Racial disparities in women with serous epithelial ovarian cancer: a Surveillance, Epidemiology, and End Results (SEER) survival analysis

Abstract

<h3>Objectives:</h3> Serous epithelial ovarian carcinoma (SOC) is the most lethal form of gynecological malignancy in the United States (US), with high-grade SOC accounting for up to 80% of cancer-specific deaths. Existing literature has identified socioeconomic barriers in gynecologic malignancies. However, patterns of racial disparity have not been fully examined. This study aims to identify racial and ethnic disparities in five-year survival rates in women affected by SOC in the US. <h3>Methods:</h3> This retrospective cohort study analyzed data from the 2010-2016 Surveillance, Epidemiology, and End Results (SEER) program database. Women with a primary malignancy of serous epithelial ovarian carcinoma, using 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. Comparison of baseline characteristics were assessed using Chi-square tests (Table 1). Unadjusted and adjusted Cox regression models were used to calculate hazard ratios (HR) and corresponding 95% confidence intervals (CI). <h3>Results:</h3> From 2010-2016, there were 9,630 women with a primary diagnosis of SOC. A higher proportion of Asian/Pacific Islander women (90.7%) were diagnosed with high grade 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%), when compared to other racial groups. A higher proportion of NHB (74.2%) and Asian/PI (71.3%) women presented with 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). Additionally, Hispanic 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). <h3>Conclusions:</h3> This study reveals that there are racial and ethnic disparities in five-year survival in patients with serous ovarian carcinoma, with NHB and Hispanic women having the highest hazards of death compared to NHW women. The racially and ethnically disparate outcomes of ovarian cancer are likely due to an interplay between several factors including unmeasured social determinants of health, and therefore future studies should aim to investigate other socioeconomic factors that may be impacting survival.