[BRAFV599E mutation and RET/PTC rearrangements in papillary thyroid carcinoma].

OBJECTIVE

To detect the BRAF(V599E) mutation and the RET/PTC chimeric gene in benign and malignant thyroid diseases and to explore their correlation with the clinicopathologic features of papillary thyroid carcinoma (PTC).

METHODS

PCR and RT-PCR were employed to detect BRAF(V599E) mutation and RET/PTC chimeric genes in 95 frozen and parraffine-embeded thyroid tissue.

RESULTS

(1) BRAF(V599E) mutation was detected only in PTC (56%, 37/66) and had a high prevalence in both classic and tall cell types (70%, 29/41 and 2/3). However, follicular types of PTC and other benign and malignant thyroid diseases were negative for BRAF(V599E) mutation. (2) Fourteen (21.2%) PTC cases expressed RET/PTC chimeric gene. Among them, 5 cases (7.6%) were RET/PTC1 and 9 cases (13.6%) were RET/PTC3 respectively. (3) Statistic data did not show any correlation between the BRAF(V599E) mutation, RET/PTC and clinicopathologic features of PTC (P > 0.05). There was no overlap between BRAF(V599E) mutation and RET/PTC rearrangements.

CONCLUSIONS

(1) BRAF(V599E) mutation and RET/PTC rearrangements were unique to PTC. The high prevalence of BRAF(V599E) mutation indicates that it is an important molecular hallmark of PTC. (2) BRAF(V599E) mutation rate was high in classic type PTC and tall cell type inferred that BRAF(V599E) mutation played an important role in their etiopathogenesis. (3) There was no overlap between BRAF(V599E) mutation and RET/PTC rearrangements suggest that they are alternative events in PTC.