Kristin A. Guertin

Regular Physical Inactivity and Ovarian Cancer Risk in the Ovarian Cancer in Women of African Ancestry Consortium

Abstract Background: Regular physical inactivity may increase ovarian cancer risk, but few studies have investigated whether this association is similar among Black and White women. Methods: In a pooled nested case–control study within the Ovarian Cancer in Women of African Ancestry consortium, logistic regression models evaluated regular recreational physical inactivity with risk of epithelial ovarian cancer among Black (223 cases; 1,472 controls) and White women (985 cases; 6,212 controls) enrolled in four cohort studies. Models were further stratified by histologic type. Results: Regular physical inactivity was not associated with the risk of overall ovarian cancer among Black [OR = 1.16; 95% confidence interval (CI), 0.83–1.61] or White women (OR = 1.03; 95% CI, 0.87–1.23). We did not detect associations according to histologic type. Conclusions: Physical inactivity was not associated with ovarian cancer among Black or White women in a consortium of cohort studies. Impact: These results are counter to case–control-based studies and emphasize the complexity of investigating physical activity prospectively.

Race Differences in the Associations between Menstrual Cycle Characteristics and Epithelial Ovarian Cancer

Abstract Background: Menstrual cycle characteristics—including age at menarche and cycle length— have been associated with ovarian cancer risk in White women. However, the associations between menstrual cycle characteristics and ovarian cancer risk among Black women have been sparsely studied. Methods: Using the Ovarian Cancer in Women of African Ancestry (OCWAA) Consortium that includes 1,024 Black and 2,910 White women diagnosed with epithelial ovarian cancer (EOC) and 2,325 Black and 7,549 White matched controls, we investigated associations between menstrual cycle characteristics (age at menarche, age at menstrual regularity, cycle length, and ever missing three periods) and EOC risk by race and menopausal status. Multivariable logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Results: Black women were more likely to be <11 years at menarche than White women (controls: 9.9% vs. 6.0%). Compared with ≥15 years at menarche, <11 years was associated with increased EOC risk for White (OR = 1.25; 95% CI, 0.99–1.57) but not Black women (OR = 1.10; 95% CI, 0.80–1.55). Among White women only, the association was greater for premenopausal (OR = 2.20; 95% CI, 1.31–3.68) than postmenopausal women (OR = 1.06; 95% CI, 0.82–1.38). Irregular cycle length was inversely associated with risk for White (OR = 0.78; 95% CI, 0.62–0.99) but not Black women (OR = 1.06; 95% CI, 0.68–1.66). Conclusions: Earlier age at menarche and cycle irregularity are associated with increased EOC risk for White but not Black women. Impact: Associations between menstrual cycle characteristics and EOC risk were not uniform by race.

Racial disparities in epithelial ovarian cancer survival: An examination of contributing factors in the Ovarian Cancer in Women of African Ancestry consortium

AbstractBlack women diagnosed with epithelial ovarian cancer have poorer survival compared to white women. Factors that contribute to this disparity, aside from socioeconomic status and guideline‐adherent treatment, have not yet been clearly identified. We examined data from the Ovarian Cancer in Women of African Ancestry (OCWAA) consortium which harmonized data on 1074 Black women and 3263 white women with ovarian cancer from seven US studies. We selected potential mediators and confounders by examining associations between each variable with race and survival. We then conducted a sequential mediation analysis using an imputation method to estimate total, direct, and indirect effects of race on ovarian cancer survival. Black women had worse survival than white women (HR = 1.30; 95% CI 1.16‐1.47) during study follow‐up; 67.9% of Black women and 69.8% of white women died. In our final model, mediators of this disparity include college education, nulliparity, smoking status, body mass index, diabetes, diabetes/race interaction, postmenopausal hormone (PMH) therapy duration, PMH duration/race interaction, PMH duration/age interaction, histotype, and stage. These mediators explained 48.8% (SE = 12.1%) of the overall disparity; histotype/stage and PMH duration accounted for the largest fraction. In summary, nearly half of the disparity in ovarian cancer survival between Black and white women in the OCWAA consortium is explained by education, lifestyle factors, diabetes, PMH use, and tumor characteristics. Our findings suggest that several potentially modifiable factors play a role. Further research to uncover additional mediators, incorporate data on social determinants of health, and identify potential avenues of intervention to reduce this disparity is urgently needed.