Bolton, Kelly L.

Abstract Purpose: To analyze the effect of germline mutations in BRCA1 and BRCA2 on mortality in patients with ovarian cancer up to 10 years after diagnosis. Experimental Design: We used unpublished survival time data for 2,242 patients from two case–control studies and extended survival time data for 4,314 patients from previously reported studies. All participants had been screened for deleterious germline mutations in BRCA1 and BRCA2. Survival time was analyzed for the combined data using Cox proportional hazard models with BRCA1 and BRCA2 as time-varying covariates. Competing risks were analyzed using Fine and Gray model. Results: The combined 10-year overall survival rate was 30% [95% confidence interval (CI), 28%–31%] for non-carriers, 25% (95% CI, 22%–28%) for BRCA1 carriers, and 35% (95% CI, 30%–41%) for BRCA2 carriers. The HR for BRCA1 was 0.53 at time zero and increased over time becoming greater than one at 4.8 years. For BRCA2, the HR was 0.42 at time zero and increased over time (predicted to become greater than 1 at 10.5 years). The results were similar when restricted to 3,202 patients with high-grade serous tumors and to ovarian cancer–specific mortality. Conclusions: BRCA1/2 mutations are associated with better short-term survival, but this advantage decreases over time and in BRCA1 carriers is eventually reversed. This may have important implications for therapy of both primary and relapsed disease and for analysis of long-term survival in clinical trials of new agents, particularly those that are effective in BRCA1/2 mutation carriers. Clin Cancer Res; 21(3); 652–7. ©2014 AACR.

Abstract Rare germline mutations in the breast and ovarian cancer predisposition genes BRCA1 and BRCA2 are present in roughly 5 percent of ovarian cancer patients. Both genes play key roles in DNA damage repair but appear to have distinct, although often complementary, functions. The risks of breast and ovarian cancer have been shown to differ between BRCA1 and BRCA2 carriers, and mutation-specific effects have also been suggested for both groups. Published reports comparing the survival of ovarian cancer patients with and without BRCA1/2 mutations generally show a survival advantage among mutation carriers. This is thought to be related to an improved response of carriers to platinum-based therapies. Since it is not known whether BRCA1 and BRCA2 carriers show similar survival patterns, we have performed a large, multicenter study to investigate the impact of germline BRCA1 and BRCA2 mutations on ovarian cancer survival. 3,531 invasive epithelial ovarian cancer cases (1,178 BRCA1, 367 BRCA2 and 1,986 BRCA-negative) with survival time data from twenty-four studies in the U.S.A, Europe, Israel and Asia were included. In our main analysis, we excluded patients who were known or who were likely to have not received platinum-based therapy. Compared to non-carriers, BRCA1 and BRCA2 carriers were more likely to present with advanced stage (BRCA1; p=2×10−4, BRCA2; p=4×10−6), high grade (BRCA1; p=4×10−9, BRCA2; p=1×10−4), serous disease (BRCA1; p=3×10−6, BRCA2; p=0.003). BRCA1 carriers were younger at diagnosis (p=2×10−9) and BRCA2 slightly older at diagnosis (p=0.002) than non-carriers. BRCA1 and BRCA2 carriers did not differ in terms of tumor stage, grade or histology but did show differences in the age at diagnosis (p=2×10−14). In an unadjusted analysis, neither BRCA1 nor BRCA2 carriers differed from non-carriers in overall survival (BRCA1: HR=1.02, p=0.77, BRCA2: HR=0.89, p=0.36). After adjusting for stage, grade, histology and age at diagnosis, BRCA1 carriers showed a modest, non-significant, survival advantage (HR=0.84, p=0.12) while BRCA2 carriers showed a marked improvement (HR=0.57, p=6×10−4) compared to non-carriers. This survival advantage was also seen when comparing BRCA2 carriers to BRCA1 carriers after adjustment for age at diagnosis (HR=0.69, p=5×10−4). Similar results were obtained when we restricted the analysis to high grade, advanced stage, serous cases. The survival differences we observed between BRCA1 and BRCA2 carriers could be related to differences in tumor biology or chemo-sensitivity. Additional analyses investigating the later will be presented in addition to mutation-specific effects within BRCA1 and BRCA2. In this study, we provide strong evidence for genetic heterogeneity of survival effects in ovarian cancer patients with BRCA mutations. This could be applied to both clinical prediction and to aid our understanding of the complex biology of BRCA mutations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2752. doi:10.1158/1538-7445.AM2011-2752

Abstract Background: Genome-wide association studies (GWAS) for epithelial ovarian cancer (EOC), the most lethal gynecologic malignancy, have identified novel susceptibility loci. GWAS for survival after EOC have had more limited success. The association of each single-nucleotide polymorphism (SNP) individually may not be well suited to detect small effects of multiple SNPs, such as those operating within the same biologic pathway. Gene set analysis (GSA) overcomes this limitation by assessing overall evidence for association of a phenotype with all measured variation in a set of genes. Methods: To determine gene sets associated with EOC overall survival, we conducted GSA using data from two large GWAS (N cases = 2,813, N deaths = 1,116), with a novel Principal Component-Gamma GSA method. Analysis was completed for all cases and then separately for high-grade serous histologic subtype. Results: Analysis of the high-grade serous subjects resulted in 43 gene sets with P < 0.005 (1.7%); of these, 21 gene sets had P < 0.10 in both GWAS, including intracellular signaling pathway (P = 7.3 × 10−5) and macrolide binding (P = 6.2 × 10−4) gene sets. The top gene sets in analysis of all cases were meiotic mismatch repair (P = 6.3 × 10−4) and macrolide binding (P = 1.0 × 10−3). Of 18 gene sets with P < 0.005 (0.7%), eight had P < 0.10 in both GWAS. Conclusion: This research detected novel gene sets associated with EOC survival. Impact: Novel gene sets associated with EOC survival might lead to new insights and avenues for development of novel therapies for EOC and pharmacogenomic studies. Cancer Epidemiol Biomarkers Prev; 21(3); 529–36. ©2012 AACR.

Abstract Genome-wide association analyses have identified an ovarian cancer susceptibility locus near BNC2 at 9p22.2 (OR 0.82, p 5.1 × 10−19, Nat Genet 41:996-1000, 2009), based on 1,772 and 2,354 Stage I cases and controls, 4,803 and 5,237 Stage 2 cases and controls, and extensive Stage 3 analysis in independent samples. Here, we report on Stage 3 analysis of nine additional regions with Stage 2 results at p < 10−4. Stage 1 samples were genotyped using the Illumina 610Quad and imputed at up to 2 million SNPs; Stage 2 samples were genotyped on an Illumina iSelect of 22,790 SNPs. Stage 3 samples from 4,335 cases (including 2,197 serous subtype) and 5,951 controls (14 studies) were genotyped using Illumina or Sequenom at up to 32 SNPs on chromosomes 1, 2, 3, 7, 8, 11, and 17. No evidence of heterogeneity by study site was observed. Logistic regression revealed four regions with ordinal p ≤ 10−7 in all cases or serous subtype only. The most significant finding for all cases was for rs2072590 at 2q31.1 (all cases OR 1.15, p=8.1 × 10−13; serous only OR 1.19 p=9.0 × 10−13) which is located 3.8 kb 3-prime of HOXD3, a homeobox gene which also had an intronic SNP (rs2301301) with p=3.1 × 10−5 (all cases). Second, we observed a locus at 8q24.21 highlighted by rs10088218 (all cases OR 0.84, p=1.3 × 10−9; serous only OR 0.75 p=2.2 × 10−14). This locus resides on the opposite side of MYC and 1.3 Mb from the 8q24 regions harboring loci for other cancers, and is independent of the other cancer-associated variants (r2 < 0.02). Third, at 3q25.31, promising results were observed at rs2665390, a SNP intronic to TIPARP (TiPARP, TCDD-inducible poly(ADP-ribose) polymerase; all cases OR 1.19, p=8.7 × 10−7; serous only OR 1.26, p=3.2 × 10−8). Finally, at 17q21.32, rs9303542 was associated with risk particularly among serous cases (all cases OR 1.13, p=1.5 × 10−6; serous only OR 1.16 p=4.3 × 10−7); this SNP is intronic to SKAP1 (src kinase associated phosphoprotein 1). We evaluated the functional role of genes at these loci in ovarian cancer and normal ovarian epithelial cells and in an in vitro model of neoplastic initiation and progression from normal ovarian epithelial cells after CYMC and KRAS activation. Both BNC2 and TiPARP were down regulated in cancer versus normal cells (p=5 × 10−9 and p=3.4 × 10−5, respectively) suggesting that loss of function is required for cancer development. Over-expressing CMYC (at 8q24) induced neoplastic transformation of normal ovarian cells. Both BNC2 and TiPARP were down-regulated following CMYC over-expression and showed significant loss of function with further transformation after mutant KRAS activation (p=7.8 × 10−7 and p=6.3 × 10−4, respectively). These results emphasize the importance of genome-wide association studies and consortia for the identification of moderate-risk alleles in rare cancers. Importantly, our findings unravel the genetic components of this disease and suggest functionally-significant novel targets. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3860.