A double-blind comparison of intensive course 5-flourouracil by oral vs. intravenous route in the treatment of colorectal carcinoma.

This radomized double-blind study was designed to compare the therapeutic effectiveness of the oral and i.v. routes for 5-FU administered in intensive courses to 100 patients with metastatic adenocarcinoma of the large bowel, treated to equivalent levels of toxicity. An oral dose of 20 mg/kg day times 5 was found to produce comparable G.I., mucocutaneous, and hematologic side effects to a dose of 13.5 mg/kg day times 5 by rapid i.v. injection. Courses were repeated at 5 weeks. Nine of 47, or 19.1%, treated by the oral route have shown objective response, compared to 14 of 53, or 26%, treated by the i.v. route. If malignant hepatomegaly is considered alone, the response rates are 8 of 23, or 34.8%, by the oral route, and 7 of 22, or 31.8%, by the i.v. route. The mean duration of response for the oral group, 11.1 weeks, was shorter than for the i.v. route, 20 weeks, a statistically significant (p less than 0.02) difference. Serial serum 5-FU levels after two doses of 5-FU were determined by microbiological assay in 19 patients. For i.v. administration the curves were comparable among different patients as well as in the same patient. There was striking variability, however, for oral administration.