TY - JOUR AU - Von Holle, Ann AU - Adami, Hans-Olov AU - Baglietto, Laura AU - Berrington, Amy AU - Bertrand, Kimberly A AU - Blot, William AU - Chen, Yu AU - DeHart, Jessica Clague AU - Dossus, Laure AU - Eliassen, A Heather AU - Fournier, Agnes AU - Garcia-Closas, Montse AU - Giles, Graham AU - Guevara, Marcela AU - Hankinson, Susan E AU - Heath, Alicia AU - Jones, Michael E AU - Joshu, Corinne E AU - Kaaks, Rudolf AU - Kirsh, Victoria A AU - Kitahara, Cari M AU - Koh, Woon-Puay AU - Linet, Martha S AU - Park, Hannah Lui AU - Masala, Giovanna AU - Mellemkjaer, Lene AU - Milne, Roger L AU - O'Brien, Katie M AU - Palmer, Julie R AU - Riboli, Elio AU - Rohan, Thomas E AU - Shrubsole, Martha J AU - Sund, Malin AU - Tamimi, Rulla AU - Tin Tin, Sandar AU - Visvanathan, Kala AU - Vermeulen, Roel Ch AU - Weiderpass, Elisabete AU - Willett, Walter C AU - Yuan, Jian-Min AU - Zeleniuch-Jacquotte, Anne AU - Nichols, Hazel B AU - Sandler, Dale P AU - Swerdlow, Anthony J AU - Schoemaker, Minouk J AU - Weinberg, Clarice R TI - BMI and breast cancer risk around age at menopause. JO - Cancer epidemiology VL - 89 SN - 1877-7821 CY - Amsterdam [u.a.] PB - Elsevier M1 - DKFZ-2024-00392 SP - 102545 PY - 2024 AB - A high body mass index (BMI, kg/m2) is associated with decreased risk of breast cancer before menopause, but increased risk after menopause. Exactly when this reversal occurs in relation to menopause is unclear. Locating that change point could provide insight into the role of adiposity in breast cancer etiology.We examined the association between BMI and breast cancer risk in the Premenopausal Breast Cancer Collaborative Group, from age 45 up to breast cancer diagnosis, loss to follow-up, death, or age 55, whichever came first. Analyses included 609,880 women in 16 prospective studies, including 9956 who developed breast cancer before age 55. We fitted three BMI hazard ratio (HR) models over age-time: constant, linear, or nonlinear (via splines), applying piecewise exponential additive mixed models, with age as the primary time scale. We divided person-time into four strata: premenopause; postmenopause due to natural menopause; postmenopause because of interventional loss of ovarian function (bilateral oophorectomy (BO) or chemotherapy); postmenopause due to hysterectomy without BO. Sensitivity analyses included stratifying by BMI in young adulthood, or excluding women using menopausal hormone therapy.The constant BMI HR model provided the best fit for all four menopausal status groups. Under this model, the estimated association between a five-unit increment in BMI and breast cancer risk was HR=0.87 (95 KW - Body mass index (Other) KW - Breast neoplasms (Other) KW - Middle aged (Other) KW - Postmenopause (Other) KW - Premenopause (Other) LB - PUB:(DE-HGF)16 C6 - pmid:38377945 DO - DOI:10.1016/j.canep.2024.102545 UR - https://inrepo02.dkfz.de/record/288522 ER -