Abstract 1138: Prognostic impact of BRAF-V600E expression and correlation with mutation status in cutaneous melanoma

Abstract

Abstract Around 50% of primary cutaneous melanomas harbour BRAF mutations, but their prognostic impact has not been clear. Recently, a BRAF-V600E mutation-specific antibody has become available for immunohistochemistry (IHC). Here, we investigated for the first time the prognostic impact of BRAF-V600E protein expression in primary melanoma. In a patient series of 248 nodular melanomas, BRAF-V600E and total BRAF expression were assessed by IHC using tissue microarray sections of paraffin-embedded archival tissue. Mutation status was assessed by real-time PCR. Positive BRAF-V600E expression was present in 86 (35%) of the cases and was significantly associated with increased tumor thickness, presence of tumor ulceration and reduced survival. Further, BRAF-V600E expression was an independent prognostic factor by multivariate survival analysis. There was 88% concordance between BRAF-V600E expression and mutation status. Our findings indicate that BRAF-V600E expression is a novel prognostic marker in primary melanoma. Citation Format: Emilia Hugdahl, May Britt Kalvenes, Hanne Puntervill, Rita Ladstein, Lars A. Akslen. Prognostic impact of BRAF-V600E expression and correlation with mutation status in cutaneous melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1138.