[Hereditary nonpolyposis colorectal carcinoma (HNPCC). Current review of etiology, clinical aspects, diagnosis and therapy]. / Hereditäres Non-Polyposis kolorektales Karzinom (HNPCC). Aktuelle Ubersicht zur Atiologie, Klinik, Diagnostik und Therapie.

ETIOLOGY: The hereditary non-polyposis colorectal carcinoma (HNPCC) is the most common monogenic colon cancer syndrome. It is characterized by autosomal dominant inherited cancers of the colon, rectum, and the endometrium. Less frequently, cancer of the upper gastrointestinal tract, the hepatobiliary system and the urogenital tract may occur. Typical characteristics are an early onset, usually before the age of 50, manifestation of colorectal cancer proximal of the splenic flexure, and often poorly differentiated carcinomas. GENETICS: Recently, germline mutations in several DNA mismatch repair genes have been identified as the molecular basis of HNPCC, resulting in deficient DNA repair and genetic instability, indicated by microsatellite instability in tumor specimens. DIAGNOSIS: New insights into pathogenesis, clinical features, and diagnosis of HNPCC have improved the identification of HNPCC patients and persons at risk. Diagnosis of HNPCC is primarily based on family history and is complemented by molecular findings. After detection of the underlying germline mutation in families with HNPCC, screening procedures can be restricted to mutation carriers. TREATMENT: Recommendations for therapy and prevention are in part controversial and are under investigation in several studies.