-related causes.
 

Benefit still to be proven

In a media briefing held prior to his presentation, Dr. Machiels was asked how he could justify his conclusions about a benefit for adding pembrolizumab given that there was no difference between the treatment groups for the primary endpoint.

He said that when the investigators designed the trial 7 years ago, the CPS score for PD-L1 expression had not yet been developed, and that if it had been they might have designed the trial to explore the effect of the pembrolizumab chemoradiation combination according to CPS subgroups.

He also pointed to the numerically superior 2-year EFS and overall rates.

In the presidential symposium, James Larkin, MD, PhD, an invited discussant from the Royal Marsden Hospital, London, said that chemotherapy and anti–PD-1 therapies are known to offer benefit in advanced cancers despite the trial’s failure.

“There is a signal, particularly as we’ve seen in the high PD-L1 group,” he said, noting that the signal was consistent with that seen in the JAVELIN 100 study, which was also a negative trial. He cautioned against relying too heavily on the comparison, however, as JAVELIN 100 was conducted with avelumab, a PD-L1 inhibitor, whereas pembrolizumab is a PD-1 inhibitor.

“Could there be an issue here with treatment schedule? An example and a comparison might be the PACIFIC study in non–small cell lung cancer, which is a positive trial, where actually the checkpoint inhibit with durvalumab was given immediately after the chemoradiotherapy, leading to benefit, rather than being concurrent,” he said.

Dr. Larkin also questioned whether, as codiscussant Sherene Loi, MD, PhD, from the Peter MacCallum Cancer Center, Melbourne, suggested radiotherapy to lymph nodes might alter the immune response to checkpoint inhibitors.

“Clearly radiotherapy is the central component of treatment in this setting, so it would be quite difficult to scale too much on that, but the question is: ‘Could it be modified?’ For example, just to irradiate the primary tumor and involved lymph nodes and potentially spare noninvolved lymph nodes,” he said.

The KEYNOTE-412 study was funded by Merck Sharp & Dohme. Dr. Machiels reported uncompensated consulting to the company. Dr. Larkin reported consulting for and receiving honoraria from Merck and others. Dr. Loi reported uncompensated advisory board activity for Merck and others.

In non–small cell lung cancer (NSCLC), mutations to the epidermal growth factor receptor (EGFR) gene are generally associated with a poor response to immune checkpoint inhibitor (ICI) therapies. However, there is a range of different EGFR mutations, and different mutation combinations can lead to different tumor characteristics that might in turn affect response to therapy.

A new real-world analysis of 159 NSCLC patients found that a combination of a mutation of the TP53 tumor suppressor gene and the EGFR Ex20 mutation is associated with worse disease outcomes, compared to patients with the EGFR Ex20 mutation alone. But the news wasn’t all bad. The same group of patients also responded better to ICB (immune checkpoint blockade) therapy than did the broader population of EGFR Ex20 patients.

The EGFR Ex20 mutation occurs in about 4% of NSCLC cases, while TP53 is quite common: The new study found a frequency of 43.9%. “We first have to mention that the findings regarding TP53 do not reach statistical significance; however, the trend is very strong, and results might be hampered due to small sample sizes. We think it is [appropriate] to exhaust more treatment options for these patients, especially targeted approaches with newer drugs that specifically target exon 20 insertions, as these drugs were not applied in our cohort,” Anna Kron, Dr. rer. medic., said in an email exchange. Dr. Kron presented the results at a poster session in Paris at the ESMO Congress. She is a researcher at University Hospital of Cologne, Germany.

The ImmunoTarget study, published in 2019, examined over 500 NSCLC patients with a range of driver mutations including EGFR and found that they responded poorly to ICIs in comparison to KRAS mutations.

But Dr. Kron’s group was not convinced. “Ex20 mutations differ clinically from other tyrosine kinase mutations in EGFR. We set out this study to rechallenge the paradigm of impaired benefit from ICI in EGFR-mutated patients, as we consider these mutations not interchangeable with other EGFR mutations,” Dr. Kron said.

“We would postulate that in EGFR Exon 20 mutations, ICI and specific inhibitors should be part of the therapeutic course. In patients with co-occurring TP53 mutations, treatment escalation could be considered,” Dr. Kron said.

The study included 159 patients with advanced NSCLC with the EGFR exon 20 insertion, who were treated between 2014 and 2020 at German hospitals. Among the patients, 37.7% were female; mean age at diagnosis was 65.87 years; 50.3% had a smoking history and 38.4% did not (data were unavailable for the rest); and 9.4% of tumors were stage I, 4.4% stage II, 8.2% stage IIIA, 3.8% stage IIIB, and 74.2% stage IV.

Over a follow-up of 4.1 years, there was a trend toward longer survival among patients with TP53 wild type (OS, 20 versus 12 months; P = .092). Sixty-six patients who received ICI therapy had better OS compared with those who did not (22 versus 10 months; P = .018). Among patients with co-occurring TP53 mutations, receipt of ICI therapy was associated with longer OS (16 versus 8 months; P = .048). There was a trend toward patients with TP53 wild type treated with ICI faring better than those who didn’t receive ICI (27.0 months versus 11.0 months; P = .109).

The researchers are continuing to study patients with EGFR Ex20 to better understand the role of TP53 and ICI therapy in these patients.

The study received no funding. Dr. Kron has no relevant financial disclosures.

In non–small cell lung cancer (NSCLC), mutations to the epidermal growth factor receptor (EGFR) gene are generally associated with a poor response to immune checkpoint inhibitor (ICI) therapies. However, there is a range of different EGFR mutations, and different mutation combinations can lead to different tumor characteristics that might in turn affect response to therapy.

A new real-world analysis of 159 NSCLC patients found that a combination of a mutation of the TP53 tumor suppressor gene and the EGFR Ex20 mutation is associated with worse disease outcomes, compared to patients with the EGFR Ex20 mutation alone. But the news wasn’t all bad. The same group of patients also responded better to ICB (immune checkpoint blockade) therapy than did the broader population of EGFR Ex20 patients.

The EGFR Ex20 mutation occurs in about 4% of NSCLC cases, while TP53 is quite common: The new study found a frequency of 43.9%. “We first have to mention that the findings regarding TP53 do not reach statistical significance; however, the trend is very strong, and results might be hampered due to small sample sizes. We think it is [appropriate] to exhaust more treatment options for these patients, especially targeted approaches with newer drugs that specifically target exon 20 insertions, as these drugs were not applied in our cohort,” Anna Kron, Dr. rer. medic., said in an email exchange. Dr. Kron presented the results at a poster session in Paris at the ESMO Congress. She is a researcher at University Hospital of Cologne, Germany.

The ImmunoTarget study, published in 2019, examined over 500 NSCLC patients with a range of driver mutations including EGFR and found that they responded poorly to ICIs in comparison to KRAS mutations.

But Dr. Kron’s group was not convinced. “Ex20 mutations differ clinically from other tyrosine kinase mutations in EGFR. We set out this study to rechallenge the paradigm of impaired benefit from ICI in EGFR-mutated patients, as we consider these mutations not interchangeable with other EGFR mutations,” Dr. Kron said.

“We would postulate that in EGFR Exon 20 mutations, ICI and specific inhibitors should be part of the therapeutic course. In patients with co-occurring TP53 mutations, treatment escalation could be considered,” Dr. Kron said.

The study included 159 patients with advanced NSCLC with the EGFR exon 20 insertion, who were treated between 2014 and 2020 at German hospitals. Among the patients, 37.7% were female; mean age at diagnosis was 65.87 years; 50.3% had a smoking history and 38.4% did not (data were unavailable for the rest); and 9.4% of tumors were stage I, 4.4% stage II, 8.2% stage IIIA, 3.8% stage IIIB, and 74.2% stage IV.

Over a follow-up of 4.1 years, there was a trend toward longer survival among patients with TP53 wild type (OS, 20 versus 12 months; P = .092). Sixty-six patients who received ICI therapy had better OS compared with those who did not (22 versus 10 months; P = .018). Among patients with co-occurring TP53 mutations, receipt of ICI therapy was associated with longer OS (16 versus 8 months; P = .048). There was a trend toward patients with TP53 wild type treated with ICI faring better than those who didn’t receive ICI (27.0 months versus 11.0 months; P = .109).

The researchers are continuing to study patients with EGFR Ex20 to better understand the role of TP53 and ICI therapy in these patients.

The study received no funding. Dr. Kron has no relevant financial disclosures.

In non–small cell lung cancer (NSCLC), mutations to the epidermal growth factor receptor (EGFR) gene are generally associated with a poor response to immune checkpoint inhibitor (ICI) therapies. However, there is a range of different EGFR mutations, and different mutation combinations can lead to different tumor characteristics that might in turn affect response to therapy.

A new real-world analysis of 159 NSCLC patients found that a combination of a mutation of the TP53 tumor suppressor gene and the EGFR Ex20 mutation is associated with worse disease outcomes, compared to patients with the EGFR Ex20 mutation alone. But the news wasn’t all bad. The same group of patients also responded better to ICB (immune checkpoint blockade) therapy than did the broader population of EGFR Ex20 patients.

The EGFR Ex20 mutation occurs in about 4% of NSCLC cases, while TP53 is quite common: The new study found a frequency of 43.9%. “We first have to mention that the findings regarding TP53 do not reach statistical significance; however, the trend is very strong, and results might be hampered due to small sample sizes. We think it is [appropriate] to exhaust more treatment options for these patients, especially targeted approaches with newer drugs that specifically target exon 20 insertions, as these drugs were not applied in our cohort,” Anna Kron, Dr. rer. medic., said in an email exchange. Dr. Kron presented the results at a poster session in Paris at the ESMO Congress. She is a researcher at University Hospital of Cologne, Germany.

The ImmunoTarget study, published in 2019, examined over 500 NSCLC patients with a range of driver mutations including EGFR and found that they responded poorly to ICIs in comparison to KRAS mutations.

But Dr. Kron’s group was not convinced. “Ex20 mutations differ clinically from other tyrosine kinase mutations in EGFR. We set out this study to rechallenge the paradigm of impaired benefit from ICI in EGFR-mutated patients, as we consider these mutations not interchangeable with other EGFR mutations,” Dr. Kron said.

“We would postulate that in EGFR Exon 20 mutations, ICI and specific inhibitors should be part of the therapeutic course. In patients with co-occurring TP53 mutations, treatment escalation could be considered,” Dr. Kron said.

The study included 159 patients with advanced NSCLC with the EGFR exon 20 insertion, who were treated between 2014 and 2020 at German hospitals. Among the patients, 37.7% were female; mean age at diagnosis was 65.87 years; 50.3% had a smoking history and 38.4% did not (data were unavailable for the rest); and 9.4% of tumors were stage I, 4.4% stage II, 8.2% stage IIIA, 3.8% stage IIIB, and 74.2% stage IV.

Over a follow-up of 4.1 years, there was a trend toward longer survival among patients with TP53 wild type (OS, 20 versus 12 months; P = .092). Sixty-six patients who received ICI therapy had better OS compared with those who did not (22 versus 10 months; P = .018). Among patients with co-occurring TP53 mutations, receipt of ICI therapy was associated with longer OS (16 versus 8 months; P = .048). There was a trend toward patients with TP53 wild type treated with ICI faring better than those who didn’t receive ICI (27.0 months versus 11.0 months; P = .109).

The researchers are continuing to study patients with EGFR Ex20 to better understand the role of TP53 and ICI therapy in these patients.

The study received no funding. Dr. Kron has no relevant financial disclosures.

Cardiometabolic and respiratory comorbidities are associated with worse survival in patients with non–small cell lung cancer (NSCLC), and new research suggests a potential mechanism.

Prior studies had shown mixed results when it came to these comorbidities and survival, according to study coauthor author Geoffrey Liu, MD, who is an epidemiology researcher at the University of Toronto Princess Margaret Cancer Centre. The new work represents data from multiple continents, from various ethnicities and cultures.

“We found that comorbidities had much greater impact on earlier than later stages of lung cancer, consistent with this previous study,” said Dr. Liu in an email. The study was presented by Miguel Garcia-Pardo, who is a researcher at University of Toronto Princess Margaret Cancer Centre, during a poster session at the annual meeting of the European Society for Medical Oncology.

“Deaths from [cardiometabolic] comorbidities were mainly from non–lung cancer competing causes, whereas the deaths from respiratory comorbidities were primarily driven by lung cancer specific survival, i.e., deaths from lung cancer itself. We conclude that it is critical to understand how these patients with different comorbidities died, as it would impact decisions on treatment planning and mitigation strategies,” Dr. Liu said.

Dr. Liu noted that controlling cardiometabolic risk factors like diabetes and hypertension is typically de-emphasized after diagnosis with early-stage lung cancer. The rationale is often that the lung cancer is a more acute concern than longer-term cardiometabolic risks. “The data from our analyses suggest a rethinking of this strategy. We need to pay more attention to controlling cardiovascular risk factors in early-stage lung cancer,” Dr. Liu said.

The findings also suggest that respiratory comorbidities should be managed more aggressively. That would allow more patients to undergo treatments like surgery and stereotactic radiation.

The Clinical Outcome Studies of the International Lung Cancer Consortium drew from two dozen studies conducted across five continents. It examined clinical, epidemiologic, genetic, and genomic factors and their potential influence on NSCLC outcomes. Cardiometabolic comorbidities included coronary artery disease, diabetes, vascular related diseases, and other heart diseases. Respiratory comorbidities included chronic obstructive pulmonary disease and asthma.

The analysis included 16,354 patients. Among patients with stage I NSCLC, there was an association between reduced overall survival (OS) and cardiometabolic comorbidity (adjusted hazard ratio, 1.17; P = .01) and respiratory comorbidity (aHR, 1.36; P < .001). For stage II/III patients, there was no significant association between OS and cardiometabolic comorbidities, but respiratory comorbidity was associated with worse OS (aHR, 1.15; P < .001). In stage 4, worse OS was associated with both cardiometabolic health comorbidity (aHR, 1.11; P = .03), but not respiratory comorbidity.

Among patients with stage IV NSCLC, there were no associations between overall survival or lung cancer–specific survival (LCSS) and respiratory or cardiometabolic risk factors. However, an examination of cause of death found a different pattern in patients with stage IB-IIIA disease: LCSS was worse among patients with respiratory comorbidities (aHR, 1.21; 95% CI, 1.09-1.34). Among those with cardiovascular comorbidities, the risk of non-NSCLC mortality was higher (aHR, 1.36; 95% CI, 1.15-1.63). The presence of respiratory comorbidity was associated with a reduced probability of undergoing surgical resection for both stage I (adjusted odds ratio, 0.45; 95% CI, 0.35-0.59) and stage II/III patients (aOR, 0.66; 95% CI, 0.53-0.80).

There was an association between non-NSCLC mortality and cardiometabolic comorbidities in stage IA (aHR, 1.37; 95% CI, 1.06-1.77) and in stages IB-IIIA (aHR, 1.32; 95% CI, 1.03-1.71) NSCLC. There were also associations between NSCLC mortality and respiratory comorbidity among stage IA (aHR, 1.51; 95% CI, 1.17-1.95) and stages IB-IIIA (aHR, 1.20; 95% CI, 1.06-1.36) NSCLC. There were no associations between respiratory comorbidity and non-NSCLC mortality.

Respiratory comorbidity was associated with a lower chance of undergoing surgical resection in stage IA (aHR, 0.54; 95% CI, 0.35-0.83) and stage IB-IIIA (aHR, 0.57; 95% CI, 0.46-0.70) cancers. Cardiometabolic comorbidity was associated with a lower rate of surgical resection only in stage 1B-3A patients (aHR, 0.73; 95% CI, 0.56-0.96). Among those who underwent resection, stage IA patients were less likely to die of lung cancer (aHR, 0.38; 95% CI, 0.28-0.52) but more likely to die of other causes (aHR, 1.73; 95% CI, 1.07-1.78). Stage IB-IIIA patients who underwent resection were less likely to die of lung cancer (aHR, 0.37; 95%, 0.32-0.42), but there was no significant association with non–lung cancer mortality.

The study was funded by the Lusi Wong Family Fund and the Alan Brown Chair. Dr. Liu has no relevant financial disclosures.

Cardiometabolic and respiratory comorbidities are associated with worse survival in patients with non–small cell lung cancer (NSCLC), and new research suggests a potential mechanism.

Prior studies had shown mixed results when it came to these comorbidities and survival, according to study coauthor author Geoffrey Liu, MD, who is an epidemiology researcher at the University of Toronto Princess Margaret Cancer Centre. The new work represents data from multiple continents, from various ethnicities and cultures.

“We found that comorbidities had much greater impact on earlier than later stages of lung cancer, consistent with this previous study,” said Dr. Liu in an email. The study was presented by Miguel Garcia-Pardo, who is a researcher at University of Toronto Princess Margaret Cancer Centre, during a poster session at the annual meeting of the European Society for Medical Oncology.

“Deaths from [cardiometabolic] comorbidities were mainly from non–lung cancer competing causes, whereas the deaths from respiratory comorbidities were primarily driven by lung cancer specific survival, i.e., deaths from lung cancer itself. We conclude that it is critical to understand how these patients with different comorbidities died, as it would impact decisions on treatment planning and mitigation strategies,” Dr. Liu said.

Dr. Liu noted that controlling cardiometabolic risk factors like diabetes and hypertension is typically de-emphasized after diagnosis with early-stage lung cancer. The rationale is often that the lung cancer is a more acute concern than longer-term cardiometabolic risks. “The data from our analyses suggest a rethinking of this strategy. We need to pay more attention to controlling cardiovascular risk factors in early-stage lung cancer,” Dr. Liu said.

The findings also suggest that respiratory comorbidities should be managed more aggressively. That would allow more patients to undergo treatments like surgery and stereotactic radiation.

The Clinical Outcome Studies of the International Lung Cancer Consortium drew from two dozen studies conducted across five continents. It examined clinical, epidemiologic, genetic, and genomic factors and their potential influence on NSCLC outcomes. Cardiometabolic comorbidities included coronary artery disease, diabetes, vascular related diseases, and other heart diseases. Respiratory comorbidities included chronic obstructive pulmonary disease and asthma.

The analysis included 16,354 patients. Among patients with stage I NSCLC, there was an association between reduced overall survival (OS) and cardiometabolic comorbidity (adjusted hazard ratio, 1.17; P = .01) and respiratory comorbidity (aHR, 1.36; P < .001). For stage II/III patients, there was no significant association between OS and cardiometabolic comorbidities, but respiratory comorbidity was associated with worse OS (aHR, 1.15; P < .001). In stage 4, worse OS was associated with both cardiometabolic health comorbidity (aHR, 1.11; P = .03), but not respiratory comorbidity.

Among patients with stage IV NSCLC, there were no associations between overall survival or lung cancer–specific survival (LCSS) and respiratory or cardiometabolic risk factors. However, an examination of cause of death found a different pattern in patients with stage IB-IIIA disease: LCSS was worse among patients with respiratory comorbidities (aHR, 1.21; 95% CI, 1.09-1.34). Among those with cardiovascular comorbidities, the risk of non-NSCLC mortality was higher (aHR, 1.36; 95% CI, 1.15-1.63). The presence of respiratory comorbidity was associated with a reduced probability of undergoing surgical resection for both stage I (adjusted odds ratio, 0.45; 95% CI, 0.35-0.59) and stage II/III patients (aOR, 0.66; 95% CI, 0.53-0.80).

There was an association between non-NSCLC mortality and cardiometabolic comorbidities in stage IA (aHR, 1.37; 95% CI, 1.06-1.77) and in stages IB-IIIA (aHR, 1.32; 95% CI, 1.03-1.71) NSCLC. There were also associations between NSCLC mortality and respiratory comorbidity among stage IA (aHR, 1.51; 95% CI, 1.17-1.95) and stages IB-IIIA (aHR, 1.20; 95% CI, 1.06-1.36) NSCLC. There were no associations between respiratory comorbidity and non-NSCLC mortality.

Respiratory comorbidity was associated with a lower chance of undergoing surgical resection in stage IA (aHR, 0.54; 95% CI, 0.35-0.83) and stage IB-IIIA (aHR, 0.57; 95% CI, 0.46-0.70) cancers. Cardiometabolic comorbidity was associated with a lower rate of surgical resection only in stage 1B-3A patients (aHR, 0.73; 95% CI, 0.56-0.96). Among those who underwent resection, stage IA patients were less likely to die of lung cancer (aHR, 0.38; 95% CI, 0.28-0.52) but more likely to die of other causes (aHR, 1.73; 95% CI, 1.07-1.78). Stage IB-IIIA patients who underwent resection were less likely to die of lung cancer (aHR, 0.37; 95%, 0.32-0.42), but there was no significant association with non–lung cancer mortality.

The study was funded by the Lusi Wong Family Fund and the Alan Brown Chair. Dr. Liu has no relevant financial disclosures.

Cardiometabolic and respiratory comorbidities are associated with worse survival in patients with non–small cell lung cancer (NSCLC), and new research suggests a potential mechanism.

Prior studies had shown mixed results when it came to these comorbidities and survival, according to study coauthor author Geoffrey Liu, MD, who is an epidemiology researcher at the University of Toronto Princess Margaret Cancer Centre. The new work represents data from multiple continents, from various ethnicities and cultures.

“We found that comorbidities had much greater impact on earlier than later stages of lung cancer, consistent with this previous study,” said Dr. Liu in an email. The study was presented by Miguel Garcia-Pardo, who is a researcher at University of Toronto Princess Margaret Cancer Centre, during a poster session at the annual meeting of the European Society for Medical Oncology.

“Deaths from [cardiometabolic] comorbidities were mainly from non–lung cancer competing causes, whereas the deaths from respiratory comorbidities were primarily driven by lung cancer specific survival, i.e., deaths from lung cancer itself. We conclude that it is critical to understand how these patients with different comorbidities died, as it would impact decisions on treatment planning and mitigation strategies,” Dr. Liu said.

Dr. Liu noted that controlling cardiometabolic risk factors like diabetes and hypertension is typically de-emphasized after diagnosis with early-stage lung cancer. The rationale is often that the lung cancer is a more acute concern than longer-term cardiometabolic risks. “The data from our analyses suggest a rethinking of this strategy. We need to pay more attention to controlling cardiovascular risk factors in early-stage lung cancer,” Dr. Liu said.

The findings also suggest that respiratory comorbidities should be managed more aggressively. That would allow more patients to undergo treatments like surgery and stereotactic radiation.

The Clinical Outcome Studies of the International Lung Cancer Consortium drew from two dozen studies conducted across five continents. It examined clinical, epidemiologic, genetic, and genomic factors and their potential influence on NSCLC outcomes. Cardiometabolic comorbidities included coronary artery disease, diabetes, vascular related diseases, and other heart diseases. Respiratory comorbidities included chronic obstructive pulmonary disease and asthma.

The analysis included 16,354 patients. Among patients with stage I NSCLC, there was an association between reduced overall survival (OS) and cardiometabolic comorbidity (adjusted hazard ratio, 1.17; P = .01) and respiratory comorbidity (aHR, 1.36; P < .001). For stage II/III patients, there was no significant association between OS and cardiometabolic comorbidities, but respiratory comorbidity was associated with worse OS (aHR, 1.15; P < .001). In stage 4, worse OS was associated with both cardiometabolic health comorbidity (aHR, 1.11; P = .03), but not respiratory comorbidity.

Among patients with stage IV NSCLC, there were no associations between overall survival or lung cancer–specific survival (LCSS) and respiratory or cardiometabolic risk factors. However, an examination of cause of death found a different pattern in patients with stage IB-IIIA disease: LCSS was worse among patients with respiratory comorbidities (aHR, 1.21; 95% CI, 1.09-1.34). Among those with cardiovascular comorbidities, the risk of non-NSCLC mortality was higher (aHR, 1.36; 95% CI, 1.15-1.63). The presence of respiratory comorbidity was associated with a reduced probability of undergoing surgical resection for both stage I (adjusted odds ratio, 0.45; 95% CI, 0.35-0.59) and stage II/III patients (aOR, 0.66; 95% CI, 0.53-0.80).

There was an association between non-NSCLC mortality and cardiometabolic comorbidities in stage IA (aHR, 1.37; 95% CI, 1.06-1.77) and in stages IB-IIIA (aHR, 1.32; 95% CI, 1.03-1.71) NSCLC. There were also associations between NSCLC mortality and respiratory comorbidity among stage IA (aHR, 1.51; 95% CI, 1.17-1.95) and stages IB-IIIA (aHR, 1.20; 95% CI, 1.06-1.36) NSCLC. There were no associations between respiratory comorbidity and non-NSCLC mortality.

Respiratory comorbidity was associated with a lower chance of undergoing surgical resection in stage IA (aHR, 0.54; 95% CI, 0.35-0.83) and stage IB-IIIA (aHR, 0.57; 95% CI, 0.46-0.70) cancers. Cardiometabolic comorbidity was associated with a lower rate of surgical resection only in stage 1B-3A patients (aHR, 0.73; 95% CI, 0.56-0.96). Among those who underwent resection, stage IA patients were less likely to die of lung cancer (aHR, 0.38; 95% CI, 0.28-0.52) but more likely to die of other causes (aHR, 1.73; 95% CI, 1.07-1.78). Stage IB-IIIA patients who underwent resection were less likely to die of lung cancer (aHR, 0.37; 95%, 0.32-0.42), but there was no significant association with non–lung cancer mortality.

The study was funded by the Lusi Wong Family Fund and the Alan Brown Chair. Dr. Liu has no relevant financial disclosures.

PARIS – Air pollution has been recognized as a risk factor for lung cancer for about 2 decades, and investigators in the UK have now identified a potential mechanism whereby the air we breathe may trigger driver mutations already present in normal lung cells to cause cancer.

Think of it as “smoking gun–level” evidence that may explain why many nonsmokers still develop non–small cell lung cancer, said Charles Swanton, PhD, from the Francis Crick Institute and Cancer Research UK Chief Clinician, London.

“What this work shows is that air pollution is directly causing lung cancer but through a slightly unexpected pathway,” he said at a briefing prior to his presentation of the data in a presidential symposium held earlier this month in Paris at the European Society for Medical Oncology Congress 2022.

Importantly, he and his team also propose a mechanism for blocking the effects of air pollution with monoclonal antibodies directed against the inflammatory cytokine interleukein-1 beta.
 

Carcinogenesis explored

Lung cancer in never-smokers has a low mutational burden, with about 5- to 10-fold fewer mutations in a nonsmoker, compared with an ever smoker or current smoker, Dr. Swanton noted.

“The other thing to say about never-smokers is that they don’t have a clear environmental carcinogenic signature. So how do you square the circle? You’ve got the problem that you know that air pollution is associated with lung cancer – we don’t know if it causes it – but we also see that we’ve got no DNA mutations due to an environmental carcinogen,” he said during his symposium presentation.

The traditional model proposed to explain how carcinogens cause cancer holds that exposure to a carcinogen causes DNA mutations that lead to clonal expansion and tumor growth.

“But there are some major problems with this model,” Dr. Swanton said.

For example, normal skin contains a “patchwork of mutant clones,” but skin cancer is still uncommon, he said, and in studies in mice, 17 of 20 environmental carcinogens did not induce DNA mutations. He also noted that a common melanoma driver mutation, BRAF V600E, is not induced by exposure to a ultraviolet light.

“Any explanation for never-smoking lung cancer would have to fulfill three criteria: one, you have to explain why geographic variation exists; two, you have to prove causation; and three, you have to explain how cancers can be initiated without directly causing DNA mutations,” he said.

Normal lung tissues in nonsmoking adults can harbor pre-existing mutations, with the number of mutations increasing likely as a consequence of aging. In fact, more than 50% of normal lung biopsy tissues have been shown to harbor driver KRAS and/or EGFR mutations, Dr. Swanton said.

“In our research, these mutations alone only weakly potentiated cancer in laboratory models. However, when lung cells with these mutations were exposed to air pollutants, we saw more cancers and these occurred more quickly than when lung cells with these mutations were not exposed to pollutants, suggesting that air pollution promotes the initiation of lung cancer in cells harboring driver gene mutations. The next step is to discover why some lung cells with mutations become cancerous when exposed to pollutants while others don’t,” he said.
 

Geographical exposures

Looking at data on 447,932 participants in the UK Biobank, the investigators found that increasing exposure to ambient air particles smaller than 2.5 mcm (PM_2.5) was significantly associated with seven cancer types, including lung cancer. They also saw an association between PM­­_2.5 exposure levels and EGFR-mutated lung cancer incidence in the United Kingdom, South Korea, and Taiwan.

And crucially, as Dr. Swanton and associates showed in mouse models, exposure of lung cells bearing somatic EGFR and KRAS mutations to PM2.5 causes recruitment of macrophages that in turn secrete IL-1B, resulting in a transdifferentiation of EGFR-mutated cells into a cancer stem cell state, and tumor formation.

Importantly, pollution-induced tumor formation can be blocked by antibodies directed against IL-1B, Dr. Swanton said.

He pointed to a 2017 study in The Lancet suggesting that anti-inflammatory therapy with the anti–IL-1 antibody canakinumab (Ilaris) could reduce incident lung cancer and lung cancer deaths.
 

‘Elegant first demonstration’

“This is a very meaningful demonstration, from epidemiological data to preclinical models of the role of PM_­2.5 air pollutants in the promotion of lung cancer, and it provides us with very important insights into the mechanism through which nonsmokers can get lung cancer,” commented Suzette Delaloge, MD, from the cancer interception program at Institut Goustave Roussy in Villejuif, France, the invited discussant.

“But beyond that, it also has a great impact on our vision of carcinogenesis, with this very elegant first demonstration of the alternative nonmutagenic, carcinogenetic promotion hypothesis for fine particulate matter,” she said.

Questions still to be answered include whether PM_2.5 pollutants could also be mutagenic, is the oncogenic pathway ubiquitous in tissue, which components of PM_2.5 might drive the effect, how long of an exposure is required to promote lung cancer, and why and how persons without cancer develop specific driver mutations such as EGFR, she said.

“This research is intriguing and exciting as it means that we can ask whether, in the future, it will be possible to use lung scans to look for precancerous lesions in the lungs and try to reverse them with medicines such as interleukin-1B inhibitors,” said Tony Mok, MD, a lung cancer specialist at the Chinese University of Hong Kong, who was not involved in the study.

“We don’t yet know whether it will be possible to use highly sensitive EGFR profiling on blood or other samples to find nonsmokers who are predisposed to lung cancer and may benefit from lung scanning, so discussions are still very speculative,” he said in a statement.

The study was supported by Cancer Research UK, the Lung Cancer Research Foundations, Rosetrees Trust, the Mark Foundation for Cancer Research and the Ruth Strauss Foundation. Dr. Swanton disclosed grants/research support, honoraria, and stock ownership with multiple entities. Dr. Delaloge disclosed institutional financing and research funding from multiple companies. Dr. Mok disclosed stock ownership and honoraria with multiple companies.

PARIS – Air pollution has been recognized as a risk factor for lung cancer for about 2 decades, and investigators in the UK have now identified a potential mechanism whereby the air we breathe may trigger driver mutations already present in normal lung cells to cause cancer.

Think of it as “smoking gun–level” evidence that may explain why many nonsmokers still develop non–small cell lung cancer, said Charles Swanton, PhD, from the Francis Crick Institute and Cancer Research UK Chief Clinician, London.

“What this work shows is that air pollution is directly causing lung cancer but through a slightly unexpected pathway,” he said at a briefing prior to his presentation of the data in a presidential symposium held earlier this month in Paris at the European Society for Medical Oncology Congress 2022.

Importantly, he and his team also propose a mechanism for blocking the effects of air pollution with monoclonal antibodies directed against the inflammatory cytokine interleukein-1 beta.
 

Carcinogenesis explored

Lung cancer in never-smokers has a low mutational burden, with about 5- to 10-fold fewer mutations in a nonsmoker, compared with an ever smoker or current smoker, Dr. Swanton noted.

“The other thing to say about never-smokers is that they don’t have a clear environmental carcinogenic signature. So how do you square the circle? You’ve got the problem that you know that air pollution is associated with lung cancer – we don’t know if it causes it – but we also see that we’ve got no DNA mutations due to an environmental carcinogen,” he said during his symposium presentation.

The traditional model proposed to explain how carcinogens cause cancer holds that exposure to a carcinogen causes DNA mutations that lead to clonal expansion and tumor growth.

“But there are some major problems with this model,” Dr. Swanton said.

For example, normal skin contains a “patchwork of mutant clones,” but skin cancer is still uncommon, he said, and in studies in mice, 17 of 20 environmental carcinogens did not induce DNA mutations. He also noted that a common melanoma driver mutation, BRAF V600E, is not induced by exposure to a ultraviolet light.

“Any explanation for never-smoking lung cancer would have to fulfill three criteria: one, you have to explain why geographic variation exists; two, you have to prove causation; and three, you have to explain how cancers can be initiated without directly causing DNA mutations,” he said.

Normal lung tissues in nonsmoking adults can harbor pre-existing mutations, with the number of mutations increasing likely as a consequence of aging. In fact, more than 50% of normal lung biopsy tissues have been shown to harbor driver KRAS and/or EGFR mutations, Dr. Swanton said.

“In our research, these mutations alone only weakly potentiated cancer in laboratory models. However, when lung cells with these mutations were exposed to air pollutants, we saw more cancers and these occurred more quickly than when lung cells with these mutations were not exposed to pollutants, suggesting that air pollution promotes the initiation of lung cancer in cells harboring driver gene mutations. The next step is to discover why some lung cells with mutations become cancerous when exposed to pollutants while others don’t,” he said.
 

Geographical exposures

Looking at data on 447,932 participants in the UK Biobank, the investigators found that increasing exposure to ambient air particles smaller than 2.5 mcm (PM_2.5) was significantly associated with seven cancer types, including lung cancer. They also saw an association between PM­­_2.5 exposure levels and EGFR-mutated lung cancer incidence in the United Kingdom, South Korea, and Taiwan.

And crucially, as Dr. Swanton and associates showed in mouse models, exposure of lung cells bearing somatic EGFR and KRAS mutations to PM2.5 causes recruitment of macrophages that in turn secrete IL-1B, resulting in a transdifferentiation of EGFR-mutated cells into a cancer stem cell state, and tumor formation.

Importantly, pollution-induced tumor formation can be blocked by antibodies directed against IL-1B, Dr. Swanton said.

He pointed to a 2017 study in The Lancet suggesting that anti-inflammatory therapy with the anti–IL-1 antibody canakinumab (Ilaris) could reduce incident lung cancer and lung cancer deaths.
 

‘Elegant first demonstration’

“This is a very meaningful demonstration, from epidemiological data to preclinical models of the role of PM_­2.5 air pollutants in the promotion of lung cancer, and it provides us with very important insights into the mechanism through which nonsmokers can get lung cancer,” commented Suzette Delaloge, MD, from the cancer interception program at Institut Goustave Roussy in Villejuif, France, the invited discussant.

“But beyond that, it also has a great impact on our vision of carcinogenesis, with this very elegant first demonstration of the alternative nonmutagenic, carcinogenetic promotion hypothesis for fine particulate matter,” she said.

Questions still to be answered include whether PM_2.5 pollutants could also be mutagenic, is the oncogenic pathway ubiquitous in tissue, which components of PM_2.5 might drive the effect, how long of an exposure is required to promote lung cancer, and why and how persons without cancer develop specific driver mutations such as EGFR, she said.

“This research is intriguing and exciting as it means that we can ask whether, in the future, it will be possible to use lung scans to look for precancerous lesions in the lungs and try to reverse them with medicines such as interleukin-1B inhibitors,” said Tony Mok, MD, a lung cancer specialist at the Chinese University of Hong Kong, who was not involved in the study.

“We don’t yet know whether it will be possible to use highly sensitive EGFR profiling on blood or other samples to find nonsmokers who are predisposed to lung cancer and may benefit from lung scanning, so discussions are still very speculative,” he said in a statement.

The study was supported by Cancer Research UK, the Lung Cancer Research Foundations, Rosetrees Trust, the Mark Foundation for Cancer Research and the Ruth Strauss Foundation. Dr. Swanton disclosed grants/research support, honoraria, and stock ownership with multiple entities. Dr. Delaloge disclosed institutional financing and research funding from multiple companies. Dr. Mok disclosed stock ownership and honoraria with multiple companies.

PARIS – Air pollution has been recognized as a risk factor for lung cancer for about 2 decades, and investigators in the UK have now identified a potential mechanism whereby the air we breathe may trigger driver mutations already present in normal lung cells to cause cancer.

Think of it as “smoking gun–level” evidence that may explain why many nonsmokers still develop non–small cell lung cancer, said Charles Swanton, PhD, from the Francis Crick Institute and Cancer Research UK Chief Clinician, London.

“What this work shows is that air pollution is directly causing lung cancer but through a slightly unexpected pathway,” he said at a briefing prior to his presentation of the data in a presidential symposium held earlier this month in Paris at the European Society for Medical Oncology Congress 2022.

Importantly, he and his team also propose a mechanism for blocking the effects of air pollution with monoclonal antibodies directed against the inflammatory cytokine interleukein-1 beta.
 

Carcinogenesis explored

Lung cancer in never-smokers has a low mutational burden, with about 5- to 10-fold fewer mutations in a nonsmoker, compared with an ever smoker or current smoker, Dr. Swanton noted.

“The other thing to say about never-smokers is that they don’t have a clear environmental carcinogenic signature. So how do you square the circle? You’ve got the problem that you know that air pollution is associated with lung cancer – we don’t know if it causes it – but we also see that we’ve got no DNA mutations due to an environmental carcinogen,” he said during his symposium presentation.

The traditional model proposed to explain how carcinogens cause cancer holds that exposure to a carcinogen causes DNA mutations that lead to clonal expansion and tumor growth.

“But there are some major problems with this model,” Dr. Swanton said.

For example, normal skin contains a “patchwork of mutant clones,” but skin cancer is still uncommon, he said, and in studies in mice, 17 of 20 environmental carcinogens did not induce DNA mutations. He also noted that a common melanoma driver mutation, BRAF V600E, is not induced by exposure to a ultraviolet light.

“Any explanation for never-smoking lung cancer would have to fulfill three criteria: one, you have to explain why geographic variation exists; two, you have to prove causation; and three, you have to explain how cancers can be initiated without directly causing DNA mutations,” he said.

Normal lung tissues in nonsmoking adults can harbor pre-existing mutations, with the number of mutations increasing likely as a consequence of aging. In fact, more than 50% of normal lung biopsy tissues have been shown to harbor driver KRAS and/or EGFR mutations, Dr. Swanton said.

“In our research, these mutations alone only weakly potentiated cancer in laboratory models. However, when lung cells with these mutations were exposed to air pollutants, we saw more cancers and these occurred more quickly than when lung cells with these mutations were not exposed to pollutants, suggesting that air pollution promotes the initiation of lung cancer in cells harboring driver gene mutations. The next step is to discover why some lung cells with mutations become cancerous when exposed to pollutants while others don’t,” he said.
 

Geographical exposures

Looking at data on 447,932 participants in the UK Biobank, the investigators found that increasing exposure to ambient air particles smaller than 2.5 mcm (PM_2.5) was significantly associated with seven cancer types, including lung cancer. They also saw an association between PM­­_2.5 exposure levels and EGFR-mutated lung cancer incidence in the United Kingdom, South Korea, and Taiwan.

And crucially, as Dr. Swanton and associates showed in mouse models, exposure of lung cells bearing somatic EGFR and KRAS mutations to PM2.5 causes recruitment of macrophages that in turn secrete IL-1B, resulting in a transdifferentiation of EGFR-mutated cells into a cancer stem cell state, and tumor formation.

Importantly, pollution-induced tumor formation can be blocked by antibodies directed against IL-1B, Dr. Swanton said.

He pointed to a 2017 study in The Lancet suggesting that anti-inflammatory therapy with the anti–IL-1 antibody canakinumab (Ilaris) could reduce incident lung cancer and lung cancer deaths.
 

‘Elegant first demonstration’

“This is a very meaningful demonstration, from epidemiological data to preclinical models of the role of PM_­2.5 air pollutants in the promotion of lung cancer, and it provides us with very important insights into the mechanism through which nonsmokers can get lung cancer,” commented Suzette Delaloge, MD, from the cancer interception program at Institut Goustave Roussy in Villejuif, France, the invited discussant.

“But beyond that, it also has a great impact on our vision of carcinogenesis, with this very elegant first demonstration of the alternative nonmutagenic, carcinogenetic promotion hypothesis for fine particulate matter,” she said.

Questions still to be answered include whether PM_2.5 pollutants could also be mutagenic, is the oncogenic pathway ubiquitous in tissue, which components of PM_2.5 might drive the effect, how long of an exposure is required to promote lung cancer, and why and how persons without cancer develop specific driver mutations such as EGFR, she said.

“This research is intriguing and exciting as it means that we can ask whether, in the future, it will be possible to use lung scans to look for precancerous lesions in the lungs and try to reverse them with medicines such as interleukin-1B inhibitors,” said Tony Mok, MD, a lung cancer specialist at the Chinese University of Hong Kong, who was not involved in the study.

“We don’t yet know whether it will be possible to use highly sensitive EGFR profiling on blood or other samples to find nonsmokers who are predisposed to lung cancer and may benefit from lung scanning, so discussions are still very speculative,” he said in a statement.

The study was supported by Cancer Research UK, the Lung Cancer Research Foundations, Rosetrees Trust, the Mark Foundation for Cancer Research and the Ruth Strauss Foundation. Dr. Swanton disclosed grants/research support, honoraria, and stock ownership with multiple entities. Dr. Delaloge disclosed institutional financing and research funding from multiple companies. Dr. Mok disclosed stock ownership and honoraria with multiple companies.

Small cell lung cancer has traditionally been attributed almost exclusively to tobacco exposure, but some recent studies have suggested a higher than expected prevalence among nonsmokers. A new retrospective analysis suggests the disease has a different genomic profile among smokers than nonsmokers, indicating that the subgroups may have unique disease characteristics. Key differences included a lower frequency of TP53 gene mutations and a higher frequency of epidermal growth factor receptor (EGFR) alterations in never smokers.

About 6.9% of small cell lung cancer patients in the CASPIAN study were nonsmokers, as were 3.0% in the IMpower133 study.

“Given that the pathogenesis of small cell lung cancer is often tied to the damaging effects of tobacco, we hypothesized that small cell lung cancer in never-smokers would possess distinct molecular attributes. Our data does not provide any solid evidence for any treatment implications, though it does raise therapeutic questions which we believe deserve further exploration,” said Michael Oh, MD, during a presentation of the study results at the annual meeting of the European Society for Medical Oncology. Dr. Oh is a fellow at the University of California, Los Angeles.

The topic is important clinically, according to Antonio Passaro, MD, PhD, who served as a discussant during the session. He noted that small cell lung cancer in never-smokers is the seventh-most common cause of cancer-related mortality worldwide. In non–small cell lung cancer, rates of tobacco-associated disease have been decreasing, but there are increases in diagnoses among never smokers. Nonsmoking small cell lung cancer patients do not have better prognoses, and novel therapies and advances like immunotherapy and low-dose CT lung cancer screening disproportionately benefit current or former smokers.

Potential risk factors for never-smokers include environmental exposures like radon gas, cooking oil vapors, indoor and outdoor wood burning, and genetic and viral factors. “At the present time we do not have the knowledge to identify the most important factor in development of lung cancer in never-smoking [patients],” said Dr. Passaro, who is a medical oncologist at the European Institute of Oncology in Milan.

He added that the current study results are interesting but need much more follow-up, such as “longitudinal studies combining detailed clinical annotation with tissue and blood sampling. Here there is a need for collaborative efforts.” Key questions include the roles of the genomic landscape in normal lung tissue may play, the lung micro-environment, genetic factors, and environmental exposures.

One key possibility is air pollution. “We know that lung cancer in never-smokers is frequent in some countries, for example in Asian countries and it is more frequent in the United States than in Europe, but to find an explanation to this kind of data is difficult at the present time,” Dr. Passaro said.

The researchers retrospectively analyzed data from 608 current or former smokers and 54 never-smokers with small cell lung cancer, with the latter making up 8% of the total population. 70.4% of never-smokers and 55.1% of current or former smokers were female (P = .031). There was no significant between-group difference with respect to age at diagnosis or race.

Somatic mutations were similar to what has been found in previous studies for current or former smokers. 85.2% had changes in TP53, compared with just 59.3% of never-smokers (Q < .001). Changes to EGFR were more common in never-smokers, occurring in 25.9% versus 2.6% (Q < .001). PIK3CA alterations were also more common in never-smokers (14.8% vs. 3.6%; Q = 0.022). There was no significant difference between the two groups with respect to changes in RB1.

Never smokers had tumors with less immune cell infiltration (P = .008), including fewer CD4+ T cells, CD8+ T cells, and macrophages. Their tumor mutation burden was also lower (median, 2.59 vs. 4.99; P < .001).

Dr. Oh has no relevant financial disclosures. Dr. Passaro has consulted, advised, and received research funding from a wide range of pharmaceutical companies.

Small cell lung cancer has traditionally been attributed almost exclusively to tobacco exposure, but some recent studies have suggested a higher than expected prevalence among nonsmokers. A new retrospective analysis suggests the disease has a different genomic profile among smokers than nonsmokers, indicating that the subgroups may have unique disease characteristics. Key differences included a lower frequency of TP53 gene mutations and a higher frequency of epidermal growth factor receptor (EGFR) alterations in never smokers.

About 6.9% of small cell lung cancer patients in the CASPIAN study were nonsmokers, as were 3.0% in the IMpower133 study.

“Given that the pathogenesis of small cell lung cancer is often tied to the damaging effects of tobacco, we hypothesized that small cell lung cancer in never-smokers would possess distinct molecular attributes. Our data does not provide any solid evidence for any treatment implications, though it does raise therapeutic questions which we believe deserve further exploration,” said Michael Oh, MD, during a presentation of the study results at the annual meeting of the European Society for Medical Oncology. Dr. Oh is a fellow at the University of California, Los Angeles.

The topic is important clinically, according to Antonio Passaro, MD, PhD, who served as a discussant during the session. He noted that small cell lung cancer in never-smokers is the seventh-most common cause of cancer-related mortality worldwide. In non–small cell lung cancer, rates of tobacco-associated disease have been decreasing, but there are increases in diagnoses among never smokers. Nonsmoking small cell lung cancer patients do not have better prognoses, and novel therapies and advances like immunotherapy and low-dose CT lung cancer screening disproportionately benefit current or former smokers.

Potential risk factors for never-smokers include environmental exposures like radon gas, cooking oil vapors, indoor and outdoor wood burning, and genetic and viral factors. “At the present time we do not have the knowledge to identify the most important factor in development of lung cancer in never-smoking [patients],” said Dr. Passaro, who is a medical oncologist at the European Institute of Oncology in Milan.

He added that the current study results are interesting but need much more follow-up, such as “longitudinal studies combining detailed clinical annotation with tissue and blood sampling. Here there is a need for collaborative efforts.” Key questions include the roles of the genomic landscape in normal lung tissue may play, the lung micro-environment, genetic factors, and environmental exposures.

One key possibility is air pollution. “We know that lung cancer in never-smokers is frequent in some countries, for example in Asian countries and it is more frequent in the United States than in Europe, but to find an explanation to this kind of data is difficult at the present time,” Dr. Passaro said.

The researchers retrospectively analyzed data from 608 current or former smokers and 54 never-smokers with small cell lung cancer, with the latter making up 8% of the total population. 70.4% of never-smokers and 55.1% of current or former smokers were female (P = .031). There was no significant between-group difference with respect to age at diagnosis or race.

Somatic mutations were similar to what has been found in previous studies for current or former smokers. 85.2% had changes in TP53, compared with just 59.3% of never-smokers (Q < .001). Changes to EGFR were more common in never-smokers, occurring in 25.9% versus 2.6% (Q < .001). PIK3CA alterations were also more common in never-smokers (14.8% vs. 3.6%; Q = 0.022). There was no significant difference between the two groups with respect to changes in RB1.

Never smokers had tumors with less immune cell infiltration (P = .008), including fewer CD4+ T cells, CD8+ T cells, and macrophages. Their tumor mutation burden was also lower (median, 2.59 vs. 4.99; P < .001).

Dr. Oh has no relevant financial disclosures. Dr. Passaro has consulted, advised, and received research funding from a wide range of pharmaceutical companies.

Small cell lung cancer has traditionally been attributed almost exclusively to tobacco exposure, but some recent studies have suggested a higher than expected prevalence among nonsmokers. A new retrospective analysis suggests the disease has a different genomic profile among smokers than nonsmokers, indicating that the subgroups may have unique disease characteristics. Key differences included a lower frequency of TP53 gene mutations and a higher frequency of epidermal growth factor receptor (EGFR) alterations in never smokers.

About 6.9% of small cell lung cancer patients in the CASPIAN study were nonsmokers, as were 3.0% in the IMpower133 study.

“Given that the pathogenesis of small cell lung cancer is often tied to the damaging effects of tobacco, we hypothesized that small cell lung cancer in never-smokers would possess distinct molecular attributes. Our data does not provide any solid evidence for any treatment implications, though it does raise therapeutic questions which we believe deserve further exploration,” said Michael Oh, MD, during a presentation of the study results at the annual meeting of the European Society for Medical Oncology. Dr. Oh is a fellow at the University of California, Los Angeles.

The topic is important clinically, according to Antonio Passaro, MD, PhD, who served as a discussant during the session. He noted that small cell lung cancer in never-smokers is the seventh-most common cause of cancer-related mortality worldwide. In non–small cell lung cancer, rates of tobacco-associated disease have been decreasing, but there are increases in diagnoses among never smokers. Nonsmoking small cell lung cancer patients do not have better prognoses, and novel therapies and advances like immunotherapy and low-dose CT lung cancer screening disproportionately benefit current or former smokers.

Potential risk factors for never-smokers include environmental exposures like radon gas, cooking oil vapors, indoor and outdoor wood burning, and genetic and viral factors. “At the present time we do not have the knowledge to identify the most important factor in development of lung cancer in never-smoking [patients],” said Dr. Passaro, who is a medical oncologist at the European Institute of Oncology in Milan.

He added that the current study results are interesting but need much more follow-up, such as “longitudinal studies combining detailed clinical annotation with tissue and blood sampling. Here there is a need for collaborative efforts.” Key questions include the roles of the genomic landscape in normal lung tissue may play, the lung micro-environment, genetic factors, and environmental exposures.

One key possibility is air pollution. “We know that lung cancer in never-smokers is frequent in some countries, for example in Asian countries and it is more frequent in the United States than in Europe, but to find an explanation to this kind of data is difficult at the present time,” Dr. Passaro said.

The researchers retrospectively analyzed data from 608 current or former smokers and 54 never-smokers with small cell lung cancer, with the latter making up 8% of the total population. 70.4% of never-smokers and 55.1% of current or former smokers were female (P = .031). There was no significant between-group difference with respect to age at diagnosis or race.

Somatic mutations were similar to what has been found in previous studies for current or former smokers. 85.2% had changes in TP53, compared with just 59.3% of never-smokers (Q < .001). Changes to EGFR were more common in never-smokers, occurring in 25.9% versus 2.6% (Q < .001). PIK3CA alterations were also more common in never-smokers (14.8% vs. 3.6%; Q = 0.022). There was no significant difference between the two groups with respect to changes in RB1.

Never smokers had tumors with less immune cell infiltration (P = .008), including fewer CD4+ T cells, CD8+ T cells, and macrophages. Their tumor mutation burden was also lower (median, 2.59 vs. 4.99; P < .001).

Dr. Oh has no relevant financial disclosures. Dr. Passaro has consulted, advised, and received research funding from a wide range of pharmaceutical companies.