Ethics approval and consent to participate
This study is being conducted according to the principles expressed in the Declaration of Helsinki, the Japanese Ethical Guidelines for Medical and Health Research Involving Human Subjects, and the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines. The JCOG Protocol Review Committee approved this protocol in January 2020. Approval from the institutional review board was obtained before starting patient enrollment in each institution. Written informed consent has been obtained from all enrolled patients. At the time of submission (July 2022), 46 institutions were participating in this study. The participating institutions were as follows: Hakodate Goryoukaku Hospital, Keiyukai Sapporo Hospital, Miyagi Cancer Center, Fukushima Medical University Hospital, Southern Tohoku General Hospital, Saitama Prefectural Cancer Center, National Cancer Center Hospital East, Chiba Cancer Center, National Cancer Center Hospital, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo Medical and Dental University Hospital, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Toranomon Hospital, Juntendo University School of Medicine Juntendo Clinic, Kanagawa Cancer Center, Kitasato University School of Medicine, Toyama Prefectural Central Hospital, Ishikawa Prefectural Central Hospital, Yamanashi Prefectural Central Hospital, Gifu University School of Medicine, Shizuoka General Hospital, Shizuoka Cancer Center, Aichi Cancer Center, Nagoya University School of Medicine, National Hospital Organization Kyoto Medical Center, Osaka University Graduate School of Medicine, Osaka Metropolitan University Hospital, Osaka International Cancer Institute, National Hospital Organization Osaka National Hospital, Osaka Medical and Pharmaceutical University, Toyonaka Municipal Hospital, Kobe University Graduate School of Medicine, Kansai Rosai Hospital, Hyogo Cancer Center, Wakayama Medical University School of Medicine, Shimane University Faculty of Medicine, Okayama University Hospital, Hiroshima University Hospital, Hiroshima City Hiroshima Citizens Hospital, Hiroshima City North Medical Center Asa Citizens Hospital, Kagawa Prefectural Central Hospital, National Hospital Organization Shikoku Cancer Center, and Kurume University Graduate School of Medicine.
Consent for publication
Not applicable.
Availability of data and materials
Data sharing is not applicable to this article because no datasets had been generated or analyzed at the time of submission.
Competing interests
The authors declare that they have no competing interests.
Funding
This study is partly supported by the National Cancer Center Research and Development Fund (29-A-3, 2020-J-3, 2023-J-03) and by the Japan Agency for Medical Research and Development (AMED) under grant number JP23ck0106844. This study is also funded by Intuitive Surgical Sàrl, which will not be involved in the research itself (including planning, management, and data analysis).
Authors’ contributions
RM and M. Terashima wrote the manuscript. RM, M. Terashima, and M. Tokunaga proposed the concept of the JCOG1907 study and drafted the protocol design for the study. M. Terada, JM, and RK contributed to the design and logistics of the protocol, proofread the manuscript, and will undertake the statistical analysis. T. Omori, T. Ojima, KE, and TK contributed to the quality control of the surgery by establishing a study-specific surgical QA committee. All authors contributed to revisions of this manuscript and approved the final manuscript.
Acknowledgments
The authors thank all JCOG Data Center/Operation office members and the SCSG of the JCOG. The authors also thank Angela Morben, DVM, ELS, from Edanz (https://jp.edanz.com/ac), for editing a draft of this manuscript.
Authors’ information
18. Department of Gastroenterological Surgery, Cancer Institute Hospital of Japanese Foundation for Cancer Research, 3-8-31, Ariake, Koto-ku, Tokyo, 135-8550, Japan.
19. Division of Gastric Surgery, Shizuoka Cancer Center, Nagaizumi, Japan.
20. Department of International Clinical Development, National Cancer Center Hospital, Tokyo, Japan.
21. Japan Clinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
22. Department of Gastrointestinal Surgery, Tokyo Medical and Dental University, Tokyo, Japan.
23. Department of Gastroenterological Surgery, Osaka International Cancer Institute, Osaka Japan.
24. Second Department of Surgery, Wakayama Medical University Scholl of Medicine, Wakayama, Japan.
25. Department of Gastroenterological Surgery, Saitama Cancer Center, Saitama, Japan.
26. Department of Gastroenterological Surgery, Shizuoka General Hospital, Shizuoka, Japan.
27. Department of Surgery, Toyonaka Municipal Hospital, Osaka, Japan.
28. Department of Gastric Surgery, National Cancer Center Hospital East, Kashiwa, Japan.
29. Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
30. Department of Surgery, Keiyukai Sapporo Hospital, Hokkaido, Japan
31. Department of Surgery, Hiroshima City North Medical Center Asa Citizens Hospital, Hiroshima, Japan
32. Department of Oncology and General Medicine, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
33. Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
34. Gastric Surgery Division, National Cancer Center Hospital, Tokyo, Japan.