title: Comparison of 5-FU versus FUDR activity in human colorectal cancer using an in vitro clonogenic assay (HTCA).
abstract: Comparative in vitro drug testing was performed in 72 of 183 surgically removed human colorectal cancer specimens (34 primary lesions, 38 metastases). In 10 of these tumors, comparative dose-response curves were obtained. Given a greater than or equal to 70% ICF (inhibition of colony formation) as threshold for in vitro sensitivity, 5-FU was active in 16/62 specimens, and FUDR in 14/62. Significantly discordant sensitivity results were observed in 8/62 tests, 5-FU being the more active agent in 5 of these cases. These data are supported by the finding of 3 considerably differing dose-response curves in 10 additional comparative studies of human primary tumors.
mesh_terms: D003110:Colonic Neoplasms / Q000188:drug therapy*; D003114:Colony-Forming Units Assay; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D005467:Floxuridine / Q000008:administration & dosage / Q000627:therapeutic use*; D005472:Fluorouracil / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D012004:Rectal Neoplasms / Q000188:drug therapy*; D014410:Tumor Stem Cell Assay
chemical_list: D005467:Floxuridine; D005472:Fluorouracil