Racial Disparities in Survival Outcomes of Patients With Serous Epithelial Ovarian Cancer: A Retrospective Cohort Analysis

Abstract

Objective: To identify racial disparities in five-year survival rates in women affected by serous epithelial ovarian carcinoma in the United States (US).Methods: This retrospective cohort study analyzed data from the 2010 to 2016 Surveillance, Epidemiology, and End Results (SEER) program database. Women with a primary malignancy of serous epithelial ovarian carcinoma, using International Classification of Diseases for Oncology (ICD-O) Topography Coding and ICD-O-3 Histology Coding, were included in this study. Race and ethnicity were combined into the following groups: Non-Hispanic White (NHW), Non-Hispanic Black (NHB), Non-Hispanic Asian/Pacific Islander (NHAPI), Non-Hispanic Other (NHO), and Hispanics. Cancer-specific survival was measured at five years post-diagnosis. A comparison of baseline characteristics was assessed using Chi-squared tests. Unadjusted and adjusted Cox regression models were used to calculate hazard ratios (HR) and corresponding 95% confidence intervals (CI).Results: From 2010 to 2016, there were 9,630 women with a primary diagnosis of serous ovarian carcinoma identified in the SEER database. A higher proportion of Asian/PI women (90.7%) were diagnosed with highgrade malignancy (poorly differentiated/undifferentiated) compared to NHW women (85.4%). NHB women (9.7%) were less likely to undergo surgery when compared to NHW women (6.7%). Hispanic women had the highest proportion of uninsured women (5.9%), while NHW and NHAPI had the lowest (2.2% each). A higher proportion of NHB (74.2%) and Asian/PI (71.3%) women presented with the distant disease compared to NHW women (70.2%). After adjustment for age, insurance, marital status, stage, metastases, and surgical resection, NHB women had the highest hazard of death within five years compared to NHW women (adjusted (adj) HR 1.22, 95% CI 1.09-1.36, p<0.001). Hispanic women also had lower five-year survival probabilities compared to NHW women (adj HR 1.21, 95% CI 1.12-1.30, p<0.001). Patients undergoing surgery had significantly increased survival probability compared to those who did not (p<0.001). As expected, women with Grade III and Grade IV disease both had significantly lower five-year survival probabilities compared to Grade I (p<0.001).Conclusion: This study reveals that there is an association between race and overall survival in patients with serous ovarian carcinoma, with NHB and Hispanic women having the highest hazards of death compared to NHW women. This adds to the existing body of literature as survival outcomes in Hispanic patients relative to NHW patients are not well documented. Because of the potential interplay between overall survival and several factors including race, future studies should aim to investigate other socioeconomic factors that may be impacting survival.