Medullary thyroid cancer and the impact of genetic testing.

Medullary thyroid cancer (MTC) consists of a rare, undifferentiated tumor and often is described as having a chronic and indolent disease process. Approximately 5%-10% of all thyroid malignancies are MTC, and about 25% of patients diagnosed with the disease have a genetic form that was inherited through a mutation of the RET proto-oncogene. The mutation is expressed by an autosomal dominant allele and, if inherited, has almost a 100% chance of developing into a malignancy. Detection of the germline mutation identifies individuals at risk and enables prophylactic treatment for the prevention of MTC. As a result, patients and family members commonly undergo genetic testing during the diagnostic phase and experience certain psychosocial stressors. The purpose of this article is to provide an overview of MTC and its symptoms, treatment, prognosis, and genetics. The psychosocial effects of genetic testing on the quality of life of patients with MTC also will be described. By learning more about the pathophysiology and psychosocial stressors, nurses can facilitate proper counseling and increase the likelihood of positive outcomes for their patients.