Gefitinib and Combination Chemotherapy in Treating Patients With Advanced Solid Tumors or Colorectal Cancer

RATIONALE: Biological therapies such as gefitinib may interfere with the growth of tumor cells and slow the growth of the tumor. Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug with gefitinib may kill more tumor cells.
PURPOSE: Phase II trial to study the effectiveness of gefitinib and oxaliplatin combined with leucovorin and fluorouracil in treating patients who have advanced solid tumors or colorectal cancer.