[Registration of hereditary non-polyposis colorectal cancer]

Hereditary non-polyposis colorectal cancer is a dominant inherited disease, with development of colorectal cancer (CRC) and other cancers too. About 3% of all CRC-cases belong to an HNPCC-family. Mutations responsible for the disease has been identified in five genes, all of them involved in DNA mismatch repair. Since the establishment of the Danish HNPCC Register 345 families have been referred, and 101 of these families had HNPCC. Median age of onset for CRC was 50 years: Approximately 60% of the tumors were situated on the right side, 9% had synchronous tumors and the risk of metachronous tumours was 40% in 20 years. Tumours were localised in 64% of the cases, and the 5-year crude survival rate was better in HNPCC compared to sporadic CRC. The number of CRC diagnosed as Dukes A in HNPCC has risen since 1990, and the survival after CRC in HNPCC has increased. The disease specific mutation is identified in 21 families, from which 152 persons at risk have had a molecular genetic diagnose, and 83 could afterwards evade screening protocols. Few years after the establishment of the HNPCC-registry, it is indicated that information, registration and screening lead to an earlier diagnosis and a better prognosis after CRC.