PROGNOSTIC VARIABLES AFFECTING PRIMARY TREATMENT OUTCOME FOR MEDULLARY THYROID CANCER

Abstract

(Endocr Pract. 2017;23:1053-1058) Abbreviations: ATA = American Thyroid Association; BRFS = biochemical recurrence-free survival; CND = central neck dissection; Ct = calcitonin; DFS = disease-free survival; MTC = medullary thyroid carcinoma; OR = odds ratio; OS = overall survival; pCND = prophylactic CND INTRODUCTION Medullary thyroid carcinoma (MTC) is a relatively uncommon tumor that arises from the calcitonin (Ct)-secreting parafollicular C-cells of the thyroid gland (1). Survival endpoints included overall survival (OS), disease-free survival (DFS, defined as no structural evidence of recurrent disease on clinical exam or imaging), and biochemical recurrence-free survival (BRFS). Because this study was performed retrospectively across a large time frame, not all patients were evaluated with the same Ct assay. Logistic regression was used to evaluate the effect of continuous independent variables on binomial dependent variables (i.e., presence of neck metastases as a function tumor size). According to the 2015 ATA recommendations, pCND (level 6) is indicated for all patients, while prophylactic lateral neck dissection can be considered based on pre-operative Ct levels (5).