Clinical significance of the BRAF V600E mutation in multifocal papillary thyroid carcinoma in Korea.Surgery. 2014 Apr; 155(4):689-95.S
We examined the frequency of the BRAF(V600E) mutation and compared the clinicopathologic features based on the BRAF(V600E) mutation status in multifocal papillary thyroid carcinoma (PTC).
A total 85 patients who were diagnosed with multifocal PTC were enrolled. We confirmed the status of the BRAF(V600E) mutation in each tumor focus by the real-time polymerase chain reaction technique.
Among the 85 patients, 49 (57.6%), 34 (40.0%), and 2 (2.4%) patients were determined to have all BRAF(V600E)-positive, mixed BRAF(V600E), and all BRAF(V600E)-negative in their tumor foci, respectively. When we compared clinicopathologic features according to the BRAF(V600E) mutation status of the dominant tumor, the BRAF(V600E) -positive group (n = 70) showed more extrathyroidal invasion in the dominant tumor (32.9% vs 6.7%, P = .041) and more lymph node metastasis (67.2% vs 40.0%, P = .049) than the BRAF(V600E) -negative group (n = 15). Considering all tumor foci, the all BRAF(V600E) mutation group exhibited a younger population (P = .039), showed increased extrathyroidal invasion (38.8% vs 14.7%, P = .017) and lymph node metastasis (71.4% vs 48.4%, P = .038), and received more radioactive iodine therapy (79.2% vs 52.9%, P = .012) than the mixed BRAF(V600E) mutation group. A larger tumor size and heavier preoperative body weight was positively correlated with the relative expression of BRAF(V600E) mutation calculated by 2(-△△Ct) method.
Most of the Korean patients with multifocal PTC had the BRAF(V600E) mutation in one or more tumor foci, and all BRAF(V600E)-positive multifocal PTC showed more aggressive features.