High c-myc protein expression in benign colorectal lesions correlates with the degree of dysplasia.

Sections of normal colon (n = 14), hyperplastic polyps (n = 31) ulcerative colitis (n = 97) and tubular adenomas (n = 40) were examined by immunohistochemistry for the expression of the c-myc proto-oncogene product in order to assess its potential diagnostic value in predicting the malignant potential of these lesions. We compared the degree of epithelial abnormality in these colorectal specimens with the extent of immunoperoxidase staining for c-myc oncoprotein, we found that high c-myc protein expression correlated with the degree of epithelial alteration in ulcerative colitis and tubular adenoma groups. Weakly positive staining was found in 10 out of 14 normal colon samples and 28 out of 31 hyperplastic polyps. High tissue expression of c-myc protein, when combined with histologic dysplasia, may prove to be an additional factor in the evaluation of malignant potential in ulcerative colitis specimens and adenomas.