Combination of ultrasound with BRAF V600E gene detection for the evaluation of aggressive behavior of papillary thyroid microcarcinoma

The Japanese clinical guidelines and the 2015 American Thyroid Association Management Guidelines recommend that indolent papillary thyroid microcarcinoma (PTMC) be monitored actively and that patients with aggressive PTMC immediately undergo surgery. This study aimed to establish a stage model and provide a reference for the preoperative identification of aggressive PTMC and indolent PTMC, which might guide the treatment of PTMC.

Risk factors for the aggressive PTMC were identified through multivariate logistic regression analysis. According to the regression coefficient, each risk factor was assigned a risk score; thereafter, a risk score (RS) model and a stage model were established.

The tumor’s largest diameter > 6 mm, BRAFV600E (v-Raf murine sarcoma viral oncogene homolog B1, V600E) mutation, ultrasound-suspected lymph node metastasis, ultrasound-suspected extrathyroidal extension, and microcalcification were identified as risk factors for aggressive PTMC. The stage model was divided into three stages: stage I (RS=0.0; predictive probability for PTMC aggressiveness <10%), stage II (RS=1.0–2.3; predictive probability for PTMC aggressiveness, 10–50%), stage III (RS=3.2–7.6; predictive probability for PTMC aggressiveness, >50%). Based on the abovementioned results, stages I and II were considered to be probably indolent PTMC, and stage III was considered as probably aggressive PTMC.

We suggest that patients with stages I and II PTMC be recommended for active surveillance, while those with stage III PTMC be recommended for immediate surgery.