Durable Cancer Control and Extended Long‐Term Survival Following Salvage Surgery for Squamous Cell Carcinoma of the Anal Canal: A Cohort Study

AIM: Salvage surgery is the standard-of-care for patients with squamous cell carcinoma of the anal canal (SCCa) who experience isolated locoregional failure after upfront chemoradiotherapy. While perioperative morbidity and short-term survival outcomes have been described, long-term outcomes of surgical salvage are unknown. This study examines recurrence patterns and survival in a cohort of patients with extended follow-up. METHOD: A retrospective chart review was performed on a cohort of consecutive patients who underwent salvage surgery at two specialized cancer centers between 1987 and 2006. Overall, disease-specific and re-recurrence-free survival (OS, DSS, RRFS) were estimated using the Kaplan-Meier method. Prognostic variables were evaluated using univariate and multivariable Cox models. RESULTS: Forty patients were included (29 female, 11 male; median age 56). Median follow-up was 16.5 years (IQR 15.0-20.5) for patients alive at last follow-up. Re-recurrence developed in 52% of patients, 95% of which occurred within 3 years of salvage surgery; re-recurrence was associated with a 91% risk of subsequent SCCa-specific mortality. DSS was 45% (95% CI 30-61) at 5 years, after which point conditional 5-year DSS was 100%. CONCLUSION: Approximately half of patients who undergo salvage surgery for persistent/recurrent SCCa experience durable cancer control with extended long-term survival. Emerging treatment options such as immunotherapy should be evaluated relative to this benchmark.