Objective: To update our experience in treating squamous cell carcinoma of the anal margin with definitive radiotherapy (RT).
Methods: A total of 26 patients treated curatively with RT between 1979 and 2008, with or without concurrent chemotherapy, were retrospectively reviewed. American Joint Committee on Cancer stage distribution was: T1, N = 1; T2, N = 16; T3, N = 9; N0, N = 25; and N1, N = 1. Concurrent chemotherapy was administered in 12 of 26 patients (T2, 19%; T3, 100%). Median age was 48.5 years (range, 31-84 years) with a median follow-up of 8.4 years (range, 0.9-16.1 years). Median total dose was 59.4 Gy in 33 fractions. Elective inguinal lymph-node irradiation was administered to 23 of 25 N0 patients.
Results: The 10-year cause-specific survival, disease-free survival, and overall survival were 92%, 88%, and 56%, respectively. Of the 26 patients, 24 experienced complete tumor regression; their local-control rate was 96%. Four patients developed recurrences (1 local, 2 regional, and 1 local/regional/distant). The 2 patients who did not receive elective inguinal lymph-node irradiation recurred in this region. Ten patients died of intercurrent disease between 2.0 and 15.9 years after RT. Two patients died with disease at 10.7 and 18.2 months after RT, whereas 1 patient is alive with local disease at 11.2 years after RT. The remaining 13 patients are alive and disease-free between 1.0 and 16.1 years after RT. The anal-sphincter-preservation rate was 88% with no severe long-term complications after RT.
Conclusions: Patients with squamous cell carcinoma of the anal margin have a high probability of cure with sphincter preservation after RT with or without concurrent chemotherapy.