Salvage Surgery for Locoregional Failure in Anal Squamous Cell Carcinoma.

Abstract

Anal squamous cell carcinoma is a rare cancer with a high cure rate, making research into the treatment of locoregional failure difficult. The purpose of this study was to examine factors related to local treatment failure and determine the outcomes of patients undergoing local salvage resection. This was a retrospective cohort study. This study was conducted at a quaternary referral center. Patients with anal squamous cell carcinoma treated with chemoradiotherapy between January 1983 and December 2015 were included. The influence of patient-, tumor-, and treatment-related factors on the primary outcome measures of locoregional failure, overall survival, and disease-free survival were investigated. Of 467 patients with anal squamous cell carcinoma, 63 experienced locoregional failure with 41 undergoing salvage resection. Twenty-seven patients (38%) had persistent disease and 36 (62%) developed locoregional recurrence. Multivariate analysis identified tumor stage (HR, 3.16; p < 0.002) as an independent predictor of locoregional failure. Thirty abdominoperineal resections and 11 pelvic exenterations were undertaken with no surgical mortality. At a median follow-up of 20 months (range, 4-150 months), 5-year overall and disease-free survival for the salvage cohort was 51% and 47%. Margin positivity was an independent predictor for relapse post-salvage surgery on multivariate analysis (HR, 20.1; p = 0.027). Nineteen patients (48%) developed further relapse, which included all 10 patients with a positive resection margin, 3 of whom underwent re-resection. Of the 19 patients with relapse, 3 remain alive and 2 have persistent disease. Limitations include the retrospective nature of the database, the prolonged time period of the study, and episodes of incomplete data. Advanced T stage is an independent predictor of local failure in anal squamous cell carcinoma. Most patients can be salvaged, with a positive resection margin being a strong predictor of further relapse and poor outcome. See Video Abstract at http://links.lww.com/DCR/A515.