Ichikura T, Tomimatsu S, Okusa Y, Yahara T, Uefuji K, Tamakuma S
First Department of Surgery, National Defense Medical College, Tokorozawa, Japan.
Cancer Chemother Pharmacol. 1996;38(5):401-5. doi: 10.1007/s002800050503.
5-Fluorouracil (5-FU) remains a standard therapy for patients with advanced gastric cancer. There has been no study using an oral regimen with a combination of tegafur, a masked compound of 5-FU, and leucovorin in gastric cancer. The purpose of this study was to determine whether orally administered low-dose leucovorin enhances thymidylate synthase (TS) inhibition when added to tegafur-uracil (UFT) in patients with gastric cancer.
A group of 26 patients with resectable gastric cancer were assigned to one of two regimens: UFT alone or UFT plus leucovorin. UFT, equivalent to 400 mg/day tegafur, with or without 30 mg/day leucovorin, was administered orally in divided daily doses every 12 h for 3 consecutive days prior to surgery. Tumor specimens were taken immediately following gastrectomy, and the TS inhibition rate (TSIR) was determined using a ligand-binding assay.
The TSIR was significantly higher in the UFT plus leucovorin group than in the UFT alone group (P < 0.01). The TSIR in the patients treated with UFT alone ranged between 14% and 50%, while six of the eight patients treated with UFT plus leucovorin had a TSIR of 55% or higher. The remaining two patients in the group treated with UFT plus leucovorin, with a TSIR of 31% and 44%, had undifferentiated tumors.
Our results suggest that orally administered low-dose leucovorin can add to the efficacy of UFT in patients with gastric cancer, and provide preliminary data for a randomized clinical trial.
