Abstract
BACKGROUND: Combination chemoradiotherapy is the standard of care for treatment of non-metastatic squamous cell carcinoma of the anus (SCCA). This population based study evaluated disparities in receipt of radiotherapy (RT) as well as comparative survival rates for SCCA patients in the United States. METHODS: The Surveillance, Epidemiology, and End Results (SEER) 18 database was used to identify patients with non-metastatic SCCA diagnosed between 1998 and 2008. Multivariate logistic regression was used to model the relationships between age, sex, and race and the receipt of RT, adjusting for marital status and stage of disease. Relative survival (RS) rates were compared by each factor, with added adjustment for RT status, using Cox proportional hazards model. RESULTS: A total of 3,885 patients with localized or regional SCCA as the only primary malignancy were included in the study, of which, 3,192 (82%) received RT. In our multivariate analysis, lower rates of RT were found for those 65+ years old [adjusted odds ratio (OR) 0.71; P<0.001], males (adjusted OR 0.65; P<0.001), and blacks (adjusted OR 0.78; P=0.049). Multivariate survival analysis showed worse survival among those 65+ years old (adjusted HR 1.65; P<0.001), males (adjusted HR 1.53; P<0.001), and blacks (adjusted HR 1.35; P=0.001). CONCLUSIONS: This population based study identified older patients, males, and blacks as less likely to receive RT. Worse survival was also found in these groups.