Pretreatment colostomy in patients with anal squamous cell carcinoma: Risk factors for a permanent stoma

Background The current standard of care for anal squamous cell carcinoma (SCC) is concurrent chemoradiation (CRT), which enables tumor eradication while preserving the anal sphincter. Patients with locally advanced tumors, however, may experience complications that preclude treatment before stoma creation. Objective To evaluate the reversal rate of pretreatment stomas and the risk factors associated with nonreversal. Methods This single-institution retrospective cohort study using a prospective database included patients diagnosed with anal SCC from January 2008 to December 2020 who required a stoma before curative CRT. Results In total, 651 patients were identified; 65 required a stoma before chemoradiation due to obstruction (43.1%), rectovaginal fistula (20%), and perianal sepsis (36.9%). The stoma was reversed in nine patients after a mean follow-up of 35.8 months. Risk factors associated with a permanent stoma were perianal sepsis (p = 0.010), interruptions during radiotherapy for more than 7 days (p = 0.010), male sex (p = 0.013), poor performance status (Eastern Cooperative Oncology Group [ECOG] >= 2) (p = 0.023), large tumors (p = 0.045), and cisplatin-based chemotherapy (p = 0.047). Conclusions Pretreatment stomas are unlikely to be reversed, and risk factors for a permanent stoma are perianal sepsis, interruptions during radiotherapy for more than 7 days, male sex, poor performance status (ECOG >= 2), large tumors, and cisplatin-based chemotherapy.