Comparison of Combination Chemotherapy Regimens With or Without Cetuximab in Treating Patients Who Have Undergone Surgery For Stage III Colon Cancer

This randomized phase III trial was originally designed to compare three different combination chemotherapy regimens to see how well they work. As of September 1, 2004, the study was expanded to a total of 6 arms (the original 3 arms (A, B, C) and 3 additional arms which were the same as the first 3 but with cetuximab) in treating patients who have undergone surgery for stage III colon cancer. Drugs used in chemotherapy, such as irinotecan hydrochloride, fluorouracil, leucovorin calcium, and oxaliplatin, work in different ways to stop tumor cells from dividing so they stop growing or die. Monoclonal antibodies such as cetuximab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. Combining more than one chemotherapy drug with monoclonal antibody therapy and giving them after surgery may kill any remaining tumor cells. It was not known at the time this study was developed which combination chemotherapy regimen is more effective after surgery in treating colon cancer. This study had several key changes, based on the results of other phase III trials. As of 6/1/2005, patients no longer received irinotecan on this study and treatment arms B, C, E, and F were discontinued. Patients on arms B and C crossed to arm A. Patients on arms E and F crossed to arm D. Patients on arms C and F who had not gotten to irinotecan continued on arms A and D, respectively. As of 8/18/2008, pre-screening for Kirsten rat sarcoma (KRAS) status was added with mutant KRAS (or KRAS not evaluable) patients put on arm G and wild-type KRAS patients randomized between arm A and arm D. Patients on arm G were treated per physician discretion and followed for disease and survival status. KRAS was determined in a central laboratory and was process for all patients on this study. The primary endpoint of this study was modified on 8/18/2008 to focus on patients having wild-type KRAS tumors. All modifications were approved by the Central Inst