Abstract 3286: Identification of genetic loci associated with ovarian cancer prognosis
Authors: Johnatty Sharon E. , Tyrer Jonathan , Beesley Jonathan , Gao Bo , Lu Yi , MacGregor Stuart , deFazio Anna , Pharoah Paul , Goode Ellen , Chenevix-Trench Georgia 
Published: May 2015

Primary and acquired chemotherapy resistance remains a major challenge in the treatment of ovarian cancer. We hypothesize that heritable polymorphisms might be associated with clinical outcome. Through the Ovarian Cancer Association Consortium, we have collected detailed clinical data from a large number of ovarian cancer patients. We have conducted association analyses of progression-free survival (PFS) and overall survival (OS) for 2,901 European women with ovarian carcinoma for ∼8 million imputed SNPs with minor allele frequency ≥ 0.02 and good imputation quality (imputation r2 ≥ 0.3) from the iCOGS experiment (Pharoah et al Nat Genet. 2013). Cox regression models adjusted for known prognostic factors were used to assess the log-additive effects of SNPs on PFS and OS in 2,825 patients who underwent cytoreductive surgery and received any chemotherapy (‘all chemo’) and in the subset of 1,098 patients who underwent cytoreductive surgery followed by ≥ 4 cycles of carboplatin AUC 5 or 6 and paclitaxel 175 or 135 mg/m2 intravenously (‘standard chemo’). We identified five SNPs at four loci that were significantly associated with outcome (p ≤ 10-7) in at least one of four analyses (Table). Analysis of expression data for genes within a 1Mb region flanking each lead SNP indicates significant associations between nearby genes and ovarian cancer survival. Of particular interest is the heat shock protein crystalline αB (CRYAB) at 11q23.1. We have also identified significant associations with KIAA1598 and RAVER2. Further analysis of these loci in a larger genotyped sample is necessary to definitively identify SNP(s) associated with outcome. Our study adds to the growing evidence that genetic variants are associated with ovarian cancer prognosis.

Table: SNPs associated with ovarian cancer outcome and gene expression

Overall Survival (P)*Progression-Free Survival (P)*Lead SNPChromosome LocusImputation R²Expression AnalysisAll chemoStandard chemoAll chemoStandard chemors1429768671p31.30.742.14E-0512.69E-044.68E-055.11E-073.64E-09rs559375217q32.30.600.198.58E-082.32E-052.80E-031.85E-03rs7885346210q26.110.602.23E-0724.57E-036.57E-081.65E-016.85E-03rs1089121911q23.10.841.53E-0531.51E-059.50E-081.50E-042.32E-04rs3579103211q23.10.811.53E-0531.66E-055.88E-086.46E-051.87E-04*P-values are adjusted for known confounders of ovarian cancer outcomes; FIGO stage, grade, histology, residual disease, and additionally for age at diagnosis for OS.1 RAVER2; 2 KIAA1598; 3 CRYAB

Citation Format: Sharon E. Johnatty, Jonathan Tyrer, Jonathan Beesley, Bo Gao, Yi Lu, Stuart MacGregor, Anna deFazio, Paul Pharoah, Ellen Goode, Georgia Chenevix-Trench. Identification of genetic loci associated with ovarian cancer prognosis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3286. doi:10.1158/1538-7445.AM2014-3286