[Clinical, morphological, and prognostic features of papillary thyroid carcinoma with different BRAF mutational status assessed by immunohistochemistry].

The somatic mutation in BRAFT1799A (BRAFV600E ), the data on the prognostic role of which are contradictory, is one of the most common molecular genetic abnormalities in the cells of papillary thyroid carcinoma (PTC).

OBJECTIVE: To investigate the association of the immunoexpression of mutant BRAF in PTC with different morphological characteristics and long-term treatment results in patients.

MATERIAL AND METHODS: Information on inpatients with PTC was obtained from the database of the Pathology Department, A.F. Tsyb Medical Radiology Research Center (a branch of the National Medical Radiology Research Center, Ministry of Health of the Russia). The paraffin-embedded blocks of surgically removed primary, metastatic, and recurrent PTC tissues were cut and stained with hematoxylin and eosin and anti-mutant BRAF monoclonal antibodies. The results of immunohistochemical tests were assessed and the frequency of BRAF immunoexpression was analyzed in relation to various clinical and morphological parameters of tumor growth, the pattern and volume of treatment in the patients, by taking into account its long-term results (the presence or absence of tumor recurrence and metastases in the postoperative period).

RESULTS: The expression of mutant BRAF (BRAF+) was noted in 29 (39.3%) of the 74 cases of PTC. The BRAF+ group differed from the BRAF group by a higher proportion of male patients, older age, advanced clinical stage of carcinoma, a predominance of papillary structure of tumors, and a higher frequency of their recurrence and/or metastases in the postoperative period.

CONCLUSION: The immunohistochemical assessment of BRAF status opens up a possibility to predict local recurrence and metastases in the postoperative period in patients treated for PTC.