Salvage surgery for locally recurrent anal cancer after intensity modulated radiation therapy with concurrent chemotherapy

INTRODUCTION: Chemoradiation (CRT) with intensity modulated radiation treatment (IMRT) has become the standard for anal cancer. In patients who fail this treatment modality, salvage surgery with abdominal perineal resection can result in long term cancer control. We aimed to evaluate a single centre's experience of salvage surgery for local recurrence since the introduction of IMRT. MATERIALS AND METHODS: A retrospective chart review was performed of all patients who underwent definitive CRT for anal carcinoma at a single tertiary referral center since IMRT became standard in 2009. Patients with recurrent or persistent disease after treatment who underwent salvage surgery were included. Details of CRT, salvage surgery and surgical complications, patterns of recurrence after surgery, and survival data were collected and described. RESULTS: Between 2009-2018, 181 patients underwent definitive treatment using IMRT for anal carcinoma. Of 26 patients who had locoregional recurrent or persistent disease, 14 underwent salvage surgery. Nine had multi-visceral resection and 8 required autologous flap reconstruction. Twelve patients had resections with clear margins and 2 had microscopic positive margins. Twelve patients (86%) experienced post-operative complications, and eight (57%) had perineal wound complications. After salvage, four patients (29%) recurred locally. None of the 8 patients with rpT2 disease recurred. After salvage surgery, 5-year disease free survival was 68.4% and 5-year overall survival was 75%. CONCLUSION: Following IMRT based chemoradiation, salvage surgery has high rates of surgical complications; however disease free and overall survival results are excellent particularly for small recurrences.