Relation between metaplastic polyp and carcinoma of the colorectum.

Carcinomas and metaplastic polyps of the colorectum share a variety of phenotypes which are not evidenced by either tubular adenomas or normal colorectal mucosa. This supports the view that adenomas and metaplastic polyps are separate entities with differing aetiologies. To explain the functional overlap between metaplastic polyps and carcinoma, it is suggested that the two separate sets of factors which lead to the development of adenomas and metaplastic polyps are both required to bring about malignant transformation within the colorectum. Identification of the factors causing metaplastic polyp formation could therefore have important implications in the prevention of colorectal cancer.