Genetic testing for familial cancer. A clinician's perspective

Molecular genetics researchers have recently identified several genes (and mutations) that result in family cancers. This has prompted the development of molecular diagnostic tests to identify individuals at risk, making it possible to prevent certain types of cancer. However, detection and prevention of certain malignancies are impeded because few medical practitioners know of these tests, and because patients fear the emotional consequences of testing. To highlight some of these issues, we describe a patient who chose to be tested for the RET gene mutation. The mutation was identified, additional family members were tested, and several were found to be at risk. The RET gene mutation is 100% predictive for the ultimate development of medullary thyroid cancer. Testing and counseling provided this patient and her family with information not only about the thyroid cancer in their family, but also about multiple endocrine neoplasia, a syndrome resulting from mutation of this particular gene. Familial cancer clinics are being established to assist patients and physicians who face questions about familial diseases and the value of genetic testing. We include in this report information about the familial cancer clinics in Minnesota and list the services and testing opportunities available at these clinics.