Correlation of papillary thyroid carcinoma different subtypes BRAF mutation and ultrasonic characteristics

Abstract

Objective To investigate the correlation of BRAF mutation frequency with cervical lymph node metastasis, and to compare the ultrasonic characteristics in patients with BRAF mutation in papillary thyroid carcinoma (PTC) different subtypes. Methods The tumor samples were collected from 139 PTC patients who underwent thyroidectomy. And they were classified by histological subtype into 3 groups: classic variant of papillary thyroid carcinoma (CVPTC) group(34 cases), follicular variant of papillary thyroid carcinoma (FVPTC) group(36 cases), tall cell variant (TCV) group(69 cases). The BRAF mutation frequency and the correlation with cervical lymph node metastasis among 3 groups were analyzed, then the ultrasonic characteristics with BRAF mutation in PTC different subtypes were compared. Results ①The frequency of BRAF mutation was statistically significant different in different subtypes(χ2=6.390, P=0.041), and the frequency in TCV was 86.9%. There was also a statistical difference between BRAF mutation frequency and cervical lymph node metastasis among three subtypes (χ2=13.106, P=0.041). ②There was no statistically significant difference among the three groups in nodule number, echo level, internal structure, boundary, crossbar, morphology and acoustic halo of patients with BRAF mutation (P>0.05). ③A single factor analysis was performed for the ultrasonographic characteristics of patients with BRAF mutation, and there were significant statistical differences among the 3 groups in calcification type (χ2=21.7, P=0.001) and close to the envelope (χ2=7.726, P=0.021). ④Multivariate logistic regression showed that BRAF mutation was an independent influence factor affecting the calcification type of different histological subtypes in PTC patients. Conclusions ①BRAF mutation is correlated with cervical lymph node metastasis in different PTC subtypes. ②BRAF mutation is an independent influence factor affecting the morphology type of different calcification subtypes in PTC. The CVPTC group is mainly microcalcification, and the TCV group is mainly macrocalcification. Key words: Ultrasonography; Papillary thyroid carcinoma; Subtypes; BRAF gene