5-Fluorouracil, mitomycin-c, and polysaccharide-k versus uracil-ftorafur and polysaccharide-K as adjuvant chemoimmunotherapy for patients with locally advanced gastric cancer with curative resection.

Background: Despite the small but significant survival benefit of adjuvant chemotherapy in locally advanced gastric cancer (LAGC), the optimal regimen remains to be determined. We conducted a randomized trial comparing oral (PO) chemoimmunotherapy (CITX) with intravenous (IV) CITX in LAGC patients (stages IB-IIIB) with curative resection (≥ D2 dissection). Methods: The patients were randomized to the IV (5-fluorouracil 500 mg/m2 weekly for 24 weeks, mitomycin-C 8 mg/m2 every 6 weeks × 4) or the PO (uracil-ftorafur (UFT) 400-600 mg/day for 12 months) group. Patients in both groups received PO polysaccharide-K (3 g/day for 4 months). The planned number of patients was 368 for proving the non-inferiority of PO CITX compared to IV CITX for overall survival. Results: The trial was closed prematurely after enrolling 82 patients (44 in the IV group, 38 in the PO group). With a median follow-up of 82 months, there were no significant differences in the 5-year disease-free survival (73% vs. 55%, p = 0.358) and overall survival (77% vs. 66%, p = 0.159) between the 2 groups. The IV group demonstrated a higher incidence of grade 2 or 3 neutropenia, thrombocytopenia, and vomiting. Conclusions: PO CITX with UFT appeared to be at least non-inferior to 5-fluorouracil and mitomycin-C CITX, with lower toxicity in the adjuvant treatment for LAGC.