Radio(chemo)therapy in anal cancer: evaluation of sex-specific disparities across AJCC stages

This study aimed to investigate sex differences in anal squamous cell carcinomas (ASCC), with a particular focus on the prognostic significance of the American Joint Committee on Cancer (AJCC) 9th edition staging system for oncological outcome.

A retrospective analysis was conducted in 188 patients with histologically confirmed ASCC who underwent definitive (chemo)radiotherapy between 2004 and 2020. Patient- and tumor-related data were collected. Tumor stage groups were classified according to the AJCC 9th edition. Overall survival (OS), disease-free survival (DFS), freedom from recurrence (FFR), and colostomy-free survival (CFS) were analyzed using the Kaplan-Meier method for univariate testing and Cox regression models for multivariate analysis. Differences between sexes were assessed.

The cohort included 134 females and 54 males, with a median follow-up of 83 months. Females exhibited significantly better OS (p = 0.01), DFS (p = 0.01), and CFS (p = 0.03). For male patients, there was a clear trend towards better OS (p = 0.08), DFS (p = 0.10), and FFR (p = 0.09) in earlier tumors as well as significantly better CFS (p = 0.04). In contrast, in the female subgroup, there were no significant differences in OS (p = 0.64), DFS (p = 0.52), and CFS (p = 0.25) with respect to tumor stage. In multivariate analysis, male sex, older age, and advanced tumor stages were significant risk factors for poorer OS, DFS, and CFS.

This study highlights significant sex differences in ASCC prognoses, with females showing better survival outcomes. The prognostic value of the AJCC 9th edition staging system differs between sexes; thus, we support the inclusion of sex as a prognostic factor in staging systems.