Early or prophylactic thyroidectomy in MEN 2/FMTC gene carriers: results in 71 thyroidectomized patients. The French Calcitonin Tumours Study Group (GETC).
BACKGROUND
Once genetic testing accurately identifies MEN 2 gene carriers, affected children are given the opportunity to undergo thyroidectomy at the earliest stages of the C-cell disease.


OBJECTIVE
To define reliable parameters by which to identify the best moment for thyroidectomy in patients who are carriers of the MEN 2 gene.


METHODS
Seventy-one MEN 2/FMTC gene carriers, collected through the national register of the French Calcitonin Tumours Study Group, were evaluated. All the patients included were younger than 20 years of age and underwent total thyroidectomy. Basal and pentagastrin-stimulated calcitonin were assayed using an immunoradiometric method (sensitivity less than 2pg/ml). Calcitonin measurement was evaluated on the basis of histopathological findings in surgical thyroid specimens.


RESULTS
We found C-cell hyperplasia or medullary thyroid carcinoma in all the 71 gene carriers - even for the youngest patients - and nodal metastases were present in four cases. Calcitonin measurement (basal or pentagastrin-stimulated) detected C-cell disease preoperatively in all patients. Six of the 71 patients were not surgically cured: one had nodal metastases, one had an advanced staged disease and four had an incomplete nodal dissection or had not undergone lymph node surgery.


CONCLUSIONS
Determination of calcitonin forms an integral part of the management of MEN 2 gene carriers. Thyroidectomy is undisputably indicated when basal calcitonin is abnormal. When basal calcitonin is undetectable, a pentagastrin-stimulated increase in calcitonin to more than 10 pg/ml indicates an early thyroidectomy to cure the patient.
Niccoli-Sire
P
P
Services d'Endocrinologie et de Chirurgie Endocrinienne, CHU Timone, Marseille, France. pnicoli-sire@ap-hm.fr
Murat
A
A
Baudin
E
E
Henry
J F
JF
Proye
C
C
Bigorgne
J C
JC
Bstandig
B
B
Modigliani
E
E
Morange
S
S
Schlumberger
M
M
Conte-Devolx
B
B
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D002116:Calcitonin / Q000097:blood; D018276:Carcinoma, Medullary / Q000235:genetics / Q000517:prevention & control / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005602:France; D006801:Humans; D007118:Immunoassay; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D018813:Multiple Endocrine Neoplasia Type 2a / Q000235:genetics / Q000517:prevention & control / Q000601:surgery*; D010418:Pentagastrin; D017422:Sequence Analysis, DNA; D013961:Thyroid Gland / Q000473:pathology; D013964:Thyroid Neoplasms / Q000235:genetics / Q000517:prevention & control / Q000601:surgery*; D013965:Thyroidectomy
D000911:Antibodies, Monoclonal; D002116:Calcitonin; D010418:Pentagastrin