Multisite analysis of high-grade serous epithelial ovarian cancers identifies genomic regions of focal and recurrent copy number variation in 3p26.2 and 8q24.3

High grade serous epithelial ovarian cancer (HGS-EOC) is a systemic disease, with marked intra and inter patient tumor heterogeneity. The issue of spatial and temporal heterogeneity has long been overlooked, hampering the possibility to identify those genomic alterations that persist, before and after therapy, in the genome of all tumor cells across the different anatomically districts. This knowledge is the first step to reveal those molecular determinants that characterize the tumor biology of HGS-EOC and their route towards malignancy. In this study, -omics data were generated from 79 snap frozen matched tumor biopsies, withdrawn before and after chemotherapy from 24 HGS-EOC patients, gathered together from independent cohorts. The landscape of somatic copy number variations (SCNAs) depicted a more homogenous and stable genomic portrait than the single nucleotide variant profile. GISTIC analysis identified two focal and minimal common region of amplification (FMCR) in the cytoband 3q26.2 (called region α, 193 kb long), and 8q24.3 (called region β, 495 kb long). Analysis in two external databases, confirmed regions α and β are features of HGS-EOC. The MECOM gene is located in region α, while 15 genes are located in region β. No functional data are still available for the genes located in the β region. In conclusion, results have identified for the first time two FMCR of amplification in HGS-EOC, unveiling potential biological role in the etiopathogenesis of HGS-EOC This article is protected by copyright. All rights reserved.