RESUMEN
BACKGROUND AND PURPOSE: To evaluate the effect of adjuvant chemotherapy (ACT) in locally advanced rectal cancer (LARC) after neoadjuvant chemoradiation (NACT-RT). The study was funded by the Italian National Research Council (CNR). METHODS: From September 1992 to January 2001, 655 patients with LARC (clinically T3-4, any N) treated with NACT-RT and surgery, were randomized in two arms: follow-up (Arm A) or 6 cycles of ACT with 5 fluorouracil (5FU)-Folinic Acid (Arm B). NACT-RT consisted of 45Gy/28/ff concurrent with 5FU (350mg/sqm) and Folinic Acid (20mg/sqm) on days 1-5 and 29-33; surgery was performed after 4-6weeks. Median follow up was 63·7months. Primary end point was overall survival (OS). RESULTS: 634/655 patients were evaluable (Arm A 310, Arm B 324); 92·5% of Arm A and 91% of Arm B patients received the preoperative treatment as in the protocol; 294 patients of Arm A (94·8%) and 296 of Arm B (91·3%) underwent a radical resection; complete pathologic response and overall downstaging rates did not show any significant difference in the two arms. 83/297 (28%) patients in Arm B, never started ACT. Five year OS and DFS did not show any significant difference in the two treatment arms. Distant metastases occurred in 62 patients (21%) in Arm A and in 58 (19·6%) in Arm B. CONCLUSIONS: In patients with LARC treated with NACT-RT, the addition of ACT did not improve 5year OS and DFS and had no impact on the distant metastasis rate.