The BRAF mutation is predictive of aggressive clinicopathological characteristics in papillary thyroid microcarcinoma.
BACKGROUND
This study analyzed the utility of BRAF mutation screening of ultrasonography-guided fine-needle aspiration biopsy (FNAB) specimens for predicting aggressive clinicopathological characteristics of papillary thyroid microcarcinoma (PTMC).


METHODS
We assessed the T1799A BRAF mutation status in FNAB specimens obtained from 61 PTMC patients before undergoing operations for PTMC. We examined whether the BRAF mutation was associated with clinicopathologic characteristics in PTMC. Additionally, we reviewed the BRAF mutation status, and clinical, ultrasound (US), hematological, and pathology records of the patients and analyzed the associations between these characteristics and lateral lymph node metastasis (LNM).


RESULTS
Analysis of the preoperative FNABs accurately reflected the BRAF status of the resected tissues in 19 of the 20 paired samples (95% concordance). We observed that the BRAF mutation was statistically significantly associated with multifocality, extrathyroidal invasion, lateral LNM, and advanced tumor stages III and IV. The BRAF mutation, pathologic features (central LNM), and US features (upper pole location) were independent predictive factors for lateral LNM in a multivariate analysis with odds ratios of 18.144 (95% confidence interval [95% CI], 1.999-164.664; P = 0.01), 8.582 (95% CI, 1.014-76.662; P = 0.049) and 9.576 (95% CI, 1.374-66.728; P = 0.023), respectively.


CONCLUSIONS
BRAF mutation-positive PTMCs were more likely to manifest aggressive characteristics (extrathyroidal extension and LNM). The BRAF mutation screening of FNAB specimens can be used to predict aggressive clinicopathological characteristics of PTMC. Lateral neck nodes should be meticulously analyzed for cases of PTMC demonstrating the following three characteristics: BRAF mutation, central LNM, and US features in the upper pole location.
Lin
Kuai-Lu
KL
Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China.
Wang
Ou-Chen
OC
Zhang
Xiao-Hua
XH
Dai
Xuan-Xuan
XX
Hu
Xiao-Qu
XQ
Qu
Jin-Miao
JM
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D044963:Biopsy, Fine-Needle; D002291:Carcinoma, Papillary / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology; D016896:Treatment Outcome; D055815:Young Adult
D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf