Body mass index, physical activity, and mortality in women diagnosed with ovarian cancer: results from the Women's Health Initiative

Background: Ovarian cancer is often diagnosed at late stages and consequently the 5-year survival rate is only 44%. However, there is limited knowledge of the association of modifiable lifestyle factors, such as physical activity and obesity on mortality among women diagnosed with ovarian cancer. The purpose of our study was to prospectively investigate the association of (1) measured body mass index (BMI), and (2) self-reported physical activity with ovarian cancer-specific and all-cause mortality in postmenopausal women enrolled in the Women's Health Initiative (WHI).

Methods: Participants were 600 women diagnosed with primary ovarian cancer subsequent to enrollment in WHI. Exposure data, including measured height and weight and reported physical activity from recreation and walking, used in this analysis were ascertained at the baseline visit for the WHI. Cox proportional hazard regression was used to examine the associations between BMI, physical activity and mortality endpoints.

Results: Vigorous-intensity physical activity was associated with a 26% lower risk of ovarian cancer specific-mortality (HR=0.74; 95% CI: 0.56-0.98) and a 24% lower risk of all-cause mortality (HR=0.76; 95% CI: 0.58-0.98) compared to no vigorous-intensity physical activity. BMI was not associated with mortality.

Conclusions: Participating in vigorous-intensity physical activity, assessed prior to ovarian cancer diagnosis, appears to be associated with a lower risk of ovarian cancer mortality.