Salvage abdominoperineal resection for anal cancer following chemoradiation: A proposed scoring system for predicting postoperative survival

Background and Objectives Anal carcinoma is treated primarily by chemoradiation. Failure of this treatment requires salvage surgery. The aims of this retrospective study were to assess the survival probability after rescue surgery and design a pathological risk score (PRS) to predict postoperative outcome. Methods From 1982 to 2011, the clinical and pathological data of 111 patients treated with chemoradiation or radiation alone and abdominoperineal resection were reviewed. The KaplanMeier method was used to assess overall survival and parametric modeling was applied to determine prognostic factors and design a PRS. Results The 2- and 5-year overall survival rates were 60% and 24.5%, respectively. The multivariate analysis showed that nodal disease (P<0.03), resection margin (P<0.001), and perineural and/or lymphovascular invasion (P<0.0001) were significantly associated with survival. Patients who presented negative values for these three variables were estimated to show a 5-year survival rate of 55% compared with 0.03% for patients who presented positive values. Conclusions Positive surgical margin, the presence of perineural and/or lymphovascular invasion and positive nodal involvement were identified as significant independent predictors of mortality. The PRS was shown to be highly predictive of postoperative outcome. J. Surg. Oncol. 2013;107:486492. (c) 2012 Wiley Periodicals, Inc.