Abstract Background: Recent genome-wide association studies (GWAS) have identified 28 susceptibility loci for Lung cancer (LC), 32 loci for smoking behavior, 10 loci for chronic obstructive pulmonary disease (COPD), 63 loci for pulmonary function and related phenotypes, totaling 107 GWAS susceptibility loci (as of November 2014). Given the common variants that have been found to be associated with LC in GWAS, targeted-region exome sequencing provides a cost-effective approach for further investigation of high-priority regions of the genome and has the great potential to identify rare causal variants in GWAS loci. Patients and Methods: Using an extreme phenotype approach, we selected 48 sporadic LC patients reporting heavy smoking histories with the presence of severe COPD in whom environmental factors are considered overwhelming, and 54 familial LC cases from families with at least three first-degree relatives with LC who are likely enriched for genomic signal, to search for the disease-causing rare mutations within the target 107 GWAS loci using exome sequencing data. Results: By focusing on exome profiles of these target 107 loci, we identified two disease-causing rare mutations on 6p21.32 TNXB p. Arg504His and 10q25.1 CCDC147 p.Arg696Cys. The homozygous Arg504His mutation presented in four familial and one sporadic LC cases. Notably, the minor allele frequency (MAF) of this variant in Caucasians from 1000 Genomes is very rare (<0.001). The heterozygous CCDC147 Arg696Cys variant were identified in two familial cases and one sporadic case. The MAF for this variant in the Caucasians from 1000 Genomes is 0.004. Both deleterious changes lead to truncation of the putative proteins, which disrupts the predicted domain and alters the cellular localization. We also observed several other suggestive rare mutations on G7C, TNS1, DBH1, and CHRNA5. Conclusion: Our target exome sequencing results demonstrate novel highly disruptive LC risk-conferring TNXB and CCDC147 mutations. Since the rare variants have appreciable effects on disease risk prediction, families and patients may warrant screening for mutations in TNXB and CCDC147 (if validated) to assess their potential LC risk. Citation Format: Yanhong Liu, Farrah Kheradmand, Michael Scheurer, Caleb Davis, David Wheeler, Edwin Silverman, Shete Sanjay, Spiridon Tsavachidis, Georgina Armstrong, Elena Kupert, Marshall Anderson, Yafang Li, Claudio Pikielny, Joan E. Bailey-Wilson, Ming You, Colette Gaba, Mariza DeAndrade, Diptasri Mandal, Claire Simpson, Susan Pinney, Christopher Amos, Margaret Spitz. Target exome sequencing for disease-causing rare mutations in familial and sporadic lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4600. doi:10.1158/1538-7445.AM2015-4600
Abstract B24: Attitudes of pancreatic cancer family members toward cancer risk and screening
Abstract B24 Purpose Pancreatic cancer (PC) is the fourth leading cause of cancer death in the United States for which no recommended screening guidelines are available. An estimated 34,290 deaths related to PC is expected to occur in 2008 and the 5-year relative survival rate for this cancer is 5% for all stages combined. A person's chance of developing this cancer increases three-fold if a first-degree relative has pancreatic cancer. The purpose of this study was to assess attitudes of unaffected family members in the Mayo Clinic Pancreas Cancer Family study toward PC cancer risk and future screening options. This is the first study to report such attitudes of PC family members. Subjects and Methods At-risk family members with two or more relatives affected with pancreas cancer in the kindred and primary care controls completed a survey asking about: perceived PC risk, degree of PC worry/concern, attitude toward cancer screening in general, and intentions regarding PC screening if it were a blood test or endoscopic ultrasound. Results 386 family members in 109 PC kindreds and 1058 controls completed surveys. Forty-six percent of PC family members reported that it was likely they would develop PC during their lifetime compared to 6% of controls. Forty-one percent of family members reported having thoughts regarding the possibility of getting pancreatic cancer during the past month versus 4.6% of controls. Similarly, 74% of family members reported concern about getting PC as compared to 40.6% of controls. 94% of family members reported they would be likely to undergo a blood-based PC screening test compared to 89.7% of controls. For endoscopic ultrasound, 71% of family members would be likely to undergo screening as compared to 55% of controls. All comparisons were statistically significant. Conclusion Compared to controls, PC family members perceive their personal PC risk to be high and report a higher rate of PC-related cancer worry/concern. A high percentage of family members and controls indicate receptivity to PC screening, especially if it were a blood test. If the screening is more invasive (i.e. EUS), interest declines, particularly among controls. This information can help investigators to understand and address potential motivators and barriers to recruitment for future PC studies and indicates that there is a need to develop educational interventions among these families to reduce their actual and perceived pancreatic cancer risk. Citation Information: Cancer Prev Res 2008;1(7 Suppl):B24.