Abstract 4235: Race differences in treatment and survival of ovarian cancer
Authors: Hildebrand Janet S. , Wallace Kristin , Kelemen Linda E. 
Published: August 2018

Black women have lower incidence rates of ovarian cancer than white women in the U.S., but their cancers are more often fatal. Factors associated with lower survival among blacks include advanced stage at diagnosis and fewer women receiving a surgery-chemotherapy sequence consistent with national guidelines for treatment of primary ovarian cancer. We examined treatment and survival among 365 white and 95 black ovarian cancer patients captured by the Hollings Cancer Center Cancer Registry in Charleston, S.C. from 2000 to 2015 with the aim of identifying factors to explain observed racial disparities. Outcomes of interest were receipt of a cytoreductive surgery-chemotherapy sequence, with or without neoadjuvant therapy, and overall survival (OS) calculated as months from diagnosis to death. We used unconditional logistic regression to estimate odds ratios (ORs) of black vs. white race associated with receipt of surgery-chemotherapy, controlling for clinical stage, histology, insurance status, smoking status, and severity of comorbidities (none, mild, moderate, moderate-severe, severe), assessed using the age-adjusted Charlson index. For survival comparisons, we plotted Kaplan-Meier curves by race and estimated the death hazard ratio (HR) using Cox proportional hazards regression. We assessed statistical interaction between race and comorbidities using −2 log likelihood tests. Age, stage and histology distributions were similar between blacks and whites; however, white women were more likely than blacks to be current or former smokers (44% vs. 32%) and to have private health insurance (38% vs. 26%), while blacks were more likely to have moderate-severe or severe comorbidities (37% vs. 30%), although differences were not statistically significant. There were significant racial differences in receipt of surgery-chemotherapy (blacks 44% vs. whites 69%, p&lt;0.0001). Women who did not receive a surgery-chemotherapy sequence were 3 times more likely to be black (adjusted OR 3.13, 95% confidence interval (CI) 1.90−5.16), but the disparity was observed only in women with comorbidity as opposed to none (interaction p=0.01). Median OS was 29.3 months among black women and 49.2 months among whites (log rank p&lt;0.001). The survival disadvantage among blacks persisted after controlling for treatment, comorbidities, stage, smoking, and insurance (HR 1.87, 95% CI 1.41−2.48), and no statistical interaction between race and comorbidities was evident (p=0.17). In this study, black women, particularly those with comorbidities, were significantly less likely than whites to receive a surgery-chemotherapy sequence for treatment of ovarian cancer. Black race was associated with an 87% higher fatality rate independent of treatment, stage, comorbidities, and insurance status. More research is needed to understand race-specific reasons for nonadherence to guideline based care and racial disparities in survival after ovarian cancer diagnosis.

Citation Format: Janet S. Hildebrand, Kristin Wallace, Linda E. Kelemen. Race differences in treatment and survival of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4235.