RT Journal Article T1 Cigarette Smoking and Endometrial Cancer Risk: Observational and Mendelian Randomization Analyses. A1 Dimou, Niki A1 Omiyale, Wemimo A1 Biessy, Carine A1 Viallon, Vivian A1 Kaaks, Rudolf A1 O'Mara, Tracy A A1 Aglago, Elom K A1 Ardanaz, Eva A1 Bergmann, Manuela M A1 Bondonno, Nicola P A1 Braaten, Tonje A1 Colorado-Yohar, Sandra M A1 Crous-Bou, Marta A1 Dahm, Christina C A1 Fortner, Renée T A1 Gram, Inger T A1 Harlid, Sophia A1 Heath, Alicia K A1 Idahl, Annika A1 Kvaskoff, Marina A1 Nøst, Therese H A1 Overvad, Kim A1 Palli, Domenico A1 Perez-Cornago, Aurora A1 Sacerdote, Carlotta A1 Sanchez-Perez, Maria-Jose A1 Schulze, Matthias B A1 Severi, Gianluca A1 Simeon, Vittorio A1 Tagliabue, Giovanna A1 Tjønneland, Anne A1 Truong, Therese A1 Tumino, Rosario A1 Johansson, Mattias A1 Weiderpass, Elisabete A1 Murphy, Neil A1 Gunter, Marc J A1 Lacey, Ben A1 Allen, Naomi E A1 Dossus, Laure K1 Cigarette Smoking K1 Endometrial Neoplasms K1 Female K1 Genetic Predisposition to Disease K1 Humans AB Current epidemiologic evidence indicates that smoking is associated with a lower endometrial cancer risk. However, it is unknown if this association is causal or confounded. To further elucidate the role of smoking in endometrial cancer risk, we conducted complementary observational and Mendelian randomization (MR) analyses. The observational analyses included 286,415 participants enrolled in the European Prospective Investigation into Cancer and Nutrition and 179,271 participants in the UK Biobank, and multivariable Cox proportional hazards models were used. In two-sample MR analyses, genetic variants robustly associated with lifetime amount of smoking (n = 126 variants) and ever having smoked regularly (n = 112 variants) were selected and their association with endometrial cancer risk (12,906 cancer/108,979 controls from the Endometrial Cancer Association Consortium) was examined. In the observational analysis, lifetime amount of smoking and ever having smoked regularly were associated with a lower endometrial cancer risk. In the MR analysis accounting for body mass index, a genetic predisposition to a higher lifetime amount of smoking was not associated with endometrial cancer risk (OR per 1-SD increment: 1.15; 95% confidence interval: 0.91-1.44). Genetic predisposition to ever having smoked regularly was not associated with risk of endometrial cancer. Smoking was inversely associated with endometrial cancer in the observational analyses, although unsupported by the MR. Additional studies are required to better understand the possible confounders and mechanisms underlying the observed associations between smoking and endometrial cancer. The results from this analysis indicate that smoking is unlikely to be causally linked with endometrial cancer risk. PB American Association for Cancer Research YR 2022 FD 2022-06-16 LK http://hdl.handle.net/10668/20183 UL http://hdl.handle.net/10668/20183 LA en NO Dimou N, Omiyale W, Biessy C, Viallon V, Kaaks R, O'Mara TA, et al. Cigarette Smoking and Endometrial Cancer Risk: Observational and Mendelian Randomization Analyses. Cancer Epidemiol Biomarkers Prev. 2022 Sep 2;31(9):1839-1848. NO This work has been conducted using the UK Biobank Resource under Application Number 41115, and we express our gratitude to the participants and those involved in building the resource. UK Biobank is an open access resource. Bona fide researchers can apply to use the UK Biobank dataset by registering and applying at http://ukbiobank.ac.uk/register-apply/. We thank the National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands, for their contribution and ongoing support to the EPIC Study. We are grateful to all the participants in the EPIC-Norfolk study who have been part of the project and to the many members of the study teams at the University of Cambridge who have enabled this research.The coordination of EPIC is financially supported by International Agency for Research on Cancer (IARC) and also by the Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, which has additional infrastructure support provided by the NIHR Imperial Biomedical Research Centre (BRC). The national cohorts are supported by Danish Cancer Society (Denmark); Ligue Contre le Cancer, Institut Gustave Roussy, Mutuelle Générale de l'Education Nationale, Institut National de la Santé et de la Recherche Médicale (INSERM) (France); German Cancer Aid, German Cancer Research Center (DKFZ), German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Federal Ministry of Education and Research (BMBF) (Germany); Associazione Italiana per la Ricerca sul Cancro-AIRC-Italy, Compagnia di SanPaolo and National Research Council (Italy); Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (the Netherlands); Health Research Fund (FIS) - Instituto de Salud Carlos III (ISCIII), Regional Governments of Andalucía, Asturias, Basque Country, Murcia and Navarra, and the Catalan Institute of Oncology - ICO (Spain); Swedish Cancer Society, Swedish Research Council and County Councils of Skåne and Västerbotten (Sweden); Cancer Research UK (14136 to EPIC-Norfolk; C8221/A29017 to EPIC-Oxford), Medical Research Council (1000143 to EPIC-Norfolk; MR/M012190/1 to EPIC-Oxford) (United Kingdom). The EPIC-Norfolk study (DOI 10.22025/2019.10.105.00004) has received funding from the Medical Research Council (MR/N003284/1, MC-UU_12015/1 and MC_UU_00006/1) and Cancer Research UK (C864/A14136). This work was supported by Cancer Research UK (grant number C18281/A29019). DS RISalud RD Apr 20, 2025