Human epidermal growth factor receptor (HER 2)/neu expression and gene amplification in colorectal cancer
To investigate the relationship between the expression/amplification of human epidermal growth factor receptor (HER 2)/neu and its clinical significance in colorectal cancer, in this study, clinicopathological data and paraffin-embedded specimen were collected on 192 consecutive patients who underwent colorectal resections from 2001 to 2005 at Renmin Hospital of Wuhan University. Using immunohistochemistry and fluorescence in situ hybridization, HER-2/neu protein overexpression and gene amplification were detected. HER 2/neu was overexpressed in 32.3% of cases (62/192), of which 38 (19.8%) were 2+ and 24 (12.5%) were 3+, over expression/amplification of HER 2/neu was associated with the differentiation and stage of the carcinoma. No association between the expression/amplification of HER 2/neu and the tumor size, location, age, gender and lymphatic invasion was found. HER 2/neu overexpression was significantly associated with HER 2/neu gene amplification according to univariate analysis; there was a significant difference in survival rates when cases with and without HER 2/neu overexpression or amplification were compared. These results indicate that HER 2/neu could be a prognostic variable in colorectal cancer; patients with colorectal cancer exhibiting high levels of HER 2/neu might benefit from the anti-HER-2 /neu therapy.
Key words: HER 2/neu, colorectal cancer, immunohistochemistry, fluorescence in situ hybridization.