Short-term morbidity and mortality following surgical treatment of anal squamous cell carcinoma in Sweden - A national multicentre study.

Abstract

Anal squamous cell carcinoma (ASCC) is primarily treated with chemoradiotherapy (CRT), but surgery can be curative following treatment failure. The treatment of ASCC was centralised in Sweden in 2017. This study aims to describe the characteristics and outcomes of surgery for ASCC nationally, focusing on short-term morbidity and mortality. All patients with ASCC who underwent surgery from 2017 to 2021 in Sweden were retrospectively identified. Perioperative complications and mortality rates were recorded, and risk factors were analysed. A total of 97 patients underwent 103 surgical procedures. The median age was 64 years (56-74), and 61% were women. Indications included recurrent tumours after CRT (43%), residual disease (34%), re-recurrence following prior salvage surgery (8%), primary surgery due to CRT contraindication (8%) and post-treatment sequelae (8%). Surgical procedures included 84 (82%) abdominoperineal excisions, 10 (10%) pelvic exenterations, 5 (5%) perineal excisions for local re-recurrences and 4 (4%) lymphadenectomies. Overall, 48% of patients experienced perineal morbidity, defined as perineal wound infection, dehiscence, necrosis or pelvic abscess. Major surgical complications (Clavien-Dindo ≥ III) were reported in 22/103 (21%) of procedures. Most reoperations (9/16) were related to flap complications. Thirty- and 90-day mortality rates were 0% and 1%, respectively. This national cohort study presents the largest recent series of surgically treated ASCC patients in Sweden. Surgery caused substantial short-term morbidity, particularly perineal morbidity, while short-term mortality remained low. Although no significant risk factors for major complications were identified, these findings highlight the need for improved perineal wound management and further evaluation of long-term outcomes.