Five-year overall survival with S-1 plus docetaxel as adjuvant treatment in curatively resected pStage III gastric cancer in JACCRO GC-07.

person Wataru Ichikawa Division of Medical Oncology, Showa University Fujigaoka Hospital, Yokohama, Japan info_outline Wataru Ichikawa, Kazuhiro Yoshida, Yasuhiro Kodera, Masato Kitazawa, Motohiro Hirao, Yasuyuki Seto, Kenji Hibi, Shinichi Kinami, Masaya Watanabe, Shigeto Makino, Mitsugu Kochi, Takeshi Sano, Yoshihiro Kakeji, Masahiro Takeuchi, Masashi Fujii

Authors person Wataru Ichikawa Division of Medical Oncology, Showa University Fujigaoka Hospital, Yokohama, Japan info_outline Wataru Ichikawa, Kazuhiro Yoshida, Yasuhiro Kodera, Masato Kitazawa, Motohiro Hirao, Yasuyuki Seto, Kenji Hibi, Shinichi Kinami, Masaya Watanabe, Shigeto Makino, Mitsugu Kochi, Takeshi Sano, Yoshihiro Kakeji, Masahiro Takeuchi, Masashi Fujii Organizations Division of Medical Oncology, Showa University Fujigaoka Hospital, Yokohama, Japan, Gifu University, Gifu, Japan, Department of Gastroenterological Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan, Department of Surgery, Shinshu University, Matsumoto, Japan, Department of Surgery, National Hospital Organization Osaka National Hospital, Osaka, Japan, Department of Gastrointestinal Surgery, The University of Tokyo, Tokyo, Japan, Department of Surgery, Tokai Central Hospital, Kakamigahara, Japan, Department of Gastroenterologic Surgery, Kanazawa Medical University, Kahoku-Gun, Japan, Division of Gastroenterological Surgery, Shizuoka General Hospital, Shizuoka-Shi, Japan, Department of Surgery, Nagaoka Chuo General Hospital, Nagaoka, Japan, Department of Gastroenterological Surgery, International University of Health and Welfare Ichikawa Hospital, Ichikawa, Japan, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan, Division of Gastrointestinal Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan, Graduate School of Mathematical Sciences, The University of Tokyo, Tokyo, Japan, Department of Digestive Surgery, Nihon University School of Medicine, Tokyo, Japan Abstract Disclosures Research Funding Other Foundation Japan Clinical Cancer Research Organization Background: JACCRO GC-07 is a randomized controlled trial to explore postoperative S-1/docetaxel compared to S-1 alone after D2 gastrectomy for pStage III gastric cancer (GC) patients. The second interim analysis demonstrated that the significant improvement of RFS was obtained by S-1/docetaxel compared to S-1 alone. The study was terminated by the recommendation of independent data and safety monitoring committee (Yoshida K et al. J Clin Oncol 2019; 37:1296-1304). Preplanned analysis to evaluate RFS at 3 years, the primary endpoint, was also published (Kakeji Y et al. Gastric Cancer 2022; 25:186-196). We report the 5-years follow-up data from the trial. Methods: Patients with pStage III GC were randomly assigned to receive either S-1/docetaxel (S-1 80-120mg/body on days 1-14 with a 7-day rest followed by docetaxel 40mg/m 2 on day 1 and S-1 80-120mg/body on days 1-14 every 21 days for 6 cycles followed by S-1 80-120mg/body on days 1-28 every 42 days for 4 cycles) or S-1 (80-120mg/body on days 1-28 every 42 days for 8 cycles) after D2 gastrectomy. Blocked randomisation was performed and stratified by the stage (IIIA, IIIB, IIIC) and histological type (differentiated or undifferentiated). The primary endpoint was 3y RFS and the secondary endpoints were OS, TTF and safety. This analysis presents the final preplanned assessment of outcomes after 5 years. Results: Of 915 randomly assigned patients, 912 patients were included in the intention-to-treat (ITT) analysis. In the final analysis, 426 recurrences and 373 deaths were confirmed among the ITT population during the median follow-up period of 63.72 months (3.52-111.87). The 5y RFS of 59.8% in the S-1/docetaxel group was significantly superior to 50.6% in the S-1 group (HR 0.726, 95% CI: 0.599-0.879, p = 0.0010) and the 5y OS was 67.9% in the S-1/docetaxel group and that of S-1 group was 60.3%, respectively (HR 0.752, 95% CI: 0.613-0.922, p = 0.0059), confirming the significant improving effect on the survival of the patient. Conclusions: Adjuvant treatment with S-1 plus docetaxel should be considered for patients with pStage III gastric cancer who underwent D2 gastrectomy without neoadjuvant chemotherapy. Clinical trial information: UMIN000010337.

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