Monthly 5-days 5-fluorouracil and low-dose leucovorin for adjuvant chemotherapy in colon cancer.

We investigated the dose-related effect of the 5-fluorouracil (5-FU)/leucovorin regimen on survival in 139 colon cancer patients with Dukes' B2 and C2 stage disease. Chemotherapy consisted of 400 mg/m(2) of 5-FU and 20 mg/m(2) of leucovorin injected daily for 5 days in every 4 weeks for a maximum of 12 cycles. The total dose of 5-FU administered per body surface area had a significant effect on the 5-year disease-free survival and 5-year overall survival in stage B2 and C2 colon cancer patients (P=0.0018, P=0.0011). Analysis with reference to the median DSDI demonstrated that there was a significant difference in 5-year survival in Dukes' C2 (P=0.0016), but survival was not affected by the dose intensity. Multivariate analysis demonstrated that only the total dose of 5-FU administered per surface area affected the 5-year disease-free survival and 5-year overall survival (P=0.0016, P=0.0007, respectively). It can be concluded that the total dose of 5-FU administered is important in planned dosage schedule of adjuvant chemotherapy in colon cancer.