Weekly regimen of 5-FU vs 5-FU + intermediate dose folinic acid in the treatment of advanced colorectal cancer.

Sixty-four patients with advanced colorectal cancer were randomized to receive 5-fluorouracil (5-FU) at the dose of 600 mg/sm weekly or the same regimen of 5-FU administered halfway through a 1 hour i.v. infusion of folinic acid (FA) at the dose of 200 mg/sm. A partial remission (PR) was obtained in 1/30 patients (3%) treated with 5-FU and in 9/34 patients (26%) treated with 5-FU + FA (P = 0.028). The objective response was accompanied by an improvement in subjective status and general conditions. The median duration of PR in 5-FU + FA arm was 10 months (range: 6-17). The median time to progression was 5 and 6 months in patients treated with 5FU and 5FU + FA, respectively (not a statistically significant difference). There were no cases of grade 4 toxicity. A higher, but not statistically significant, incidence and intensity of diarrhoea was observed in the 5-FU + FA arm. However, 14 patients on 5-FU + FA as opposed to 3 on 5-FU had to stop the treatment temporarily because of side-effects (P = 0.011). Median survival was higher with 5-FU + FA treatment (10 vs 7 months), but the difference is not statistically significant. This study confirms that the addition of an intermediate dose of FA enhances the cytotoxicity of 5-FU. Although its clinical advantage was limited, this weekly 5-FU + FA regimen appears useful in the treatment of advanced colo-rectal cancer on a outpatient basis.