Impact of clinical risk scores and BRAF V600E mutation status on outcome in papillary thyroid cancer.

Background: To evaluate the relationship between the BRAF V600E mutation and clinicopathologic parameters and to assess the impact of the BRAF V600E mutation and established risk scores on survival in patients with papillary thyroid carcinoma (PTC).

Methods: Retrospective analysis of a consecutive, single-institutional cohort of patients with PTC larger than 1 cm. Clinical risk scores according to the Metastases, Age, Completeness of Resection, Invasion, Size (MACIS), European Organisation for Research and Treatment of Cancer (EORTC), and tumor, node, metastases (TNM) scoring systems were determined. BRAF exon 15 mutation analysis was performed by polymerase chain reaction and Sanger sequencing.

Results: BRAF V600E mutations were found in 75/116 (65%) PTC. The rates for 5- and 10-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were 92% and 87%, 98% and 96%, and 96% and 94%, respectively. Low MACIS scores were associated with longer OS (10 y 95% vs 75%, P = .008), DSS (10 y 100% vs 89%, P = .02) and RFS (100% vs 85%, P = .006). Comparable survival advantages were observed for patients with early EORTC scores and low TNM stage. BRAF V600E mutation status was not associated with clinicopathologic characteristics of aggressive behavior such as extrathyroidal extension, lymph node metastases, higher T-categories, male sex, and greater age. Furthermore, BRAF V600E mutation status was not correlated with clinical risk scores and decreased survival.

Conclusion: In concordance with other studies, we did not find a negative prognostic impact of a positive BRAF V600E mutation status on survival. In contrast, the risk algorithms MACIS, EORTC score, and TNM stage were associated with impaired prognosis. Therefore, clinical staging systems represent better tools for risk stratification than BRAF V600E mutation status.