Schwartz, Ann G.

Abstract Pancreatic ductal adenocarcinoma (PDA) affects over 44,000 people in the United States every year and carries a dismal prognosis, with a 5-year survival rate of just 5%. A subset of these patients (5-10%) report a familial history of the disease. The genetic etiology in these familial cases is poorly defined, with known susceptibility genes, such as: BRCA2, PALB2, CDKN2A, BRCA1, PRSS1 and STK11, accounting for only 10-15% of familial pancreatic cancer. In an effort to identify previously unappreciated pancreatic cancer susceptibility genes, we used next generation sequencing technology to evaluate the whole genome and whole exome sequences of 16 (6 families) and 22 individuals (10 families) respectively. All of these families enrolled into one of the familial pancreatic cancer registries participating in the Pancreatic Cancer Genetic Epidemiology (PacGene) Consortium, all had at least three members with PDA, and DNA was available from at least two affected members in each kindred. Using this approach, we identified heterozygous, inactivating, ATM mutations in two kindreds with familial pancreatic cancer (c.8266A>AT; p.K2756X and c.170G>GA; p.W57X). These mutations were previously reported as disease causing variants in patients with ataxia-telangiectasia, an autosomal recessive condition resulting from bi-allelic deleterious mutations of ATM. Interestingly, heterozygotes of deleterious ATM mutations have an increased risk of breast cancer. However, there have been no previous reports of deleterious ATM mutations in the germline of familial PDA patients. In our study, mutations segregated with disease in both kindreds and tumor analysis demonstrated Loss of heterozygosity (LOH) of the wild-type allele. Sequence analysis of the entire ATM gene in an additional 166 familial pancreatic cancer probands indentified four additional patients with deleterious mutations in the ATM gene (c.3214G>GT; p.E1072X, c.6095G>GA; p.R2032K, IVS41-1G>GT and c.3801delG), while no deleterious mutations were identified in 190 spouse controls (p=0.046). When considering only the mostly severely affected families, those with three or more pancreatic cancer cases, four deleterious mutations were found in 87 families (P=0.009). These results indicate that ATM mutations play an important role in familial pancreatic cancer predisposition and have significant implications in the management of affected individuals and the risk assessment of family members. 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 2628. doi:1538-7445.AM2012-2628

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

Abstract To clarify the role of previous lung diseases (PLDs) (chronic bronchitis, emphysema, pneumonia, tuberculosis, asbestosis and silicosis) in the development of lung cancer we conducted a pooled analysis in the International Lung Cancer Consortium (ILCCO). Data from 16 studies (9 population based case-control, 4 hospital based case-control, 2 mixed case-control and 1 cohort - 10 from North America, 5 from Europe and 1 from Asia) were pooled, including 24044 cases and 81256 controls. Study-specific effect estimates were derived using logistic regression models for case-control studies and Cox proportional hazards models for cohort studies adjusted for age, sex, education and pack-years of smoking. Effect estimates were then pooled using random effects models where summary effects for each of the PLDs were evaluated separately. Stratified analyses were conducted based on smoking status, histology and study design or control source. Heterogeneity was evaluated using the Cochrane Q statistic and Galbraith plots, and publication bias was evaluated using funnel plots as well as the Begg test. A previous history of emphysema conferred a relative risk (RR) of 2.17, 95% confidence interval (CI): 1.67-2.82 (from 15 studies, p-het<.001). A previous history of chronic bronchitis conferred a RR of 1.49, 95% CI: 1.33-1.60 (from 12 studies, p-het.=0.434). Tuberculosis was associated with a RR of 1.54, 95% CI: 1.19-1.99 (from 15 studies, p-het.=0.001). Both asbestosis (RR 2.51, 95% CI: 1.53-4.12 (from 7 studies, p-het=0.379)) and silicosis (RR 1.70, 95% CI: 1.15-2.54, (from 3 studies, p-het. p=0.476)) were also associated with lung cancer risk. When the outlying studies were removed, effect estimates changed minimally and heterogeneity was reduced. Findings were consistent in subgroup analyses by smoking status and histology (adenocarcinoma, squamous cell carcinoma and small cell lung cancer). Effect estimates among never smokers were for emphysema a RR of 2.21, 95% CI: 0.99-4.90 (from 8 studies), for chronic bronchitis 1.12, 95% CI: 0.78-1.62 (from 9 studies), for pneumonia 1.37, 95% CI: 1.10-1.70 (from 10 studies) and for tuberculosis 1.54, 95% CI: 0.99-2.39 (from 9 studies). In this analysis of data from multiple continents, PLDs were associated with an increased risk of lung cancer. The evidence among never smokers supports a direct relationship between previous lung diseases and lung cancer. 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 4826.

Abstract Background: Genetic susceptibility for cancer can differ substantially among families. We use trait-related covariates to identify a genetically homogeneous subset of families with the best evidence for linkage in the presence of heterogeneity. Methods: We performed a genome-wide linkage screen in 93 families. Samples and data were collected by the familial lung cancer recruitment sites of the Genetic Epidemiology of Lung Cancer Consortium. We estimated linkage scores for each family by the Markov chain Monte Carlo procedure using SimWalk2 software. We used ordered subset analysis (OSA) to identify genetically homogenous families by ordering families based on a disease-associated covariate. We performed permutation tests to determine the relationship between the trait-related covariate and the evidence for linkage. Results: A genome-wide screen for lung cancer loci identified strong evidence for linkage to 6q23–25 and suggestive evidence for linkage to 12q24 using OSA, with peak logarithm of odds (LOD) scores of 4.19 and 2.79, respectively. We found other chromosomes also suggestive for linkages, including 5q31–q33, 14q11, and 16q24. Conclusions: Our OSA results support 6q as a lung cancer susceptibility locus and provide evidence for disease linkage on 12q24. This study further increased our understanding of the inheritability for lung cancer. Validation studies using larger sample size are needed to verify the presence of several other chromosomal regions suggestive of an increased risk for lung cancer and/or other cancers. Impact: OSA can reduce genetic heterogeneity in linkage study and may assist in revealing novel susceptibility loci. Cancer Epidemiol Biomarkers Prev; 19(12); 3157–66. ©2010 AACR.

Abstract A common variant on chromosomal region 15q24-25.1, marked by rs1051730, was found to be associated with lung cancer risk. Here, we attempted to confirm the second variant on 15q24-25.1 in several large sporadic lung cancer populations and determined what percentage of additional risk for lung cancer is due to the genetic effect of the second variant. SNPs rs1051730 and rs481134 were genotyped in 2,818 lung cancer cases and 2,766 controls from four populations. Joint analysis of these two variants (rs1051730 and rs481134) on 15q24-25.1 identified three major haplotypes (G_T, A_C, and G_C) and provided stronger evidence for association of 15q24-25.1 with lung cancer (P = 9.72 × 10−9). These two variants represent three levels of risk associated with lung cancer. The most common haplotype G_T is neutral; the haplotype A_C is associated with increased risk for lung cancer with 5.0% higher frequency in cases than in controls [P = 1.68 × 10−7; odds ratio (OR), 1.24; 95% confidence interval (95% CI), 1.14–1.35]; whereas the haplotype G_C is associated with reduced risk for lung cancer with 4.4% lower frequency in cases than in controls (P = 7.39 × 10−7; OR, 0.80; 95% CI, 0.73–0.87). We further showed that these two genetic variants on 15q24-25.1 independently influence lung cancer risk (rs1051730: P = 4.42 × 10−11; OR, 1.60; 95% CI, 1.46–1.74; rs481134: P = 7.01 × 10−4; OR, 0.81; 95% CI, 0.72–0.92). The second variant on 15q24-25.1, marked by rs481134, explains an additional 13.2% of population attributable risk for lung cancer. Cancer Res; 70(8); 3128–35. ©2010 AACR.

Abstract Cigarette smoking is the major cause for lung cancer, but genetic factors also affect susceptibility. We studied families that included multiple relatives affected by lung cancer. Results from linkage analysis showed strong evidence that a region of chromosome 6q affects lung cancer risk. To characterize the effects that this region of chromosome 6q region has on lung cancer risk, we identified a haplotype that segregated with lung cancer. We then performed Cox regression analysis to estimate the differential effects that smoking behaviors have on lung cancer risk according to whether each individual carried a risk-associated haplotype or could not be classified and was assigned unknown haplotypic status. We divided smoking exposures into never smokers, light smokers (<20 pack-years), moderate smokers (20 to <40 pack-years), and heavy smokers (≥40 pack-years). Comparing results according to smoking behavior stratified by carrier status, compared with never smokers, there was weakly increasing risk for increasing smoking behaviors, with the hazards ratios being 3.44, 4.91, and 5.18, respectively, for light, moderate, or heavy smokers, whereas among the individuals from families without the risk haplotype, the risks associated with smoking increased strongly with exposure, the hazards ratios being, respectively, 4.25, 9.17, and 11.89 for light, moderate, and heavy smokers. The never smoking carriers had a 4.71-fold higher risk than the never smoking individuals without known risk haplotypes. These results identify a region of chromosome 6q that increases risk for lung cancer and that confers particularly higher risks to never and light smokers. Cancer Res; 70(6); 2359–67

Abstract Background: Genetic factors play important roles in lung cancer susceptibility. In this study, we replicated the association of 5p15.33 and 6p21.33 with familial lung cancer. Taking into account the previously identified genetic susceptibility variants on 6q23-25/RGS17 and 15q24-25.1, we further determined the cumulative association of these four genetic regions and the population attributable risk percent of familial lung cancer they account for. Methods: One hundred ninety-four case patients and 219 cancer-free control subjects from the Genetic Epidemiology of Lung Cancer Consortium were used for the association analysis. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. Single nucleotide polymorphisms (SNP) on chromosomal regions 5p15.33, 6p21.33, 6q23-25/RGS17, and 15q24-25.1 were assessed for their associations with familial lung cancer. The cumulative association of the four chromosomal regions with familial lung cancer was evaluated with the use of a linear logistic model. Population attributable risk percent was calculated for each SNP using risk ratio. Results: SNP rs31489 showed the strongest evidence of familial lung cancer association on 5p15.33 (P = 2 × 10−4; odds ratio, 0.57; 95% confidence interval, 0.42-0.77), whereas rs3117582 showed a weak association on 6p21.33 (P = 0.09; odds ratio, 1.47; 95% confidence interval, 0.94-2.31). Analysis of a combination of SNPs from the four regions provided a stronger cumulative association with familial lung cancer (P = 6.70 × 10−6) than any individual SNPs. The risk of lung cancer was increased to 3- to 11-fold among those subjects who had at least one copy of risk allele at each region compared with subjects without any of the risk factors. These four genetic regions contribute to a total of 34.6% of familial lung cancer in smokers. Conclusions: The SNPs in four chromosomal regions have a cumulative and significant association with familial lung cancer and account for about one-third of the population attributable risk for familial lung cancer. Cancer Epidemiol Biomarkers Prev; 19(2); 517–24

Abstract Recent genome-wide association studies have linked the chromosome 15q24-25.1 locus to nicotine addiction and lung cancer susceptibility. To refine the 15q24-25.1 locus, we performed a haplotype-based association analysis of 194 familial lung cases and 219 cancer-free controls from the Genetic Epidemiology of Lung Cancer Consortium (GELCC) collection, and used proliferation and apoptosis analyses to determine which gene(s) in the 15q24-25.1 locus mediates effects on lung cancer cell growth in vitro. We identified two distinct subregions, hapL (P = 3.20 × 10−6) and hapN (P = 1.51 × 10−6), which were significantly associated with familial lung cancer. hapL encompasses IREB2, LOC123688, and PSMA4, and hapN encompasses the three nicotinic acetylcholine receptor subunit genes CHRNA5, CHRNA3, and CHRNB4. Examination of the genes around hapL revealed that PSMA4 plays a role in promoting cancer cell proliferation. PSMA4 mRNA levels were increased in lung tumors compared with normal lung tissues. Down-regulation of PSMA4 expression decreased proteasome activity and induced apoptosis. Proteasome dysfunction leads to many diseases including cancer, and drugs that inhibit proteasome activity show promise as a form of cancer treatment. Genes around hapN were also investigated, but did not show any direct effect on lung cancer cell proliferation. We concluded that PSMA4 is a strong candidate mediator of lung cancer cell growth, and may directly affect lung cancer susceptibility through its modulation of cell proliferation and apoptosis. [Cancer Res 2009;69(19):7844–50]

Abstract Purpose: We have previously mapped a major susceptibility locus influencing familial lung cancer risk to chromosome 6q23-25. However, the causal gene at this locus remains undetermined. In this study, we further refined this locus to identify a single candidate gene, by fine mapping using microsatellite markers and association studies using high-density single nucleotide polymorphisms (SNP). Experimental Design: Six multigenerational families with five or more affected members were chosen for fine-mapping the 6q linkage region using microsatellite markers. For association mapping, we genotyped 24 6q-linked cases and 72 unrelated noncancer controls from the Genetic Epidemiology of Lung Cancer Consortium resources using the Affymetrix 500K chipset. Significant associations were validated in two independent familial lung cancer populations: 226 familial lung cases and 313 controls from the Genetic Epidemiology of Lung Cancer Consortium, and 154 familial cases and 325 controls from Mayo Clinic. Each familial case was chosen from one high-risk lung cancer family that has three or more affected members. Results: A region-wide scan across 6q23-25 found significant association between lung cancer susceptibility and three single nucleotide polymorphisms in the first intron of the RGS17 gene. This association was further confirmed in two independent familial lung cancer populations. By quantitative real-time PCR analysis of matched tumor and normal human tissues, we found that RGS17 transcript accumulation is highly and consistently increased in sporadic lung cancers. Human lung tumor cell proliferation and tumorigenesis in nude mice are inhibited upon knockdown of RGS17 levels. Conclusion: RGS17 is a major candidate for the familial lung cancer susceptibility locus on chromosome 6q23-25.