OUTLINE: This is a multicenter study. Patients are stratified according to participating center, ECOG performance status (0 vs 1-2), disease-free interval from the last administration of first-line chemotherapy for metastatic disease (≤ 3 months vs > 3 months), and type of second-line chemotherapy (irinotecan hydrochloride, leucovorin calcium, and fluorouracil [FOLFIRI] vs oxaliplatin, leucovorin calcium, and fluorouracil [mFOLFOX-6]). Patients are randomized to 1 of 2 treatment arms.