71973 - Short-term morbidity and mortality following surgical treatment of anal squamous cell carcinoma in Sweden – a national multicenter study

Introduction Anal squamous cell carcinoma (ASCC) is primarily treated with chemoradiotherapy (CRT). Salvage surgery is a potentially curative treatment following CRT failure. Centralization of surgery was implemented in 2017 to improve ASCC care in Sweden. The aim of this study was to describe the characteristics and use of surgery for ASCC on a national level including short-term morbidity and mortality. Method All consecutive patients with ASCC who underwent surgical treatment between 2017 and 2021 in Sweden were retrospectively identified. Intra- and postoperative complications and mortality rates were recorded, and risk factors analyzed. Result Ninety-seven patients underwent surgery. Fifty-nine patients (61%) were female, the median age was 64 years (range, 56-74). A total of 103 surgeries were performed for recurrent (43%) and residual (34%) tumor after CRT, re-recurrence after previous salvage surgery (8%), primary surgical treatment due to contraindication to CRT (8%) and sequel (8%). Eighty-four (82%) abdominoperineal excisions, 10 (10%) pelvic exenterations, 5 (5%) perineal excisions of local re-recurrences and 4 (4%) lymphadenectomies (as sole procedure), were performed. The overall perineal morbidity rate was 47%. Major surgical complications (Clavien-Dindo ≥ III) followed 22/103 (21%) surgeries. Age was a risk factor for developing major surgical complications (OR 1.051, 95% CI 1.005-1.098). Myocutaneous flap complications (infection, necrosis and/or dehiscence) led reoperation for nine patients. The 30- and 90-day mortality was 0 and 1%, respectively. Discussion Surgery for ASCC leads to substantial perineal short-term morbidity. Mortality is low, indicating that surgeries are safely performed with adequate identification and management of complications.