Hereditary nonpolyposis colorectal carcinoma: cancer family syndrome

During the past 20 years details of hundreds of families with aggregation of nonpolyposis colorectal carcinoma (CRC) have been published. High frequency of CRC and some other adenocarcinomas with early age of onset, with common multiplicity and with dominant mode of genetic transmission are characteristic for this inherited disorder originally called the cancer family syndrome (CFS). It has now been shown that at least 5% of all CRCs can be classified as CFS and it constitutes a potentially important subject for family screening for CRC. About 50 CFS families have been identified in Finland and systematic family screening for CRC has been performed since 1983. Positive screening results in CFS are at least 20 to 30 times higher than in the general population of corresponding age. However, the problem of definite verification of the syndrome in the absence of a specific biomarker and difficulties in establishing continuity of the follow up once started have handicapped arrangements for nation wide screening programmes. Nevertheless, there are good reasons to identify all cases of CFS in clinical practice because this has clear implications for the surgical and follow up strategies in individual patients with CFS.