Abstract B037: Physical inactivity is associated with ovarian cancer in women of African ancestry
Authors: Minlikeeva Albina , Lima Sarah M. , Johnson Courtney , Bandera Elisa V. , Beeghly-Fadiel Alicia , Bethea Traci N. , Petrick Jessica , Joslin Charlotte E. , Myers Evan , Harris Holly R. , Peres Lauren C. , Setiawan V. Wendy , Wu Anna H. , Rosenberg Lynn , Schildkraut Joellen M. , Ochs-Balcom Heather M. 
Published: March 2024

Abstract
Background: While there is growing evidence that physical activity increases ovarian cancer risk, studies to date have been focused primarily on women of European ancestry. Little is known about whether physical inactivity is also associated with ovarian cancer risk in women of African ancestry. Methods: In three studies in the Ovarian Cancer in Women of African Ancestry (OCWAA) consortium (Los Angeles County Ovarian Cancer Study, the Southern Community Cohort Study, and the Women’s Health Initiative), we classified women as being physically inactive in their lifetime (yes/no) by either a ‘no’ response to a question about ever participating in regular, weekly, recreational physical activity (case-control study), or if participants reported no regular weekly moderate or vigorous recreational physical activity in all time periods prior to the reference date (cohort studies). We evaluated associations of lifetime physical inactivity and ovarian cancer risk overall and according to histologic subtype (high-grade serous, non-high-grade serous) and stage (localized/regional, distant). Associations were estimated using logistic regression models adjusted for age, study, education, parity, oral contraceptive use, menopausal status, tubal ligation status, postmenopausal hormone use, smoking status, and family history of breast/ovarian cancer. Results: The sample includes 195 African ancestry (AA) cases, 606 AA controls, 2,009 White cases, and 7,229 White controls. AA women had a higher proportion of chronic inactivity than White women: 94 (48%) of cases and 182 (30%) of controls, vs 576 (29%) of cases and 1,467 (20%) of controls, respectively. In AA women, we observed higher risk for invasive ovarian cancer (OR=1.49, 95% CI: 1.02, 2.18) for women who were physically inactive, compared to physically active women. In AA women, no heterogeneity in this association was observed by histologic subtype, but when stratified by stage, we found higher odds of ovarian cancer for physically inactive women with localized/regional stage disease (OR: 2.24, 95% CI: 1.22, 4.09) and no association among women with distant stage disease (OR: 1.18, 95% CI: 0.75, 1.85). In White women, we observed borderline significant associations for invasive ovarian cancer only (OR=1.12, 95% CI: 0.99, 1.27); no differences in this association were observed by histotype or stage. Conclusion: Our study suggests that physical inactivity contributes to invasive ovarian cancer risk in AA women.
Citation Format: Albina Minlikeeva, Sarah M. Lima, Courtney Johnson, Elisa V. Bandera, Alicia Beeghly-Fadiel, Traci N. Bethea, Jessica Petrick, Charlotte E. Joslin, Evan Myers, Holly R. Harris, Lauren C. Peres, V. Wendy Setiawan, Anna H. Wu, Lynn Rosenberg, Joellen M. Schildkraut, Heather M. Ochs-Balcom. Physical inactivity is associated with ovarian cancer in women of African ancestry [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B037.