Colon polyps and colon cancer

Abstract

Among the various pathologies of the large intestine, special attention should be paid to polyps of the colon. Although the ability of polyps to progress from benign tissue to invasive malignancy is a very well known phenomenon, diagnostic tools allowing to identify suspicious specimens have not been developed so far. The risk of cancer development is higher in villous lesions greater than 2 cm in diameter and in squat polyps. In the early stages of neoplasmatic transformation a K-ras mutation takes place. Another well-known gene which becomes mutated very often in carcinogenesis, especially in colorectal cancer, is the p53 gene.
At present some important data concerning apoptosis, proliferation and inflammatory factors in colorectal cancers as well as in polyps have been collected. Recent findings suggest that the quantity of metyloproteinase matrix (MMP-2, MMP-9) and tissue MMP inhibitors (TIMP1 TIMP2) increases together with a cell’s ability to carcinogenesis, reaching the highest levels in adenocarcinomatous tissue. The activity of apoptotic factors (CD95, bcl, bax) is different in hyperplastic polyps, adenomatous polyps and in normal mucosa.