DNA SCREENING FOR BREAST OVARIAN-CANCER SUSCEPTIBILITY BASED ON LINKED MARKERS - A FAMILY STUDY

Background: Linkage to chromosome 17q has been identified in hereditar y breast cancer and hereditary breast/ovarian cancer syndrome. A hered itary breast/ovarian cancer syndrome kindred was identified that yield ed a highly significant lod score (4.20) when 17q markers were studied , enabling us to identify those who probably carried the cancer-associ ated gene among the high-risk members of the family. Methods: High-ris k members of the hereditary breast/ovarian cancer syndrome kindred wer e offered counseling on the basis of 17q markers. Family members respo nding positively received one-to-one genetic counseling in a structure d setting. Subjects were educated before disclosure, and the immediate impact of this information was assessed after disclosure. Results: We provided genetic counseling on the basis of linkage findings to 32 re latives (four men and 28 women). Women who were told they were linkage positive expressed an increased motivation for surveillance and proph ylactic surgery. Most women who were told they were linkage negative i ndicated that they would not proceed with prophylactic surgery but wou ld continue careful surveillance. To date, there has been no evidence of serious emotional disturbances resulting from this disclosure. We b elieve that this experience can be used by cancer geneticists and phys icians in developing protocols for genetic counseling in cancer-associ ated hereditary disorders. Conclusions: Physicians must understand cur rent developments in cancer genetics and linkage so that they can be a pplied to genetic counseling and treatment of high-risk patients.