Prognostic Value of Genetic Mutations in Thyroid Cancer: A Meta-Analysis

Background: Genetic mutations have been found to be associated with thyroid cancer. Previous studies have been focused on the relation between genetic mutations and thyroid cancer. We sought to evaluate the prognostic value of the three most common genetic mutations (BRAF, RAS, and RET) in patients with thyroid cancer. Methods: Sources from MEDLINE (inception to December 2013) and EMBASE (inception to December 2013) were searched. Studies of thyroid cancer with results of genetic mutations and studies that reported survival data were included and two authors performed the data extraction independently. Any discrepancies were resolved by a consensus. Results: Fourteen studies assessing BRAF mutations, 6 RAS mutations, 4 RET mutations, and 1 with analysis of both BRAF and RAS mutations were included in this meta-analysis. Patients with papillary thyroid cancer with BRAF mutations showed a 1.59-fold higher risk of events or a 2.66-fold higher risk of death than patients with papillary thyroid cancer without a BRAF mutation. Also, patients with RAS mutations showed a 2.90-fold higher risk of death by thyroid cancer than patients without a RAS mutation. In addition, patients with medullary thyroid cancer with RET mutations showed a 5.82-fold higher risk of death by the disease than without a RET mutation. Conclusions: Genetic mutations should be considered as a poor prognostic marker in thyroid cancer and may lead to better management of individual patients. However, the use of genetic mutations as prognostic markers should not be generalized, but individualized in the specific clinic setting.