ABSTRACT
<p><b>OBJECTIVE</b>To investigate the clinicopathological significance of positive CK7 expression in human colorectal carcinoma (HCC).</p><p><b>METHODS</b>Immunohistochemistry was used to detect CK7 and CK20 protein expressions in 68 cases of HCC, 20 cases of canalicular adenoma (CA), 5 cases of serrated adenoma (SA) and 20 cases of hyperplastic polyps (HP).</p><p><b>RESULTS</b>The positivity rate of CK20 expression was 89.7% in HCC, and 100% in CA, SA and HP. In HCC, the expression rate of CK7 (39.7%) was not correlated with Dukes' classification, differentiation and tumor location. CK7 positivity rate in colon cancer was 35.7% (15/52) and 42.3% (11/26) in rectal cancer. CK7 expression was negative in CA. CK7 positivity rate in SA was 49% and 30% in HP.</p><p><b>CONCLUSION</b>CK7 is a possible marker for colorectal carcinogenesis from HP to SA, and ultimately to HCC, and examination of the colorectal polypoid lesions for CK7 expression can be significant for estimating the colorectal polypous cancerization.</p>