177P - New staging system for colorectal cancer patients with synchronous peritoneal metastasis in accordance with the Japanese Classification of Colorect...

Date 17 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Colon and Rectal Cancer
Rectal Cancer
Staging procedures (clinical staging)
Presenter Shingo Noura
Citation Annals of Oncology (2016) 27 (suppl_9): ix53-ix67. 10.1093/annonc/mdw581
Authors S. Noura1, M. Ohue1, J. Hasegawa1, M. Hirota1, T. Matsumura1, Y. Ito2, N. Miyoshi3, H. Kobayashi4, K. Kotake5, K. Sugihara6
  • 1Surgery, Osaka Rosai Hospital, 591-8025 - Sakai, Osaka/JP
  • 2Cancer Control And Statistics, Osaka Medical Center for Cancer and Cardiovascular Dideases, 537-8511 - Osaka/JP
  • 3Surgery, Osaka Medical Center for Cancer and Cardiovascular Dideases, 537-8511 - Osaka/JP
  • 4Surgery, Tokyo Metropolitan Hiroo Hospital, 150-0013 - Tokyo/JP
  • 5Surgery, Tochigi Cancer Center, 320-0834 - Utsunomiya/JP
  • 6Surgery, Tokyo Medical and Dental University, 113-8510 - Tokyo/JP



Peritoneal metastasis of colorectal cancer (CRC) is often discovered during initial surgery. The aim of this study is to propose a new staging system that could be used to help determine the management.


We evaluated a total of 766 Stage IV CRC patients with synchronous peritoneal metastasis. According to the Japanese Classification, we divided the peritoneal metastasis into P1, P2, and P3. We distinguish distant metastasis from liver metastasis and peritoneal metastasis. According to the Cox proportional hazard model, we construct a new staging group.


According to a comparison of the R2 statistics, the combination of liver metastasis and peritoneal metastasis was selected as the final variables. Next, we defined P1H(-) as Grade A, P2H(-) as Grade B, and other groups as Grade C. Our proposed new stage (AIC, 7338.82; c-index, 0.644; R2, 0.123) could thus divide the patients into different prognostic group more clearly than the current Japanese Classification (AIC, 7373.89; c-index, 0.619; R2, 0.097).


Our proposed new staging system is very simple and easy for general surgeons. This system is useful for determining the appropriate operative strategy for CRC patients with peritoneal metastasis and for estimating the patients’ prognosis.

Clinical trial indentification

Legal entity responsible for the study





All authors have declared no conflicts of interest.