[Prevention of familial tumor diseases using genetic counseling and early diagnosis].

Several types of familial cancer can be prevented from progressing into an advanced stage through genetic counselling and regular medical control of persons at risk. Measures of secondary cancer prevention and their efficacy are described for retinoblastoma, MEN2 syndrome, familial colorectal carcinoma with (FAP) or without (HNPCC) pre-existing polyposis coli, dysplastic naevi syndrome, basal cell naevi syndrome and von Hippel-Lindau syndrome. The prevention of malignancies is promising primarily for the familial forms, since persons at risk are motivated to employ preventive measures, especially if they can be identified through DNA diagnosis and counselled with concrete information. The establishment of familial cancer registries should be considered which improve the continuous medical care for all family members, even in the case of a change of the family physician or a loss of contact.