Phase III trial of adjuvant 5-fluorouracil and adriamycin versus 5-fluorouracil, adriamycin, and polyadenylic-polyuridylic acid (poly A:U) for locally advanced gastric cancer after curative surgery: Final results of 15-year follow-up

Background: This phase III trial was to compare 5-fluorouracil (5-FU), adriamycin, and polyadenylic-polyuridylic acid (poly A:U) against 5-fluorouracil plus adriamycin (FA) for operable gastric cancer. Patients and methods: From 1984 to 1989, patients who had D_2-3 curative resection were randomly assigned to receive chemotherapy or chemoimmunotherapy. Chemotherapy consisted of 12 mg/kg 5-FU every week for 18 months and 40 mg/m² adriamycin every 3 weeks for 12 cycles. Chemoimmunotherapy consisted of FA plus 100 mg of poly A:U weekly for six cycles and was followed 6 months later by six weekly 50-mg booster injections. Results: A total of 292 patients were enrolled. After excluding 12 ineligible patients, 142 and 138 patients were allocated to each treatment. Patients were balanced with prognostic variables: age, sex, tumor location, differentiation, degree of tumor invasion (T₂ -T_4a), and lymph node status (N₀-N₂). During the 15-year follow-up, chemoimmunotherapy significantly prolonged overall (P = 0.013) and recurrence-free (P = 0.005) survivals compared with chemotherapy alone. The survival benefits were prominent in the subset of patients with T₃/T_4a, N₂, or stage III. Treatments were generally well tolerated in both arms. Conclusions: These results indicate a survival advantage of chemoimmunotherapy with a regimen of FA and poly A:U in curatively resected gastric adenocarcinoma.