Citations 209

Abstract 893: Associations between HGF, MET, and phospho-MET expression, overall survival, and HGF genotypes in epithelial ovarian cancer

Cancer Research | June 27, 2012 | Volume: 71 | Issue: 8_Supplement | Pages: 893-893

10.1158/1538-7445.am2011-893

Abstract Background. The hepatocyte growth factor (HGF) signaling pathway regulates key cellular functions related to tumor invasion and metastasis including cell motility, cell proliferation, and morphogenesis. We previously found that minor alleles at a single-nucleotide polymorphism (SNP; rs5745709) in the gene encoding the cytokine HGF was associated with poorer overall survival in women with invasive epithelial ovarian cancer (EOC) enrolled at Mayo Clinic (MAY) and The Cancer Genome Atlas (TCGA) (HR 1.6, 95% CI 1.3-1.9, p=8.9×10−5). In addition, we found that that genotype correlated with HGF expression in ovarian cancer tissue from TCGA women, suggesting that genetically-regulated expression of HGF may play a role in post-diagnosis survival. To further examine this possibility, we evaluated intensity of antibody immunostaining for HGF, MET (HGF's transmembrane tyrosine kinase receptor), and phospho-MET (pMET; MET's activated form) in tumor cells using tissue microarrays (TMAs) created from genotyped primary peritoneal and EOC cases, and correlated these expression levels with overall survival and HGF SNP genotypes. Methods. Participants were 326 white non-Hispanic women over 20 years of age with histologically-confirmed invasive EOC diagnosed between 1998 and 2009. All cases were enrolled at MAY within one year of diagnosis. Five μm sections of TMAs including three 0.6 mm cores per case were immunostained with HGF, MET, and pMET primary antibodies. Staining levels were classified according to combinations of staining extent and intensity as negative (< 10% cells stained), weak, moderate, or strong. The maximal expression value recorded over the multiple cores for each case was used. Cox proportional hazards regression was used to examine associations of overall survival with HGF, MET and pMET expression levels, adjusted for relevant clinical variables. Associations between expression levels and HGF SNP rs5745709 genotypes were examined using linear regression models. Results. HGF and MET expression were not associated with overall survival in our series of EOC cases (p=0.48 and 0.90, respectively). pMET expression was associated with survival, but in the opposite direction of that hypothesized (HR 0.77, 95% CI 0.39-1.52 for moderate expression; HR 0.55, 95% CI 0.27-1.10 for strong expression; each referent to negative/weak, p=0.01). Expression levels were not significantly associated with HGF rs5745709 genotypes (p=0.80 for HGF expression, p=0.89 for MET, p=0.41 for pMET). Conclusion. HGF expression levels were not associated with overall survival or with HGF SNP genotypes that correlated with survival in a previous study. Functional studies such as this one are crucial as a follow-up to discovery-based studies in order to assess biologic plausibility of observed results. 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 893. doi:10.1158/1538-7445.AM2011-893
Abstract 5616: Assessment of differential DNA methylation by genotype in ovarian cancer cases and controls

Cancer Research | June 27, 2012 | Volume: 71 | Issue: 8_Supplement | Pages: 5616-5616

10.1158/1538-7445.am2011-5616

Abstract Ovarian carcinoma is a significant cause of cancer mortality in women in the United States. Increasing evidence has demonstrated that differential methylation status in lymphocyte DNA may be linked to risk of carcinogenesis. We are investigating the differential DNA methylation in germline DNA obtained from pre-treatment ovarian cancer cases (n=256) and individually-age matched controls (n=274) using the Illumina Infinium Human Methylation 27K BeadChip. We are first studying methylation and the common moderate-risk alleles for ovarian cancer on chromosomes 2q31, 3q25, 8q24, 9p22, 17q21, and 19p13. Within each locus, we correlated single nucleotide polymorphism (SNP) genotypes with methylation values at relevant nearby CpG sites. Preliminary results are available on the first set of 84 cases and 90 controls. At 2q31, cases with TG or TT genotype at rs2072590 were hypomethylated at HOXD1 (a homeobox transcription factor) compared to cases with GG genotype (mean beta TG/TT=0.08, GG=0.09, p=0.034); and at 17q21, cases with AG or GG genotype at rs9303542 were hypomethylated at SKAP1 (a T-cell adaptor protein) compared to cases with AA genotype (mean beta AG/GG=0.14, AA=0.16, p=0.045). At these two loci, similar trends were seen among controls. Logistic regression adjusted for age and methylation chip was then used to assess the association between SNP genotype and ovarian cancer risk, with and without inclusion of the relevant methylation value. At HOXD1 rs2072590, the per-allele ovarian cancer risk of 1.34 attenuated to 1.25 with inclusion of the HOXD1 methylation value as a covariate, suggesting that the disease association may be mediated in part through methylation. Though based on preliminary data, results are consistent with a role for inherited variation on germline methylation at HOXD1 and SKAP1. Analysis of methylation on additional genotyped cases and controls is underway. Finally, because, trans effects may also exist, we are assessing relationships between genotype and methylation at other loci throughout the genome. Such correlative molecular studies have the potential to help elucidate mechanisms underlying associations from genome-wide association studies. 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 5616. doi:10.1158/1538-7445.AM2011-5616
Common Variation in Nemo-Like Kinase Is Associated with Risk of Ovarian Cancer

Cancer Epidemiology, Biomarkers & Prevention | March 7, 2012 | Volume: 21 | Issue: 3 | Pages: 523-528

10.1158/1055-9965.epi-11-0797 | PMID 22253297

Abstract Background: Overexpression of mitotic kinases has been associated with prognosis, histologic grade, and clinical stage in ovarian cancer, but the relationship between inherited variation in these genes and ovarian cancer risk has not been well defined. Methods: We measured associations between 397 single nucleotide polymorphisms (SNPs) from 67 mitotic kinases and invasive epithelial ovarian cancer risk in two case–control studies (n = 671 cases; n = 939 controls). Thirty-six candidate SNPs (P < 0.05) were assessed in a replication analysis consisting of three additional studies (n = 1,094 cases; n = 829 controls). Results: In initial analysis, thirty-six SNPs were suggestive of association with risk of serous ovarian cancer, all subtypes of ovarian cancer, or both (P < 0.05). Replication analyses suggested an association between rs2125846 in the Nemo-like kinase (NLK) gene and ovarian cancer (serous OR = 1.36, 95% CI: 1.11–1.67, P = 1.77 × 10−3; all subtypes OR = 1.30, 95% CI: 1.08–1.56, P = 2.97 × 10−3). Furthermore, rs2125846 was associated with risk in the combined discovery and replication sets (serous OR = 1.33, 95% CI: 1.15–1.54; all subtypes OR = 1.27, 95% CI: 1.12–1.45). Conclusions: Variation in NLK may be associated with risk of invasive epithelial ovarian cancer. Further studies are needed to confirm and understand the biologic relationship between this mitotic kinase and ovarian cancer risk. Impact: An association between SNPs in NLK and ovarian cancer may provide biologic insight into the development of this disease. Cancer Epidemiol Biomarkers Prev; 21(3); 523–8. ©2012 AACR.
Gene Set Analysis of Survival Following Ovarian Cancer Implicates Macrolide Binding and Intracellular Signaling Genes

Cancer Epidemiology, Biomarkers & Prevention | March 7, 2012 | Volume: 21 | Issue: 3 | Pages: 529-536

10.1158/1055-9965.epi-11-0741 | PMID 22302016

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.
A Population-Based Study of Prevalence and Adherence Trends in Average Risk Colorectal Cancer Screening, 1997 to 2008

Cancer Epidemiology, Biomarkers & Prevention | February 7, 2012 | Volume: 21 | Issue: 2 | Pages: 347-350

10.1158/1055-9965.epi-11-0818 | PMID 22144500

Abstract Background: Increasing colorectal cancer screening (CRCS) is important for attaining the Healthy People 2020 goal of reducing CRC-related morbidity and mortality. Evaluating CRCS trends can help identify shifts in CRCS, and specific groups that might be targeted for CRCS. Methods: We utilized medical records to describe population-based adherence to average-risk CRCS guidelines from 1997 to 2008 in Olmsted County, MN. CRCS trends were analyzed overall and by gender, age, and adherence to screening mammography (women only). We also carried out an analysis to examine whether CRCS is being initiated at the recommended age of 50. Results: From 1997 to 2008, the size of the total eligible sample ranged from 20,585 to 21,468 people. CRCS increased from 22% to 65% for women and from 17% to 59% for men (P < 0.001 for both) between 1997 and 2008. CRCS among women current with mammography screening increased from 26% to 74%, and this group was more likely to be adherent to CRCS than all other subgroups analyzed (P < 0.001).The mean ages of screening initiation were stable throughout the study period, with a mean age of 55 years among both men and women in 2008. Conclusion: Although overall CRCS tripled during the study period, there is still room for improvement. Impact: Working to decrease the age at first screening, exploration of gender differences in screening behavior, and targeting women adherent to mammography but not to CRCS seem warranted. Cancer Epidemiol Biomarkers Prev; 21(2); 347–50. ©2011 AACR.
Ovarian Cancer Risk Associated with Inherited Inflammation-Related Variants

Cancer Research | January 26, 2012 | Volume: 72 | Issue: 5 | Pages: 1064-1069

10.1158/0008-5472.can-11-3512 | PMID 22282663

Abstract The importance of inflammation pathways to the development of many human cancers prompted us to examine the associations between single-nucleotide polymorphisms (SNP) in inflammation-related genes and risk of ovarian cancer. In a multisite case–control study, we genotyped SNPs in a large panel of inflammatory genes in 930 epithelial ovarian cancer cases and 1,037 controls using a custom array and analyzed by logistic regression. SNPs with P < 0.10 were evaluated among 3,143 cases and 2,102 controls from the Follow-up of Ovarian Cancer Genetic Association and Interaction Studies (FOCI) post-GWAS collaboration. Combined analysis revealed association with SNPs rs17561 and rs4848300 in the interleukin gene IL1A which varied by histologic subtype (Pheterogeneity = 0.03). For example, IL1A rs17561, which correlates with numerous inflammatory phenotypes, was associated with decreased risk of clear cell, mucinous, and endometrioid subtype, but not with the most common serous subtype. Genotype at rs1864414 in the arachidonate 5-lipoxygenase ALOX5 was also associated with decreased risk. Thus, inherited variation in IL1A and ALOX5 seems to affect ovarian cancer risk which, for IL1A, is limited to rarer subtypes. Given the importance of inflammation in tumorigenesis and growing evidence of subtype-specific features in ovarian cancer, functional investigations will be important to help clarify the importance of inherited variation related to inflammation in ovarian carcinogenesis. Cancer Res; 72(5); 1064–9. ©2012 AACR.
Confirmation of 5p12 As a Susceptibility Locus for Progesterone-Receptor–Positive, Lower Grade Breast Cancer

Cancer Epidemiology, Biomarkers & Prevention | October 6, 2011 | Volume: 20 | Issue: 10 | Pages: 2222-2231

10.1158/1055-9965.epi-11-0569 | PMID 21795498

Abstract Background: The single-nucleotide polymorphism (SNP) 5p12-rs10941679 has been found to be associated with risk of breast cancer, particularly estrogen receptor (ER)-positive disease. We aimed to further explore this association overall, and by tumor histopathology, in the Breast Cancer Association Consortium. Methods: Data were combined from 37 studies, including 40,972 invasive cases, 1,398 cases of ductal carcinoma in situ (DCIS), and 46,334 controls, all of white European ancestry, as well as 3,007 invasive cases and 2,337 controls of Asian ancestry. Associations overall and by tumor invasiveness and histopathology were assessed using logistic regression. Results: For white Europeans, the per-allele OR associated with 5p12-rs10941679 was 1.11 (95% CI = 1.08–1.14, P = 7 × 10−18) for invasive breast cancer and 1.10 (95% CI = 1.01–1.21, P = 0.03) for DCIS. For Asian women, the estimated OR for invasive disease was similar (OR = 1.07, 95%CI = 0.99–1.15, P = 0.09). Further analyses suggested that the association in white Europeans was largely limited to progesterone receptor (PR)-positive disease (per-allele OR = 1.16, 95% CI = 1.12–1.20, P = 1 × 10−18 vs. OR = 1.03, 95% CI = 0.99–1.07, P = 0.2 for PR-negative disease; Pheterogeneity = 2 × 10−7); heterogeneity by ER status was not observed (P = 0.2) once PR status was accounted for. The association was also stronger for lower grade tumors [per-allele OR (95% CI) = 1.20 (1.14–1.25), 1.13 (1.09–1.16), and 1.04 (0.99–1.08) for grade 1, 2, and 3/4, respectively; Ptrend = 5 × 10−7]. Conclusion: 5p12 is a breast cancer susceptibility locus for PR-positive, lower grade breast cancer. Impact: Multicenter fine-mapping studies of this region are needed as a first step to identifying the causal variant or variants. Cancer Epidemiol Biomarkers Prev; 20(10); 2222–31. ©2011 AACR.
MicroRNA Processing and Binding Site Polymorphisms Are Not Replicated in the Ovarian Cancer Association Consortium

Cancer Epidemiology, Biomarkers & Prevention | August 8, 2011 | Volume: 20 | Issue: 8 | Pages: 1793-1797

10.1158/1055-9965.epi-11-0397 | PMID 21636674

Abstract Background: Single nucleotide polymorphisms (SNP) in microRNA-related genes have been associated with epithelial ovarian cancer (EOC) risk in two reports, yet associated alleles may be inconsistent across studies. Methods: We conducted a pooled analysis of previously identified SNPs by combining genotype data from 3,973 invasive EOC cases and 3,276 controls from the Ovarian Cancer Association Consortium. We also conducted imputation to obtain dense coverage of genes and comparable genotype data for all studies. In total, 226 SNPs within 15 kb of 4 miRNA biogenesis genes (DDX20, DROSHA, GEMIN4, and XPO5) and 23 SNPs located within putative miRNA binding sites of 6 genes (CAV1, COL18A1, E2F2, IL1R1, KRAS, and UGT2A3) were genotyped or imputed and analyzed in the entire dataset. Results: After adjustment for European ancestry, no overall association was observed between any of the analyzed SNPs and EOC risk. Conclusions: Common variants in these evaluated genes do not seem to be strongly associated with EOC risk. Impact: This analysis suggests earlier associations between EOC risk and SNPs in these genes may have been chance findings, possibly confounded by population admixture. To more adequately evaluate the relationship between genetic variants and cancer risk, large sample sizes are needed, adjustment for population stratification should be carried out, and use of imputed SNP data should be considered. Cancer Epidemiol Biomarkers Prev; 20(8); 1793–7. ©2011 AACR.
Assessment of Hepatocyte Growth Factor in Ovarian Cancer Mortality

Cancer Epidemiology, Biomarkers & Prevention | August 8, 2011 | Volume: 20 | Issue: 8 | Pages: 1638-1648

10.1158/1055-9965.epi-11-0455 | PMID 21724856

Abstract Background: Invasive ovarian cancer is a significant cause of gynecologic cancer mortality. Methods: We examined whether this mortality was associated with inherited variation in approximately 170 candidate genes/regions [993 single-nucleotide polymorphisms (SNPs)] in a multistage analysis based initially on 312 Mayo Clinic cases (172 deaths). Additional analyses used The Cancer Genome Atlas (TCGA; 127 cases, 62 deaths). For the most compelling gene, we immunostained Mayo Clinic tissue microarrays (TMA, 326 cases) and conducted consortium-based SNP replication analysis (2,560 cases, 1,046 deaths). Results: The strongest initial mortality association was in HGF (hepatocyte growth factor) at rs1800793 (HR = 1.7, 95% CI = 1.3–2.2, P = 2.0 × 10−5) and with overall variation in HGF (gene-level test, P = 3.7 × 10−4). Analysis of TCGA data revealed consistent associations [e.g., rs5745709 (r2 = 0.96 with rs1800793): TCGA HR = 2.4, CI = 1.4–4.1, P = 2.2 × 10−3; Mayo Clinic + TCGA HR = 1.6, CI = 1.3–1.9, P = 7.0 × 10−5] and suggested genotype correlation with reduced HGF mRNA levels (P = 0.01). In Mayo Clinic TMAs, protein levels of HGF, its receptor MET (C-MET), and phospho-MET were not associated with genotype and did not serve as an intermediate phenotype; however, phospho-MET was associated with reduced mortality (P = 0.01) likely due to higher expression in early-stage disease. In eight additional ovarian cancer case series, HGF rs5745709 was not associated with mortality (HR = 1.0, CI = 0.9–1.1, P = 0.87). Conclusions: We conclude that although HGF signaling is critical to migration, invasion, and apoptosis, it is unlikely that HGF genetic variation plays a major role in ovarian cancer mortality. Furthermore, any minor role is not related to genetically-determined expression. Impact: Our study shows the utility of multiple data types and multiple data sets in observational studies. Cancer Epidemiol Biomarkers Prev; 20(8); 1638–48. ©2011 AACR.
Platinum Sensitivity–Related Germline Polymorphism Discovered via a Cell-Based Approach and Analysis of Its Association with Outcome in Ovarian Cancer Patients

Clinical Cancer Research | June 25, 2011 | Volume: 17 | Issue: 16 | Pages: 5490-5500

10.1158/1078-0432.ccr-11-0724 | PMID 21705454

Abstract Purpose: Cell-based approaches were used to identify genetic markers predictive of patients' risk for poor response prior to chemotherapy. Experimental Design: We conducted genome-wide association studies (GWAS) to identify single-nucleotide polymorphisms (SNP) associated with cellular sensitivity to carboplatin through their effects on mRNA expression using International HapMap lymphoblastoid cell lines (LCL) and replicated them in additional LCLs. SNPs passing both stages of the cell-based study were tested for association with progression-free survival (PFS) in patients. Phase 1 validation was based on 377 ovarian cancer patients receiving at least four cycles of carboplatin and paclitaxel from the Australian Ovarian Cancer Study (AOCS). Positive associations were then assessed in phase 2 validation analysis of 1,326 patients from the Ovarian Cancer Association Consortium and The Cancer Genome Atlas. Results: In the initial GWAS, 342 SNPs were associated with carboplatin-induced cytotoxicity, of which 18 unique SNPs were retained after assessing their association with gene expression. One SNP (rs1649942) was replicated in an independent LCL set (Bonferroni adjusted P < 0.05). It was found to be significantly associated with decreased PFS in phase 1 AOCS patients (Pper-allele = 2 × 10−2), with a stronger effect in the subset of women with optimally debulked tumors (Pper-allele = 4 × 10−3). rs1649942 was also associated with poorer overall survival in women with optimally debulked tumors (Pper-allele = 9 × 10−3). However, this SNP was not significant in phase 2 validation analysis with patients from numerous cohorts. Conclusion: This study shows the potential of cell-based, genome-wide approaches to identify germline predictors of treatment outcome and highlights the need for extensive validation in patients to assess their clinical effect. Clin Cancer Res; 17(16); 5490–500. ©2011 AACR.