Abstract 3228: Body mass index and ovarian cancer: Changes after diagnosis and associations with overall survival

Background: While excess adiposity is positively associated with ovarian cancer risk, the relationship with patient prognosis remains to be fully elucidated, especially with regard to changes over time during survivorship. Methods: We assembled a retrospective cohort of tumor registry confirmed ovarian, fallopian tube, and primary peritoneal cancer cases and evaluated peri- and post-diagnosis (±30 days and up to 5 years after, respectively) body mass index (BMI) from electronic medical records (EMR) from the Vanderbilt University Medical Center. Associations with overall survival (OS) were quantified by Hazards Ratios (HRs) and corresponding 95% confidence intervals (CIs) from Cox proportional hazards regression; multivariable adjustment included age, stage, grade, histologic subtype, treatment, race, and year of diagnosis. Results: We evaluated 13,676 peri- and post-diagnosis BMI observations for 616 predominantly Caucasian (87.0%) cases; the majority had serous histology (62.5%), advanced stage (58.1% Stage III or IV), high grade (52.4% poorly or undifferentiated) disease. Compared to peri-diagnosis (median =29.0), BMI was lowest 6 months post-diagnosis (median=27.4) and then gradually increased over time among survivors. In multivariable adjusted models, each 5-unit increase in mean peri-diagnosis BMI corresponded with a nonsignificant increase (HR: 1.07, 95% CI: 0.97-1.18) while higher mean post-diagnosis BMI corresponded to a significantly decreased risk of death (HR: 0.92, 95% CI: 0.84-1.00). Adjusted models that incorporated all peri- and post-diagnosis BMI observations evaluated indicated that each 5-unit increase in BMI was associated with a 15% reduced risk of death (HR: 0.85, 95% CI: 0.77-0.94). Conclusions: Whereas lower adiposity may be beneficial in terms of risk, higher adiposity appears to benefit ovarian cancer survival. Factors including cancer cachexia, weight loss among ill patients, and weight gain among survivors may contribute to this seemingly protective association. Additional research to disentangle the influence of BMI on ovarian cancer outcomes and inform adiposity guidance for ovarian cancer survivors is needed. Citation Format: Alicia Beeghly-Fadiel, Sharon Phillips, George Bukenya, Pranoti Pradhan, Sara Duque, Nneka Anyanwu, Deok-Soo Son, Andrew J. Wilson, Demetra H. Hufnagel, Marta A. Crispens. Body mass index and ovarian cancer: Changes after diagnosis and associations with overall survival [abstract]. In: Proceedings of th