BRAF(V600E) mutation is not a positive predictor for distant metastasis in sporadic papillary thyroid carcinoma.

BACKGROUND: BRAF(V600E) 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 BRAF(V600E) 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 BRAF(V600E) mutation, while immunohistochemistry was performed to detect vascular endothelial growth factor (VEGF) expression. The associations between distant metastasis and BRAF(V600E) 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 BRAF(V600E) mutation, which was significantly lower than in the without distant metastasis group (68.8%, P < 0.001). BRAF(V600E) 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 BRAF(V600E) 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). BRAF(V600E) mutation was negatively correlated with distant metastasis in adult subgroup analysis (P = 0.005) but was not an independent parameter.

CONCLUSIONS: BRAF(V600E) mutation is predictive for distant metastasis in papillary thyroid carcinoma but not positively. VEGF may be involved in the pathogenesis of distant metastasis.