Petersen, Gloria M.

Abstract Pancreatic cancer is highly lethal with an estimated 5-year relative survival rate of less than 5%. A genome wide association study (GWAS) of pancreatic cancer (PanScan) conducted within the NCI Cohort Consortium and the Pancreatic Cancer Case-Control Consortium (PANC4) recently identified four common susceptibility loci for pancreatic cancer on chromosomes 1q32.1, 5p15.33, 9q34.2 and 13q22.1. To investigate how these germline variants influence pancreatic cancer risk, we are employing both genome wide and targeted approaches. For the former, we are characterizing the epigenome and transcriptome of pancreatic cell lines and tissue samples for genomic annotation and prioritization of methods to use in targeted approaches with the aim of directly linking pancreatic cancer risk variants to molecular phenotypes and mechanisms that underlie the association signals. As an example of our approach we will present results in a pancreatic cancer susceptibility locus on chromosome 1q32.2 marked by SNP (single nucleotide polymorphism) rs3790844. This SNP is located in the first intron of the NR5A2 gene that encodes a nuclear receptor of the Ftz-F1 family known to be involved in pancreatic development, cholesterol and bile acid homeostasis, steroidogenesis and cell proliferation. In ChIP-sequencing and MeDIP-chip experiments, we observed repressive histone modification marks (H3K27me3) and regions of DNA methylation in the NR5A2 gene locus in pancreatic cell lines whereas only a few weak positive histone modification marks were observed (H3K4me1 and H3K4me3). This pattern of epigenetic marks correlates well with low expression of NR5A2 in the same cell lines. Expression of the NR5A2 gene at the RNA level is high in normal pancreatic tissue samples as compared to stage I-III pancreatic adenocarcinoma, most islet cell and neuroendocrine tumors. Using immunohistochemistry, nuclear NR5A2 was detected in normal acinar cells and – at lower levels – in normal ductal cells. The protein was also expressed in low and high grade PanINs and in the majority of PDAC analyzed. Our analysis of the tissue specific expression of NR5A2 shows that it is mainly expressed in normal pancreas, colon, small intestine, liver and breast but detected at low levels or not at all in most other tissue types and cancer cell lines. Furthermore we have identified a novel NR5A2 transcript by rapid amplification of cDNA ends (RACE) and mapped a promoter in front of this transcript in the genomic region corresponding to first intron of the two annotated Refseq transcripts. Establishing a comprehensive catalog of epigenetic patterns coupled with targeted analysis to correlate risk variants to molecular phenotypes could provide functional plausibility for known pancreatic cancer association signals discovered by GWAS findings. 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 4965. doi:10.1158/1538-7445.AM2011-4965

Abstract Introduction: Short constitutional telomere length is associated with aging and cancer, but the correlation of telomere length and age at diagnosis of CRC has not been evaluated. Methods: We measured telomere length using quantitative PCR of peripheral blood leukocyte DNA in 1026 individuals diagnosed with MSS CRC who were ≤60 years of age and were chemo-radiotherapy naïve at the time of blood draw. We compared telomere length with 1972 unrelated healthy controls who were frequency matched for gender and age at time of blood collection. We used constructed percentiles of telomere length using the data from the controls. Results: Overall, regardless of cancer status, there was a weak negative correlation of telomere length with age such that as age increased telomere length decreased (Pearson correlation coefficient =−0.1, p< 0.0001); and men had shorter telomeres than women (p=0.0002). The odds ratio (OR) for MSS CRC increased with longer telomere length (OR 1.62 [CI: 1.31-1.99] for those with telomere lengths in the 90th percentile compared to those with telomere lengths in the 50th percentile. In multivariate analysis with adjustment for gender, BMI, smoking, alcohol, and diabetes, telomere length remained an independent risk factor for CRC (p< 0.001), with interaction between telomere length and age (≤50, longer telomeres increased CRC risk; > 50 years old, increasing telomere length associated with decreased CRC risk). Risk was higher for MSS CRC ≤50 years for patients with telomere lengths in the 90th percentile compared to those in the 50th percentile (OR 2.31; CI:1.65-3.23). For subjects diagnosed 50-60 yrs, longer telomere length was associated with lower risk of CRC, and shorter telomere length was associated with the development of CRC (OR 1.22 for telomere lengths in the 10th percentile compared to those in the 50th percentile (OR 1.22:CI; 1.05-1.43). Conclusion: Telomere dynamics appear to influence MSS CRC risk and may differ on the basis of age of cancer diagnosis. 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 2994. doi:10.1158/1538-7445.AM2011-2994

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 Short constitutional telomere length has been associated with aging and cancer, but how telomere length is affected by other epidemiologic or environmental variables in health has not been thoroughly studied. Understanding these associations with telomere length in health is important for studies to evaluate the relationship of telomere length and diseases such as cancer. We measured peripheral blood leukocyte DNA telomere length with quantitative PCR in 1977 non-related healthy controls collected through the Colon Cancer Family Registry (an NCI cooperative group) and through the Mayo Biobank and Biobank for Gastrointestinal Health Research, two IRB approved prospective biospecimen collections based at Mayo Clinic, Rochester, MN. The controls were a median age of 50.6 years old, and 49.6% of the controls were male. Ninety-six percent of the controls were white; 1.8% were Asian, and <1% were either black, Pacific Islander, or Native American. Less than 1% of controls were Hispanic. On univariate analysis, as age increased, telomere length decreased (Pearson correlation coefficient = −0.07, 95% CI: −0.11, −0.03). Telomeres were longer in people who consumed more fruits (p<0.01) and vegetables (p<0.01); took aspirin on a regular basis (p<0.01); or had a family history of cancers of any type (p=0.05). Women had longer telomeres than men (p=0.03). Telomeres were shorter in people who consumed alcohol (p<0.01), took folate on a regular basis (p=0.01), or who consumed red meat (p<0.01). Statistical significance was not found in the following variables: tobacco use, diagnosis of diabetes, intake of calcium, use of hormone replacement therapy in women, or body mass index. On multivariate analysis, age, vegetable consumption, family history of colorectal cancer or any type of cancer, and folate intake were identified as being significantly associated with telomere length. Telomere length may be associated with multiple environmental and demographic variables in healthy individuals, and adjusting for these may be important for studies that test for an association between telomere length and diseases such as cancer. Citation Information: Cancer Prev Res 2011;4(10 Suppl):A82.

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.

Abstract Pancreatic cancers are the fourth most-common cause of cancer-related deaths in the Western world, with >200,000 cases reported in 2010. Although up to 10% of these cases occur in familial patterns, the hereditary basis for predisposition in the vast majority of affected families is unknown. We used next-generation sequencing, including whole-genome and whole-exome analyses, and identified heterozygous, constitutional, ataxia telangiectasia mutated (ATM) gene mutations in 2 kindreds with familial pancreatic cancer. Mutations segregated with disease in both kindreds and tumor analysis demonstrated LOH of the wild-type allele. By using sequence analysis of an additional 166 familial pancreatic cancer probands, we identified 4 additional patients with deleterious mutations in the ATM gene, whereas we identified no deleterious mutations in 190 spouse controls (P = 0.046). When we considered only the mostly severely affected families with 3 or more pancreatic cancer cases, 4 deleterious mutations were found in 87 families (P = 0.009). Our results indicate that inherited ATM mutations play an important role in familial pancreatic cancer predisposition. Significance: The genes responsible for the majority of cases of familial pancreatic ductal adenocarcinoma are unknown. We here identify ATM as a predisposition gene for pancreatic ductal adenocarcinoma. Our results have important implications for the management of patients in affected families and illustrate the power of genome-wide sequencing to identify the basis of familial cancer syndromes. Cancer Discovery; 2(1): 41–6. ©2011 AACR. Read the Commentary on this article by Bakker and de Winter, p. 14 This article is highlighted in the In This Issue feature, p. 1

AbstractAspirin and other nonsteroidal anti-inflammatory drugs (NSAID) show indisputable promise as cancer chemoprevention agents. However, studies have been inconsistent as to whether aspirin has a protective effect in development of pancreatic cancer. To further evaluate the association between aspirin, NSAID, and acetaminophen use with pancreatic cancer risk, we used a clinic-based case–control study of 904 rapidly ascertained histologically or clinically documented pancreatic ductal adenocarcinoma cases, and 1,224 age- and sex-matched healthy controls evaluated at Mayo Clinic from April 2004 to September 2010. Overall, there is no relationship between non-aspirin NSAID or acetaminophen use and risk of pancreatic cancer. Aspirin use for 1 d/mo or greater was associated with a significantly decreased risk of pancreatic cancer (OR = 0.74, 95% CI: 0.60–0.91, P = 0.005) compared with never or less than 1 d/mo. Analysis by frequency and frequency-dosage of use categories showed reduced risk (P = 0.007 and 0.022, respectively). This inverse association was also found for those who took low-dose aspirin for heart disease prevention (OR = 0.67, 95% CI: 0.49–0.92, P = 0.013). In subgroup analyses, the association between aspirin use and pancreatic cancer was not significantly affected by pancreatic cancer stage, smoking status, or body mass index. Our data suggest that aspirin use, but not non-aspirin NSAID use, is associated with lowered risk of developing pancreatic cancer. Cancer Prev Res; 4(11); 1835–41. ©2011 AACR.

Abstract Background: Recent reports support an association between chronic inflammation and progression to pancreatic cancer (PC). Methods: This case–control, candidate gene association study evaluated 1,354 Caucasian patients with pancreatic ductal adenocarcinoma and 1,189 healthy Caucasian controls. We genotyped 1,538 single nucleotide polymorphism (SNP) in 102 genes from inflammatory pathways involving NF-κB. Primary tests of association assumed a multiplicative (log-additive) genotype effect; secondary analyses examined dominant, additive, and recessive SNP effects. Results: After adjusting for known risk factors for PC, single SNP analysis revealed an association between four SNPs in NOS1 and one in the CD101 gene with PC risk. These results, however, were not replicated in a PC case–control and cohort population. Conclusion:NOS1 and CD101 may be associated with a risk of PC; however, these findings did not replicate in other PC populations. Future research is needed into the possible role of NOS1 and CD101 for PC. Impact: This research shows a lack of association between genetic variation in 102 inflammation-related genes and PC. Future research is needed into the possible role of other inflammation-related genes and PC risk. Cancer Epidemiol Biomarkers Prev; 20(6); 1251–4. ©2011 AACR.

Abstract Pancreatic cancer is a devastating disease for which the role of dietary risk factors remains inconclusive. We evaluated fruit, vegetable, fiber, and grain consumption with pancreatic cancer risk using a clinic-based case-control design, excluding participants who reported changing their diet within 5 years prior to entering the study. Our study included 384 rapidly ascertained cases and 983 non-cases (frequency matched on age at time of recruitment (± 5 years), race, sex, and region of residence) who completed epidemiologic surveys and a 144-item food frequency questionnaire developed by the National Cancer Institute. Logistic regression was used to calculate odds ratios (OR) and 95% CIs, adjusted for age, sex, smoking, body mass index, energy intake, and alcohol consumption. Comparing highest to lowest quintiles, we observed significant (OR < 0.01) inverse associations with significant trends (ptrend < 0.01) for citrus, melon, and berries, other fruit, dark green vegetables, deep yellow vegetables, tomato, other vegetables, dry bean and pea, insoluble fiber, soluble fiber, and whole grains. Adjusting for diabetes or total sugar intake in the multivariate logistic regression model did not significantly affect results. Consuming a diet high in fruits, vegetables, fiber, and whole grains may reduce the risk of developing pancreatic cancer. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A85.

Abstract Background: Mitosis is a highly regulated process that serves to ensure the fidelity of cell division. The disruption of mitotic regulators leading to aneuploidy and polyploidy is commonly observed in cancer cells. Single nucleotide polymorphisms (SNP) in regulators of mitosis may promote chromosome missegregation and influence pancreatic cancer and/or survival. Methods: Thirty-four SNPs, previously associated with breast cancer risk, from 33 genes involved in the regulation of mitosis, were investigated for associations with pancreatic cancer risk in 1,143 Caucasian patients with pancreatic adenocarcinoma and 1,097 unaffected controls from the Mayo Clinic. Associations with survival from pancreatic cancer were also assessed using 1,030 pancreatic cancer cases with known outcome. Results: Two SNPs in the APC (rs2431238) and NIN (rs10145182) loci, of 34 examined, were significantly associated with pancreatic cancer risk (P = 0.035 and P = 0.038, respectively). Further analyses of individuals categorized by smoking and body mass index identified several SNPs displaying significant associations (P < 0.05) with pancreatic cancer risk, including APC rs2431238 in individuals with high body mass index (≥30; P = 0.031) and NIN rs10145182 in ever smokers (P = 0.01). In addition, survival analyses detected significant associations between SNPs in EIF3S10 and overall survival (P = 0.009), SNPs from five genes and survival in resected cancer cases (P < 0.05), and SNPs from two other genes (P < 0.05) and survival of locally advanced cancer cases. Conclusion: Common variation in genes encoding regulators of mitosis may independently influence pancreatic cancer susceptibility and survival. Cancer Epidemiol Biomarkers Prev; 19(1); 251–7