Can We Predict the Lateral Compartment Lymph Node Involvement in RET-Negative Patients with Medullary Thyroid Carcinoma?
Lateral lymph node dissection (LND) in the absence of macroscopic nodal metastasis remains controversial in sporadic medullary thyroid carcinoma (MTC).



The aims of our study were to determine the risk of lateral lymph node (LN) metastases with a focus on lateral contralateral N1, and to define a risk-adapted surgical treatment for these patients.



All patients who underwent surgery from 1980 to 2012 for previously untreated RET-negative MTC were reviewed. We focused on the lateral compartments of LN metastases and identified three groups: no lateral LN metastases, ipsilateral lateral (ILL)-LN metastases with no contralateral LN involvement, and contralateral lateral (CLL)-LN metastases.



Overall, 131 patients underwent surgery for RET-negative MTC. A total thyroidectomy with LND was performed in 112 patients (85 %), including 97 patients who had an ILL-LND and 92 patients who had a CLL-LND. Lateral LN metastases (N1) occurred in 40 patients (37 %): 31 patients (32 %) had ILL-LN metastases with no contralateral LN involvement, and 9 patients (10 %) had CLL-LN metastases. The preoperative cut-offs for LN metastases in the ILL compartment were very low, with a smallest tumor size of 5 mm, and lowest serum calcitonin level of 38 pg/ml. Disease-free survival rates decreased from 92 % for patients with no lateral LN metastases to 41 % for patients with ILL-LN metastases and 0 % for patients with CLL-LN metastases.



ILL-LND should be performed in every patient and only a minority of MTC patients with small micro-MTC, and low serum calcitonin levels should not have a CLL-LND.
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Marie-Maelle
MM
Chandeze
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Severine
S
Noullet
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Matthieu
M
Faron
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Christophe
C
Trésallet
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Gaelle
G
Godiris-Petit
Department of Pathology, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Frederique
F
Tissier
Department of Endocrinology, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Camille
C
Buffet
Department of Endocrinology, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Laurence
L
Leenhardt
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France.
Nathalie
N
Chereau
Department of General and Endocrine Surgery, Hospital Pitié Salpêtrière, APHP, University Pierre and Marie Curie (Paris VI), Paris, France. fabrice.menegaux@aphp.fr.|Service de Chirurgie Générale, Hôpital de la Pitie Salpêtrière, Paris Cedex 13, France. fabrice.menegaux@aphp.fr.
Fabrice
F
Menegaux
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002116:Calcitonin / Q000097:blood; D018276:Carcinoma, Medullary / Q000235:genetics / Q000556:secondary* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009333:Neck; D037981:Neck Dissection; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012307:Risk Factors; D012737:Sex Factors; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D047368:Tumor Burden
D002116:Calcitonin; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human