Racial and gender disparities in therapy and outcomes of squamous cell cancer of the anus.

Abstract

691 Background: Squamous cell carcinoma of the anus (SCCA) is one of the few cancers with a rising incidence in the United States. We aimed to characterize race and gender-based disparities in receipt of therapy, and overall survival (OS) of SCCA using the Surveillance, Epidemiology and End Results (SEER) database. Methods: Cases of locoregional SCCA diagnosed between 2000-2012 in the SEER database were included. Demographics, tumor characteristics, therapy and outcomes were extracted. Primary end point was OS. Univariable and multivariable Cox proportional hazard models were constructed to test factors associated with OS. Data were reported as hazard ratios (HR) and 95% confidence intervals (CI). SAS version 9.4 was used for analysis. Results: We identified 7882 cases of locoregional SCCA, median age 58 years, 61.2% women, 86.3% white. A majority of patients (82.3%) received radiation therapy; with the lowest rate in black males (76.7%) and highest in white females (86.1%). The median OS was 135 months, and it was lower in the elderly, > 65 years (68 months), men (108 months), blacks (109 months) and those who did not receive radiation therapy (121 months). In multivariate analysis, increasing age (HR 1.19, 95 % CI 1.16-1.20 per 5 years increase), gender (HR 1.59, 95% CI 1.47- 1.73, men vs women), race (HR 1.51, 95% CI 1.34- 1.71, blacks vs whites), and receipt of radiation therapy (HR 0.90, 95% CI 0.82-0.99), were associated with OS (all p < 0.05). Race was a significant predictor of receiving radiation therapy on univariate analysis. Table 1 outlines the rates of receipt of radiation and the median OS of the four racial/gender groups. Conclusions: Significant race and gender-based disparities exist in the survival of patients with locoregional SCCA. Even after adjusting for baseline and treatment characteristics, blacks had poorer OS, suggesting difference in tumor biology. Further investigation into the causes, and methods to eliminate these disparities are warranted. [Table: see text]