Screening of families predisposed to cancer development in The Netherlands.

Screening for hereditary tumours provides a basis for secondary prevention. In 1985, the Foundation for the Detection of Hereditary Tumours was established in The Netherlands to coordinate screening in families with hereditary tumours. In the initial period of four years a large number of families were collected. Registration started with families with the multiple endocrine neoplasia syndrome type 2 and familial adenomatous polyposis. Later, families with the familial dysplastic nevus syndrome, hereditary nonpolyposis colorectal cancer and the multiple endocrine neoplasia syndrome type 1 were also collected and inventoried, because expansion of the registry to include these syndromes was considered. As a general conclusion based on our studies, it may be said that screening of families with the multiple endocrine neoplasia syndrome type 2, familial adenomatous polyposis, familial dysplastic nevus syndrome, and hereditary nonpolyposis colorectal cancer leads to detection of these tumours in an earlier stage, which in turn may permit curative treatment and improvement of the prognosis and life expectancy. Screening of the MEN-1 syndrome may improve the prognosis by favouring appropriate management decisions. It is evident that a detailed family cancer history is extremely important as an indicator of a genetic basis and has implications for family screening and follow up. The doctor's task of ensuring that the necessary investigations are carried out is made easier by use of the facilities of the Foundation for the Detection of Hereditary Tumours. The registration system in particular has assured the continuation of periodic examination, because the specialist is kept informed at all times. The collection of data and the preparation of an inventory of the data of families with hereditary tumours on a national scale have contributed to both the understanding of these syndromes and the optimalization of the screening procedures. The study of hereditary tumours is important, because it can provide clues concerning carcinogenesis in general.