Yosuke Kano1, Manabu Ohashi2, Naoki Hiki1, Daisuke Takahari3, Keisho Chin3, Kensei Yamaguchi3, Yasuo Tsuda1, Yoshiaki Shoji1, Itaru Yasufuku1, Kojiro Eto1, Satoshi Ida1, Koshi Kumagai1, Souya Nunobe1, Takeshi Sano1. 1. Department of Gastroenterological Surgery, Gastroenterological Center, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. 2. Department of Gastroenterological Surgery, Gastroenterological Center, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. manabu.ohashi@jfcr.or.jp. 3. Department of Gastroenterological Medicine, Gastroenterological Center, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan.
Abstract
BACKGROUND: One-year adjuvant S-1 monotherapy following D2 gastrectomy has been the Japanese treatment standard for pathological stage II or III gastric cancer since the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) was concluded in 2007. Trial patients were selected according to the 13th edition of the Japanese classification (JC-13). The JC-13 and the TNM classification underwent major revisions in 2010 (JC-14/TNM-7). However, neither the recent therapeutic results for patients with stage II/III disease defined by the current system nor comparisons with the ACTS-GC-results have been reported. METHODS: The 390 study patients had pathological stage II/III gastric cancer defined by the JC-14/TNM-7 and treated with S-1 following D2 gastrectomy between 2008 and 2012. The completion rate of 1-year S-1, first relapse site, and stage-specific survival according to the JC-14/TNM-7, JC-13, and TNM-6 were examined and the results compared with those of the ACTS-GC. RESULTS: The completion rate for 1-year S-1 (69.5%) was slightly higher than in the ACTS-GC. The recurrence pattern was almost identical. The 5-year overall survival rates of pathological IIA, IIB, IIIA, IIIB, and IIIC in the JC-14/TNM-7 were 96.0, 85.5, 81.8, 72.0, and 51.1%, respectively. Their 5-year overall and relapse-free survival rates by the JC-13 and TNM-6 systems were favorable as compared to those of ACTS-GC patients for all substages. CONCLUSIONS: Survival outcome shown in this study of patients treated with 1-year adjuvant S-1 after D2 gastrectomy at a high-volume cancer hospital will provide a reference for future adjuvant trials targeting JC-14/TNM-7 stage II/III disease.
BACKGROUND: One-year adjuvant S-1 monotherapy following D2 gastrectomy has been the Japanese treatment standard for pathological stage II or III gastric cancer since the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer (ACTS-GC) was concluded in 2007. Trial patients were selected according to the 13th edition of the Japanese classification (JC-13). The JC-13 and the TNM classification underwent major revisions in 2010 (JC-14/TNM-7). However, neither the recent therapeutic results for patients with stage II/III disease defined by the current system nor comparisons with the ACTS-GC-results have been reported. METHODS: The 390 study patients had pathological stage II/III gastric cancer defined by the JC-14/TNM-7 and treated with S-1 following D2 gastrectomy between 2008 and 2012. The completion rate of 1-year S-1, first relapse site, and stage-specific survival according to the JC-14/TNM-7, JC-13, and TNM-6 were examined and the results compared with those of the ACTS-GC. RESULTS: The completion rate for 1-year S-1 (69.5%) was slightly higher than in the ACTS-GC. The recurrence pattern was almost identical. The 5-year overall survival rates of pathological IIA, IIB, IIIA, IIIB, and IIIC in the JC-14/TNM-7 were 96.0, 85.5, 81.8, 72.0, and 51.1%, respectively. Their 5-year overall and relapse-free survival rates by the JC-13 and TNM-6 systems were favorable as compared to those of ACTS-GC patients for all substages. CONCLUSIONS: Survival outcome shown in this study of patients treated with 1-year adjuvant S-1 after D2 gastrectomy at a high-volume cancer hospital will provide a reference for future adjuvant trials targeting JC-14/TNM-7 stage II/III disease.