1MO Air pollution-induced non-small cell lung cancer: Towards molecular cancer prevention

BackgroundA mechanistic basis for non-small cell lung cancer (NSCLC) initiation in never smokers, a disease with high frequency EGFR mutations (EGFRm), is unknown. Air pollution particulate matter (PM) is known to be associated with the risk of NSCLC, however a direct cause and mechanism remain elusive.MethodsWe analysed 463,679 individuals to address the associations of increasing 2.5μm PM (PM2.5) concentrations with cancer risk. We performed ultra-deep profiling of 247 normal lung tissue samples, analysed normal lung tissue from humans and mice following exposures to PM, and investigated the consequences of PM in mouse lung cancer models.ResultsIncreasing PM2.5 levels are associated with increased risk of EGFRm NSCLC in England, S.Korea and Taiwan and with increased risk of mesothelioma, lung, anal, small intestine, GBM and laryngeal carcinomas in UK Biobank (HR>1.1 for each 1ug/m3 PM2.5 increment). 18-33% of normal lung tissue samples harbour driver mutations in EGFR and KRAS in the absence of malignancy. PM promotes a macrophage response and a progenitor-like state in lung epithelium harbouring mutant EGFR. Consistent with PM promoting NSCLC in at-risk epithelium harbouring driver mutations, PM accelerates tumourigenesis in three EGFR or KRAS driven lung cancer models in a dose-dependent manner. Finally, we uncover an actionable inflammatory axis driven by IL1B in response to PM, in agreement with reductions in lung cancer incidence with anti-IL1B therapy.ConclusionsThese results shed light on the etiology of EGFRm lung cancer and suggest that oncogenic mutations may be necessary but insufficient for tumour formation. These data reveal a mechanistic basis for PM driven lung cancer in the absence of classical carcinogen-driven mutagenesis, reminiscent of models of tumour initiation and promotion proposed 70 years ago, providing an urgent mandate to limit air pollution and reveal opportunities for molecular targeted cancer prevention.Legal entity responsible for the studyThe authors.FundingCancer Research UK, Mark Foundation, Lung Cancer Research Foundation, Rosetrees Trust, Bristol Myers Squibb.DisclosureK.R. Litchfield: Financial Interests, Personal, Invited Speaker: Roche Tissue Diagnostics; Financial Interests, Personal, Other, Consulting work: Monopteros Therapeutics; Financial Interests, Institutional, Research Grant: Ono/LifeArc; Financial Interests, Institutional, Research Grant, Research funding: Genesis Therapeutics; Non-Financial Interests, Institutional, Proprietary Information, Collaboration on data analysis: BMS. M. Jamal-Hanjani: Financial Interests, Personal, Invited Speaker, Invited speaker honorarium: Oslo Cancer Cluster, Astex Pharmaceutical; Non-Financial Interests, Personal, Advisory Role, Scientific Advisory Board and Steering Committee member: Achilles Therapeutics; Other, Personal, Other, I am named as co-inventor on patent PCT/US2017/028013 relating to methods for lung cancer detection: Patent. C. Swanton: Financial Interests, Personal, Invited Speaker, Activity took place in 2016: Pfizer, Celgene; Financial Interests, Personal, Invited Speaker, October 26th 2020: Novartis; Financial Interests, Personal, Invited Speaker: Roche/Ventana, BMS, AstraZeneca, MSD, Illumina, GlaxoSmithKline; Financial Interests, Personal, Advisory Board, AdBoard - November 12th, 2020: Amgen; Financial Interests, Personal, Advisory Board: Genentech, Sarah Canon Research Institute, Medicxi; Financial Interests, Personal, Advisory Board, Joined October 2020. Also have stock options: Bicycle Therapeutics; Financial Interests, Personal, Advisory Board, Member of the Science Management Committee. Also have stock options: GRAIL; Financial Interests, Personal, Other, Consultancy agreement: Roche Innovation Centre Shanghai; Financial Interests, Personal, Full or part-time Employment, Chief Clinician since October 2017: Cancer Research UK; Financial Interests, Personal, Ownership Interest, Co-Founder of Achilles Therapeutics. Also, have stock options in this company: Achilles Therapeutics; Financial Interests, Personal, Stocks/Shares, Stocks owned until June 2021: GRAIL, ApoGen Biotechnologies; Financial Interests, Personal, Stocks/Shares: Epic Biosciences, Bicycle Therapeutics; Financial Interests, Institutional, Research Grant, Funded RUBICON grant - October 2018 - April 2021: Bristol Myers Squibb; Financial Interests, Institutional, Research Grant, Collaboration in minimal residual disease sequencing technologies: Archer Dx Inc.; Financial Interests, Institutional, Research Grant: Pfizer, Ono Pharmaceutical, Boehringer Ingelheim; Financial Interests, Institutional, Invited Speaker, Chief Investigator for the MeRmaiD1 clinical trial and chair of the steering committee: AstraZeneca; Financial Interests, Institutional, Research Grant, Research Grants from 2015-2019: Roche-Ventana; Financial Interests, Personal, Other, Co-chief investigator: NHS-Galleri Clinical Trial; Non-Financial Interests, Personal, Principal Investigator, Chief Investigator for MeRmaiD1 clinical trial: AstraZeneca; Non-Financial Interests, Personal, Invited Speaker, From 2019: AACR; Non-Financial Interests, Personal, Other, Board of Directors: AACR; Non-Financial Interests, Personal, Advisory Role, EACR Advisory Council member: EACR. All other authors have declared no conflicts of interest. BackgroundA mechanistic basis for non-small cell lung cancer (NSCLC) initiation in never smokers, a disease with high frequency EGFR mutations (EGFRm), is unknown. Air pollution particulate matter (PM) is known to be associated with the risk of NSCLC, however a direct cause and mechanism remain elusive. A mechanistic basis for non-small cell lung cancer (NSCLC) initiation in never smokers, a disease with high frequency EGFR mutations (EGFRm), is unknown. Air pollution particulate matter (PM) is known to be associated with the risk of NSCLC, however a direct cause and mechanism remain elusive. MethodsWe analysed 463,679 individuals to address the associations of increasing 2.5μm PM (PM2.5) concentrations with cancer risk. We performed ultra-deep profiling of 247 normal lung tissue samples, analysed normal lung tissue from humans and mice following exposures to PM, and investigated the consequences of PM in mouse lung cancer models. We analysed 463,679 individuals to address the associations of increasing 2.5μm PM (PM2.5) concentrations with cancer risk. We performed ultra-deep profiling of 247 normal lung tissue samples, analysed normal lung tissue from humans and mice following exposures to PM, and investigated the consequences of PM in mouse lung cancer models. ResultsIncreasing PM2.5 levels are associated with increased risk of EGFRm NSCLC in England, S.Korea and Taiwan and with increased risk of mesothelioma, lung, anal, small intestine, GBM and laryngeal carcinomas in UK Biobank (HR>1.1 for each 1ug/m3 PM2.5 increment). 18-33% of normal lung tissue samples harbour driver mutations in EGFR and KRAS in the absence of malignancy. PM promotes a macrophage response and a progenitor-like state in lung epithelium harbouring mutant EGFR. Consistent with PM promoting NSCLC in at-risk epithelium harbouring driver mutations, PM accelerates tumourigenesis in three EGFR or KRAS driven lung cancer models in a dose-dependent manner. Finally, we uncover an actionable inflammatory axis driven by IL1B in response to PM, in agreement with reductions in lung cancer incidence with anti-IL1B therapy. Increasing PM2.5 levels are associated with increased risk of EGFRm NSCLC in England, S.Korea and Taiwan and with increased risk of mesothelioma, lung, anal, small intestine, GBM and laryngeal carcinomas in UK Biobank (HR>1.1 for each 1ug/m3 PM2.5 increment). 18-33% of normal lung tissue samples harbour driver mutations in EGFR and KRAS in the absence of malignancy. PM promotes a macrophage response and a progenitor-like state in lung epithelium harbouring mutant EGFR. Consistent with PM promoting NSCLC in at-risk epithelium harbouring driver mutations, PM accelerates tumourigenesis in three EGFR or KRAS driven lung cancer models in a dose-dependent manner. Finally, we uncover an actionable inflammatory axis driven by IL1B in response to PM, in agreement with reductions in lung cancer incidence with anti-IL1B therapy. ConclusionsThese results shed light on the etiology of EGFRm lung cancer and suggest that oncogenic mutations may be necessary but insufficient for tumour formation. These data reveal a mechanistic basis for PM driven lung cancer in the absence of classical carcinogen-driven mutagenesis, reminiscent of models of tumour initiation and promotion proposed 70 years ago, providing an urgent mandate to limit air pollution and reveal opportunities for molecular targeted cancer prevention. These results shed light on the etiology of EGFRm lung cancer and suggest that oncogenic mutations may be necessary but insufficient for tumour formation. These data reveal a mechanistic basis for PM driven lung cancer in the absence of classical carcinogen-driven mutagenesis, reminiscent of models of tumour initiation and promotion proposed 70 years ago, providing an urgent mandate to limit air pollution and reveal opportunities for molecular targeted cancer prevention.