Adjuvant Chemoradiation for Gastric Cancer with Infusional 5-Fluorouracil and Cisplatin: A Phase I Study

Objective: This phase I study aimed to determine the maximal tolerated dose of cisplatin administered every 2 weeks with infusional 5-fluorouracil (5FU) and concurrent radiation therapy (RT) in patients after complete resection of gastric adenocarcinoma. Methods: Patients with resected stage IB to IV (M0) gastric adenocarcinoma were treated with 12 weeks of infusional 5FU (200 mg/m² daily) and with RT (45 Gy in 25 fractions starting on day 16). Cisplatin was administered in escalating doses (0, 20, 30, and 40 mg/m²) in weeks 1, 3, 5, and 7. In the final cohort, patients received an additional dose of cisplatin (40 mg/m²) in week 9. Results: Among the 34 patients [median age: 56 years (range: 31–77 years)] who were assessable for toxicity, 5 experienced dose-limiting toxicities: 1 sepsis (cohort 1), 1 fatigue (cohort 2), 3 upper gastrointestinal toxicity (1 in cohort 2, 2 in cohort 5). Cohort 5 exceeded the maximal tolerated dose. Median follow-up was 2.5 years (range: 0.3–5 years). The 3-year overall and relapse-free survival rates were 86% and 71% respectively; median survival was not reached. Conclusions: Cisplatin was well tolerated in combination with infusional 5FU and RT, showing promising activity in the adjuvant treatment of gastric cancer. Infusional 5FU 200 mg/m² daily for 12 weeks with cisplatin 40 mg/m² in weeks 1, 3, 5, and 7 and with concurrent RT 45 Gy in 25 fractions, starting at day 16, is being explored in a phase II study at our institution.