Across histologies other than clear cell, Black women with stage 1 endometrial cancer experienced routinely poorer cancer-specific survival (CSS), regardless of receiving similar adjuvant therapy, according to findings published in Gynecologic Oncology Reports.
For this retrospective cohort study, Emily M. Ko, MD, MSCR, and colleagues examined women with endometrial cancer who underwent primary hysterectomy. Study participants were mostly White (85.5%); 8.6% of participants were Black and 5.9% identified as other. Most cases (N=19,351; 80.1%) were stage 1, followed by stage 3 (N=3,307; 13.7%) and stage 2 (N=1,484; 6.2%). Histologies included endometrioid adenocarcinoma (N=20,373; 84.4%), serous (N=1,994; 8.3%), clear cell (N=433; 1.8%), and carcinosarcoma (N=1,342; 5.6%).
Comparing Black & White Women
Histology varied more among Black women with endometrial cancer and included endometrioid (64.1%), serous (18.4%), carcinosarcoma (14.1%), and clear cell (3.5%), whereas White women had endometrioid histology (86.6%), followed by serous (7.0%), carcinosarcoma (4.7%) and clear cell (1.6%). Age at diagnosis was younger among Black women with endometrioid adenocarcinoma histology of all stages and for serous histology stages 1 and 3.
Black women more often lived in the South across all disease stages and histologies, represented a greater proportion of participants in the lowest income bracket (<$40,000/year), and had the highest number of participants living in metropolitan areas across all stage and histologies. Dr. Ko and colleagues observed no difference by race for having undergone surgical nodal evaluation at all stages and histologies except for stage 1 endometrioid, with which slightly more Black women (63%) had nodal dissection compared with White women (58.9%; P<0.0001). The study team also reported no differences regarding adjuvant therapy by race across all stages and histologies except for stage 3 endometrioid adenocarcinoma, for which Black women were treated with adjuvant therapy less often: 38% of Black women received no adjuvant therapy compared with 30% of White women and 24% of those who identified as other (OR, 0.68; P=0.03).
Disparities Among Black Women
Within each stage and with histologies combined, overall survival was lower for Black women. Adjusted analyses demonstrated that disparities in overall survival retained significance for Black women with stage I serous (adjusted HR [aHR], 1.60; 95% CI, 1.24-2.07; P=0.0003) and carcinosarcoma (aHR, 1.38; 95% CI, 1.08-1.77; P=0.01) histologies. Stage by stage, Black women also had lower CSS than White women or women of other races (log-rank P<0.0001 for all stages). For stage 1 disease, Black women experienced poorer CSS for all histologies except for clear cell in unadjusted and adjusted analyses. For stage 2 disease, Black women experienced poorer CSS for endometrioid histology in unadjusted analyses and similar OS. For stage 3 disease, Black women with endometrioid carcinoma experienced poorer CSS and OS in unadjusted analyses, but no significant difference in CSS in adjusted analyses.
The study team noted that future research should examine race beyond a biological construct and account for factors such as social determinants of health and access to care in cancer-specific and overall health outcomes. They also suggested that future research examine the development of post-treatment interventions within survivorship, surveillance, and treating recurrence to decrease disparities.