Tobacco-related cancers and inflammation-related SNPs Molecular markers of genetic susceptibility

1. Tobacco-related cancers and inflammation-related SNPsMolecular markers of genetic susceptibility EPI 243 May 7, 2009 Sam S. Oh, MPH

2. Tobacco smoking • Major risk factor for cancers of lung, upper aero-digestive tract (UADT), stomach, pancreas, liver, kidney, urinary tract, uterine cervix, and bone marrow • Epithelial cells in many of these organs repeatedly exposed to tobacco smoke components and metabolites • Carcinogenic and potent inducers of inflammation • Free radicals contained in and generated by tobacco smoke can lead to cancer through oxidative DNA damage mediated by inflammation-associated production of reactive oxygen species

3. Inflammation & Cancer • Chronic inflammation associated with various cancers • Hepatitis/liver • H. pylori/stomach • Asbestosis/lung • IBD/colorectal • Inflammation mediating cells from cancers promote tumor growth in vitro • Altered immune cytokines found in cancer cells

4. Modulation of Immune Response Achieved through balance of T-helper (Th) cells via cytokine expression Type 1: pro-inflammatory, cellular immune response Type 2: anti-inflammatory, humoral immune response Activation of one Th-cell pathway inactivates the other

5. Inflammatory Anti-inflammatory

6. Research Summary • Investigate association of inflammation-related SNPs with tobacco-related cancers • Lung, oropharynx, nasopharynx, larynx, esophagus, stomach, liver, bladder; and kidney cancer • Pooled analysis across all three case-control studies • Los Angeles (LA) • Taixing, China • Memorial Sloan-Kettering Cancer Center (MSKCC) • All epidemiological data collected in person by trained interviewers using study-specific standardized questionnaires • Including factors associated with or known to affect study-specific cancer risk, including age, race, medical history, education, and history of tobacco and alcohol exposure

7. Study Locations

8. LA Study • Cases obtained from LA County cancer registry • Healthy controls matched on age, gender, and neighborhood • Eligibility criteria • New, histologically diagnosed cases or no history of lung cancer and head & neck cancer (controls)‏ • Aged 18-65 years • Resident of LA County during 1999-2005 • English- or Spanish-speaking or available translator • Buccal cells collected post-interview • Recruitment rate: lung 39%, UADT 46%, control 79%

9. Taixing Study • Incident and pathologically or clinically diagnosed stomach, esophageal, and liver cases obtained from Taixing Tumor Registry • Healthy common controls from general population matched on age, gender, and village • Eligibility criteria (cases and controls) • Stable medical condition • At least 20 years old • Living in Taixing for at least 10 years • Blood samples collected post-interview • Recruitment rate: esophagus 67%, stomach 65%, liver 57%, control 89%

10. MSKCC Study • Pathologically confirmed bladder cancer cases recently diagnosed or undergone bladder surgery at MSKCC • Controls: MSKCC blood bank donors or stable non-cancer MSKCC patients • Blood samples collected post-interview • Recruitment rate: 95% case, 92% control

11. Pooled Study • Variable standardization • Study location • Gender • Ethnicity • Age • Smoking • Adjusting for ethnicity and study location • Control for which variable? • Combined study location and ethnicity into one variable

12. SNP Selection &Genotyping Criteria Minor allele frequency ≥5% in general population Functional change associated with polymorphism Located along gene transcription regulation areas HWE P value > Bonferroni-adjusted P value Genotyping call rate ≥80% (SNPlex), ≥95% (TaqMan) Case/control DNA randomized onto PCR plates Genotyped on SNPlex and TaqMan platforms Most reliable signal reported for SNPs in LD Reproducibility SNPlex: 0.978 TaqMan: 0.997 SNPlex-TaqMan concordance: 0.943

13. Investigated SNPs

15. Adjusted for study location (pooled analysis), age, gender, education (cancer site-stratified analyses), tobacco smoking, ethnicity, and alcohol use (oropharynx and esophagus).

17. G*E Interaction Adjusted for study location/ethnicity (pooled analysis only), ethnicity (lung and esophagus analyses only), age, gender, education (lung and esophagus analyses only), pack-years (lung and esophagus analyses only), and alcohol use (esophagus only)

18. Limitations • Confounding • Standardized in-person questionnaires • Population stratification for pooled results • TNFA rs1796664 MAF does not vary appreciably • Information bias • Misclassification errors • Strict inclusion/exclusion criteria • Quality control measures for genotyping • Differential recall between cases and controls • Selection bias • Participation rates • Genotype unknown to participants • Tumor stage and grade unassociated with SNP

19. Strengths • Large sample size to estimate main and smoking-stratified effects • Ability to pool genotypes across studies • Population-based design for 7 of the 9 tobacco-related cancers • Control for multiple comparisons using two Bayesian approaches

20. Summary • “Noteworthy” associations were among synonymous SNPs in promoter regions • Some SNP-cancer associations became apparent within strata of smoking status • TNFA rs1799964 among never smokers associated with smoking-related cancer as a whole • Some SNP-cancer associations are site-specific • IL10 rs1800871 association with lung cancer is observed only among never smokers

21. Conclusions • TNFA rs1799964 is associated with smoking-related cancers among never smokers • IL10 rs1800871 is a susceptibility marker for oropharyngeal cancer, especially among ever smokers • IL10 rs1800871 is a susceptibility marker for lung cancer among never smokers

22. Co-authors UCLA Arie Belldegrun, Shen-Chih Chang, Sander Greenland, Leeka Kheifets, YC Amy Lee, Simin Liu, Jenny T Mao, Allan Pantuck, S Lani Park, Jian Yu Rao, Donald P Tashkin, Yuko You, Zuo-Feng Zhang USC Anh Le University of Michigan Hal Morgenstern SUNY Buffalo Li-Na Mu MSKCC Ming-Lan Lu, Victor E Reuter Columbia University Carlos Cordon-Cardo China Fudan University SPH Na He, Qingwu Jiang, Shun-Zhang Yu Fujian Medical University SPH Lin Cai Gates Foundation Beijing Office Jin-Kou Zhao Jiangsu CDC Hua Wang Taixing CDC Bao-Guo Ding