Although the age-adjusted incidence of endometrial cancer is 12% lower among black women than white women, age-adjusted mortality among black women is 87% higher and this racial disparity has continued to increase over the past two decades. Preliminary evidence from the Epidemiology of Endometrial Cancer Consortium (E2C2) suggests that oral contraceptive use, parity, and older age at first and last birth are not as protective against endometrial cancer in black women as they are in white women. We propose to assess the influence of anthropometric, reproductive, hormonal, and metabolic factors on incident endometrial cancer diagnosed over 18 years of follow-up (1995-2013) in the Black Women's Health Study (BWHS), a large prospective cohort study of U.S. black women. We then propose to perform a meta-analysis of results from the BWHS, the Case-Control Surveillance Study (CCS), and 10 additional studies from the E2C2 that include black women to investigate predictors of incidence and histology (types I, II, and II). Type II and II tumors are more aggressive than type I tumors, and they are also more prevalent in black women. Little is known about risk factors for type II and III tumors. Our assessment of different histologic types for endometrial cancer has the potential to address important questions about the black-white discrepancy in mortality. The meta-analysis will involve more than 800 black cases of endometrial cancer. We will compute a relative risk (RR) for each study, evaluate heterogeneity in the RRs, and then estimate a RR for all studies combined and according to study design (e.g., cohort vs. case-control). In addition, we will perform separate analyses of histologic type to assess whether the environmental factors of interest predict types II and III cancer, which are more prevalent in black women. Black women are understudied with regard to endometrial cancer etiology. Many of the putative risk factors that we propose to study are of particular relevance to black women;for example, U.S. black women have significantly higher rates of obesity, type 2 diabetes, and uterine fibroids, and give birth at earlier ages and have more children than white women. New data about modifiable risk factors has the potential to influence primary prevention of disease. The proposed study of an underserved minority population at increasing risk of death from endometrial cancer will address gaps in research, as almost all data on determinants of endometrial cancer come from studies of white women. The proposed study can be carried out at modest cost because data collection and infrastructure are supported by other grants.
Although the age-adjusted incidence of endometrial cancer is 12% lower among black women than white women, age-adjusted mortality among black women is 87% higher and the discrepancy has increased over the past two decades. There is little information about determinants of endometrial cancer in black women. Using data from the Black Women's Health Study and 11 other cohort and case-control studies in black women, we will assess putative risk factors for endometrial cancer that are of particular relevance to black women, including obesity, earlier and increased parity, uterine fibroids, and type 2 diabetes.