The role of systemic chemotherapy and multidisciplinary management in improving the overall survival of patients with metastatic squamous cell carcinoma of the anal canal.

Metastatic squamous cell carcinoma (SCCA) of the anal canal is a rare malignancy for which no standard treatment algorithm exists. To determine the best approach, all patients diagnosed with metastatic SCCA of the anal canal treated at a single institution were evaluated for choice of chemotherapy and treatment outcome. A retrospective study from January 2000 to May 2012 was conducted. Electronic medical records were reviewed for diagnosis of metastatic SCCA of the anal canal. All patients were treatment naïve for metastatic disease and completed all radiographic imaging at our institution. The purpose of this study was to evaluate outcomes among patients who received systemic chemotherapy and if appropriate were referred for multidisciplinary intervention (e.g., surgery, radiofrequency ablation, etc.). Seventy-seven patients fulfilled eligibility criteria. Forty-two patients (55%) received 5-fluorouracil (5-FU) + cisplatin (PF); 24 patients (31%) received carboplatin + paclitaxel (CP); 11 patients (14%) received an alternative regimen. After a median follow-up of 42 months, the median progression-free survival (PFS) for all patients was 7 months; the median overall survival (OS) was 22 months. Thirty-three patients (43%) underwent multidisciplinary management for metastatic disease resulting in a median PFS of 16 months (95% CI: 9.2 -22.8) and median OS of 53 months (95% CI: 28.3 - 77.6). Systemic chemotherapy provides durable survival for patients with surgically unresectable metastatic SCCA of the anal canal. Multidisciplinary management for select patients with metastatic disease effectively improves survival and should be considered whenever possible.