Retrospective Cohort Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Nov 10, 2018; 9(7): 148-161
Published online Nov 10, 2018. doi: 10.5306/wjco.v9.i7.148
Comparison of the eighth version of the American Joint Committee on Cancer manual to the seventh version for colorectal cancer: A retrospective review of our data
Guo-Jun Tong, Gui-Yang Zhang, Jian Liu, Zhao-Zheng Zheng, Yan Chen, Ping-Ping Niu, Xu-Ting Xu
Guo-Jun Tong, Gui-Yang Zhang, Jian Liu, Zhao-Zheng Zheng, Yan Chen, General Surgery Department, Huzhou Central Hospital, Huzhou 313000, Zhejiang Province, China
Guo-Jun Tong, Ping-Ping Niu, Xu-Ting Xu, Central Laboratory, Huzhou Central Hospital, Huzhou 313000, Zhejiang Province, China
Author contributions: Tong GJ, Zhang GY, Liu J, and Zheng ZZ provided vital reagents and analytical tools and edited the manuscript; Chen Y, Niu PP, and Xu XT coordinated and provided the collection of all the human material; Tong GJ and Zhang GY designed the study and wrote the manuscript.
Institutional review board statement: The study was reviewed and approved by Huzhou Central Hospital Review Board.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
STROBE statement: The STROBE Statement has been adopted.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Gui-Yang Zhang, BS, Professor, General Surgery Department, Huzhou Central Hospital, Hongqi Road No. 198, Huzhou 313000, Zhejiang Province, China. kjk6616@126.com
Telephone: +86-572-2555387 Fax: +86-572-2555803
Received: May 22, 2018
Peer-review started: May 23, 2018
First decision: July 9, 2018
Revised: August 30, 2018
Accepted: October 9, 2018
Article in press: October 9, 2018
Published online: November 10, 2018
ARTICLE HIGHLIGHTS
Research background

Colorectal cancer (CRC) is a common malignant tumors. Clinicians have been using the American Joint Committee on Cancer (AJCC) system to guide clinical diagnosis and treatment for CRC. The eighth edition of the AJCC (AJCC-8th) has received extensive attention since its promulgation in 2016. Compared to the previous version, AJCC-8th refined the stage IV classification to separate peritoneal metastasis and organ metastasis.

Research motivation

In China, there are still many hospital surgeons and physicians who still use the old version to guide clinical practice and are uneducated about the new AJCC-8th classifications.

Research objectives

We analyzed our institution’s CRC cohort to determine differences in the survival trends based on the diagnostic classifications between AJCC-8th and the previous version.

Research methods

A total 1090 patients of 2080 CRC patients were included in the study. The data were classified by AJCC-7th and AJCC-8th standards. Five-year disease-free survival (DFS) and overall survival (OS) were compared.

Research results

Linear regression and automatic linear regression showed lymph node positive functional equations by TNM staging from AJCC-7 and TNM staging from AJCC-8th. Neurological invasion, venous infiltration, lymphatic infiltration, and tumor deposition put forward stricter requirements for pathological examination. AJCC-8th staging yielded a proportional decrease of IVB from 2.8% to 0.8% and a new staging of IVC to 2%. Log-rank test showed that DFS and OS survival time of patients with IVC vs IVB was significantly shorter (P = 0.012).

Research conclusions

The addition of a sub-stage to classify peritoneal metastasis separately from distant organ metastasis in the AJCC-8th manual has shown that peritoneal metastasis has a worse prognosis than organ metastasis in our cohort. Considering many prognostic factors, individualized treatment is particularly important to improve the survival time of stage IV patients, especially IVC patients.

Research perspective

Further studies can be done to improve outcomes for peritoneal metastasis CRC patients. Further analysis of additional institutional databases is needed to confirm our findings.