A randomized trial comparing local recurrence (LR) rates between short-course (SC) and long-course (LC) preoperative radiotherapy (RT) for clinical T3 rectal cancer: An intergroup trial (TROG, AGITG, CSSANZ, RACS).

Abstract

3509 Background: Both SC and LC preoperative radiotherapy have been accepted as standard of care for locally advanced rectal cancer. The primary aim of the trial was to compare LR rates (cumulative incidences) at 3 years between SC and LC. Methods: Main eligibility criteria were clinical T3NxM0 rectal adenocarcinoma, with the lower border within 12 cm of the anal verge, and ECOG performance status 0-2. SC consisted of pelvic RT 25 Gy in 5 fractions in 1 week, followed by surgery the following week, and 6 (monthly) courses of postoperative chemotherapy. LC consisted of pelvic RT 50.4 Gy, 1.8 Gy/fraction, in 5.5 weeks, continuous infusion 5-FU 225 mg/m2/day during RT, followed by surgery in 4 to 6 weeks, and 4 (monthly) courses of postoperative chemotherapy. Each course of postoperative chemotherapy was to be 5-FU 425 mg/m2 and folinic acid 20 mg/m2 for 5 days. The trial was powered (80%; 310 patients) to detect a difference of 15% versus 5% in LR rates at 3 years. Results: 326 patients, accrued from 2001-0...