About the Authors

Kiyoshi Hasegawa

Contributed equally to this work with: Kiyoshi Hasegawa, Akio Saiura, Yutaka Matsuyama, Masatoshi Makuuchi, Norihiro Kokudo

Affiliation Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan

Akio Saiura

Contributed equally to this work with: Kiyoshi Hasegawa, Akio Saiura, Yutaka Matsuyama, Masatoshi Makuuchi, Norihiro Kokudo

Affiliation Department of Gastrointestinal Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan

Tadatoshi Takayama

‡ These authors also contributed equally to this work.

Affiliation Department of Digestive Surgery, Nihon University School of Medicine, Tokyo, Japan

Shinichi Miyagawa

‡ These authors also contributed equally to this work.

Affiliation First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan

Junji Yamamoto

‡ These authors also contributed equally to this work.

Affiliation Department of Surgery, National Defense Medical College, Tokorozawa, Japan

Masayoshi Ijichi

‡ These authors also contributed equally to this work.

Affiliation Department of Surgery, JCHO Tokyo Yamate Medical Center, Tokyo, Japan

Masanori Teruya

‡ These authors also contributed equally to this work.

Affiliation Department of Surgery, Showa General Hospital, Tokyo, Japan

Fuyo Yoshimi

‡ These authors also contributed equally to this work.

Affiliation Department of Surgery, Ibaraki Prefectural Central Hospital and Cancer Center, Ibaraki, Japan

Seiji Kawasaki

‡ These authors also contributed equally to this work.

Affiliation Department of Hepatobiliary-Pancreatic Surgery, Juntendo University School of Medicine, Tokyo, Japan

Hiroto Koyama

‡ These authors also contributed equally to this work.

Affiliation Department of Surgery, JCHO Tokyo Takanawa Hospital, Tokyo, Japan

Masaru Oba

‡ These authors also contributed equally to this work.

Affiliation Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan

Michiro Takahashi

‡ These authors also contributed equally to this work.

Affiliation Department of Gastrointestinal Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan

Nobuyuki Mizunuma

‡ These authors also contributed equally to this work.

Affiliation Department of Gastroenterology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan

Yutaka Matsuyama

Contributed equally to this work with: Kiyoshi Hasegawa, Akio Saiura, Yutaka Matsuyama, Masatoshi Makuuchi, Norihiro Kokudo

Affiliation Department of Biostatistics, School of Public Health University of Tokyo, Tokyo, Japan

Toshiaki Watanabe

‡ These authors also contributed equally to this work.

Affiliation Department of Surgical Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan

Masatoshi Makuuchi

Contributed equally to this work with: Kiyoshi Hasegawa, Akio Saiura, Yutaka Matsuyama, Masatoshi Makuuchi, Norihiro Kokudo

Affiliation Department of Hepato-Biliary-Pancreatic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan

Norihiro Kokudo

Contributed equally to this work with: Kiyoshi Hasegawa, Akio Saiura, Yutaka Matsuyama, Masatoshi Makuuchi, Norihiro Kokudo

KOKUDO-2SU@h.u-tokyo.ac.jp

Affiliation Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan

Competing Interests

NK reports personal fees for seminar presentations from Merck Serono, Chugai Pharma, and Taiho Pharmaceutical during the conduct of the study. All other authors declare no competing interests. We now confirm that this does not alter our adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceptualization: KH NK. Formal analysis: YM. Funding acquisition: KH NK. Investigation: KH AS TT SM JY MI M Teruya FY SK HK MO M Takahashi NM TW MM NK. Project administration: NK. Supervision: MO YM TW MM. Visualization: KH. Writing – original draft: KH. Writing – review & editing: YM NK.