BRAF 1799T>A Mutation Frequency in Mexican Mestizo Patients with Papillary Thyroid Cancer

Abstract

Thyroid cancer is the most frequent endocrine malignancy, and its incidence and prevalence are increasing worldwide. Despite its generally good prognosis, the observed mortality rates are higher in the less-developed regions. This indicates that timely diagnosis and appropriate initial management of this disease are important to achieve a positive outcome. We performed an observational study in order to describe the frequency of the BRAF 1799T>A mutation in Mexican mestizo patients with thyroid nodules, a scarcely studied ethnic group with large populations. Competitive allele-specific Taqman PCR was performed in 147 samples of thyroid tissue DNA obtained from patients histologically diagnosed with papillary thyroid cancer (PTC), colloid goiters, and follicular adenomas. The BRAF 1799T>A mutation frequency was 61.1% in PTC samples (p = 4.99 × 10-11). Potential diagnostic values were as follows: sensitivity, 61.1%; specificity, 96%; PPV, 94.2%; NPV, 69.5%; accuracy, 77.9%. Taking into account the fact that this mutation is not frequently found in cytologically indeterminate nodules, we suggest that the BRAF mutational analysis should be implemented in the clinical setting along with other diagnostic criteria such as USG, in order to contribute to diagnosis and to surgical decision-making during the initial management of thyroid nodules in Mexican public hospitals.