Background: Thyroid carcinoma is the most common endocrine malignancy. BRAF (V600E) mutation is the most frequent detected genetic change in papillary thyroid carcinomas (PTC). There are some discrepancies regarding the overall frequency of the mutation, its prevalence in PTC-variants and its relationship with clinicopathological parameters of poor outcome.
Aims: To investigate the relationship of clinicopathological features of PTC with BRAF mutation with particular reference to histological subtype.
Patients and methods: We analysed 97 patients (77.3% female, mean follow up 33.9±26.7 months) with pathological diagnosis of PTC. DNA was extracted from tissues blocks or fresh tissue and BRAF (V600E) mutations were detected by PCR and sequencing. Univariate (χ2 and Students t test) and multivariate analysis were realised.
Results: BRAF (V600E) was detected in 45.4% of the study group. The prevalence of mutation was found in 54.4% of classical PTC, 22.2% of follicular variant and 30.8% of microcarcinomas (P< 0.05).
BRAF (V600E) mutation was associated with male sex (P<0.05), extrathyroidal extension (P< 0.05) and with tumours of greater size or locally invasive (T1+T2 versus T3) (P<0.05). There were no associations with age, tumour size, multicentricity or lymph node metastasis. BRAF (V600E) was negatively associated with the presence of distant metastasis in our group (P<0.05). By multivariate analysis, there was not any parameter independently associated with the presence of BRAF (V600E) mutation.
Conclusions: Our data suggest that BRAF (V600E) mutation is associated with some histological subtypes of PTC and with cancers with locally invasive growth. The small number of cases in this report could explain the insufficient statistical significance in multivariate analysis.
30 Apr - 04 May 2011
European Society of Endocrinology