T1-2 anal carcinoma requires elective inguinal radiation treatment--the results of Trans Tasman Radiation Oncology Group study TROG 99.02.

ABSTRACT

BACKGROUND AND PURPOSE: Elective inguinal irradiation increases morbidity. We describe outcomes of moderate intensity chemoradiation treating anal canal and adjacent pelvic nodes only. MATERIAL AND METHODS: Forty patients with T1-2, N0 anal carcinoma were enrolled between March 1999 and March 2003. Inguinal nodes were NOT electively irradiated. The anal canal and regional pelvic nodes received 36 Gy/20# over 4 weeks, and 2 weeks later the anal canal was boosted with 14.4 Gy/8#. Chemotherapy was 5 fluorouracil 800 mg/m(2)/day on days 1-4 and 36-39, and Mitomycin C 10mg/m(2) on day 1. RESULTS: Median follow-up was 44 months. Complete response was 95%. Four year results were; overall survival 71%, local control 82%, and colostomy-free survival (including salvage) 85%. Inguinal failure occurred in 22.5% but was isolated in only 12.5%. Treatment was well tolerated acutely with no toxic deaths. Severe late toxicity occurred in 7.5%. CONCLUSIONS: This moderate dose 'non inguinal' chemoradiation regimen resulted in modest acute toxicity, minimal long term morbidity and local control in line with other series. However staging failed to identify 12.5% of patients whose isolated inguinal failure might have been prevented by elective irradiation. Without more effective staging, all patients should receive elective inguinal irradiation.