Survival outcomes following salvage abdominoperineal resection for recurrent and persistent anal squamous cell carcinoma

The primary treatment for locoregional failure following chemoradiotherapy for squamous cell carcinoma of the anus (SCCA) is salvage abdominoperineal resection (APR). However, it is necessary to distinguish between recurrent and persistent diseases because of their varied pathologies. We aimed to clarify the survival outcomes following salvage APR for recurrent and persistent diseases and investigate the significance of salvage APR.

This multicentre retrospective cohort study used clinical data from 47 hospitals. All patients were diagnosed with SCCA and underwent definitive radiotherapy as the primary treatment between 1991 and 2015. Overall survival (OS) was compared between the following cohorts: salvage APR for recurrence, salvage APR for persistence, non-salvage APR for recurrence, and non-salvage APR for persistence.

Five-year OS of salvage APR for recurrence, salvage APR for persistence, non-salvage APR for recurrence, and non-salvage APR for persistence were 75% (46%-90%), 36% (21%-51%), 42% (21%-61%), and 47% (33%-60%), respectively. OS of salvage APR for the recurrent disease was significantly higher than that for persistent disease (p = 0.00597). For recurrent disease, OS following salvage APR was significantly higher than that following non-salvage APR (p = 0.0204); however, for persistent disease, there was no significant difference between salvage and non-salvage APR (p = 0.928).

Survival outcomes following salvage APR for persistent disease were significantly worse than that for recurrent disease. Salvage APR did not improve survival outcomes for persistent disease compared to non-salvage APR. These results will elicit a review of persistent disease treatment strategies.