Outcomes of anal cancer treated with definitive IMRT-based chemoradiation

Abstract

Objective: Despite excellent long-term outcomes, definitive chemoradiation (CRT) for squamous cell carcinoma (SqCC) of the anal canal with traditional radiotherapy techniques results in significant morbidity. Accruing data supports intensity-modulated radiotherapy (IMRT)-based treatment, and we report our institutional experience using this approach. Methods: We reviewed patients with nonmetastatic anal canal SqCC treated with definitive IMRT-CRT. Clinically node-negative patients initially received 36 Gy to the elective pelvic and inguinal lymph nodes and 40 Gy to gross tumor volume (GTV) while node-positive patients received 45 and 50 Gy, respectively. All patients were considered for a GTV boost depending on the degree of clinical response and acute treatment-related toxicity. Results: We identified 52 patients with T1-4N0-3M0 SqCC of the anal canal. Median follow-up was 21 months (range, 7.7-68.1 months). Two-year locoregional control, overall survival, disease-free survival, distant metastasis-free survival, and colostomy-free survival were 94.6, 100, 82.6, 90, and 94.7 %, respectively. Acute grade 3+ nonhematologic and hematologic toxicities were observed in 21.1 and 63.5 %, respectively. No acute grade 4 nonhematologic toxicity was observed. Conclusion: Our series demonstrates that definitive IMRT-based chemoradiation with standard fractionation for anal SqCC results in excellent outcomes with minimal toxicity. © 2012 Springer-Verlag.