Clinical significance of the BRAF ^V600E mutation in PTC and its effect on radioiodine therapy

Abstract

The goal of this study was to explore the relationship of the BRAF ^V600E mutation with clinicopathologic factors and evaluate the effect of radioactive iodine (RAI) therapy in a large group of intermediate- and high-risk papillary thyroid cancer (PTC) patients with the BRAF ^V600E mutation and without distant metastases. We collected data for PTC patients who underwent total or near-total thyroidectomy and RAI treatment in our hospital from January 2014–December 2017. There were 1220 PTC patients who met the criteria, and the BRAF ^V600E mutation was observed in 979 of them (80.2%). Multivariate analysis identified that the BRAF ^V600E mutation remained independently associated with age at diagnosis, and bilaterality (OR = 1.023, 95% CI = 1.012–1.039, P < 0.001; OR = 1.685, 95% CI = 1.213–2.341, P = 0.002, respectively). In addition, the patients with bilateral PTCs had a higher prevalence of extrathyroid invasion, capsular invasion and fusion of metastatic lymph nodes than the unilateral PTC patients. The response to RAI therapy was evaluated in both the entire series and the patients with a high recurrence risk; no significant difference was discerned between the BRAF ^V600E mutation and the wild-type groups ( P = 0.237 and P = 0.498, respectively). To summarize, our results confirmed that PTC patients with the BRAF ^V600E mutation exhibit more aggressive characteristics. In addition, the patients with bilateral PTC have a higher incidence of extrathyroid invasion. Moreover, BRAF ^V600E mutation PTC patients did not show a poorer clinical response after postsurgical RAI therapy, suggesting that RAI therapy may improve the general clinical outcome of these patients.