Yoshiaki Nakamura1, Takeharu Yamanaka2, Keisho Chin3, Haruhiko Cho4,5, Hitoshi Katai6, Masanori Terashima7, Kazunari Misawa8, Motohiro Hirao9, Kazuhiro Yoshida10, Eiji Oki11, Mitsuru Sasako12, Yasunori Emi13, Hideaki Bando1, Yoshiyuki Kawashima14, Tetsu Fukunaga15, Masahiro Gotoh16, Takako Ishibashi17, Kohei Shitara18. 1. Department of Gastroenterology and Gastrointestinal Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. 2. Department of Biostatistics, Yokohama City University, Yokohama, Kanagawa, Japan. 3. Department of Gastroenterology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan. 4. Department of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Kanagawa, Japan. 5. Department of Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Bunkyo-ku, Tokyo, Japan. 6. Division of Gastric Surgery, National Cancer Center Hospital, Chuo-ku, Tokyo, Japan. 7. Division of Gastric Surgery, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan. 8. Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan. 9. Department of Surgery, National Hospital Organization Osaka National Hospital, Osaka, Osaka, Japan. 10. Department of Surgical Oncology, Graduate School of Medicine, Gifu University, Gifu, Gifu, Japan. 11. Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University Hospital, Fukuoka, Fukuoka, Japan. 12. Department of Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan. 13. Department of Surgery, Saiseikai Fukuoka General Hospital, Fukuoka, Fukuoka, Japan. 14. Department of Gastroenterological Surgery, Saitama Cancer Center, Ina-machi, Saitama, Japan. 15. Department of Gastroenterological and General Surgery, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan. 16. Cancer Chemotherapy Center, Osaka Medical College, Takatsuki, Osaka, Japan. 17. Center for Novel and Exploratory Clinical Trials, Yokohama City University Hospital, Yokohama, Kanagawa, Japan. 18. Department of Gastroenterology and Gastrointestinal Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. kshitara@east.ncc.go.jp.
Abstract
BACKGROUND: Two phase 2 trials of oxaliplatin-containing adjuvant therapy for patients with gastric cancer (GC) after D2 gastrectomy were conducted in Japan. The SOXaGC trial evaluated the tolerability and safety of adjuvant therapy with S-1 plus oxaliplatin (SOX), whereas the J-CLASSIC trial evaluated the feasibility of adjuvant therapy with capecitabine plus oxaliplatin (CAPOX). Because both were studies that did not evaluate survival results as study end points, the authors evaluated the survival outcomes for the patients in the two trials. METHODS: All 62 and 100 patients in the full analysis set of the SOXaGC and J-CLASSIC trials, respectively, were included in the current study. Their information about survival outcome was collected. The primary end point was relapse-free survival (RFS), and the secondary end point was overall survival (OS). RESULTS: For the pathologic stage (pStage 2) patients treated with CAPOX, the 3-year RFS rate was 87.8% and the 3-year OS rate was 92.7%. For the pStage 3 patients treated with SOX and CAPOX, the 3-year RFS rates were respectively 70.9% and 67.8% (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.50-1.72), whereas the 3-year OS rates were respectively 75.7% and 79.3% (HR, 1.10; 95% CI, 0.54-2.26). Subgroup analysis showed significant interactions between the treatment (SOX vs. CAPOX) and both sex (male vs. female; P = 0.024) and histologic type (diffuse vs. other, P = 0.069). CONCLUSIONS: This exploratory analysis demonstrated that SOX and CAPOX are suggested to have similar efficacy for pStage 3 GC patients after D2 gastrectomy. Differences in the treatment effect according to sex and histologic type warrant further evaluation.
BACKGROUND: Two phase 2 trials of oxaliplatin-containing adjuvant therapy for patients with gastric cancer (GC) after D2 gastrectomy were conducted in Japan. The SOXaGC trial evaluated the tolerability and safety of adjuvant therapy with S-1 plus oxaliplatin (SOX), whereas the J-CLASSIC trial evaluated the feasibility of adjuvant therapy with capecitabine plus oxaliplatin (CAPOX). Because both were studies that did not evaluate survival results as study end points, the authors evaluated the survival outcomes for the patients in the two trials. METHODS: All 62 and 100 patients in the full analysis set of the SOXaGC and J-CLASSIC trials, respectively, were included in the current study. Their information about survival outcome was collected. The primary end point was relapse-free survival (RFS), and the secondary end point was overall survival (OS). RESULTS: For the pathologic stage (pStage 2) patients treated with CAPOX, the 3-year RFS rate was 87.8% and the 3-year OS rate was 92.7%. For the pStage 3 patients treated with SOX and CAPOX, the 3-year RFS rates were respectively 70.9% and 67.8% (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.50-1.72), whereas the 3-year OS rates were respectively 75.7% and 79.3% (HR, 1.10; 95% CI, 0.54-2.26). Subgroup analysis showed significant interactions between the treatment (SOX vs. CAPOX) and both sex (male vs. female; P = 0.024) and histologic type (diffuse vs. other, P = 0.069). CONCLUSIONS: This exploratory analysis demonstrated that SOX and CAPOX are suggested to have similar efficacy for pStage 3 GC patients after D2 gastrectomy. Differences in the treatment effect according to sex and histologic type warrant further evaluation.