Published in:
21-11-2023 | Gastric Cancer | Original Article
5-year follow-up results of a JCOG1104 (OPAS-1) phase III non-inferiority trial to compare 4 courses and 8 courses of S-1 adjuvant chemotherapy for pathological stage II gastric cancer
Authors:
Takaki Yoshikawa, Masanori Terashima, Junki Mizusawa, Souya Nunobe, Yasunori Nishida, Takanobu Yamada, Masahide Kaji, Takashi Nomura, Shinji Hato, Yasuhiro Choda, Hiroshi Yabusaki, Kazuhiro Yoshida, Kazunari Misawa, Toru Masuzawa, Masahiro Tsuda, Yasuyuki Kawachi, Hiroshi Katayama, Haruhiko Fukuda, Yukinori Kurokawa, Narikazu Boku, Takeshi Sano, Mitsuru Sasako
Published in:
Gastric Cancer
|
Issue 1/2024
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Abstract
Background
Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is the standard treatment for pathological stage II gastric cancer. The phase III trial (JCOG1104) investigating the non-inferiority of four courses of S-1 to eight courses was terminated due to futility at the first interim analysis. To confirm the primary results, we reported the results after a 5-years follow-up in JCOG1104.
Methods
Patients histologically diagnosed with stage II gastric cancer after radical gastrectomy were randomly assigned to receive S-1 for eight or four courses. In detail, 80 mg/m2/day S-1 was administered for 4 weeks followed by a 2-week rest as a single course.
Results
Between February 16, 2012, and March 19, 2017, 590 patients were enrolled and randomly assigned to 8-course (295 patients) and 4-course (295 patients) regimens. After a 5-years follow-up, the relapse-free survival at 3 years was 92.2% for the 8-course arm and 90.1% for the 4-course arm, and that at 5 years was 87.7% for the 8-course arm and 85.6% for the 4-course arm (hazard ratio 1.265, 95% CI 0.846–1.892). The overall survival at 3 years was 94.9% for the 8-course arm, 93.2% for the 4-course arm, and that at 5 years was 89.7% for the 8-course arm, and 88.6% for the 4-course arm (HR 1.121, 95% CI 0.719–1.749).
Conclusions
The survival of the four-course arm was slightly but consistently inferior to that of the eight-course arm. Eight-course S-1 should thus remain the standard adjuvant chemotherapy for pathological stage II gastric cancer.