Enhanced tumorocidal effect of chemotherapy with preoperative radiotherapy for rectal cancer: preliminary results--EORTC 22921.

Purpose: The European Organisation for Research and Treatment of Cancer (EORTC) trial evaluated the addition of chemotherapy (CT) to preoperative radiation (preop RT) and the value of postoperative CT for improving the survival in patients with T3-4 resectable rectal cancer. Patients were allocated to the following four arms: arm 1, preop RT 45 Gy in 5 weeks; arm 2, preop RT plus two 5-day CT courses (fluorouracil 350 mg/m2/d and leucovorin 20 mg/m2/d) in the first and fifth week of RT; arm 3, preop RT plus four postoperative CT courses; and arm 4, preop RT and CT plus postoperative CT. We investigated the effect of adding CT on the pathologic parameters.