Role of prophylactic thyroidectomy in RET 790 familial medullary thyroid carcinoma

Background We describe a family harboring RET 790 mutation and review the role of prophylactic thyroidectomy for medullary thyroid carcinoma. Methods We evaluated in detail both clinical and biological follow-up and reviewed literature reports. Results Among 86 family members, 15 of 22 members screened harbored the 790 mutation. Abnormal calcitonin levels were found in 8/15. Total thyroidectomy with lymph node dissection cured the 5 operated patients (range, 45-76 years). Tumor staging was pT1N0M0. Among 10 carriers who did not undergo surgery, 3 patients had abnormal calcitonin levels. For the others, calcitonin levels remained <30 pg/mL. Two asymptomatic carriers were older than 70 years. Four subjects were lost to follow-up. Conclusions In RET codon 790 mutations families, a case-by-case decision instead of systematic prophylactic thyroidectomy should be discussed. Difficulties of follow-up should be taken into account and represent the main challenge.