Prognostic role of the BRAF V600E variant in the preoperative biopsy in differentiated thyroid cancer

The incidence of thyroid carcinoma (TC) has increased worldwide, and the prognostic role of the BRAF V600E variant is controversial.

This study aims to define its prognostic role in TC, as defined in the preoperative period. This is a STROBE-compliant cohort study of patients with differentiated TC treated in a cancer center. Exposure was the presence of the BRAF V600E variant in the cellular blocks from the fine-needle aspiration biopsy; the outcome were the TC recurrence and recurrence-free survival (RFS).

Eighty-seven patients with TC were included; 65 were women (74.7%), 64 (73.6%) papillary TC and 55 (63.2%) had the BRAF V600E variant. Ten patients (11.5%) were low-, 33 (37.9%) intermediate-, and 44 (50.6%) high-risk. The BRAF V600E variant was associated with RFS in non-papillary subtypes. By bivariate analysis, the BRAF V600E variant was not clearly associated with recurrence. Nonetheless, by multivariate analysis, males (Hazard ratio [HR] 2.608, 95% Confidence interval [CI] 1.28-5.32), tumor size (HR 1.209; 95% CI 1.07-1.36), poor differentiation (HR 2.16; 95% CI 1.03-4.56), extrathyroidal invasion (HR 3.04; 95% CI 0.91-10.8), presence of BRAF V600E variant (HR 2.16; 95% CI 0.98-4.73) and adjuvant ¹³¹I dose ≥ 200mCi (HR 2.54; 95% CI 1.21-5.34) were independently associated with RFS.

The BRAF V600E variant, determined by cytology in the preoperative setting was independently associated with decreased RFS in males, large tumors, poor grade and extrathyroidal invasion. This multivariate model could contribute to define risk in the preoperative setting to design treatment strategy.