Endocrine Abstracts

Introduction: BRAF (V600E) mutation is the most frequent detected genetic change in papillary thyroid cancer (PTC) and its presence has been related to aggressive clinical and pathological features. Lymph node metastases (LNMx) are common in PTC and are associated with an increase in loco-regional recurrence. However, prophylactic lymph node dissection is not routinely performed because of high rate of surgery complications. Therefore, there is a need to find a good marker to decide the extent of initial surgery.

Methods: We evaluated 31 patients (77.5% females) with pathological diagnosis of PTC. All of them underwent total thyroidectomy and 28 central lymph node dissection, being in 20 prophylactic. DNA was extracted from neoplastic cells and BRAF mutation was detected by PCR and sequencing. Analysis included age, preoperatively TSH, tumour size, multifocality, extrathyroidal extension (EET), LNMx, histological subtype, clinical stage and ultrasound features.

Results: The prevalence of the BRAF mutation (BRAF+) in our patients was 51.6%; 48.4% were negative (BRAF−). According to sex, 57% males and 45% females were BRAF+ (P=0.68). Mean age was 46.8 years in BRAF+ vs 55.4 in BRAF− (P=0.28); mean tumour size was 17.8 mm in BRAF+ vs 22.8 in BRAF− (P=0.35). Multifocality was present in 66.6% of BRAF− and 50% of BRAF+ (P=0.47). EET was found in 33% of BRAF− vs 56.2% of BRAF+ (P=0.28)). In 69% of BRAF+, classic variant of PTC was diagnosed, whereas 6% corresponded to follicular variant (P=0.07). Mean TSH level was 3.97 mU/l in BRAF+ vs 2.17 in BRAF− (P=0.35). The rate of central LNMx in patients undergoing PLNCD, was higher in BRAF+ than in BRAF− (63.6 vs 33%) (P=0.37). Thyroglobulin level before thyroid RAI ablation was 5.65 ng/ml in BRAF+ vs 3 ng/mL in BRAF− (P=0.9).

Conclusions: We did not find any significant association between BRAF+ and clinical and pathological features, not even with the presence of LNMx, probably due to the small size of the sample. Nevertheless, considering the high prevalence of occult LNMx in patients harbouring BRAF mutation, preoperative analyses of BRAF could possibly be helpful to decide initial surgery in patients affected of PTC, as it has been suggested previously.