Pre-diagnosis body mass index, physical activity and ovarian cancer mortality

Ovarian cancer is the deadliest gynecologic malignancy, yet the effects on survival of modifiable pre-diagnosis lifestyle factors, such as obesity and physical activity, remain largely unexplored. Our objective was to evaluate the effect of pre-diagnosis BMI and physical activity on ovarian cancer mortality using prospectively collected data.

Data on women who developed ovarian cancer after enrollment into the NIH-AARP Diet and Health Study were analyzed. Cancer incidence was ascertained through linkage state cancer registries and consisted of 741 cases of epithelial ovarian cancer.

Higher pre-diagnosis BMI was associated with increased overall and ovarian cancer-specific mortality. Comparing women with BMI 25-29.9, 30-34.9 and ≥ 35 to normal weight women, the HRs of overall mortality were 1.18 (95%CI 0.96-1.45), 1.05 (0.82-1.36) and 1.59 (1.14-2.18, p-trend = 0.02). The findings were similar for ovarian cancer-specific mortality comparing women with BMI ≥ 35 to normal weight women (BMI <25) with a HR of 1.47 (95%CI 1.03-2.09, p-trend 0.08). Pre-diagnosis physical activity was not associated with mortality, with HRs for overall mortality of 1.06 (95%CI 0.79-1.43), 0.94 (0.72-1.23), 0.98 (0.76-1.25), and 0.98 (0.75-1.28, p-trend = 0.91), comparing women who engaged in vigorous physical activity 1-3 times/month, 1-2 times/week, 3-4 times/week and 5 times/week, respectively, with those who never/rarely engaged in such activity.

Women who were obese before developing ovarian cancer had increased mortality than those who were normal weight, but physical activity before diagnosis was not associated with mortality in this study population. These results suggest that maintaining a healthy weight is a powerful preventative tool.