Itabashi Michio    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position   Professor (Fixed Term)
Article types	Original article
Language	English
Peer review	Non peer reviewed
Title	A proposed new Japanese classification of synchronous peritoneal metastases from colorectal cancer: A multi-institutional, prospective, observational study conducted by the Japanese Society for Cancer of the Colon and Rectum
Journal	Formal name：Annals of gastroenterological surgery Abbreviation：Ann Gastroenterol Surg ISSN code：24750328/24750328
Domestic / Foregin	Domestic
Volume, Issue, Page	7(5),pp.765-771
Author and coauthor	KOBAYASHI Hirotoshi,KOTAKE Kenjiro,KAWASAKI Masayasu,KANEMITSU Yukihide,KINUGASA Yusuke,UENO Hideki,MAEDA Kotaro,SUTO Takeshi,ITABASHI Michio,FUNAHASHI Kimihiko,OZAWA Heita,KOYAMA Fumikazu,NOURA Shingo,ISHIDA Hideyuki,OHUE Masayuki,KIYOMATSU Tomomichi,ISHIHARA Soichiro,KODA Keiji,BABA Hideo,KAWADA Kenji,HASHIGUCHI Yojiro,GOIi Takanori,TOIYAMA Yuji,TOMIYTA Naohiro,SUNAMI Eiji,AKAGI Yoshito,WATANABE Jun,HAKAMADA Kenichi,NAKAYAMA Goro,SUGIHARA Kenichi,AJIOKA Yoichi
Publication date	2023/09
Summary	AIM:To establish a new Japanese classification of synchronous peritoneal metastases from colorectal cancer.METHODS:This multi-institutional, prospective, observational study enrolled patients who underwent surgery for colorectal cancer with synchronous peritoneal metastases. Overall survival rates were compared according to the various models using objective indicators. Each model was evaluated by Akaike's information criterion (AIC). The region of peritoneal metastases was evaluated by the peritoneal cancer index (PCI).RESULTS:Between October 2012 and December 2016, 150 patients were enrolled. The AIC of the present Japanese classification was 1020.7. P1 metastasis was defined as confined to two regions. The minimum AIC was obtained with the cutoff number of 10 or less for P2 metastasis and 11 or more for P3 metastasis. As for size, the best discrimination ability between P2 and P3 metastasis was obtained with a cutoff value of 3 cm. The AIC of the proposed classification was 1014.7. The classification was as follows: P0, no peritoneal metastases; P1, metastases localized to adjacent peritoneum (within two regions of PCI); P2, metastases to distant peritoneum, number ≤10 and size ≤3 cm; P3, metastases to distant peritoneum, number ≥11 or size >3 cm; P3a, metastases to distant peritoneum, number ≥11 and size ≤3 cm, or number ≤10 and size >3 cm; P3b, metastases to distant peritoneum, number ≥11 and size >3 cm.CONCLUSION:This objective classification could improve the ability to discriminate prognosis in patients with synchronous peritoneal metastases from colorectal cancer.
DOI	10.1002/ags3.12679
PMID	37663965