A randomized trial of chemoradiation using mitomycin or cisplatin, with or without maintenance cisplatin/5FU in squamous cell carcinoma of the anus (ACT II)

LBA4009 Background: Chemoradiotherapy (CRT) with 5-fluorouracil (5-FU) and mitomycin-C (MMC) is standard treatment for anal cancer. This trial addresses two questions: whether (i) replacing MMC with cisplatin (CDDP) improves the complete response (CR) rate, and (ii) two cycles of maintenance chemotherapy after CRT reduces recurrence. Methods: Between 2001 and 2008, 940 patients (pts) were recruited to a multicenter, randomized factorial trial. Pts received 5-FU (1,000mg/m2/day on d1–4 and 29–32), radiotherapy (RT) (50.4Gy in 28 fractions), and either MMC (12mg/m2, d1; n=471) or CDDP (60mg/m2 on d1 and 29; n=469). Pts were also randomized to receive maintenance therapy (n=448) 4 weeks after CRT (two cycles of CDDP and 5-FU weeks 11 and 14) or no maintenance (n=446). Maintenance randomization was not considered appropriate in 46 pts. Statistical power was ≥80% to detect a difference in the CR rate of 5% (CDDP vs MMC), and 30% reduction in recurrence (maintenance vs no maintenance). Results: Median age 58 yr...