Fiche publication
Date publication
février 2015
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BOUCHE Olivier
,
Dr DALSTEIN Véronique
,
Dr BOULAGNON-ROMBI Camille
Tous les auteurs :
Boulagnon C, Dudez O, Beaudoux O, Dalstein V, Kianmanesh R, Bouche O, Diebold MD
Lien Pubmed
Résumé
The detection of BRAF mutation in colorectal cancer has several clinical applications: enabling the discrimination between sporadic and Lynch syndrome-related colorectal carcinoma, and providing warning of a poorer prognosis. Few immunohistochemical studies using whole-tissue tumor section staining have recently been performed on colorectal cancer. The aim of this study was to evaluate the detection of BRAF mutation by immunohistochemistry (IHC) on tissue microarray (TMA). IHC was performed with the BRAF-specific antibody using TMA on a retrospective series of 86 colonic adenocarcinomas with known BRAF status. IHC using BRAF-specific antibody allowed to detect 20/21 BRAF mutated colonic adenocarcinomas and 60/65 BRAF wild-type cases. The staining was equivocal because of equivocal staining in 4 cases and heterogeneity in 3 cases. When compared with TaqMan real-time PCR, the sensitivity and specificity were 95.2% and 92.3%, respectively. Comparison with the whole section immunostaining improved sensitivity to 100% and specificity to 95.4%. Furthermore, in this study we found that BRAF mutated colonic adenocarcinoma were significantly more frequent in women, older patients, and right-sided. Moreover, morphologic features significantly associated with BRAF mutation were: serrated adenocarcinoma subtype, adenocarcinomas with a mucinous component, high histologic grade, pushing margins, stromal inflammation. BRAF-specific antibody can be used on TMA to screen BRAF-mutated colorectal carcinomas. Cases with equivocal or heterogenous staining must be compared with whole section staining. Moreover, BRAF mutated colonic carcinomas have distinct clinical and histopathologic features.
Référence
Appl Immunohistochem Mol Morphol. 2015 Feb 21.
