[Basic molecular biology of colon and rectal carcinoma--when differential diagnosis?].

: Colorectal cancer (CRC) is one of the most common cancers in Western populations, striking both women and men at approximately equal rates. A genetic basis for the development of cancer has already been suggested by Karl Heinrich Bauer in 1928 but only since the advancement of molecular biology direct evidence has been obtained to support the notion that cancer is a genetic disease. Recent progress in our understanding of the molecular basis of the most prevalent colorectal cancer syndromes, such as hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP), is reflected by modifications in diagnosis and therapy. Identification of genetic risk factors for the development of adenomas and associated carcinomas of the colon and rectum results in predictive molecular diagnosis of malignant disease and enables preventive treatment.