Concurrent Chemotherapy and Intensity-Modulated Radiation Therapy for Anal Canal Cancer Patients: A Multicenter Experience

Abstract

To report a multicenter experience treating anal canal cancer patients with concurrent chemotherapy and intensity-modulated radiation therapy (IMRT). From October 2000 to June 2006, 53 patients were treated with concurrent chemotherapy and IMRT for anal squamous cell carcinoma at three tertiary-care academic medical centers. Sixty-two percent were T1-2, and 67% were N0; eight patients were HIV positive. Forty-eight patients received fluorouracil (FU)/mitomycin, one received FU/cisplatin, and four received FU alone. All patients underwent computed tomography-based treatment planning with pelvic regions and inguinal nodes receiving a median of 45 Gy. Primary sites and involved nodes were boosted to a median dose of 51.5 Gy. All acute toxicity was scored according to the Common Terminology Criteria for Adverse Events, version 3.0. All late toxicity was scored using Radiation Therapy Oncology Group criteria. Median follow-up was 14.5 months (range, 5.2 to 102.8 months). Acute grade 3+ toxicity included 15.1% GI and 37.7% dermatologic toxicity; all acute grade 4 toxicities were hematologic; and acute grade 4 leukopenia and neutropenia occurred in 30.2% and 34.0% of patients, respectively. Treatment breaks occurred in 41.5% of patients, lasting a median of 4 days. Forty-nine patients (92.5%) had a complete response, one patient had a partial response, and three had stable disease. All HIV-positive patients achieved a complete response. Eighteen-month colostomy-free survival, overall survival, freedom from local failure, and freedom from distant failure were 83.7%, 93.4%, 83.9%, and 92.9%, respectively. Preliminary outcomes suggest that concurrent chemotherapy and IMRT for anal canal cancers is effective and tolerated favorably compared with historical standards.