An update, with more than a 10-year median follow-up, from Intergroup 0116 (INT-0116), a randomized phase III trial of postoperative chemotherapy in patients at moderate risk of locoregional failure following curative gastric cancer resection, “demonstrates strong persistent benefit from adjuvant radiochemotherapy.” Median overall survival was 35 months among patients receiving chemoradiotherapy vs 27 months for observation after resection, and the median relapse-free survival was 27 vs 19 months. The hazard ratio for overall survival was 1.32 (95% CI = 1.10–1.60; P = .0046), and the hazard ratio for relapse-free survival was 1.51 (95% CI =1.25–1.83; P < .001), the investigators reported in the Journal of Clinical Oncology.
Among the 559 eligible patients with primaries ≥ T3 and/or node-positive gastric cancer, 277 were randomly assigned to observation and 282 to radiochemotherapy. Fluorouracil and leucovorin were given before, during, and after radiotherapy, which was given to all locoregional failure sites to a dose of 45 Gy, the authors explained. “[Locoregional failure] reduction may account for the majority of overall relapse reduction,” they added.
Previously reported acute toxicity effects were predominantly hematologic and gastrointestinal. There were no reports of excess treatment-related toxicities during long-term follow-up. Among patients receiving radiotherapy, 21 patients had second malignancies (25 separate cancers) vs 8 patients in the observation group. “Toxicities, including second malignancies, appear acceptable, given the magnitude of [relapse-free failure] and [overall survival] improvement,” the investigators noted.
“Adjuvant radiochemotherapy remains a rational standard therapy for curatively resected gastric cancer with primaries T3 or greater and/or positive nodes,” they concluded. ■
Smalley SR, et al: J Clin Oncol 30:2327-2333, 2012.