Outcomes of salvage surgery for squamous cell carcinoma of the anal canal

Background: For patients with anal canal cancer who fail combined modality treatment (CMT), salvage surgery (SS) offers the potential for long term survival. The literature regarding SS is limited by small patient numbers and/or heterogeneous treatment protocols. We report on a large series of patients initially treated with chemoradiation at a major referral center. Methods: We identified 60 patients with persistent or recurrent anal cancer who had undergone SS; 20 were excluded. Overall and disease-free survival (OS, DFS) curves were constructed using the Kaplan Meier method. Univariate analysis was done using the Log-Rank test, and multivariable analysis using Cox proportional hazards. Results: The 40 patients (29 women, 11 men, median age 57) underwent curative intent resection. The initial procedure was multivisceral resection (n = 24), abdominoperineal resection alone (n = 14) or local excision (n = 2). Postoperative mortality was 5%. Postoperative complications were seen in 72%. Median follow-up was 18 months overall and 36 months in survivors. Median OS was 41 months; OS and disease free survival at 5 years were 39% and 30%, respectively. Recurrence was present in 21 patients at time of analysis. Failure was locoregional in 86% (18 of 21) and distant in 48% (10 of 21). Independent predictors of poor OS were male gender, Charlson Comorbidity Score and tumor size. Independent predictors of poor disease free survival were positive margins and lymphovascular invasion. Conclusions: SS for anal canal cancer was associated with significant morbidity. Long-term survival was achieved in 39% of patients. Comorbidities should guide patient selection, and R0 resection should be the goal.