A comparative study with two administration schedules of leucovorin and 5-fluorouracil in advanced colorectal cancer.

One hundred and seven previously untreated patients with measurable metastatic colorectal cancer who were treated with 5-fluorouracil (5FU) and leucovorin (LV) in two different maximum doses and schedules were retrospectively analyzed. Group A, 52 pts, was treated with LV 200 mg/m2/D i.v. push, followed by 5FU 700 mg/m2/D i.v. 1 h infusion for 5 D. Cycle was repeated every 21 D. Group B, 55 pts, was treated with LV 500 mg/m2/D in a 2 h infusion and 5FU 600 mg/m2/D i.v. bolus at mid-time of LV infusion, repeated every week for 6 wk followed by 2-wk rest period. There was no difference in response (A 8%, B 11%). Median survival for A was 37 (2-131) wk, B was 59 (1-112) wk (P = 0.021), time to progression for A was 20 (0-131) wk, B 30 (0-102) wk (P = 0.021). Administered mean dose intensity of LV was 350.8 mg/m2/wk in group A and 405.0 mg/m2/wk in group B without any significant difference; that of 5FU was significantly higher in group A as compared to group B (1205.3 vs 468.9 mg/m2/wk, respectively) (p < 0.0001). This difference was a consequence of the planned dose intensity for this drug in the two treatment regimens. Toxicity was more frequent and intense in group A for mucositis (P < 0.001), fatigue (P < 0.01), and neurotoxicity (P < 0.05), and in group B for neutropenia (P < 0.001) and nausea-vomiting (P < 0.001). There were one and four iatrogenic deaths in group A and B patients, respectively (NS).(ABSTRACT TRUNCATED AT 250 WORDS)