Sensitivity and Usefulness of VE1 Immunohistochemical Staining in Acral Melanomas with BRAF Mutation

BACKGROUND: Acral melanomas are known to have a low frequency of BRAF mutation, in contrary to higher KIT mutation. Recently, VE1 immunostaining was reported to have a good correlation with BRAF mutation status. OBJECTIVE: We aimed to evaluate the clinicopathological features of BRAF-mutated acral melanomas and validate the correlation of the VE1 immunohistochemical stains in those cases. METHODS: The clinical features (age, sex, anatomical site), and histopathological characteristics of 41 patients with acral melanoma were evaluated. We performed a next-generation sequencing to detect BRAF mutation status. We also determined the correlation of VE1 immunohistochemical staining with BRAF mutation status. RESULTS: Among 19 acral melanomas with BRAF mutation, common histopathological subtype was acral lentiginous melanoma (8/19, 42%) and nodular melanoma (8/19, 42%) and superficial spreading melanoma (3/19, 16%) followed. VE1 immunostaining results were positive in all 15 cases with BRAF V600E mutation (sensitivity 100%), and negative in 4 cases of BRAF non-V600E mutation. However, VE1 immunostaining was negative in all 22 patients with BRAF wild-type. CONCLUSION: VE1 immunostaining had a good correlation with BRAF V600E mutation status.

BRAF V600E mutation and expression of its protein in papillary thyroid carcinoma / 中国癌症杂志

Background and purpose:The BRAF V600E mutation is a highly attractive drug target. Therefore, determining the BRAF gene mutation status of patients is essential in order to assess patients' eligibility for targeted BRAF geneinhibitor therapy. The aim of this study was to validate the utility of immunohistochemistry to rapidly obtain the BRAF gene mutation status. This study aimed to analyze the correlation of the BRAF V600E gene mutation and VE1 protein ex-pression with the clinical pathological characteristics in papillary thyroid carcinoma (PTC).Methods:The mutation status of BRAF V600E was detected by DNA sequencing. Immunohistochemistry was used to detect the expression of BRAF V600E protein in 108 cases of PTC, 54 cases of thyroid adenoma and 54 cases of normal thyroid tissue.Results:The gene mutation rate of BRAF V600E is 67.6%, and VE1 protein expression rate is 64.8% in 108 cases of PTC. The differences were statistically significant compared with thyroid adenoma and goiter (P<0.05), but have no correlation with the clinical pathological characteristics.Conclusion:BRAF V600E gene mutation and VE1 protein expression are useful biomarkers for the pathological diagnosis of PTC. High consistency was observed between the immunohistochemical staining results and the DNA sequencingresults of BRAF V600E gene mutations. Immunohistochemical technique detecting the BRAF V600E protein expression can effectively reflect indirectly BRAF V600E gene mutation status in PTC.BRAF V600E gene mutation has no contribution to the development of papillary thyroid carcinoma.