Clinical Significance of BRAF^V600E Mutation in Papillary Thyroid Carcinoma

Objective To investigate the expression of BRAF^V600E mutation in papillary thyroid carcinoma and analyze its relationship with clinicopathological features. Methods Immunohistochemistry was used to detect the expression of BRAF^V600E mutant protein in 244 patients with papillary thyroid carcinoma and adjacent tissues. The relationship between BRAF^V600E mutation and clinicopathological parameters was analyzed with clinical pathological data. Results BRAF^V600E mutant protein was expressed only in papillary thyroid carcinoma, and the expression rate was 86.48%. The non-tumor tissue adjacent to the tumor was not expressed. The expression rate was 88.89% in classic papillary thyroid carcinoma, 85% in lymph node metastasis group, and 94.64% in capsule invasion group, which were higher than follicular type（78.18%）（χ²=4.176,P=0.041）, non-lymph node metastasis group （68.42%）（χ²=4.526,P=0.033） and non-capsule invasion group （84.04%）（χ²=4.145,P=0.042）, respectively, and corresponding comparison have significant statistical difference（P<0.05）. There were no significant differences between the different tumor diameters, ages, genders and lesions number（P>0.05）. Conclusion BRAF^V600E mutant protein is highly expressed in papillary thyroid carcinoma, and its expression is significantly associated with lymph node metastasis and capsular invasion. It suggests that BRAF^V600E mutation may be associated with tumor invasion and may be a predictor of papillary thyroid carcinoma prognosis.