Immunohistochemical Expression of Ki67 and HER2 in Colorectal Cancer Compared to Adenomatous and Normal Samples

Colorectal cancer (CRC) is one of the most common cancers worldwide. Due to the high rate of mortality in advanced metastatic stages, finding new detecting techniques seems to be necessary.
This study aimed to investigate the immunohistochemical expression of Ki67 and human epidermal growth factor receptor 2 (HER2) in colorectal cancer compared to adenomatous and normal samples.
This case-control study was conducted to evaluate Ki67 and HER2 protein immunohistochemical (IHC) expressions in 137 colorectal formalin fixed paraffin-embedded tissue blocks. The blocks were classified into 3 groups; normal (n = 36), adenomatous (n = 38), and adenocarcinoma (n = 63). All tissue blocks were selected through convenience sampling method from the archive of pathology in Ali-Ebne-Abitaleb Hospital, Zahedan, Iran from 2010 to 2015. The sections were evaluated, using semi-quantitative scoring. Ki67 and HER2 expressions were reported as negative and positive. Clinicopathological characteristics were also assessed. The data was analyzed by Kruskal-Wallis and Chi-square or Fisher tests. The significance level set as P The expression of Ki67 in CRC, adenomatous, and normal colorectal tissues were 79.30%, 44.80%, 25.00%, and in HER2 were 54.00%, 36.80%, and 19.40%, respectively. Ki67 and HER2 overexpressions were significantly higher in CRC than the adenomatous and normal tissues (P Considering the significant overexpression of Ki67 and HER2 in CRC, it seems that these biomarkers can be used as useful predictors in primary screening and identifying of CRCs. Further research should be conducted on this matter.