[Mechanism of synergism and clinical results of sequential methotrexate and 5-fluorouracil in the treatment of gastric cancer].

Mechanism of synergism and clinical results of methotrexate and 5-fluorouracil (MTX/5-FU) combination therapy for gastric cancer were studied. The response rate against poorly differentiated gastric cancers was 35% in this treatment. This treatment also showed a remarkable effect against cases with pleural and abdominal effusion caused by cancerous disseminations. A promising result was obtained by this treatment as neoadjuvant and postoperative chemotherapy against Borrmann type 4 gastric cancer. A greater dependence on the de novo pathway of pyrimidine synthesis against poorly differentiated gastric carcinoma, which was estimated by the fact that the thymidylate synthetase/thymidine kinase ratio was significantly higher in poorly differentiated gastric cancer than in well differentiated cancer, may potentiate therapeutic results of this treatment.