The need for oncogenetic counselling. Ten years' experience of a regional oncogenetic clinic.

A monogenic inheritance, mainly seen as a dominant pattern, accounts for 5-10% of all cancer cases. The increased knowledge and identification of high-risk genes have led to a need for specialized cancer family clinic was the expression used by Eeles and Murday. The Oncogenetic Clinic at the University Hospital in Lund was started in 1993 and the authors' 10-year experience is summarized in this paper. The clinic offers service to the South Swedish Health Care Region comprising a total of 1.6 million inhabitants. During these first 10 years a total of 1059 individuals from 789 families have been individually counselled. The most common reason for referral was a family history of breast cancer, followed by a family history of colorectal cancer. According to the commonly used criteria, 437 (55%) of the families were considered as autosomal dominantly inherited; 147 families (19%) did not fulfil these criteria but had a strong clustering of breast/ovarian or colorectal/endometrial cancer. The remaining 205 families (26%) were not recognized as any previously described hereditary cancer syndrome with early onset. However, most of these families had a family history of cancer. Mutation analysis was performed in 386/789 (49%) of the families. In families with breast and ovarian cancer a genetic aberration was identified in 45/76 (59%) and in breast-only families in 27/129 (21%). In MSI-positive colon cancer families 16/34 (47%) of the families had a germline mutation. Thus, the majority of the families referred to the clinic were in obvious need of genetic counselling concerning cancer and heredity and in a substantial number of the families a germline mutation could be identified.