유두상 갑상선암에서의 BRAF 변이와 임상병리학적 인자와의 관계

Relationship between BRAF Mutations in Papillary Thyroid Carcinomas and Clinicopathologic Factors

Purpose: Papillary thyroid carcinomas (PTCs) account for about 80% of all thyroid cancers. B-Raf proto-oncogene serine/threonine-protein kinase (BRAF) transversion mutation T1796A is present in 29&#8764;69% of PTCs, and is a potential prognostic marker for PTC as it may be associated with aggressive tumors. This study investigated the prevalence of BRAF exon 15 T1796A in thyroid tissues obtained by a thyroidectomy, and correlation of the mutation with clinicopathological factors. Methods: One hundred nine PTC patients as determined histologically by thyroidectomy between January 2007 and June 2009 were evaluated to detect T1796A in intraoperative fresh tissue. The mutation was sought in all specimens using DNA sequencing. Results: The mean patient age at surgery was 45.1 years and tumors had a median tumor diameter of 11.4 mm. At the time of diagnosis, 28 of the 109 patients presented with some kind of extrathyroideal invasion of the tumor, and 48 had lymph node metastases. Sixty two patients were stages 1 or 2. There was no distant metastasis, A missense mutation was found at T1796A in exon 15 in 35 of the 109 (32%) PTCs. In patients with conventional papillary thyroid cancer, the BRAF<SUP>V600E</SUP> mutation was significantly associated with lymph node metastasis (P=0.024), high TNM stage (1 and 2 vs. 3 and 4, P=0.022), tumor size (P=0.01) and capsular invasion (P=0.033). Conclusion: The BRAF<SUP>V600E</SUP> mutation is a poor prognostic factor independent from other clinicopathological features. (Korean J Endocrine Surg 2010;10:147-151)