BRAFV600E status and clinical characteristics in solitary and multiple papillary thyroid carcinoma: experience of 512 cases at a clinical center in China

BACKGROUND Papillary thyroid carcinoma (PTC) is one of the most frequent endocrine malignancies. In most cases, it often presents as multifocal tumor. It has been reported that multifocal tumors are associated with elevated risk of lymph node and distant metastases. Multifocality is also one of the factors predicting prognosis. Recent studies show that BRAFV600E mutation occurs more frequently in aggressive PTC. The purpose of this study was to evaluate BRAFV600E status and clinicopathological features in multiple and solitary PTC. METHODS We performed a retrospective study to analyze 512 PTC cases who received surgery, including 376 solitary PTCs and 136 multiple PTCs. RESULTS Multiple PTC is more related to lymph node metastasis and vascular invasion than solitary PTC. However, the distant metastasis rate and 10-year survival rate showed no difference between these two groups. BRAFV600E mutation status was more frequent in multiple PTC patients with lymph node metastasis and late stage at diagnosis. CONCLUSION BRAFV600E mutation is most commonly associated with extra-thyroidal extension and lymph node metastasis in PTC. Multiple PTC patients with young age, large tumors and BRAFV600E mutation should be followed carefully. Our study provides useful information for PTC patients' followup and treatment.