Failure of Initial Curative Treatment for Non-Metastatic Anal Squamous Cell Carcinoma: From Prognostic Factors Analysis to Stratified Treatment.

In squamous cell anal canal neoplasms, persistent disease or recurrence after initial chemoradiotherapy are not the rule, yet their occurrence deserves to be analyzed to better identify prognostics factors. The aim of our study was to describe the patterns of failures of the initial treatment, their subsequent evolution and to identify prognostic factors in these relapsed patients. All patients with non-metastatic anal squamous cell carcinoma initially treated with curative intent at the Centre Antoine Lacassagne between 1999 and 2019, and who presented persistent disease or recurrence were analyzed. The median follow-up was 44 months. Univariate and multivariate analyses were performed to identify prognostic factors. From our database of 528 patients, 77 patients were eligible: 25 with persistent disease and 52 with recurrence after complete response. The median overall survival was 39 months (95% CI: 25.5-52.3 months) from the date of treatment failure. In univariate analysis, prognostic factors were gender, initial lymph node status, type of failure, response to treatment's failure. In multivariate analysis, only female gender remained statistically significant (HR 0.43- P=0.016). 32% of patients with persistent disease had metastatic status. 17.3% and 5.8% of recurrences respectively occurred after three and five years of follow-up. Systematic imaging could be performed after initial treatment because of distant lesions in one third of patients with persistent disease. The follow-up should not be interrupted before five years, given the significant frequency of late recurrences. In multivariate analysis, only female gender was statistically significant. Stratified treatment based on prognostic factors could be envisaged, the details of which remain to be defined.