Clinico-pathological factors associated with BRAF-V600E mutation in colorectal serrated adenomas

Serrated adenomas are genetically heterogeneous, and the histological classification into sessile serrated (SSA) adenoma and traditional serrated adenoma (TSA) does not reflect the molecular landscape.To assess clinical or pathological factors associated with BRAF-V600E mutation in serrated adenomas. To assess clinical or pathological factors associated with BRAF-V600E mutation in serrated adenomas systematic review and meta-analysis was performed by searching electronic databases from January 2011 to January 2019 for studies assessing the association of BRAF-V600E mutation with clinical or pathological features of serrated adenomas. Odds ratio (OR) was calculated for each factor; a p-value<0.05 was considered significant. RESULTS: Forty studies assessing 3511 serrated adenomas (2375 SSAs and 1136 TSAs) were included. BRAF-V600E mutation was significantly associated with proximal localization (OR=2.71;p<0.00001) and CIMP-H status (OR=4.81;p<0.0001) in both SSA and TSA, with polyp size <10mm (OR=0.41;p=0.02) in TSA, and with endoscopic pit pattern II-O (OR=13.11;p<0.00001) and expression of MUC5A5 (OR=4.43;p=0.003) and MUC6 (OR=2.28;p<0.05) in SSA. On the other hand, BRAF mutation was not associated with age<70 (OR=1.63;p=0.34), age<60 (OR=0.86;p=0.79), female sex (OR=0.77;p=0.12), flat morphology (OR=1.52;p=0.16), presence of any dysplasia (OR=1.01;p=0.59), serrated dysplasia (OR=1.23;p=0.72) and invasive cancer (OR=0.67;p=0.32), nuclear β-catenin expression (OR=0.73;p=0.21) and p-53 overexpression (OR=1.24;p=0.82).