Racial disparities in treatment and survival from ovarian cancer

Background: Black women with ovarian cancer in the U.S. have lower survival than whites. We aimed to identify factors associated with racial differences in ovarian cancer treatment and overall survival (OS).

Methods: We examined data from 365 white and 95 black ovarian cancer patients from the Hollings Cancer Center Cancer Registry in Charleston, S.C. between 2000 and 2015. We used unconditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between race and receipt of surgery and chemotherapy, and Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% CIs between race and OS. Model variables included diagnosis center, stage, histology, insurance status, smoking, age-adjusted Charlson comorbidity index (AACI) and residual disease. Interactions between race and AACI were assessed using -2 log likelihood tests.

Results: Blacks vs. whites were over two-fold less likely to receive a surgery-chemotherapy sequence (multivariable-adjusted OR 2.46, 95% CI 1.43-4.21), particularly if they had a higher AACI (interaction p = 0.008). In multivariable-adjusted Cox models, black women were at higher risk of death (HR 1.81, 95% CI 1.35-2.43) than whites, even when restricted to patients who received a surgery-chemotherapy sequence (HR 1.79, 95% CI 1.10-2.89) and particularly for those with higher AACI (HR 4.70, 95% CI 2.00 - 11.02, interaction p = 0.01).

Conclusions: Among blacks, higher comorbidity associates with less chance of receiving guideline-based treatment and also modifies OS. Differences in receipt of guideline-based care do not completely explain survival differences between blacks and whites with ovarian cancer. These results highlight opportunities for further research.