Hereditary Factors in The Pathogenesis of Colorectal Cancer

A precise understanding of both categories of inherited susceptibility is important in delineating the pathogenesis of colorectal cancer and in planning effective cancer screening programs. This chapter reviews the phenotypic characteristics and evidence for inheritance in both the rare and the common forms of colorectal cancer. There are a number of rare inherited syndromes which give rise to colorectal cancer. In addition to the well-characterized inherited syndromes, epidemiological studies of colorectal cancer have consistently demonstrated familial occurrence in excess of that expected by chance. Cancers in the pedigree were typical of common large bowel cancer in terms of age of onset and colonic distribution. Mapping of the gene for familial polyposis coli has been a major advance toward understanding the genetics of the adenomatous polyposis syndromes. Gene markers of common inherited susceptibilities would be of particular value in the control of colorectal cancer.