Risk factors and outcome following salvage surgery for squamous cell carcinoma of the anus

Chemoradiotherapy is the primary treatment for anal cancer. 15-33% of patients will have persistent or recurrent disease after treatment requiring salvage surgery. Relapse after surgery, postoperative complications, and mortality as well as possible risk factors are not fully understood due to the rareness of the disease. The aim of the study was to report outcomes after salvage surgery as well as evaluate risk factors for postoperative complications, cancer relapse and survival.

Data were retrospectively collected from electronical patients charts and pathology reports from all patients undergoing salvage surgery from July 1st^, 2011 to July 1st^, 2021 at the Department of Surgery, Aarhus University Hospital, Denmark.

A total of 98 patients were included in the study. The 5-year overall survival was 61.8%. Relapse after surgery occurred in 36.7% of patients and was significantly associated with R1-resection (HR = 4.4) and preoperative nodal metastases (HR = 4.5). Negative prognostic factors for survival were found to be R1-resection (HR = 3.2), preoperative nodal metastases (HR = 2.9), and male gender (HR = 0.5). There was no association found between complications and survival (HR 1.2). None of the possible risk factors were associated with major postoperative complications.

An acceptable overall survival after surgery was found. Survival and relapse-free survival was negatively associated with R1 resections and positive preoperative lymph nodes. Complications did not influence long-term survival.