Abstract Background Ovarian cancer is the fifth most common cause of cancer death in women in the US; approximately 15,000 women will die from this disease in 2011 (ACS, 2011). The 5 year survival rate for stage IV disease is only 18%. Only a handful of independent significant prognostic factors are known, including tumor stage at surgery, size of residual tumor at the end of primary surgery, and age at diagnosis. Understanding how the variation of cytosine methylation in the context of cytosine-guanine dinucleotides (CpGs) affects complex disease etiology and survival is the current focus of many ongoing research studies. We conducted an epigenome-wide study of methylation in ovarian cancer cases to evaluate whether variation in methylation of CpG sites in genomic DNA may be associated with ovarian cancer survival. Methods Subjects included cases from an ongoing case-control study. The Mayo Clinic Ovarian Cancer Study is a clinic-based study that recruits ovarian cancer cases within 12 months of diagnosis. Pre-treatment, germline DNA from lymphocytes from 137 cases was bisulfite-modified, amplified and genotyped on the Illumina 450K methylation chip and included in these analyses. Quality control (QC) analyses include the elimination of all methylation probes with a single nucleotide polymorphism (SNP) or insertion/deletion (in/del) at the same location; removal of non-specific probes; and estimation of bisulfite conversion rates using embedded control probes. Planned analyses include assessment of clinical covariates (age, stage, extent of surgical debulking, grade, presence of ascites) to determine which are associated with overall survival in our data. Additional analyses will assess the age- and multi-variate-adjusted association of each methylation probe with overall survival using Cox proportional hazards regression models with each methylation probe modeled as a continuous variable. Data will be summarized using Manhattan plots. These analyses will be repeated using ‘time to recurrence’ as the outcome variable, with recurrence defined as time to ovarian cancer recurrence/progression or death. Results Bioinformatics analyses suggest that 36,659 probes were located at the site of a SNP or in/del and should be removed from future analyses. Another 448 probes had a detection rate of p< 0.01 and 6630 probes had signals for the negative control samples; all were removed from analyses. A total of 43,802 probes were removed. In addition, ten cases were excluded due to either poor bisulfite conversion (N=9) or extremely low raw methylation values across all probes (N=1). This leaves a total of 127 cases for analyses. Results from planned analyses will be presented, including estimation of the association of methylation probes with both overall survival and time to recurrence. Conclusions Data to be presented will describe whether there is any evidence that methylation of genomic DNA in ovarian cancer cases is associated with outcome of ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5008. doi:1538-7445.AM2012-5008
Abstract 3749: Polymorphisms in metabolism genes may mediate the effect of dietary intake on pancreatic cancer risk
Cancer Research | June 27, 2012 | Volume: 71 | Issue: 8_Supplement | Pages: 3749-3749
Abstract Background: The role of dietary fruit, vegetable, fiber, and whole grain intake is implicated as a potential protective factor against pancreatic cancer, but studies are inconsistent. A possible explanation for the variability is that individuals who carry constitutional metabolism gene variants (minor alleles) may differentially benefit compared to those who are homozygous for the major allele, which over a life-time could lead to altered pancreatic cancer risk. Methods: We genotyped 70 SNPs that tag ten candidate metabolism genes (CAT, GAA, GCK, MT1E, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT2B4, and UGT2B7) involved in the metabolism of components of fruits, vegetables, fibers, and whole grains to test if differential associations exist with pancreatic adenocarcinoma. We used a clinic-based case-control design, excluding participants who reported changing their diet within 5 years prior to entering the study. Three hundred eighty-four rapidly ascertained cases and nine hundred eighty-three non-cases from a primary care clinic (frequency matched on age at recruitment (+ 5 years), race, sex, and region of residence) provided blood samples for DNA and completed epidemiologic surveys plus a 144-item food frequency questionnaire developed by the National Cancer Institute. We used a dominant model to code SNPs and split dietary intake categories based on the sex-specific median intake level among non-cases. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals, adjusted for age, sex, family-history of pancreatic cancer, smoking (never/ former/ current), body mass index, energy intake, and alcohol consumption. The reference group was defined as carriers of no minor alleles in the lowest intake category. Results: The greatest benefit was observed for carriers of no minor alleles, for rs11032702 (CAT) with higher insoluble dietary fiber intake (OR [95%CI]: 0.515 [0.37, 0.71]); for rs735670 (GCK) with higher soluble dietary intake (0.473 [0.34, 0.67]); for rs2070971 (GCK) and rs2268569 (GCK) with higher fruit intake not from citrus, melon, and berries (0.513 [0.36, 0.73] and 0.554 [0.40, 0.78]); and for rs17832252 (GCK) with higher whole grain intake (0.530 [0.37, 0.76]); all comparisons had a reference group of no minor alleles with low dietary intake and a p-value for interaction <0.001. Conclusions: Inter-individual variation in metabolism of fruits, vegetables, fiber, and whole grain via metabolism gene variants may influence pancreatic cancer risk. 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 3749. doi:10.1158/1538-7445.AM2011-3749
Abstract 3716: The Mayo Mammography Health Study (MMHS): A prospective cohort study on mammographic breast density and breast cancer
Cancer Research | June 27, 2012 | Volume: 71 | Issue: 8_Supplement | Pages: 3716-3716
Abstract INTRODUCTION: Mammographic breast density is a strong risk factor for breast cancer (BC). We established the Mayo Mammography Health Study (MMHS) cohort study at the Mayo Clinic in Rochester, Minnesota (MN) to examine the association of breast density with BC. We evaluated the influence of the image acquisition technique on the density and BC association. METHODS: From October 2003 to September 2006, all women scheduled for screening mammography at the Mayo Clinic were invited to participate. Eligible women were residents of MN, Iowa (IA) or Wisconsin (WI); age 35+; and had no personal history of BC. A risk factor questionnaire, consent form and permission to link to tumor registries were obtained. Incident BC was identified through 2009 by linkage to the Mayo and state cancer registries. A case-cohort of all incident BCs and 2300 randomly selected women (the subcohort) were used to examine the association of breast density and BC using digitized film mammograms at the time of enrollment while controlling for the influence of the acquisition parameters (peak kilovoltage, milliampere-second, and compressed breast thickness). Two density measures were considered: a quantitative percent density (PD) measure estimated using the computer-assisted thresholding program, Cumulus (University of Toronto), and the 4-category clinical BI-RADS measure. Proportional hazards regression was used to calculate hazards ratios (HR) and 95% confidence intervals (CI) for BC associated with quartiles of PD (0-6.2%,6.3-14.9%, 15.0-25.7% and 25.8%+) and BI-RADS categories 1-4 (almost entirely fatty to extremely dense). All models included age, postmenopausal hormone use (PMH), BMI, and menopausal status. The influence of acquisition parameters was evaluated by examining models with and without their inclusion. RESULTS: A total of 20,982 (50%) women participated in MMHS; 1058 (5%) with a prior history of BC were excluded, for a total cohort of 19,924. Compared to nonresponders, responders were younger (57.5 vs. 58.4 yrs), more likely to have ever used PMH (45% vs. 33%), and more likely to have a BC family history (19% vs 16%). The case-cohort consisted of 317 incident cases and 2300 women in the subcohort. Women were excluded from the current analysis if PD could not be estimated or if acquisition parameters were not available, leaving 249 cases and 1937 in the subcohort. As expected, PD was associated with BC [HR (95% CI): 1.0 (REF), 2.1 (1.4-3.1), 3.0 (2.0-4.5), and 4.6 (3.0-7.0) for quartiles; p-trend<0.001]. Controlling for acquisition parameters attenuated the association [HR (95% CI): 1.0 (REF), 2.3 (1.5-3.4), 2.4 (1.6-3.7), and 3.0 (1.8-5.0) for quartiles; p-trend<0.001]. Results for BI-RADS density were similar to those for PD. CONCLUSION: This study confirms that breast density is a significant risk factor for BC and demonstrates that the acquisition technique confounds the density and BC risk association. 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 3716. doi:10.1158/1538-7445.AM2011-3716
The role of genetic breast cancer susceptibility variants as prognostic factors
Human Molecular Genetics | April 25, 2012 | Volume: 21 | Issue: 17 | Pages: 3926-3939
Abstract S1-2: ACOSOG Z1031: A Randomized Neoadjuvant Comparison between Letrozole (LET), Anastrozole (ANA) and Exemestane (EXE) for Postmenopausal Women with ER Rich Stage 2/3 Breast Cancer: Biomarker Outcomes and the Predictive Value of the Baseline PAM5
Cancer Research | April 27, 2011 | Volume: 70 | Issue: 24_Supplement | Pages: S1-2-S1-2
Abstract Background: Neoadjuvant endocrine therapy (NET) trials serve to inform design and selection of agents for larger adjuvant endocrine trials. The neoadjuvant aromatase inhibitor (AI) trial ACOSOG Z1031 randomized the treatment of postmenopausal women with ER rich (Allred 6-8) clinical stage 2/3 breast cancer to either EXE, ANA and LET. The results are therefore of interest in the context of new data that compares these AIs in the adjuvant setting. The opportunity to develop predictive biomarker tests for NET sensitivity was also a key study objective in order guide future selection of patients for inclusion in studies that compare NET versus neoadjuvant chemotherapy (NCT). The value of a baseline PAM50 intrinsic subtype test for NET patient selection was therefore an embedded objective of the study. Methods: Of the 374 women who began study treatment on Z1031, pretreatment biopsy specimen for central IHC testing for ER and Ki67 was available on 304 patients. The PAM50 intrinsic subtype test (PMCID: 2667820) could be conducted on 170 baseline samples. The Preoperative Endocrine Prognostic Index (PEPI) an approach to predicting long term outcomes based on pathological stage and surgical specimen ER and Ki67 status was also conducted because patients with a PEPI of zero (T1/2 N0, ER+, Ki67<=2.7%) have been found to have an excellent long term prognosis and therefore unlikely to benefit from chemotherapy (PMCID: 255670). Results: The degree of Ki67 suppression, the absolute level of Ki67 in the surgical specimen and the PEPI results were not significantly different by treatment arm (Kruskal-Wallis tests p >0.05). Thirty Percent (95%CI: 19.6-42.9%) of women with pre-AI LumA subtype and 12% (95%CI: 6.4-20.0%) of women with pre-AI LumB subtype had a PEPI of zero predicting excellent prognosis. Multivariate logistic modeling found that the likelihood of a PEPI score of zero is 3.2 fold higher (95%CI: 1.43 7.12) among 66 women with a pre-AI LumA subtype compared to 100 women with a pre-AI LumB subtype. Additional baseline variables (clinical T and N stage, HER2 status, pre-AI Ki-67 level (< = 10% vs. >10%) were not found to modify the chance of a PEPI of zero. Baseline PAM50 Subtype versus PEPI Conclusion: The results of Z1031 show no differences in clinical or biologic response between LET, EXE, and ANA in the neoadjuvant setting; predicting that no difference in efficacy will be seen between these agents in adjuvant studies. Pre-AI LumA versus LumB status, defined by the PAM50 subtype, identifies patients who are more likely to be in the most favorable PEPI score following neoadjuvant AI therapy. Patients with pretreatment LumA status may, therefore, not be suitable for a randomized trial of NET versus NCT since approximately one third of these patients may be able to avoid chemotherapy altogether. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S1-2.