Mesorectal failure after chemoradiotherapy for squamous cell carcinoma of the anus: is sphincter-saving surgery reasonable?

BACKGROUND: Abdominoperineal resection (APR) is today the standard treatment for improving survival in case of mesorectal failure without anal canal recurrence after chemoradiotherapy (CRT) for squamous cell carcinoma of the anus (SCC). The aim of this study was to assess if a sphincter-saving surgery is a safe alternative to classical salvage APR in these patients. METHODS: A retrospective study was conducted on all patients who had total mesorectal excision (TME) with sphincter-saving surgery either with coloanal or low colorectal anastomosis, for mesorectal failure after CRT for SCC between 2012 and 2020 at our institution. The main endpoint of our study was oncological results at the end of follow-up. Postoperative morbidity and mortality were secondary endpoints. RESULTS: There were 10 patients, (8 women, median age 55 years [range 45-61 years]). On TME specimens, R0 resections were noted in five (50%), R1 resection in four (40%) and R2 resection in one (10%). After a median follow-up of 42 months (4-74 months), five patients were alive, and four (40%) were alive at 5-year follow-up. During follow-up, locoregional failure after TME was noted in two patients (20%), distant relapse in three patients (30%) and both locoregional plus distant failure in two patients (20%). Only two patients (20%) had anal recurrence, one in the anal canal, the other in the peri-anastomotic area. Long- term local control was achieved in 2 of the 5 patients (40%) who underwent R0 resection versus only 1/4 patients (25%) with R1 resection. CONCLUSIONS: Our preliminary study suggested that sphincter-saving surgery could be proposed in selected patients with SCC presenting mesorectal failure after CRT, providing a feasible R0 resection.