Oncologic outcomes of salvage surgery for epidermoid carcinoma of the anus initially managed with combined modality therapy

PURPOSE: Primary chemoradiation failure for epidermoid carcinoma of the anus is treated by surgical resection. This study evaluates the outcome of salvage surgery at one institution. METHODS: All patients (n = 177) with a diagnosis of epidermoid carcinoma of the anus undergoing surgery since 1980 were reviewed. After criteria-based exclusion (n = 115), the remaining patients (n = 62) were analyzed. Kaplan-Meier survival analysis was performed on abdominoperineal resection/low anterior resection patients. Variable comparisons were made using log-rank and Cox regression analyses. Inguinal lymph node dissection patients (n = 5) were analyzed separately. RESULTS: Median follow-up was 24.2 months. Actuarial five-year survival in all abdominoperineal resection/low anterior resection patients (n = 57) was 33 percent (median, 34.1 months). Univariate predictors of decreased survival were tumor size > 5 cm or adjacent organ involvement at salvage, positive nodal disease at salvage, and positive margins. Independent predictors of decreased survival were the same except for tumor size or adjacent organ involvement at salvage (not significant). Patients undergoing potentially curative resections (n = 47) had an actuarial five-year Survival of 40 percent (median, 49 months). The univariate and multivariate predictors of both decreased survival and recurrence in this subgroup included: disease persistence after chemoradiation and nodal disease at salvage. Tumor size > 5 cm or adjacent organ involvement at salvage predicted recurrence with only univariate analysis. Interestingly, actuarial five-year survival after potentially curative resection for recurrence after chemoradiation was 51 percent (as opposed to 31 percent for persistence). After potentially curative resections, most documented recurrences (79 percent) occurred within two years and were locoregional (74 percent). Actuarial five-year recurrence-free survival was 46 percent. Three of five inguinal lymph node dissection patients were alive without disease at 21.2, 81.7, and 84.3 months. CONCLUSIONS: Salvage surgery after failed chemoradiation therapy has a reasonable chance of cure. Favorable independent prognostic factors include recurrence (vs. persistence) after chemoradiation (when salvage is potentially curative), absence of nodal disease at salvage, and negative margins. Salvage inguinal lymph node dissection after failed chemoradiation therapy also is potentially curative.