Results of surgical salvage after failed chemoradiation therapy for epidermoid carcinoma of the anal canal

Background: The standard treatment for epidermoid carcinoma of the anal canal consists of combined radiation and chemotherapy. For patients who present with persistent or locally recurrent disease, salvage abdominoperineal resection is the treatment of choice. The purpose of this study is to review our experience with salvage surgery in this group of patients. Methods: From 1990-2002, 31 patients underwent radical salvage surgery with curative intent after failure of initial sphincter-conserving therapy, and the medical records of these patients were retrospectively reviewed. Clinicopathologic variables were determined and comparisons performed with the Cox proportional hazards model. Survival was calculated by the Kaplan-Meier method. Results: Eleven patients underwent radical salvage surgery for persistent disease and 20 patients for recurrent disease. The median follow-up time was 29 months. The actuarial 5-year overall survival was 64%. Twelve patients developed recurrent disease after radical salvage surgery. Patients who received an initial radiation dose of less than 55 Gy had a significantly worse survival than those who received at least 55 Gy as part of their initial treatment (5-year overall survival 37.5% vs. 75%; age-adjusted hazard ratio 8.2 [95% CI: 1.1-59.8], P = .037). The presence of positive lymph nodes at presentation also adversely affected survival (P < .05). Factors that were not found to have an impact on survival included the presence of persistent versus recurrent disease, tumor (T) stage, and margin status of resection. Conclusions: Long-term survival following salvage surgery for persistent or locally recurrent epidermoid carcinoma of the anal canal can be achieved in the majority of patients. However, patients who initially present with node-positive disease and patients who receive a radiation dose of less than 55 Gy as part of their initial chemoradiation therapy regimen have a worse prognosis after radical salvage surgery.