Disparities in treatment and survival in germ cell tumors

Abstract

<h3>Objectives:</h3> Ovarian Germ Cell Tumors (GCT) are rare, and understudied, subtypes of ovarian cancer. Our objective was to evaluate the effects of race, ethnicity, and clinicopathologic characteristics on treatment selection, treatment delays, and overall survival in this disease. <h3>Methods:</h3> Data from the National Cancer Database between 2004 and 2015 were evaluated for adult women with invasive ovarian GCT. Mann-Whitney U-test and Chi Square analysis were used to identify differences in sociodemographic factors based on race and ethnicity. Logistic regression and Poisson regression were used to evaluate associations between treatment receipt and treatment delays, respectively. Time to treatment initiation (TTI) was defined as the duration between date of diagnosis and the first treatment received, and overall survival (OS) was defined as the time from date of diagnosis to either date of death from any cause or date of last contact. Cox proportional hazards regression model was used to calculate hazard ratios for OS. Statistical significance was set at p<0.05. <h3>Results:</h3> There were 3,049 evaluable women with GCT. 74.1% of patients were White and 15.6% were Black. 15.6% were Hispanic and 78.2% were non-Hispanic. The median age of the overall cohort was 27 (range 18-90). There was no difference in mean age at diagnosis between Blacks and Whites, while Hispanics were diagnosed significantly younger than Non-Hispanics (28.0 vs 30.8 years, p<0.001). Though adjuvant treatment after surgical resection was not associated with a difference in OS, younger patients (OR 1.20, 95% CI=[1.04, 1.39], p=0.01), Black women (OR 1.50, 95% CI=[1.21, 1.86], p<0.01) compared to White women, and those at academic institutions (OR 2.04, 95% CI=[1.35, 3.03], p<0.01) compared to community centers were more likely to receive adjuvant therapy after primary surgical resection.Increased TTI was observed in younger patients (RR 1.11, 95% CI=[1.03, 1.21], p=0.01), those with early stage disease (RR 1.39, 95% CI=[1.28, 1.52], p<0.001), those undergoing minimally invasive surgery (RR 1.19, 95% CI=[1.05, 1.33], p<0.01), those with higher household incomes (RR 1.13, 95% CI=[1.03, 1.24], p=0.01), and those treated at facilities not associated with the Commission on Cancer (CoC) (RR 1.16, 95% CI=[1.08, 1.27], p<0.001).On univariable analysis, older age at diagnosis (HR 3.32, 95% CI=[2.50, 4.42], p<0.001), Black race (HR 1.71, 95% CI=[1.27, 2.30], p<0.001) compared to White race, and non-Hispanic ethnicity (HR 1.92, 95% CI=[1.24, 2.94], p<0.01) compared to Hispanic, were associated with worse OS, while on multivariable analysis, government insurance (HR 1.79, 95% CI=[1.33, 2.39], p<0.001) compared to private insurance, treatment at CoC facilities (HR 0.35, 95% CI=[0.15, 0.80, p=0.013) compared to academic institutions, and grade 3 tumors (HR 6.80, 95% CI=[2.65, 17.44], p<0.001) compared to grade 1 tumors were associated with worse OS. Relative to dysgerminoma, all other histologies had worse OS (all p<0.001). Race/ethnicity were not independently associated with OS in the multivariable model. <h3>Conclusions:</h3> Multiple clinical, socioeconomic, and systematic factors are associated with increasing time to treatment and adjuvant therapy selection after primary surgical resection in GCT. Of these factors, type of insurance, and accreditation status of the treating institution are associated with worse overall survival, reflecting the possible need for centralization of care for this rare tumor.