Double Modulation of 5-Fluorouracil in the Treatment of Advanced Colorectal Carcinoma: Report of a Trial with Sequential Methotrexate, Intravenous (Loading Dose) Folinic Acid, 5-Fluorouracil, and a Literature Review

Abstract

5-Fluorouracil (5-FU) modulation with either folinic acid (FA) or methotrexate (MTX) has improved 5-FU's potential cytoreductivity. We combined MTX and FA with 5-FU to further augment 5-FU's cytoreductivity. Patients (n = 34) with advanced colorectal carcinoma were first given intravenous MTX (escalated from 30 mg/m2 to 70 mg/m²). FA (100 mg/m²) was infused 17–24 hr later, followed by 5-FU (600 mg/m²). Oral rescue doses of FA were begun 24 hr after MTX. Patients were treated every 2 weeks. No previously treated patient (n = 6) responded. Eight of the remaining 28 (29%) (95% confidence interval, 15–47%) patients achieved a PR. Median survival was 9.3 months. Toxicity (primarily gastrointestinal) necessitated dosage modification in 10 patients (29%). These results, in addition to a literature review, reveal that the manipulation of 5-FU by two modulating agents does not improve the response rate seen with single-agent modulation.