Clinicopathological Significance Of HER-2 Protein Expression And Gene Amplification In Colorectal Carcinoma

ObjectiveTo investigate the clinicopathological significance of HER-2 protein expression and the correlation between HER-2 gene amplification and HER-2 protein overexpression, in colorectal cancer (CRC).MethodsHER-2 protein and HER-2 gene in the surgically removed tissues of 106 colorectal carcinoma cases was evaluated by immunohistochemistry(IHC) and silver in situ hybridization(SISH) methods.Results1 Results of immunihistochemistry(IHC): In 30 cases of adjacent normal colorectal mucosa, the positive expression rate of HER-2 protein was 10.0%(3/30),In 106 cases of CRC,the positive expression rate of HER-2 protein was 45.3%(48/ 106).The positive expression of HER-2 protein correlated with the Dukes staging , serosa infiltration and lymph node metastasis of CRC (P <0.05).2 Results of silver in situ hybridization(SISH): 30 cases with HER-2 protein overexpression(3+/2+)by IHC ,10 cases showed HER-2 gene amplification by SISH. 76 cases with HER-2 protein overexpression(1+/0) by IHC, 2 cases showed HER-2 gene amplification by SISH. ConclusionsThe expression of HER-2 protein may be intimately correlated to the occurrence and development of colorectal carcinoma. HER-2 can be used as prognostic indicators in CRC. The correlation between HER-2 protein overexpression and HER-2 gene amplification is statistically significant. Therefore immunohistochemistry can be regarded as an initial screening method for HER-2 expression status, and then SISH testing should be done as well. It is useful for molecular target therapy to detect HER-2 status in colorectal carcinoma.