RESUMEN
PURPOSE: Anal cancer (AC) is a rare disease with scarce evidence from developing countries. We performed a population-based cohort study to investigate the relationship between tumor, patient, and social determinants of health with treatment outcomes of AC treated by chemoradiation (CRT). METHODS AND MATERIALS: Patients who received a diagnosis of AC from 1999 to 2020 were identified from the Fundação Oncocentro de São Paulo database. Only patients with AC stage I-III treated by CRT were included. Age, sex, tumor category (T), nodal category (N), education level, practice setting, time to radiation therapy, histology, and treatment local data were extracted. With the Cox proportional hazard model, the hazard ratio and 95% confidence interval were used to test the relationship between tumor, patient, and social factors with overall survival (OS) and cancer-specific survival (CSS). RESULTS: With 1462 patients assessed, the median follow-up was 72 months, and the OS and CSS at 5/10 years were 61%/46% and 67%/60%, respectively. In the univariate analysis, T category, N category, sex, practice setting, and education level were associated with OS and CSS (P < .05). In the multivariate analysis, female sex, T1/2 category, N0 category, and private service were independently associated with OS (P < .05). For CSS, female sex, T1/2 category, private service, and N0 category remained significant (P < .05). CONCLUSIONS: CRT produced satisfactory rates of OS and CSS in patients with AC, with tumor, patient, and social determinants of health influencing the outcomes. These data could help mitigate the effects of social distortions on the survival of AC.