The Genetic Aspects of Medullary Thyroid Carcinoma: Recognition and Management

OBJECTIVE: to examine the extent to which clinicians recognize the genetic aspects of medullary thyroid carcinoma (MTC) and undertake appropriate investigation and management of patients and their at-risk relatives. DESIGN: retrospective review of case notes. SUBJECTS: all individuals aged 70 or under with a 'raised' calcitonin level during 1990-91. Information was obtained from a questionnaire. Forty-one cases were diagnosed in 1990—91: 10 (24%) multiple endocrine neoplasia (MEN) type 2A, four (10%) MEN type 2B, and 27 (66%) sporadic MTC. Between 1980 and 1989, 87 cases were diagnosed: 20 (23%) MEN type 2A, six (7%) MEN type 2B, four (5%) familial MTC, 53 (61%) sporadic MTC, and four (5%) of uncertain diagnosis. MAIN RESULTS: a pedigree was drawn in only 7/37 (19%) and 26/83 (31%) of cases diagnosed in 1990—91 and 1980—89, respectively, where a family history had been taken. All known hereditary cases were investigated for phaeochromocytoma. In 9/27 (33%) and 14/52 (27%) apparently sporadic cases diagnosed in the two periods respectively, no investigations were performed. Genetic counselling was offered to all known hereditary cases except one, but no offer was made in 11/25 (44%) and 16/52 (31%) apparently sporadic cases. There was no record that screening should be offered to the family in 15/35 (43%) and 25/68 (37%) cases identified from clinical investigations; in the majority it could be argued that it should have been. CONCLUSIONS: this study has shown that clinicians do not always have the necessary training or experience to undertake family studies and screening in this rare disorder.