Correlation among the BRAF gene mutation status, clinicopathological features of primary tumour, and lymph node metastasizing of papillary thyroid carcinoma.

Abstract

Papillary thyroid carcinoma (PTC) is the most common malignant thyroid tumour. A common mutation of papillary thyroid carcinoma (PTC) is the somatic mutation of the BRAF (V600E) gene. The aim was to 1) determine the association of lymph node metastases of PTC with the BRAF gene mutation of primary tumour; 2) evaluate association of the BRAF mutation in the -primary tumour with clinicopathological para-meters; 3) examine the extent of genetic heterogeneity by monitoring the BRAF mutation in multicentric tumours. Retrospective analysis of the BRAF (V600E) mutation in PTC and PTC neck lymph node metastases in 156 patients operated from 2003 to 2012 in Prague and Zlín, the Czech Republic, using a qPCR assay. The results were correlated with clinicopathological factors. DNA was successfully extracted from 137 samples. The BRAF (V600E) mutation was detected in 78 cases (56.9%). The patients with BRAF p.Val600Glu mutation of primary tumour had only non-significantly higher risk of cervical lymph node metastases [OR=2.39 (95%) CI 1.00-5.75, p=0.052]. In the classic papillary variant, the BRAF (V600E) mutation was found significantly more often than in other PTC subtypes (p=0.022). We did not confirm any significant association between the BRAF (V600E) mutation and other clinicopathological findings. Except for the higher prevalence in papillary variant of PTC, BRAF p.Val600Glu mutation was not associated with other prognostic clinicopathological factors of PTC. BRAF mutation cannot be regarded as a reliable marker of node metastases in patients with PTC.