A Study Of The Prognostic Significance Of BRAF V600E Mutation In Multifocal Papillary Thyroid Carcinoma Based On Clonal Original Analysis

Objective:To study the clonal origin of multifocal papillary thyroid cancer as well as the prognostic significance of BRAF V600E mutation in thyroid cancer.Materials and methods:Paraffin specimens from thirteen surgery patients with multifocal papillary thyroid cancer are visualized by HE staining method to confirm the pathological diagnosis. Tumor cells are obtained by the laser capture microdissection system. Genomic DNA is extracted via QIAamp DNA FFPE Tissue Kit. Using the PCR assay involving the HUMARA gene and BRAF gene, we analyzed the patterns of X chromosome inactivation as well as the BRAF mutations of multiple distinct foci of multifocal papillary thyroid cancer.Results:5of11patients were independent clonal origins via X chromosome inactivation analysis,6of13were independent clonal origins via analysis the patterns.of the BRAF mutations.6of13patients were BRAF mutation-positive. No significant differences were observed in the average tumor diameter or the LNMs between2groups of PTCs with or without the BRAF mutation. But a significant difference is revealed in the age between the2groups. Conclusion:The distribution of BRAF mutation is heterogeneous. Intrathyroid metastasis may play an important role in the development of the multifocal papillary thyroid cancer. No significant differences were observed in the average tumor diameter or the LNMs between2groups of PTCs with or without the BRAF mutation. BRAF mutation may be a secondary genetic event in PTC. But a significant difference is revealed in the age between the2groups.