Recreational physical activity and ovarian cancer risk in African American women

The literature on recreational physical activity (RPA) and ovarian cancer risk is inconclusive and most studies of RPA and ovarian cancer have been conducted in white populations. This study is the first to investigate the association between RPA and ovarian cancer in an exclusively African American (AA) population. We analyzed data from an ongoing U.S. population‐based, case–control study of AA women, which included 393 women recently diagnosed with invasive epithelial ovarian cancer (IEOC) and 611 controls. A baseline interview assessed RPA frequency, intensity, and duration. Each RPA intensity was assigned a metabolic equivalent of task (MET) value and MET‐min/week were calculated. Unconditional multivariable logistic regression was performed to investigate associations between RPA and IEOC risk. Compared with sedentary women, predominantly mild intensity RPA was significantly inversely associated with IEOC risk for women reporting above median (>297) MET‐min/week (odds ratio [OR] = 0.52; 95% confidence interval [CI]: 0.34, 0.78) and nonsignificantly for 540) MET‐min/week (OR = 1.51; 95% CI: 1.03, 2.23). Predominantly strenuous intensity RPA was nonsignificantly associated with lower IEOC risk for women reporting above median (>1800) MET‐min/week (OR = 0.72; 95% CI: 0.33, 1.57). The inverse associations for mild and strenuous intensity RPA were most pronounced in obese women (body mass index >30 kg/m2). The findings that mild and strenuous RPA may reduce the risk of IEOC particularly among obese women are difficult to reconcile with the increased risk observed for moderate RPA. Further research is warranted to determine whether these findings are genuine and, if so, their mechanistic basis. This is the first study of recreational physical activity (RPA) and ovarian cancer in an exclusively African American population, who have a higher prevalence of obesity and poorer ovarian cancer survival compared with whites. We found that mild and strenuous intensity RPA may be associated with reduced ovarian cancer risk. Further, our data suggest that these associations may be more pronounced in obese women.