Published online Jul 28, 2015. doi: 10.3748/wjg.v21.i28.8687
Peer-review started: December 21, 2014
First decision: January 22, 2015
Revised: March 23, 2015
Accepted: April 16, 2015
Article in press: April 17, 2015
Published online: July 28, 2015
Processing time: 222 Days and 20.6 Hours
AIM: To investigate the correlation between human epidermal growth factor receptor (HER-2) protein expression and colorectal cancer (CRC) using a case-control study and meta-analysis.
METHODS: Tumor tissue specimens from 162 CRC patients were selected for the case group. Fifty cases were randomly selected, and normal CRC tissue at least 10 cm away from the tumor margins of these cases was used to generate the control group. The expression of the HER-2 protein in the 162 CRC tissue samples and the 50 adjacent normal mucosa tissue samples was detected via immunohistochemistry. The experimental data were analyzed using SPSS 18.0 software, and R software version 3.1.0 was utilized for further verification.
RESULTS: The expression of HER-2 protein in the 162 CRC tissue samples was significantly higher than in the normal tissue specimens. The data showed that the expression of HER-2 in CRC was related to the Dukes’ stage, the depth of invasion and lymph node metastasis. The HER-2-positive patients had lower 3- and 5-year OS rates than the HER-2-negative patients, but there was no significant difference. However, there was a statistically significant difference in the 3- and 5-year disease-free survival (DFS) rates of HER-2-positive and HER-2-negative patients. The results of the meta-analysis showed that the expression of HER-2 in CRC patients was statistically significantly increased over that of healthy people. The 3-year DFS rate in HER-2-positive patients was markedly lower than that in HER-2-negative patients.
CONCLUSION: Down-regulation of HER-2 expression might be a dependable strategy for CRC therapy.
Core tip: The first meta-analysis to evaluate the role of human epidermal growth factor receptor (HER-2) expression in colorectal cancer (CRC); HER-2 expression level is associated with the clinic-pathological features of CRC; HER-2 expression level is associated with the prognostic factors of CRC; HER-2 expression level is a biomarker for diagnosis of CRC; HER-2 expression level is a biomarker for determining the prognosis of CRC.