8. Patients must have adequate bone marrow function (Absolute neutrophil count (ANC)>/= 1,500/mm^3 and platelet count of >/= 100,000/mm^3), adequate liver function [aspartate aminotransferase (AST or SGOT) or alanine aminotransferase (ALT or SGPT) </= 2.5 times normal for patients without liver metastasis and ALT (SGPT) and AST (SGOT) </= 5, times normal for patients with liver metastasis], serum bilirubin </= 2 mg/dl), and adequate renal function (BUN and creatinine >/= 1.5 times institutional normal) prior to starting therapy