Concurrent paclitaxel, capecitabine, mitomycin C and pelvic radiation therapy for patients with squamous cell anal carcinoma.

Purpose: The goals of this study were to assess safety and efficacy of triplet chemoradiotherapy (CRT) with paclitaxel for squamous cell anal carcinoma (SCAC).

Methods: Patients with stage I-IIIB SCAC were enrolled and received 52-58 Gy intensity-modulated radiotherapy (IMRT) (with dose based on the T stage) in consecutive daily 1.8-2.2 Gy fractions. The concurrent chemotherapy consisted of paclitaxel 45 mg/m days 3, 10, 17, 24, 31, capecitabine 625 mg/m bid on treatment days and mitomycin C 10 g/m on day 1. Primary endpoints were complete clinical response at 26 weeks and protocol compliance; secondary endpoints included toxicity, overall survival (OS) and progression-free survival (PFS).

Results: Thirty-eight patients were enrolled. The percentage of patients with stage I, II, IIIA, and IIIB disease were 1 (2.6%), 5 (13.2%), 15 (39.5%), and 17 (44.7%), respectively. 32 patients (84.2%) completed CRT without significant alterations. Grade 3-4 toxicity occurred in 23 (60.5%) patients. 33 (86.8%) patients had complete clinical response at 26 weeks. Median follow-up was 25.6 months. Seven (18.4%) patients experienced disease progression: four patients had residual tumor after CRT, 2 patients developed distant metastases and 1 patient developed a local recurrence 12 months after CRT. Two-year OS was 93.6%, 2-year PFS was 83.9%.

Conclusions: Investigated treatment scheme is feasible despite high toxicity profile, and may be beneficial for patients with advanced SCAC. Further research is warranted.