Prediagnosis and postdiagnosis leisure time physical activity and survival following diagnosis with ovarian cancer.

Little is known about the influence of prediagnosis and postdiagnosis physical activity on ovarian cancer survival. We investigated this association in two large cohorts, the Nurses' Health Study (NHS) and NHSII. Analyses included 1461 women with confirmed invasive, epithelial ovarian cancer and data on physical activity. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for ovarian cancer-specific mortality. Ovarian cancer-specific mortality was not associated with physical activity reported 1-8 years before diagnosis overall (≥7.5 vs <1.5 MET-hours/week, HR = 0.96), for high-grade serous/ poorly differentiated tumors, or non-serous/ low-grade serous tumors (P-heterogeneity = .45). An inverse association was observed for activity 1-4 years after diagnosis (≥7.5 vs <1.5 MET-hours/week, HR = 0.67, 95%CI: 0.48-0.94), with similar results by histotype (P-heterogeneity = .53). Women who decreased their activity from ≥7.5 MET-hours/week 1-8 years before diagnosis to <7.5 MET-hours/week 1-4 years after diagnosis, compared to those with <7.5 MET-hours/week across periods, had a 49% increased risk of death (HR = 1.49, 95%CI: 1.07-2.08). Physical activity after, but not before, ovarian cancer diagnosis was associated with better prognosis.