Chemoradiation with capecitabine and mitomycin-C for stage I-III anal squamous cell carcinoma

Standard therapy for patients with stage I-III squamous cell carcinoma (SCC) of the anal canal is chemo-radiotherapy with 5-fluorouracil (5-FU) and mitomycin C (MMC). While there is limited published evidence to substitute capecitabine (CAP) for 5-FU, the objectives of the study were to describe the toxicity, dose intensity and outcomes of a sequential cohort of patients treated with chemo-radiotherapy with CAP and MCC in a population-based setting.

Patients with stage I-III malignancies of the anal canal referred between February 2010 and March 2012 were included. Dose intensity was calculated by comparing delivered versus planned radiation and chemotherapy treatments and toxicity was retrospectively graded according to standard protocol-specified criteria.

Among 66 eligible patients, median planned dose of radiation was 51.9 Gy over 5.5 weeks, range 25.0 to 63 Gy, and dose intensity was 98%. Median delivered dose of MCC delivered was 12 mg/m2 on day one, week one while median CAP dose was 825 mg/m2 twice daily on radiation days. CAP dose reductions due to toxicity were recorded for 13 patients (20%). Median follow-up was 20 months and 94% of patients with squamous cell histology had no evidence of relapse.

Chemo-radiation with CAP plus MMC is well tolerated and may be a reasonable consideration for patients with stage I-III SCC of the anal canal. A range of planned radiation dose was observed and longer follow-up is necessary to ensure that patients who received lower doses of radiation have similar outcomes to those who received larger doses.