BRAFV600E mutation is not a positive predictor for distant metastasis in sporadic papillary thyroid carcinoma

摘要

Background BRAFV600E mutation is correlated with local aggressive clinicopathological features in papillary thyroid carcinoma; yet the relationship between this genetic variation and distant papillary thyroid carcinoma metastasis was unclear.This study aimed to investigate whether BRAFV600E is predictive for distant metastasis in the Chinese population.Methods One hundred and seven patients with papillary thyroid carcinoma were enrolled in this study,including 43 patients with distant metastasis and 64 patients without.Quantitative real-time polymerase chain reaction was used to detect BRAFV600E mutation,while immunohistochemistry was performed to detect vascular endothelial growth factor (VEGF) expression.The associations between distant metastasis and BRAFV600E mutation,and VEGF expression as well as local clinicopathological factors were determined.Results A total of 28.6％ of the patients in the distant metastasis group harbored BRAFV600E mutation,which was significantly lower than in the without distant metastasis group (68.8％,P ＜0.001).BRAFV600E mutation was negatively correlated with positive VEGF expression (P=0.001).Furthermore,52.2％ of the patients with distant metastasis exhibited VEGF expression,compared with 25.0％ of those without.Higher levels of VEGF expression were also observed in the distant metastasis group.Tumor size,extra-thyroid invasion,and BRAFV600E mutation were independent predictors for distant metastasis according to multivariate analysis (odds ratios were 2.8,12.4,and 0.3; 95％ CI 1.483-5.334,and 2.950-52.407,0.100-0.890; P=0.002,0.001,and 0.030,respectively).BRAFV600E mutation was negatively correlated with distant metastasis in adult subgroup analysis (P=0.005) but was not an independent parameter.Conclusions BRAFV600E mutation is predictive for distant metastasis in papillary thyroid carcinoma but not positively.VEGF may be involved in the pathogenesis of distant metastasis.