Alarming trends in high-risk uterine cancer histologies in Black women in the US: Is obesity responsible? (138)

Abstract

<b>Objectives:</b> The incidence and mortality of uterine cancer are increasing, particularly for Black women. Although lack of access to care may explain some of these findings, high-risk histological cell types also contribute to the poor prognosis. We analyzed the current trends, projections, and potential socio-behavioral factors responsible for high-risk histologies in Black women in the United States. <b>Methods:</b> Data were obtained from the United States Cancer Statistics (USCS) database and the Behavioral Risk Factors Surveillance System (BRFSS) survey from 2001 to 2017. The average annual percent change (AAPC) was calculated using Joinpoint regression. Incidence rates and demographic factors, including age (divided into 5–10-year age groups), sex, and race (non-Hispanic White, Hispanic, non-Hispanic Black, and non-Hispanic Asian/Pacific Islander), were reported. <b>Results:</b> From 2001 to 2017, 778,891 patients were diagnosed with uterine cancer. While uterine cancer incidence increased among all racial/ethnic groups, the rate of increase was 3.6-fold higher in Black women than White women (AAPC: 2.31% vs 0.63%). From 2001 to 2013, white women had the highest incidence of uterine cancer. However, the incidence rates in White and Black women converged in 2014 due to decreasing incidence in White women and increasing incidence in Black women. We then divided uterine cancer histology into low-risk (grade 1 endometrioid) and high-risk cell types (serous, clear cell, carcinosarcoma). By 2017, high-risk types were 2.8-fold higher in Black women than White women (9.11 vs 3.20 per 100,000) and increased at a 1.6-fold higher rate (AAPC: 4.03 vs 2.53). For Black women, low-risk types increased at only 1.30% annually, whereas high-risk histologies rose 4.03% annually. Furthermore, Black women had the lowest incidence of uterine cancer during their premenopausal years but the highest incidence during their postmenopausal years. Using a predictive model with the current rate of increase, we demonstrated that the incidence of high-risk histologies in Black women would be 2.8-fold higher than that of low-risk histologies by the year 2030 (15.2 vs 5.4 per 100,000). Given that the proposed obesity axis explained high-risk histologic type in Black women with breast cancer, we then used the BRFSS data to estimate obesity trends in Black women. Our results showed that the obesity rate was highest in perimenopausal (45-54 years) Black women at 47.3% compared to 30.0% in White women in 2017. <b>Conclusions:</b> Compared to White women, Black women are twice as likely to present with serous, clear cell, and carcinosarcoma compared to low-grade endometrioid uterine cancer with increasing divergence. These findings may only be partially explained by increasing obesity rates. Transdisciplinary studies are warranted to help bridge this disparity with a focus on environmental and genetic risk factors and differential oncogenic pathways.