High-resolution genome-wide copy number analysis of low grade serous ovarian tumours

Integration of genomic copy number analysis (Affymetrix SNP6.0 arrays) and oncogenic RAS/RAF mutation status with clinical features and tumour progression. This study found that loss of the 9p and the CDKN2A locus with the most significantly enriched copy number aberration distinguishing serous border tumors from low grade serous carcinomas, suggesting this is a key step to tumor progression. Epithelial tissue from 57 serous borderline tumors (SBTs), 19 low grade serous carcinomas (LGSC)(data for 4 of the carcinomas have previously been submitted to GEO - Series GSE19539) and 355 high grade serous carinomas (HGSC)(TCGA, 2011; GSE19539; and 8 new) were analysed for copy number aberrations using Affymetrix SNP6.0 arrays and normalised SNP6.0 data. Stromal tissue from 38 SBT and 1 HGSC were analysed for copy number aberrations using Affymetrix SNP6.0 arrays. Matching lymphocyte DNA was availabe for 54 SBT, 3 LGSC and 1 HGSC. Sanger sequencing of KRAS, BRAF, NRAS, HRAS, ERBB2 and TP53 mutational hotspots was performed on the epithelial and stromal DNA. This information was then correlated with clinical features of the tumors.