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
To analyze the survival trends in colorectal cancer (CRC) based on the different classifications recommended by the seventh and eighth editions of the American Joint Committee on Cancer staging system (AJCC-7th and AJCC-8th).
The database from our institution was queried to identify patients with pathologically confirmed stage 0-IV CRC diagnosed between 2006 and 2012. Data from 2080 cases were collected and 1090 cases were evaluated through standardized inclusion and exclusion criteria. CRC was staged by AJCC-7th and then restaged by AJCC-8th. Five-year disease-free survival (DFS) and overall survival (OS) were compared. SPSS 21.0 software was used for all data. DFS and OS were compared and analyzed by Kaplan-Meier and Log-rank test.
Linear regression and automatic linear regression showed lymph node positive functional equations by tumor-node-metastasis staging from AJCC-7th and tumor-node-metastasis staging from AJCC-8th. Neurological invasion, venous infiltration, lymphatic infiltration, and tumor deposition put forward stricter requirements for pathological examination in AJCC-8th compared to AJCC-7th. After re-analyzing our cohort with AJCC-8th, the percentage of stage IVB cases decreased from 2.8% to 0.8%. As a result 2% of the cases were classified under the new IVC staging. DFS and OS was significantly shorter (P = 0.012) in stage IVC patients compared to stage IVB patients.
The addition of stage IVC in AJCC-8th has shown that peritoneal metastasis has a worse prognosis than distant organ metastasis in our institution’s CRC cohort. Additional datasets should be analyzed to confirm these findings.
Core tip: Since the promulgation of the eighth edition of the American Joint Committee on Cancer staging system manual (AJCC-8th), it has attracted the attention of many clinicians around the world and guided clinical work. Using our institution data we explored the prognostic differences between AJCC-8th and the seventh edition of the AJCC manual (AJCC-7th) for colorectal cancer. We found that patients with stage IVC colorectal cancer have a worse prognosis. This shows that peritoneal metastasis has a worse prognosis than organ metastasis. Considering many prognostic factors, individualized treatment is particularly important to improve the survival time of stage IV patients, especially stage IVC patients.