Association between BRAF (V600E) mutation and clinicopathological features of papillary thyroid carcinoma: a Brazilian single-centre case series

Abstract

Objectives: We aimed to investigate the prevalence of the BRAF (V600E) mutation in consecutive cases of papillary thyroid carcinoma (PTC) in patients diagnosed and treated at the Hospital Sao Rafael (Salvador, BA, Brazil) and evaluate its association with clinical and pathological characteristics of PTC.

Subjects and methods: We retrospectively enrolled in the study a total of 43 consecutive PTC patients who underwent total thyroidectomy. We performed DNA extraction from formalin-fixed paraffin-embedded (FFPE) tumour tissue samples. Polymerase chain reaction (PCR) and direct sequencing were used to determine BRAF (V600E) mutation status. Univariate and multivariate logistic regression analyses were employed to identify independent associations.

Results: The prevalence of BRAF (V600E) mutation was 65.1% (28/43). A high frequency of older patients (p value: 0.004) was observed among the BRAF-mutated PTC group and, in contrast, a low frequency of concurrent Hashimoto's thyroiditis (HT) (p value: 0.011) was noted. Multivariate analysis confirmed that older age (OR: 1.15; 95% CI: 1.00 - 1.33; p value: 0.047) and HT (OR: 0.05; 95% CI: 0.006-0.40; p value: 0.005) were independent factors associated with BRAF (V600E) mutation.

Conclusion: We found a high prevalence of BRAF (V600E) mutation in PTC cases. Older age and no concurrent HT were independently associated with BRAF (V600E) mutation.

Figure 1. Representative DNA sequencing of BRAF exon 15. A) Absence of thymine to adenine replacement (T1799A), indicating a wild-type BRAF. B) Heterozygous BRAF (V600E) mutation.