Patrich T, Wang Y, Elshaikh MA, Zhu S, Damast S, Li JY, Fields EC, Beriwal S, Keller A, Kidd EA, Usoz M, Jolly S, Jaworski E, Leung EW, Donovan E, Taunk NK, Chino JP, Russo AL, Lea JS, Lee LJ, Albuquerque K, and Hathout L. Racial Disparities in Patients with Stage IIIC Endometrial Cancer. Int J Radiat Oncol Biol Phys 2022; 114(3):e273-e274.
Int J Radiat Oncol Biol Phys
Purpose/Objective(s): To report the impact of race on clinical outcomes in patients with stage IIIC endometrial carcinoma (EC).
Materials/Methods: A retrospective multi-institutional cohort study was conducted across 13 Northern American academic centers and included patients with stage IIIC endometrial carcinoma (EC) who received both chemotherapy and radiation in an adjuvant setting. Overall survival (OS) and recurrence-free survival (RFS) were calculated by Kaplan-Meier method. Univariable and multivariable analysis were performed by Cox proportional hazard models for RFS/OS. Propensity score matching was used to estimate the effect of race on survival outcomes. Statistical analyses were conducted using statistical software.
Results: A total of 90 Black and 568 non-Black patients (83%) were identified with a median age at diagnosis of 62 (Interquartile Range (IQR) 55-70). Median follow-up was 45.3 months (IQR 24-71 months). Black patients were significantly older (p<0.0001), had significantly more non-endometrioid histology (p<0.0001), grade 3 tumors (p<0.0001) and were more likely to have >1 positive paraaortic lymph nodes (PALN) compared to non-black patients. The presence of lymphovascular space invasion (LVSI), depth of myometrial involvement, number of total nodes involved, adnexal and cervical involvement and stage were not correlated with race (all p>0.1). As for treatment type, chemoradiotherapy sequencing approach was not correlated with race and no difference in number of chemotherapy cycles between Black and non-Black patients (p=0.32) was observed. Black patients were more often treated with external beam radiation therapy (EBRT) (43.3% and 24%, respectively) while a higher proportion of non-black patients received both EBRT and vaginal cuff brachytherapy (VBT) (65% vs. 38 %) (P<0.0001) despite similar cervical involvement. The 5-year estimated OS and RFS rates were 45% and 47% compared to 77% and 68% for Black patients vs. non-black patients, respectively (p<0.001). After propensity score matching, the 2 groups were well balanced for most of the covariates (age, histology, stage, grade, number of positive PALN, adnexal and cervical involvement) except for depth of myometrial invasion and radiation type. The estimated hazard ratios (HRs) of Black vs. non-Black patients were 1.613 (95% CI = (1.01, 2.575), p-value = 0.045) for OS and 1.487 (95% CI = (0.906, 2.440), p-value = 0.116) for RFS, indicating that Black patients have significantly worse OS. RFS differences did not reach statistical significance.
Conclusion: Compared to non-Black patients, Black patients have higher rates of non-endometrioid histology, grade 3 tumors and number of PALNs. After propensity score matching, Black patients had worse OS but no statistically significant difference in RFS. Racial disparities could be mitigated by better access to care, equitable inclusion on randomized trials, and identification of genomic/molecular differences to better tailor adjuvant treatment.