BRAF V600E expression in ameloblastomas-A 36-patient cohort from Helsinki University Hospital

: Jetta Kelppe, Hanna Thorén, Ari Ristimäki, Caj Haglund, Timo Sorsa, Jaana Hagström

Publisher: WILEY

: 2019

: Oral Diseases

: ORAL DISEASES

: ORAL DIS

: 25

: 4

: 1169

: 1174

: 6

: 1354-523X

: 1601-0825

DOI: https://doi.org/10.1111/odi.13072

: https://research.utu.fi/converis/portal/detail/Publication/40203941

Objectives: We aimed to investigate BRAF V600E percentage immunohistochemically in ameloblastomas of a single institute cohort. We were interested if age, location, histological properties, or tumor recurrence depend on the BRAF status.
Subjects, materials and methods: We had 36 formalin-fixed, paraffin-embedded ameloblastoma tissue samples of patients treated at the Helsinki University Hospital between the years 1983-2016. Tissue sections underwent immunohistochemistry by Ventana BenchMark XT immunostainer using Ms Anti-Braf V600E (VE1) MAB. We used R 3.4.2 and RStudio 1.1.383 to conduct statistical analysis for BRAF positivity and earlier onset as well as tumor location. We used chi-squared tests and 2-by-2 table functions to determine connections between BRAF positivity and recurrence, growth pattern, and type.

Results: BRAF-positive tumors occurred in younger patients compared to BRAF-negative tumors (p = 0.015) and they located mostly to the mandible (p < 0.001). Growth patterns were limited to two in BRAF-negative tumors when BRAF-positive tumors presented with one to four growth patterns (p = 0.02). None of the maxillary tumors showed BRAF positivity and of these, 72.2% recurred.
Conclusions: An immunohistochemical BRAF marker could be a beneficial tool to predict the outcome of patients with this aggressive, easily recurring tumor.

BRAF_V600E_expression_in_ameloblastomas.pdf