Hyperfractionated accelerated reirradiation for patients with recurrent anal cancer previously treated with definitive chemoradiation

Objectives: Although chemoradiation is the standard of care for anal cancer, limited data exist regarding pelvic reirradiation (re-RT) for recurrent disease. We investigated toxicity and outcomes in patients who received prior pelvic radiation therapy (RT), and subsequently underwent hyperfractionated accelerated re-RT to the pelvis for recurrent anal cancer. Materials and Methods: We reviewed records of 10 patients with recurrent anal squamous cell carcinoma who previously received pelvic RT to at least 30 Gy as a component of their chemoradiation and underwent re-RT in 1.5 Gy twice daily fractions to the pelvis, with either preoperative (N=7) or definitive (N=3) intent. Results: The 3-year disease-free survival and 3-year overall survival rates were 40% and 60%. Four patients recurred within the reirradiated field, with a 3-year freedom from local progression rate of 56%. Of the 7 patients treated with preoperative intent, 5 proceeded to surgery, of whom 3 are alive and disease-free at a median duration of 43 months. Of the 3 patients treated definitively with no surgery, all are alive and disease-free at a median duration of 84 months. Re-RT resulted in one grade 3 acute toxicity and no grade 3 or higher late complications. Conclusions: Hyperfractionated accelerated re-RT was well-tolerated in patients with previously irradiated anal cancer. Patients treated with either definitive re-RT or re-RT followed by surgical resection had excellent rates of overall survival and freedom from local progression.