Published online Nov 10, 2018. doi: 10.5306/wjco.v9.i7.148
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
Processing time: 171 Days and 15.1 Hours
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.
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.
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.
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.
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).
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.
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.