Prognostic impact of N staging in 715 medullary thyroid cancer patients: proposal for a revised staging system.

Abstract

OBJECTIVE:

This institutional study aimed at quantifying a medullary thyroid cancer (MTC) patient's risk of lung, liver, or bone metastasis.

BACKGROUND:

Without quantitative information regarding risk factors for lung, liver, and bone metastasis, risk stratification is liable to be haphazard, resulting in poor cost-effectiveness of screening programs.

METHODS:

Included in this study were 715 patients with MTC for whom histopathologic information was available for each lymph node removed.

RESULTS:

Seventy-two patients (10.1%) were diagnosed with lung metastasis, 58 patients (8.1%) with liver metastasis, and 34 patients (4.8%) with bone metastasis. Multivariate analyses were limited to patients revealing no more than 1 type of distant metastasis to avoid confounding by other distant metastasis. Extrathyroidal extension and 1 to 10 involved nodes indicated a small risk of lung metastasis [3%-4%; odds ratio (OR) 3-4], tumors greater than 40 mm and 11 to 20 involved nodes implied an intermediate risk (13%; OR 6), and more than 20 involved nodes entailed a high risk (26%-30%; OR 14-16). In the multivariate logistic regressions on liver and bone metastasis, in which the number of involved nodes was omitted on statistic grounds, extrathyroidal extension signified a strong risk of liver metastasis (19%, OR 23), whereas no clinical-pathologic variables were significantly associated with bone metastasis. Cumulative rates of lung, liver, and bone metastasis, plotted against the number of lymph node metastases, were similar.

DISCUSSION:

N categories encompassing 1 to 10 (N1), 11 to 20 (N2), and more than 20 (N3) lymph node metastases are important prognostic classifiers that should be incorporated into MTC staging systems for better risk stratification.

• Authors: Andreas Machens, Henning Dralle
• Journal: Annals of surgery (Ann Surg) Vol. 257 Issue 2 Pg. 323-9 (Feb 2013) ISSN: 1528-1140 [Electronic] United States
• PMID: 22968075 (Publication Type: Journal Article)

Topics

• Adult
• Bone Neoplasms (secondary)
• Carcinoma, Medullary (pathology)
• Female
• Humans
• Immunohistochemistry
• Liver Neoplasms (secondary)
• Lung Neoplasms (secondary)
• Lymphatic Metastasis
• Male
• Middle Aged
• Multivariate Analysis
• Neoplasm Staging (classification)
• Prognosis
• Risk Assessment
• Thyroid Neoplasms (metabolism, pathology, surgery)
• Thyroidectomy