Prophylactic thyroidectomy in MEN 2A syndrome: experience in a single center

Area of Science:

• Endocrinology
• Oncology
• Genetics

Background:

• Genetic studies of the RET proto-oncogene have improved management for medullary thyroid carcinoma (MTC) and multiple endocrine neoplasia type 2A (MEN 2A).
• Traditionally, diagnosis relied on elevated calcitonin levels (bCT and pCT).
• Prophylactic thyroidectomy guided by genetic testing can lower MTC recurrence rates.

Purpose of the Study:

• To evaluate the effectiveness of prophylactic thyroidectomy in genetically identified MTC (MEN 2A) patients.
• To analyze clinical and pathological data of patients undergoing prophylactic thyroidectomy.
• To assess the impact of genetic testing on early disease detection and recurrence rates.

Main Methods:

• Retrospective analysis of 82 MTC (MEN 2A) patients, with a focus on 22 who received prophylactic thyroidectomy.
• Data collected included age, gender, RET mutation status, cervical ultrasound, calcitonin (bCT, pCT), CEA, surgical details, histology, TNM staging, and follow-up.
• Patients undergoing prophylactic thyroidectomy were RET-positive, asymptomatic, with normal basal and poststimulus calcitonin levels.

Main Results:

• Twenty-two patients from 8 families with MTC (MEN 2A) underwent prophylactic thyroidectomy, with a mean age of 15.2 years.
• The most common RET mutation was Cys-->Tyr in exon 11 (21 patients).
• Post-surgery, all patients achieved normal calcitonin levels with a 100% cure rate; 7 patients had C-cell hyperplasia, and 15 had MTC (median size 0.2 cm), with one case of metastatic adenopathy.

Conclusions:

• Prophylactic thyroidectomy based on genetic testing facilitates early diagnosis and treatment, leading to decreased recurrence rates in MTC (MEN 2A).
• Elevated poststimulus calcitonin (pCT) levels may indicate MTC presence and should guide surgical decisions.
• Genetic screening and timely intervention are crucial for managing MTC and MEN 2A.