BRAF V600E mutation is associated with tumor aggressiveness in papillary thyroid cancer.

BACKGROUND

The BRAF(V600E) mutation is the most common genetic alteration found in papillary thyroid cancer (PTC). Recent studies show that this mutation occurs more frequently in patients with PTC showing aggressive clinicopathologic features. The aim of the present study was to evaluate the prevalence of the BRAF(V600E) mutation in tumor samples and its association with high-risk clinicopathologic features prospectively.

PATIENTS AND METHODS

From February 2009 to January 2010, 547 PTC patients who underwent surgery in Seoul National University Hospital were enrolled in the study. Polymerase chain reaction was used to amplify exon 15 of the BRAF gene from paraffin-embedded thyroid tumor specimens, followed by direct sequencing to detect the BRAF(V600E) mutation. Both univariate and multivariate analyses were performed to analyze associations between the BRAF(V600E) mutation and clinicopathologic features.

RESULTS

The BRAF(V600E) mutation was found in 381/547 (69.7%) patients with primary PTC. The BRAF(V600E) mutation was significantly associated with age (≥ 45 years), tumor size (>1 cm), extrathyroidal extension, and cervical lymph node metastases (P < 0.05). Multiple logistic regression showed that it was significantly associated with gender (OR = 1.834; 95% CI 1.021-3.463), tumor size (OR = 1.972; 95% CI 1.250-3.103), and extra-thyroidal extension (OR = 2.428; 95% CI 1.484-3.992), but not with age, multifocality, lymph node metastases, and advanced disease stage. The proportion of BRAF(V600E) mutation was significantly associated with the number of high-risk factors of tumor recurrence (P < 0.001).

CONCLUSIONS

The BRAF(V600E) mutation was associated with high-risk clinicopathologic characteristics in patients with PTC. The BRAF(V600E) mutation may be a potential prognostic factor in PTC patients.