The Association Between Radioiodine Refractory in Papillary Thyroid Carcinoma, Sodium/Iodide Symporter Expression, and BRAFV600E Mutation

Objective: To study the association between radioiodine refractory papillary thyroid carcinoma, sodium/iodide symporter (NIS) expression, and the BRAF(V)(600E) mutation. Methods: A study was conducted on 30 radioiodine refractory papillary thyroid carcinoma patients and 30 radioiodine-avid papillary thyroid carcinoma patients. The expressions of sodium/iodide symporter and BRAF(V)(600E) mutated protein were determined by immunohistochemistry using formalin-fixed, paraffin-embedded tissue. Results: The mutated BRAF(V)(600E) protein was identified in 26 radioiodine refractory papillary thyroid carcinoma subjects (86.7%) and 22 radioiodine-avid papillary thyroid carcinoma subjects (73.3%), with no significant difference between the 2 groups (P = 0.3). Sodium/iodide symporter expression was detected in 4 of 30 cases (13.3%) from the radioiodine-avid papillary thyroid carcinoma group but was negative for all radioiodine refractory cases. There was no association between sodium/iodide symporter expression and radioiodine refractory papillary thyroid carcinoma (P = 0.11). Cases with positive NIS expression were likely negative for BRAF(V)(600E )mutation (3/4; P = 0.02). Conclusion: Papillary thyroid carcinomas with BRAF(V)(600E) mutation were more likely to be negative for NIS expression. BRAF(V)(600E) mutation and NIS expressions cannot be used to predict radioiodine sensitivity.

Automated summary

The study found that papillary thyroid carcinomas with BRAF(V)(600E) mutation were more likely to be negative for NIS expression. Both BRAF(V)(600E) mutation and NIS expression cannot be used as predictors for radioiodine sensitivity.