THE RELATIONSHIP BETWEEN BRAFV600E MUTATION AND THE CLINICOPATHOLOGICAL FEATURESOFTHEPAPILLARY THYROID CARCINOMA

Yi Shi, Yimingjiang. Maiweilidan, Xue-lian Pang, Zhi-ping Ma, Wen-li Cui, Wei-Zhang^* 

Pathology, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, China

There has been a dramatic increase in the morbidity of papillary thyroid carcinoma (PTC), which accounts for 85–90% of all thyroid malignancies. A somatic BRAF V600E oncogenic mutation has been recognized as the most frequent genetic alteration, occurring in approximately 32–83% of PTC cases and being associated with more aggressive clinical behaviors and worse prognoses. Still, the prognostic value of the mutation remains unvalidated, leading this study to investigate it by performing qPCR as well as immunohistochemistry (IHC) and analyzing the relationship between BRAF V600E mutation status and multiple clinicopathological features of 188 PTC patients. There was no significant difference in the prevalence of the mutation between patients of different gender (χ²=1.252, P=0.263), ethnicity (χ²=0.756, P=0.384) or age (younger than 40 years compared to 40 years or older; χ²=0.002, P=0.957). Also, the study found no association between the frequency of the BRAF V600E mutation and various pathological characteristics of PTC; characteristics considered were calcification (χ²=0.2186, P=0.640), hashimoto (χ²=0.072, P=0.789), tumor size (χ²=1.453, P=0.228), tumor multifocality (χ²=0.183, P=0.668), thyroid capsular invasion (χ²=0.138, P=0.710), vascular invasion (χ²=1.132, P=0.860) and lymph node metastasis (χ²=0.080, P=0.777). Considering that the mutation is widespread among PTC cases, it is speculated that the mutation is related to tumorigenesis rather than tumor progression. Moreover, the clinical value of an IHC approach to detecting the mutation was evaluated in comparison to the qPCR method; using IHC, the mutation was identified in 153 of 188 (81.38%) cases, whereas 160 (85.11%) patients were identified using the PCR assay. Thus, it can be concluded that the qPCR method features superior sensitivity to IHC.