Race-driven survival differential in women diagnosed with endometrial cancers in the USA.

Objective: African American women are increasingly being diagnosed with advanced and type II histology endometrial cancers. Outcomes have been observed to be worse in African American women, but whether or not race itself is a factor is unclear. We sought to evaluate the rates of diagnosis and outcomes on a stage-by-stage basis with respect to race using a large national cancer registry database.

Methods: The National Cancer Data Base was searched for patients with surgically staged non-metastatic endometrial cancer between 2004 and 2015. Women were excluded if surgical stage/histology was unknown, there was no follow-up, or no information on subsequent treatment. Pairwise comparison was used to determine temporal trends and Cox hazards tests with Bonferroni correction were used to determine overall survival.

Results: A total of 286 920 women were diagnosed with endometrial cancer and met the criteria for analysis. Median follow-up was 51 months (IQR 25.7-85.3). In multivariable models, in women with stage I disease, African American women had a higher risk of death than Caucasian women (HR 1.262, 95% CI 1.191 to 1.338, p<0.001) and Asian/Pacific Islander women had a lower risk of death than Caucasian women (HR 0.742, 95% CI 0.689 to 0.801, p<0.001). This held for African American women with stage II type I and type II disease (HR 1.26, 95% CI 1.109 to 1.444, p<0.001 and HR 1.235, 95% CI 1.098 to 1.388, p<0.001) but not for Asian/Pacific Islander women. African American women with stage IIIA-B disease also had a higher risk of death for type I and type II disease versus Caucasian women (HR 1.221, 95% CI 1.045 to 1.422, p=0.010 and HR 1.295, 95% CI 1.155 to 1.452, p<0.001). Asian/Pacific Islander women had a lower risk of death than Caucasian women with type I disease (HR 0.783, 95% CI 0.638 to 0.960, p=0.019) and type II disease (HR 0.790, 95% CI 0.624 to 0.999, p=0.05). African American women with stage IIIC1-2 had a higher risk of death with type I disease (HR 1.343, 95% CI 1.207 to 1.494, p<0.001) and type II disease (HR 1.141, 95% CI 1.055 to 1.233, p=0.001) whereas there was no significant difference between Caucasian women and Asian/Pacific Islander women.

Conclusion: Race appears to play an independent role in survival from endometrial cancer in the USA, with African American women having worse survival on a stage-for-stage basis compared with Caucasian women.