BRAF V600E immunohistochemistry is reliable in primary and metastatic colorectal carcinoma regardless of treatment status and shows high intratumoral homogeneity.

摘要: In colorectal carcinoma the evaluation of BRAF mutation status is increasingly being performed given its utility as a prognostic and predictive biomarker. However, there are conflicting reports sensitivity specificity V600E immunohistochemistry (IHC), little known about reliability in tissues collected from metastatic sites or after chemotherapy, radiation therapy and/or targeted therapy. The degree intratumoral staining heterogeneity also not well established. We IHC for (VE1) on 204 cases including 59 with mutation. These included primary (n=147) metastatic/recurrent (n=57) tumors, before (n=133) (n=71) Evaluation test cohort (39 cases) knowledge established specific pattern mutation: diffuse cytoplasmic near-uniform intensity, regardless strength staining. Using this pattern, pathologists at 3 levels training independently blinded remaining cases. was 96.3% sensitive 98.5% mutation, both pretreatment posttreatment specimens. Fleiss κ interobserver agreement 0.96. Staining whole sections mutants showed all uniform intensity 91%. 20 specimens, 100% accuracy between samples. conclude that reliable mutational site prior treatment history, shows high homogeneity.