Factors associated with BRAF V600E gene mutation in patients with undiagnosed papillary thyroid carcinoma by fine needle aspiration cytology

To investigate the associated factors of BRAF V600E gene mutation in patients classified as Bethesda I~V nodes by fine needle aspiration cytology (FNAC) but confirmed as papillary thyroid carcinoma (PTC) by postoperative histopathology.

A retrospective analysis was performed on the clinical data of the patients with FNAC classification of Bethesda I~V but confirmed by postoperative histopathology as PTC who were treated in our hospital from June 2020 to June 2021. According to the results of BRAF V600E gene test in preoperative puncture specimens, the patients were divided into mutation positive group and negative group. The clinical data were compared between the 2 groups, and the indicators associated with BRAF V600E gene mutation were analyzed.

Of the 127 enrolled patients, they were 27 males (21.26%) and 100 females (78.74%), with a mean age of 42.51 years (median age: 42 years). Eight-two patients (64.57%) harbored the BRAF V600E gene mutation, and 45 (35.43%) did not. Univariate analysis showed that there were significant differences in the capsular boundary, nodule morphology, abnormal cervical lymph nodes, TIRADS grade, FNAC class, and T-stage between the 2 groups (P<0.05). Multivariate logistic regression analysis indicated that capsular boundary and abnormal cervical lymph nodes were independent influencing factors of BRAF V600E gene mutation in these patients. ROC curve analysis suggested that the area under the curve (AUC) was 0.921 (95%CI: 0.876~0.967), with a sensitivity and specificity of 82.9% and 86.7%, respectively, when taking capsular boundary, nodule morphology, abnormal cervical lymph nodes and TIRADS grade combined together.

BRAF V600E gene mutation is associated with capsular boundary, nodule morphology, abnormal cervical lymph nodes on ultrasonogram, TIRADS grade, FNAC class, and T-stage in PTC patients. Among them, ultrasonographic indication of abnormal cervical lymph nodes and the boundary between nodules and capsule can be used to predict BRAF V600E gene mutation.