Intensity-modulated radiation therapy with concurrent chemotherapy for anal cancer: outcomes and toxicity

To evaluate toxicity, local control, and survival in anal cancer patients treated with intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy.

Sixty-five patients were treated at a single institution with IMRT and concurrent chemotherapy for localized squamous cell carcinoma of the anal canal. Radiotherapy was delivered with a simultaneous integrated boost technique, with dose based on the T stage. The median dose to the primary tumor and pelvis were 54 Gy (range, 50 to 58.8 Gy) and 45 Gy (range, 40.5 to 50.4 Gy), respectively. The most common concurrent chemotherapy regimens were 5-fluorouracil and cisplatin (75%), capecitabine and oxaliplatin (11%), and 5-fluorouracil and mitomycin C (5%).

The percentage of patients with Tx, T1, T2, T3, and T4 disease were 8%, 17%, 49%, 15%, and 11%, respectively. The percentage of patients with N0, N1, N2, and N3 disease were 46%, 17%, 9%, and 28%, respectively. Ninety-one percent of patients completed treatment without a break. Grade 3 gastrointestinal toxicity occurred in 9%, and moist desquamation beyond the perianal area occurred in 17%. The use of a vaginal dilator during simulation and treatment seemed to lower the rates of acute skin and late sexual toxicity. With a median follow-up of 19 months, the 2-year local and distant control rates were both 93%. The 2-year overall and disease-free survival rates were 96% and 86%, respectively.

Concurrent chemotherapy and IMRT was well tolerated, and was associated with low rates of acute and late toxicity and excellent local control, disease-free survival, and overall survival.