Age at lung cancer diagnosis in females versus males who never smoke by race and ethnicity

BACKGROUND

We characterized age at diagnosis and estimated sex differences for lung cancer and its histological subtypes among individuals who never smoke.

METHODS

We analyzed the distribution of age at lung cancer diagnosis in 33,793 individuals across 8 cohort studies and two national registries from East Asia, the United States (US) and the United Kingdom (UK). Student's t-tests were used to assess the study population differences (Δ years) in age at diagnosis comparing females and males who never smoke across subgroups defined by race/ethnicity, geographic location, and histological subtypes.

RESULTS

We found that among Chinese individuals diagnosed with lung cancer who never smoke, females were diagnosed with lung cancer younger than males in the Taiwan Cancer Registry (n = 29,832) (Δ years = -2.2 (95% confidence interval (CI):-2.5, -1.9), in Shanghai (n = 1049) (Δ years = -1.6 (95% CI:-2.9, -0.3), and in Sutter Health and Kaiser Permanente Hawai'i in the US (n = 82) (Δ years = -11.3 (95% CI: -17.7, -4.9). While there was a suggestion of similar patterns in African American and non-Hispanic White individuals. the estimated differences were not consistent across studies and were not statistically significant.

CONCLUSIONS

We found evidence of sex differences for age at lung cancer diagnosis among individuals who never smoke.

A nested case-control study of untargeted plasma metabolomics and lung cancer among never-smoking women within the prospective Shanghai Women's Health Study

The etiology of lung cancer in never-smokers remains elusive, despite 15% of lung cancer cases in men and 53% in women worldwide being unrelated to smoking. Here, we aimed to enhance our understanding of lung cancer pathogenesis among never-smokers using untargeted metabolomics. This nested case-control study included 395 never-smoking women who developed lung cancer and 395 matched never-smoking cancer-free women from the prospective Shanghai Women's Health Study with 15,353 metabolic features quantified in pre-diagnostic plasma using liquid chromatography high-resolution mass spectrometry. Recognizing that metabolites often correlate and seldom act independently in biological processes, we utilized a weighted correlation network analysis to agnostically construct 28 network modules of correlated metabolites. Using conditional logistic regression models, we assessed the associations for both metabolic network modules and individual metabolic features with lung cancer, accounting for multiple testing using a false discovery rate (FDR) < 0.20. We identified a network module of 121 features inversely associated with all lung cancer (p = .001, FDR = 0.028) and lung adenocarcinoma (p = .002, FDR = 0.056), where lyso-glycerophospholipids played a key role driving these associations. Another module of 440 features was inversely associated with lung adenocarcinoma (p = .014, FDR = 0.196). Individual metabolites within these network modules were enriched in biological pathways linked to oxidative stress, and energy metabolism. These pathways have been implicated in previous metabolomics studies involving populations exposed to known lung cancer risk factors such as traffic-related air pollution and polycyclic aromatic hydrocarbons. Our results suggest that untargeted plasma metabolomics could provide novel insights into the etiology and risk factors of lung cancer among never-smokers.

Associations between Longer Leukocyte Telomere Length and Increased Lung Cancer Risk among Never Smokers in Urban China

BACKGROUND

The complex relationship between measured leukocyte telomere length (LTL), genetically predicted LTL (gTL), and carcinogenesis is exemplified by lung cancer. We previously reported associations between longer pre-diagnostic LTL, gTL, and increased lung cancer risk among European and East Asian populations. However, we had limited statistical power to examine the associations among never smokers by gender and histology.

METHODS

To investigate further, we conducted nested case-control analyses on an expanded sample of never smokers from the prospective Shanghai Women's Health Studies (798 cases and 792 controls) and Shanghai Men's Health Studies (161 cases and 162 controls). We broke the case-control matching and used multivariable unconditional logistic regression models to estimate the ORs and 95% confidence intervals (CI) of incident lung cancer and adenocarcinoma (LUAD), in relation to LTL measured using quantitative PCR and gTL determined using a polygenic score. In addition, we conducted Mendelian randomization (MR) using MR-PRESSO.

RESULTS

We found striking dose-response relationships between longer LTL and gTL, and increased lung cancer risk among never-smoking women (P trendLTL = 4×10-6; P trendgTL = 3×10-4). Similarly, among never-smoking men, longer measured LTL was associated with over triple the risk compared with those with the shortest (OR, 3.48; 95% CI, 1.85-6.57). The overall results were similar for LUAD among women and men. MR analyses supported causal associations with LUAD among women (OR1 SD gTL, 1.19; 95% CI, 1.03-1.37; P = 0.03).

CONCLUSIONS

Longer pre-diagnostic LTL is associated with increased lung cancer risk among never smokers.

IMPACT

Our findings firmly support the role of longer telomeres in lung carcinogenesis.

Exposure to smoky coal combustion emissions and leukocyte Alu retroelement copy number

Household air pollution (HAP) from indoor combustion of solid fuel is a global health burden that has been linked to multiple diseases including lung cancer. In Xuanwei, China, lung cancer rate for non-smoking women is among the highest in the world and largely attributed to high levels of polycyclic aromatic hydrocarbons (PAHs) that are produced from combustion of smoky (bituminous) coal. Alu retroelements, repetitive mobile DNA sequences that can somatically multiply and promote genomic instability have been associated with risk of lung cancer and diesel engine exhaust exposure. We conducted analyses for 160 non-smoking women in an exposure assessment study in Xuanwei, China with a repeat sample from 49 subjects. Quantitative PCR was used to measure Alu repeat copy number relative to albumin gene copy number (Alu/ALB ratio). Associations between clusters derived from predicted levels of 43 HAP constituents, 5-methylchrysene (5-MC), a PAH previously associated with lung cancer in Xuanwei and was selected a priori for analysis, and Alu repeats were analyzed using generalized estimating equations. A cluster of 31 PAHs reflecting current exposure was associated with increased Alu copy number (β:0.03 per standard deviation change; 95% confidence interval (CI):0.01,0.04; P-value = 2E-04). One compound within this cluster, 5-MC, was also associated with increased Alu copy number (P-value = 0.02). Our findings suggest that exposure to PAHs due to indoor smoky coal combustion may contribute to genomic instability. Additionally, our study provides further support for 5-MC as a prominent carcinogenic component of smoky coal emissions. Further studies are needed to replicate our findings.

Household air pollution and epigenetic aging in Xuanwei, China

BACKGROUND

Household air pollution (HAP) from indoor combustion of solid fuel is a global health burden linked to lung cancer. In Xuanwei, China, lung cancer rate for nonsmoking women is among the highest in the world and largely attributed to high levels of polycyclic aromatic hydrocarbons (PAHs) that are produced from combustion of smoky (bituminous) coal used for cooking and heating. Epigenetic age acceleration (EAA), a DNA methylation-based biomarker of aging, has been shown to be highly correlated with biological processes underlying the susceptibility of age-related diseases. We aim to assess the association between HAP exposure and EAA.

METHODS

We analyzed data from 106 never-smoking women from Xuanwei, China. Information on fuel type was collected using a questionnaire, and validated exposure models were used to predict levels of 43 HAP constituents. Exposure clusters were identified using hierarchical clustering. EAA was derived for five epigenetic clocks defined as the residuals resulting from regressing each clock on chronological age. We used generalized estimating equations to test associations between exposure clusters derived from predicted levels of HAP exposure, ambient 5-methylchrysene (5-MC), a PAH previously found to be associated with risk of lung cancer, and EAA, while accounting for repeated-measurements and confounders.

RESULTS

We observed an increase in GrimAge EAA for clusters with 31 and 33 PAHs reflecting current (β = 0.77 y per standard deviation (SD) increase, 95 % CI:0.36,1.19) and childhood (β = 0.92 y per SD, 95 % CI:0.40,1.45) exposure, respectively. 5-MC (ng/m3-year) was found to be associated with GrimAge EAA for current (β = 0.15 y, 95 % CI:0.05,0.25) and childhood (β = 0.30 y, 95 % CI:0.13,0.47) exposure.

CONCLUSIONS

Our findings suggest that exposure to PAHs from indoor smoky coal combustion, particularly 5-MC, is associated with GrimAge EAA, a biomarker of mortality.

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications.

Alterations to biomarkers related to long-term exposure to diesel exhaust at concentrations below occupational exposure limits in the European Union and the USA

BACKGROUND

We previously found that occupational exposure to diesel engine exhaust (DEE) was associated with alterations to 19 biomarkers that potentially reflect the mechanisms of carcinogenesis. Whether DEE is associated with biological alterations at concentrations under existing or recommended occupational exposure limits (OELs) is unclear.

METHODS

In a cross-sectional study of 54 factory workers exposed long-term to DEE and 55 unexposed controls, we reanalysed the 19 previously identified biomarkers. Multivariable linear regression was used to compare biomarker levels between DEE-exposed versus unexposed subjects and to assess elemental carbon (EC) exposure-response relationships, adjusted for age and smoking status. We analysed each biomarker at EC concentrations below the US Mine Safety and Health Administration (MSHA) OEL (<106 µg/m3), below the European Union (EU) OEL (<50 µg/m3) and below the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation (<20 µg/m3).

RESULTS

Below the MSHA OEL, 17 biomarkers were altered between DEE-exposed workers and unexposed controls. Below the EU OEL, DEE-exposed workers had elevated lymphocytes (p=9E-03, false discovery rate (FDR)=0.04), CD4+ count (p=0.02, FDR=0.05), CD8+ count (p=5E-03, FDR=0.03) and miR-92a-3p (p=0.02, FDR=0.05), and nasal turbinate gene expression (first principal component: p=1E-06, FDR=2E-05), as well as decreased C-reactive protein (p=0.02, FDR=0.05), macrophage inflammatory protein-1β (p=0.04, FDR=0.09), miR-423-3p (p=0.04, FDR=0.09) and miR-122-5p (p=2E-03, FDR=0.02). Even at EC concentrations under the ACGIH recommendation, we found some evidence of exposure-response relationships for miR-423-3p (ptrend=0.01, FDR=0.19) and gene expression (ptrend=0.02, FDR=0.19).

CONCLUSIONS

DEE exposure under existing or recommended OELs may be associated with biomarkers reflective of cancer-related processes, including inflammatory/immune response.

Methylated polycyclic aromatic hydrocarbons from household coal use across the life course and risk of lung cancer in a large cohort of 42,420 subjects in Xuanwei, China

BACKGROUND

We previously showed that exposure to 5-methylchrysene (5MC) and other methylated polycyclic aromatic hydrocarbons (PAHs) best explains lung cancer risks in a case-control study among non-smoking women using smoky coal in China. Time-related factors (e.g., age at exposure) and non-linear relations were not explored.

OBJECTIVE

We investigated the relation between coal-derived air pollutants and lung cancer mortality using data from a large retrospective cohort.

METHODS

Participants were smoky (bituminous) or smokeless (anthracite) coal users from a cohort of 42,420 subjects from four communes in XuanWei. Follow-up was from 1976 to 2011, during which 4,827 deaths from lung-cancer occurred. Exposures were predicted for 43 different pollutants. Exposure clusters were identified using hierarchical clustering. Cox regression was used to estimate exposure-response relations for 5MC, while effect modification by age at exposure was investigated for cluster prototypes. A Bayesian penalized multi-pollutant model was fitted on a nested case-control sample, with more restricted models fitted to investigate non-linear exposure-response relations.

RESULTS

We confirmed the strong exposure-response relation for 5MC (Hazard Ratio [95% Confidence Interval] = 2.5 [2.4, 2.6] per standard-deviation (SD)). We identified four pollutant clusters, with all but two PAHs in a single cluster. Exposure to PAHs in the large cluster was associated with a higher lung cancer mortality rate (HR [95%CI] = 2.4 [2.2, 2.6] per SD), while exposure accrued before 18 years of age appeared more important than adulthood exposures. Results from the multi-pollutant model identified anthanthrene (ANT) and benzo(a)chrysene (BaC) as risk factors. 5MC remained strongly associated with lung cancer in models that included ANT and BaC and also benzo(a)pyrene (BaP).

CONCLUSION

We confirmed the link between PAH exposures and lung cancer in smoky coal users and found exposures before age 18 to be especially important. We found some evidence for the carcinogen 5MC and non-carcinogens ANT and BaC.

Association between diesel exhaust exposure and mitochondrial DNA methylation

BACKGROUND

Diesel exhaust is an established human carcinogen, however the mechanisms by which it leads to cancer development are not fully understood. Mitochondrial dysfunction is an established contributor to carcinogenesis. Recent studies have improved our understanding of the role played by epigenetic modifications in the mitochondrial genome on tumorigenesis. In this study, we aim to evaluate the association between diesel engine exhaust (DEE) exposure with mitochondrial DNA (mtDNA) methylation levels in workers exposed to DEE.

METHODS

The study population consisted of 53 male workers employed at a diesel engine manufacturing facility in Northern China who were routinely exposed to diesel exhaust in their occupational setting, as well as 55 unexposed male control workers from other unrelated factories in the same geographic area. Exposure to DEE, elemental carbon, organic carbon, and particulate matter (PM2.5) were assessed. mtDNA methylation for CpG sites (CpGs) from seven mitochondrial genes (D-Loop, MT-RNR1, MT-CO2, MT-CO3, MT-ATP6, MT-ATP8, MT-ND5) was measured in blood samples. Linear regression models were used to estimate the associations between DEE, elemental carbon, organic carbon and PM2.5 exposures with mtDNA methylation levels, adjusting for potential confounders.

RESULTS

DEE exposure was associated with decreased MT-ATP6 (difference= -35.6%, p-value= 0.019) and MT-ATP8 methylation (difference= -30%, p-value= 0.029) compared to unexposed controls. Exposures to elemental carbon, organic carbon, and PM2.5 were also significantly and inversely associated with methylation in MT-ATP6 and MT-ATP8 genes (all p-values < 0.05).

CONCLUSIONS

Our findings suggest that DEE exposure perturbs mtDNA methylation, which may be of importance for tumorigenesis.

Exposure to diesel engine exhaust and alterations to the Cys34/Lys525 adductome of human serum albumin

We investigated whether exposure to carcinogenic diesel engine exhaust (DEE) was associated with altered adduct levels in human serum albumin (HSA) residues. Nano-liquid chromatography-high resolution mass spectrometry (nLC-HRMS) was used to measure adducts of Cys34 and Lys525 residues in plasma samples from 54 diesel engine factory workers and 55 unexposed controls. An untargeted adductomics and bioinformatics pipeline was used to find signatures of Cys34/Lys525 adductome modifications. To identify adducts that were altered between DEE-exposed and unexposed participants, we used an ensemble feature selection approach that ranks and combines findings from linear regression and penalized logistic regression, then aggregates the important findings with those determined by random forest. We detected 40 Cys34 and 9 Lys525 adducts. Among these findings, we found evidence that 6 Cys34 adducts were altered between DEE-exposed and unexposed participants (i.e., 841.75, 851.76, 856.10, 860.77, 870.43, and 913.45). These adducts were biologically related to antioxidant activity.

Abstract 2254: Risk models for lung cancer in never-smoking women in Shanghai with implications for screening

Background: The majority of female lung cancer cases in Asia are never-smokers with distinct risk factor profiles. Given the high burden of disease in this population, there is an increasing need to improve the understanding of lung cancer. Current risk models for lung cancer focus on active smokers and individuals of European ancestry. Therefore, we developed statistical models by integrating genetic and environmental risk factors to estimate absolute and population attribute risk of lung cancer among never-smoking women in Asia.

Methods: We built absolute risk models for lung cancer among never-smoking women using data from 71,300 women (760 incident cases) in the Shanghai Women’s Health Study (SWHS), a population-based prospective cohort study. Relative risks were estimated using a multivariable Cox regression model with questionnaire-based risk factors. To account for missing genetic data for some subjects, we simulated genotypes for 10 common single nucleotide polymorphisms (SNP) using information on minor allele frequencies (MAF) and odds ratio estimates from previous genome-wide association studies (GWAS), conditional on family history of lung cancer. We used the iCARE tool to build two models for predicting lifetime (40 years) and 6-year absolute risk of lung cancer using age-specific lung cancer incidence rates, age-specific competing mortality rates, and risk factor distribution with: 1) questionnaire-based risk factors only and 2) questionnaire and genetic data. We then used the full absolute risk model to estimate the population attributable risk (PAR) due to modifiable risk factors, namely coal use and exposure to environmental tobacco smoke (ETS).

Results: The questionnaire-based only model included family history of lung cancer, coal use, exposure to ETS, and body mass index (BMI). The full model also included data on 10 lung cancer related SNPs from our previous GWAS and had a wider spread in distribution of absolute lifetime risk (median=2.41%; range=0.43-12.36) compared to the questionnaire-based only model (median=2.72%; range=1.93-4.87). We used the full model to estimate the PAR and found that 1.74% and 6.33% of lung cancer cases could be prevented if never-smoking women in Shanghai did not use coal and were not exposed to ETS, respectively. Furthermore, we found that the full model estimated that 2.5% of the study population had a 6-year absolute risk of lung cancer higher than 1.51%, which is the suggested risk threshold for screening by existing risk models.

Conclusion: We built risk models for never-smoking Asian women and estimated the contribution of coal use and ETS to the burden of lung cancer in Shanghai. This initial work shows promise for expanding and validating risk models in this population with potential translational implications, such as providing insight to identifying high risk individuals that may be eligible for lung cancer screening and primary prevention efforts.

Citation Format: Batel Blechter, Parichoy Pal Choudhury, Xiao-ou Shu, Wei Zheng, Qiuyin Cai, Gong Yang, Jason Y.Y. Wong, Bu-Tian Ji, Wei Hu, Anne Rositch, Nilanjan Chatterjee, Nathaniel Rothman, Qing Lan. Risk models for lung cancer in never-smoking women in Shanghai with implications for screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2254.

Benzene exposure and risk of benzene poisoning in Chinese workers

OBJECTIVES

Benzene is a known haematoxin and leukemogen that can cause benzene poisoning (BP), that is, a persistent reduction in white cell counts that is strongly associated with increased risk of lymphohaematopoietic malignancies. Data are needed on the exposure-response, particularly at low doses and susceptible populations for clinical and regulatory purposes.

METHODS

In a case-cohort study among 110 631 Chinese workers first employed 1949-1987 and followed up during 1972-1999, we evaluated BP risk according to benzene exposure level and investigated risk modification by subject (sex, attained age) and exposure-related factors (latency, exposure windows, age at first benzene exposure, coexposure to toluene) using excess relative risk and excess absolute risk models.

RESULTS

There were 538 BP cases and 909 benzene-exposed referents. The exposure metric with best model fit was cumulative benzene exposure during a 5-year risk window, followed by a 9-month lag period before BP diagnosis. Estimated excess absolute risk of BP at age 60 increased from 0.5% for subjects in the lowest benzene exposure category (>0 to 10 ppm-years) to 5.0% for those in the highest category (>100 ppm-years) compared with unexposed subjects. Increased risks were apparent at low cumulative exposure levels and for workers who were first exposed at <30 years of age.

CONCLUSIONS

Our data show a clear association between benzene exposure and BP, beginning at low cumulative benzene exposure levels with no threshold, and with higher risks for workers exposed at younger ages. These findings are important because BP has been linked to a strongly increased development of lymphohaematopoietic malignancies.

Characterization of the humoral immune response to the EBV proteome in extranodal NK/T-cell lymphoma

Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy that has been etiologically linked to Epstein-Barr virus (EBV) infection, with EBV gene transcripts identified in almost all cases. However, the humoral immune response to EBV in NKTCL patients has not been well characterized. We examined the antibody response to EBV in plasma samples from 51 NKTCL cases and 154 controls from Hong Kong and Taiwan who were part of the multi-center, hospital-based AsiaLymph case–control study. The EBV-directed serological response was characterized using a protein microarray that measured IgG and IgA antibodies against 202 protein sequences representing the entire EBV proteome. We analyzed 157 IgG antibodies and 127 IgA antibodies that fulfilled quality control requirements. Associations between EBV serology and NKTCL status were disproportionately observed for IgG rather than IgA antibodies. Nine anti-EBV IgG responses were significantly elevated in NKTCL cases compared with controls and had ORs_{highest vs. lowest tertile} > 6.0 (Bonferroni-corrected P-values < 0.05). Among these nine elevated IgG responses in NKTCL patients, three IgG antibodies (all targeting EBNA3A) are novel and have not been observed for other EBV-associated tumors of B-cell or epithelial origin. IgG antibodies against EBNA1, which have consistently been elevated in other EBV-associated tumors, were not elevated in NKTCL cases. We characterize the antibody response against EBV for patients with NKTCL and identify IgG antibody responses against six distinct EBV proteins. Our findings suggest distinct serologic patterns of this NK/T-cell lymphoma compared with other EBV-associated tumors of B-cell or epithelial origin.

Commute patterns, residential traffic-related air pollution, and lung cancer risk in the prospective UK Biobank cohort study

INTRODUCTION

Commuting exposes millions of people to carcinogens from traffic-related air pollution (TRAP) but is seldomly considered in epidemiologic studies of lung cancer. In the prospective United Kingdom (UK) Biobank cohort study, we investigated associations between commute patterns, residential nitrogen dioxide concentrations (NO2; a surrogate for TRAP), and lung cancer risk.

METHODS

We analyzed 234,124 employed participants at baseline (2006-2010). There were 493 incident lung cancer cases diagnosed over an average 7-year follow-up. Subjects were cross-classified into exclusive categories of commute mode (automobile, public transportation, walking, cycling, active mixture, and other mixture) and frequency (regular: 1-4, often: ≥5 work-bound trips/week). Annual average residential NO2 concentrations in 2005-2007 were estimated with land use regression. Multivariable Cox regression was used to estimate associations between commute patterns, NO2 quartiles, and incident lung cancer. We conducted analyses stratified by NO2 (>, ≤median = 28.3 µg/m3) and potential confounders such as sex and smoking.

RESULTS

Compared to regular automobile use, commuting often by public transportation was associated with increased lung cancer risk (hazard ratio (HR) = 1.58, 95% confidence intervals (CI):1.08-2.33). Additionally, we found a positive exposure-response relationship with residential NO2 (HRQ2 = 1.21, 95 %CI: 0.90-1.62; HRQ3 = 1.48, 95 %CI: 1.10-1.99; HRQ4 = 1.58, 95 %CI: 1.13-2.23; p-trend = 3.1 × 10-3). The public transportation association was observed among those with higher NO2 (p-interaction = 0.02). Other commute categories were not associated with risk.

CONCLUSIONS

Commuters residing in high-NO2 areas who often use public transportation could have elevated lung cancer risk compared to regular automobile users. These results warrant investigations into which component(s) of public transportation contribute to the observed association with increased lung cancer risk.

Abstract 833: Characterization of the humoral immune response to the EBV proteome in extranodal natural killer T-cell lymphoma

Background: Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy that has been linked to infection with Epstein-Barr virus (EBV). However, the humoral immune response to EBV in relation to NKTCL has not been well studied.

Methods: We examined plasma samples from 51 NKTCL cases and 154 controls from Hong Kong and Taiwan from the multi-center hospital-based AsiaLymph case-control study using a protein microarray that measured IgG and IgA antibodies against 202 sequences across the entire EBV proteome. Internal validation was performed by using four ELISA assays targeting IgG and IgA antibodies against viral capsid antigen (VCA) and nuclear antigen 1 (EBNA1), antibodies that have previously been linked to other EBV-associated cancers and reported in NKTCL cases. Differences in the mean standardized signal intensity (SSI) for IgG and IgA antibodies against each of the array sequences between NKTCL and controls were compared using unpaired t tests. Odds ratios (ORs) and 95% CIs for the association between each three-level categorical anti-EBV antibody variable (i.e., tertiles) and NKTCL status were calculated using logistic regression models adjusted for sex, age and study area.

Results: We analyzed 157 IgG antibodies and 127 IgA antibodies that fulfilled quality control requirements. NKTCL disease associations were disproportionately observed for IgG rather than IgA markers. Nine anti-EBV IgG responses were elevated in NKTCL cases compared with controls with odds ratios highest vs. lowest tertile &gt; 6.0 (Bonferroni-corrected p-values&lt;0.05). Among these nine responses, three (all mapping to EBNA3A) are novel and have not been found to be strongly associated with other EBV-associated tumors of B-cell or epithelial origin while six mapped to proteins (BALF2, BMRF1, BZLF1, BVRF2, and BPLF1) that have been reported previously to be associated with other EBV-associated cancers. IgG antibodies against EBNA1, which have consistently been associated with other EBV-associated tumors in different populations, were not elevated in NKTCL cases. Results from ELISA assays confirmed our array-based findings.

Conclusions: Our data suggest that the anti-EBV humoral response profiles are altered in NKTCL, but that alterations observed differ from those for other EBV-associated tumors of B-cell or epithelial origin. Our findings provide clues for future NKTCL pathogenesis research.

Citation Format: Zhiwei Liu, Yomani Sarathkumara, John K. Chan, Yok-Lam Kwong, Tai Hing Lam, Dennis Kai Ming Ip, Brian Chiu, Jun Xu, Yu-Chieh Su, Carla Proietti, Kelly J. Yu, Raymond Liang, Wei Hu, Bu-Tian Ji, Anna E. Coghill, Ruth M. Pfeiffer, Allan Hildesheim, Nathaniel Rothman, Denise Doolan, Qing Lan. Characterization of the humoral immune response to the EBV proteome in extranodal natural killer T-cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 833.

Elevated Alu retroelement copy number among workers exposed to diesel engine exhaust

BACKGROUND

Millions of workers worldwide are exposed to diesel engine exhaust (DEE), a known genotoxic carcinogen. Alu retroelements are repetitive DNA sequences that can multiply and compromise genomic stability. There is some evidence linking altered Alu repeats to cancer and elevated mortality risks. However, whether Alu repeats are influenced by environmental pollutants is unexplored. In an occupational setting with high DEE exposure levels, we investigated associations with Alu repeat copy number.

METHODS

A cross-sectional study of 54 male DEE-exposed workers from an engine testing facility and a comparison group of 55 male unexposed controls was conducted in China. Personal air samples were assessed for elemental carbon, a DEE surrogate, using NIOSH Method 5040. Quantitative PCR (qPCR) was used to measure Alu repeat copy number relative to albumin (Alb) single-gene copy number in leucocyte DNA. The unitless Alu/Alb ratio reflects the average quantity of Alu repeats per cell. Linear regression models adjusted for age and smoking status were used to estimate relations between DEE-exposed workers versus unexposed controls, DEE tertiles (6.1-39.0, 39.1-54.5 and 54.6-107.7 µg/m³) and Alu/Alb ratio.

RESULTS

DEE-exposed workers had a higher average Alu/Alb ratio than the unexposed controls (p=0.03). Further, we found a positive exposure-response relationship (p=0.02). The Alu/Alb ratio was highest among workers exposed to the top tertile of DEE versus the unexposed controls (1.12±0.08 SD vs 1.06±0.07 SD, p=0.01).

CONCLUSION

Our findings suggest that DEE exposure may contribute to genomic instability. Further investigations of environmental pollutants, Alu copy number and carcinogenesis are warranted.

A Prospective Investigation of Circulating Metabolome Identifies Potential Biomarkers for Gastric Cancer Risk

BACKGROUND

Metabolomics is widely used to identify potential novel biomarkers for cancer risk. No investigation, however, has been conducted to prospectively evaluate the role of perturbation of metabolome in gastric cancer development.

METHODS

250 incident cases diagnosed with primary gastric cancer were selected from the Shanghai Women's Health and the Shanghai Men's Health Study, and each was individually matched to one control by incidence density sampling. An untargeted global profiling platform was used to measure approximately 1,000 metabolites in prediagnostic plasma. Conditional logistic regression was utilized to generate ORs and P values.

RESULTS

Eighteen metabolites were associated with gastric cancer risk at P < 0.01. Among them, 11 metabolites were lysophospholipids or lipids of other classes; for example, 1-(1-enyl-palmitoyl)-GPE (P-16:0) (OR = 1.56; P = 1.89 × 10^-4). Levels of methylmalonate, a suggested biomarker of vitamin B12 deficiency, was correlated with increased gastric cancer risk (OR = 1.42; P = 0.004). Inverse associations were found for three biomarkers for coffee/tea consumption (3-hydroxypyridine sulfate, quinate and N-(2-furoyl) glycine), although the associations were only significant when comparing cases that were diagnosed within 5 years after the blood collection to matched controls. Most of the identified associations were more profound in women and never smokers than their male or ever smoking counterparts and some with notable significant interactions.

CONCLUSIONS

Our study identified multiple potential risk biomarkers for gastric cancer independent of Helicobacter pylori infection and other major risk factors.

IMPACT

New risk-assessment tools to identify high-risk population could be developed to improve prevention of gastric cancer.See related commentary by Drew et al., p. 1601.

Sub-multiplicative interaction between polygenic risk score and household coal use in relation to lung adenocarcinoma among never-smoking women in Asia

We previously identified 10 lung adenocarcinoma susceptibility loci in a genome-wide association study (GWAS) conducted in the Female Lung Cancer Consortium in Asia (FLCCA), the largest genomic study of lung cancer among never-smoking women to date. Furthermore, household coal use for cooking and heating has been linked to lung cancer in Asia, especially in Xuanwei, China. We investigated the potential interaction between genetic susceptibility and coal use in FLCCA. We analyzed GWAS-data from Taiwan, Shanghai, and Shenyang (1472 cases; 1497 controls), as well as a separate study conducted in Xuanwei (152 cases; 522 controls) for additional analyses. We summarized genetic susceptibility using a polygenic risk score (PRS), which was the weighted sum of the risk-alleles from the 10 previously identified loci. We estimated associations between a PRS, coal use (ever/never), and lung adenocarcinoma with multivariable logistic regression models, and evaluated potential gene-environment interactions using likelihood ratio tests. There was a strong association between continuous PRS and lung adenocarcinoma among never coal users (Odds Ratio (OR) = 1.69 (95% Confidence Interval (CI) = 1.53, 1.87), p=1 × 10^-26). This effect was attenuated among ever coal users (OR = 1.24 (95% CI: 1.03, 1.50), p = 0.02, p-interaction = 6 × 10^-3). We observed similar attenuation among coal users from Xuanwei. Our study provides evidence that genetic susceptibility to lung adenocarcinoma among never-smoking Asian women is weaker among coal users. These results suggest that lung cancer pathogenesis may differ, at least partially, depending on exposure to coal combustion products. Notably, these novel findings are among the few instances of sub-multiplicative gene-environment interactions in the cancer literature.

Variation in oral microbiome is associated with future risk of lung cancer among never-smokers

OBJECTIVE

To prospectively investigate whether diversity in oral microbiota is associated with risk of lung cancer among never-smokers.

DESIGN AND SETTING

A nested case-control study within two prospective cohort studies, the Shanghai Women's Health Study (n=74 941) and the Shanghai Men's Health Study (n=61 480).

PARTICIPANTS

Lifetime never-smokers who had no cancer at baseline. Cases were subjects who were diagnosed with incident lung cancer (n=114) and were matched 1:1 with controls on sex, age (≤2 years), date (≤30 days) and time (morning/afternoon) of sample collection, antibiotic use during the week before sample collection (yes/no) and menopausal status (for women).

MAIN OUTCOMES AND MEASURES

Metagenomic shotgun sequencing was used to measure the community structure and abundance of the oral microbiome in pre-diagnostic oral rinse samples of each case and control. Multivariable logistic regression models were used to estimate the association of lung cancer risk with alpha diversity metrics and relative abundance of taxa. The Microbiome Regression-Based Kernel Association Test (MiRKAT) evaluated the association between risk and the microbiome beta diversity.

RESULTS

Subjects with lower microbiota alpha diversity had an increased risk of lung cancer compared with those with higher microbial alpha diversity (Shannon: p_trend=0.05; Simpson: p_trend=0.04; Observed Species: p_trend=0.64). No case-control differences were apparent for beta diversity (p_MiRKAT=0.30). After accounting for multiple comparisons, a greater abundance of Spirochaetia (OR_low 1.00 (reference), OR_medium 0.61 (95% CI 0.32 to 1.18), OR_high 0.42 (95% CI 0.21 to 0.85)) and Bacteroidetes (OR_low 1.00 (reference), OR_medium 0.66 (95% CI 0.35 to 1.25), OR_high 0.31 (95% CI 0.15 to 0.64)) was associated with a decreased risk of lung cancer, while a greater abundance of the Bacilli class (OR_low 1.00 (reference), OR_medium 1.49 (95% CI 0.73 to 3.08), OR_high 2.40 (95% CI 1.18 to 4.87)) and Lactobacillales order (OR_low 1.00 (reference), OR_medium 2.15 (95% CI 1.03 to 4.47), OR_high 3.26 (95% CI 1.58 to 6.70)) was associated with an increased risk of lung cancer.

CONCLUSIONS

Our prospective study of never-smokers suggests that lower alpha diversity was associated with a greater risk of lung cancer and the abundance of certain specific taxa was associated with altered risk, providing further insight into the aetiology of lung cancer in the absence of active tobacco smoking.

Benzene exposure-response and risk of lymphoid neoplasms in Chinese workers: A multicenter case-cohort study

BACKGROUND

While international agreement supports a causal relationship of benzene exposure with acute myeloid leukemia, there is debate about benzene and lymphoid neoplasm risks.

METHODS

In a case-cohort study with follow-up of 110 631 Chinese workers during 1972-1999, we evaluated benzene exposure-response for non-Hodgkin lymphoma (NHL), lymphoid leukemias (LL), acute lymphocytic leukemia (ALL), and total lymphoid neoplasms (LN). We estimated benzene exposures using state-of-the-art hierarchical modeling of occupational factors calibrated with historical routine measurements and evaluated cumulative exposure-response using Cox regression.

RESULTS

NHL and other specified LN were increased in exposed vs unexposed workers. However, there was no evidence of exposure-response for NHL or other specified LN. Based on a linear exposure-response, relative risks at 100 parts per million-years (RR at 100 ppm-years) for cumulative benzene exposure using a 2-year lag (exposure at least 2 years before the time at risk) were 1.05 for NHL (95 percent confidence interval (CI) = 0.97, 1.27; 32 cases), 1.11 for LL (95% CI < 0, 1.66; 12 cases), 1.21 for ALL (95% CI < 0, 3.53; 10 cases), and 1.02 for total LN (95% CI < 0, 1.16; 49 cases). No statistically significant exposure-response trends were apparent for these LN for 2 to <10-year or ≥10-year lags. NHL risks were not significantly modified by sex, age, or year at first exposure, attained age, or time since exposure.

CONCLUSION

Given the study strengths and limitations, we found little evidence of exposure-response for benzene and NHL, LL, ALL, or total LN, although NHL and other specified LN were increased in exposed vs unexposed individuals.

Benzene Exposure Response and Risk of Myeloid Neoplasms in Chinese Workers: A Multicenter Case-Cohort Study

BACKGROUND

There is international consensus that benzene exposure is causally related to acute myeloid leukemia (AML), and more recent evidence of association with myelodysplastic syndromes (MDS). However, there are uncertainties about the exposure response, particularly risks by time since exposure and age at exposure.

METHODS

In a case-cohort study in 110 631 Chinese workers followed up during 1972-1999 we evaluated combined MDS/AML (n = 44) and chronic myeloid leukemia (n = 18). We estimated benzene exposures using hierarchical modeling of occupational factors calibrated with historical routine measurements, and evaluated exposure response for cumulative exposure and average intensity using Cox regression; P values were two-sided.

RESULTS

Increased MDS/AML risk with increasing cumulative exposure in our a priori defined time window (2 to <10 years) before the time at risk was suggested (Ptrend = 08). For first exposure (within the 2 to <10-year window) before age 30 years, the exposure response was stronger (P = .004) with rate ratios of 1.12 (95% confidence interval [CI] = 0.27 to 4.29), 5.58 (95% CI = 1.65 to 19.68), and 4.50 (95% CI = 1.22 to 16.68) for cumulative exposures of more than 0 to less than 40, 40 to less than 100, and at least 100 ppm-years, respectively, compared with no exposure. There was little evidence of exposure response after at least 10 years (Ptrend = .94), regardless of age at first exposure. Average intensity results were generally similar. The risk for chronic myeloid leukemia was increased in exposed vs unexposed workers, but appeared to increase and then decrease with increasing exposure.

CONCLUSION

For myeloid neoplasms, the strongest effects were apparent for MDS/AML arising within 10 years of benzene exposure and for first exposure in the 2 to less than 10-year window before age 30 years.

Prediagnostic blood levels of organochlorines and risk of non-Hodgkin lymphoma in three prospective cohorts in China and Singapore

Specific organochlorines (OCs) have been associated with non-Hodgkin lymphoma (NHL) with varying degrees of evidence. These associations have not been evaluated in Asia, where the high exposure and historical environmental contamination of certain OC pesticides (e.g., dichlorodiphenyltrichloroethane [DDT], hexachlorocyclohexane [HCH]) are different from Western populations. We evaluated NHL risk and prediagnostic blood levels of OC pesticides/metabolites and polychlorinated biphenyl congeners in a case-control study of 167 NHL cases and 167 controls nested within three prospective cohorts in Shanghai and Singapore. Conditional logistic regression was used to analyze lipid-adjusted OC levels and NHL risk. Median levels of p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), the primary DDT metabolite, and β-HCH were up to 12 and 65 times higher, respectively, in samples from the Asian cohorts compared to several cohorts in the United States and Norway. An increased risk of NHL was observed among those with higher β-HCH levels both overall (3rd vs. 1st tertile OR = 1.8, 95%CI = 1.0-3.2; ptrend = 0.049) and after excluding cases diagnosed within 2 years of blood collection (3rd vs. 1st tertile OR = 2.0, 95%CI = 1.1-3.9; ptrend = 0.03), and the association was highly consistent across the three cohorts. No significant associations were observed for other OCs, including p,p'-DDE. Our findings provide support for an association between β-HCH blood levels and NHL risk. This is a concern because substantial quantities of persistent, toxic residues of HCH are present in the environment worldwide. Although there is some evidence that DDT is associated with NHL, our findings for p,p'-DDE do not support an association.

Ischaemic heart disease and stroke mortality by specific coal type among non-smoking women with substantial indoor air pollution exposure in China

BACKGROUND

Lifetime use of bituminous ('smoky') coal is associated with nearly a 100-fold higher risk of lung cancer mortality compared with anthracite ('smokeless') coal use in rural Xuanwei, China, among women. Risk of mortality from ischaemic heart disease (IHD) and stroke for these coal types has not been evaluated.

METHODS

A cohort of 16 323 non-smoking women in Xuanwei, who were lifetime users of either smoky or smokeless coal, were followed up from 1976 to 2011. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) to evaluate lifetime use of coal types and stoves in the home in relation to risk of IHD and stroke mortality.

RESULTS

Among lifetime users of smokeless coal, higher average exposure intensity (≥4 tons/year vs <2.5 tons/year, HR = 7.9, 95% CI = 3.5-17.8; Ptrend =<0.0001) and cumulative exposure (>64 ton-years vs ≤28 ton-years, HR = 6.5, 95% CI = 1.5-28.3; Ptrend =0.003) during follow-up and over their lifetime was associated with increased IHD mortality, and ventilated stove use dramatically reduced this risk (HR = 0.2, 95% CI 0.1-0.5). Higher cumulative exposure to smoky coal during follow-up showed positive associations with IHD mortality, but the evidence for other metrics was less consistent compared with associations with smokeless coal use.

CONCLUSIONS

Higher use of smokeless coal, which is burned throughout China and is generally regarded to be a cleaner fuel type, is associated with IHD mortality. Use of cleaner fuels or stove interventions may be effective in reducing the increasing burden of IHD in developing regions that currently rely on smokeless coal for cooking and heating.

White Blood Cell Count and Risk of Incident Lung Cancer in the UK Biobank

Background

The contribution of measurable immunological and inflammatory parameters to lung cancer development remains unclear, particularly among never smokers. We investigated the relationship between total and differential white blood cell (WBC) counts and incident lung cancer risk overall and among subgroups defined by smoking status and sex in the United Kingdom (UK).

Methods

We evaluated 424 407 adults aged 37-73 years from the UK Biobank. Questionnaires, physical measurements, and blood were administered and collected at baseline in 2006-2010. Complete blood cell counts were measured using standard methods. Lung cancer diagnoses and histological classifications were obtained from cancer registries. Multivariable Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence intervals of incident lung cancer in relation to quartiles (Q) of total WBC and subtype-specific counts, with Q1 as the reference.

Results

There were 1493 incident cases diagnosed over an average 7-year follow-up. Overall, the highest quartile of total WBC count was statistically significantly associated with elevated lung cancer risk (HR_Q4 = 1.67, 95% CI = 1.41 to 1.98). Among women, increased risks were found in current smokers (n _cases / n = 244 / 19 464, HR_Q4 = 2.15, 95% CI = 1.46 to 3.16), former smokers (n _cases / n = 280 / 69 198, HR_Q4 = 1.75, 95% CI = 1.24 to 2.47), and never smokers without environmental tobacco smoke exposure (n_cases / n = 108 / 111 294, HR_Q4 = 1.93, 95% CI = 1.11 to 3.35). Among men, stronger associations were identified in current smokers (n_{case s} / n = 329 / 22 934, HR_Q4 = 2.95, 95% CI = 2.04 to 4.26) and former smokers (n_{c ases} / n = 358/71 616, HR_Q4 = 2.38, 95% CI = 1.74 to 3.27) but not in never smokers. Findings were similar for lung adenocarcinoma and squamous cell carcinoma and were driven primarily by elevated neutrophil fractions.

Conclusions

Elevated WBCs could potentially be one of many important markers for increased lung cancer risk, especially among never-smoking women and ever-smoking men.

Association of Untargeted Urinary Metabolomics and Lung Cancer Risk Among Never-Smoking Women in China

IMPORTANCE

Chinese women have the highest rate of lung cancer among female never-smokers in the world, and the etiology is poorly understood.

OBJECTIVE

To assess the association between metabolomics and lung cancer risk among never-smoking women.

DESIGN, SETTING, AND PARTICIPANTS

This nested case-control study included 275 never-smoking female patients with lung cancer and 289 never-smoking cancer-free control participants from the prospective Shanghai Women's Health Study recruited from December 28, 1996, to May 23, 2000. Validated food frequency questionnaires were used for the collection of dietary information. Metabolomic analysis was conducted from November 13, 2015, to January 6, 2016. Data analysis was conducted from January 6, 2016, to November 29, 2018.

EXPOSURES

Untargeted ultra-high-performance liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance metabolomic profiles were characterized using prediagnosis urine samples. A total of 39 416 metabolites were measured.

MAIN OUTCOMES AND MEASURES

Incident lung cancer.

RESULTS

Among the 564 women, those who developed lung cancer (275 participants; median [interquartile range] age, 61.0 [52-65] years) and those who did not develop lung cancer (289 participants; median [interquartile range] age, 62.0 [53-66] years) at follow-up (median [interquartile range] follow-up, 10.9 [9.0-11.7] years) were similar in terms of their secondhand smoke exposure, history of respiratory diseases, and body mass index. A peak metabolite, identified as 5-methyl-2-furoic acid, was significantly associated with lower lung cancer risk (odds ratio, 0.57 [95% CI, 0.46-0.72]; P < .001; false discovery rate = 0.039). Furthermore, this peak was weakly correlated with self-reported dietary soy intake (ρ = 0.21; P < .001). Increasing tertiles of this metabolite were associated with lower lung cancer risk (in comparison with first tertile, odds ratio for second tertile, 0.52 [95% CI, 0.34-0.80]; and odds ratio for third tertile, 0.46 [95% CI, 0.30-0.70]), and the association was consistent across different histological subtypes and follow-up times. Additionally, metabolic pathway analysis found several systemic biological alterations that were associated with lung cancer risk, including 1-carbon metabolism, nucleotide metabolism, oxidative stress, and inflammation.

CONCLUSIONS AND RELEVANCE

This prospective study of the untargeted urinary metabolome and lung cancer among never-smoking women in China provides support for the hypothesis that soy-based metabolites are associated with lower lung cancer risk in never-smoking women and suggests that biological processes linked to air pollution may be associated with higher lung cancer risk in this population.

Constituents of Household Air Pollution and Risk of Lung Cancer among Never-Smoking Women in Xuanwei and Fuyuan, China

BACKGROUND

Lung cancer rates among never-smoking women in Xuanwei and Fuyuan in China are among the highest in the world and have been attributed to the domestic use of smoky (bituminous) coal for heating and cooking. However, the key components of coal that drive lung cancer risk have not been identified.

OBJECTIVES

We aimed to investigate the relationship between lifelong exposure to the constituents of smoky coal (and other fuel types) and lung cancer.

METHODS

Using a population-based case-control study of lung cancer among 1,015 never-smoking female cases and 485 controls, we examined the association between exposure to 43 household air pollutants and lung cancer. Pollutant predictions were derived from a comprehensive exposure assessment study, which included methylated polycyclic aromatic hydrocarbons (PAHs), which have never been directly evaluated in an epidemiological study of any cancer. Hierarchical clustering and penalized regression were applied in order to address high colinearity in exposure variables.

RESULTS

The strongest association with lung cancer was for a cluster of 25 PAHs [odds ratio (OR): 2.21; 95% confidence interval (CI): 1.67, 2.87 per 1 standard deviation (SD) change], within which 5-methylchrysene (5-MC), a mutagenic and carcinogenic PAH, had the highest individual observed OR (5.42; 95% CI: 0.94, 27.5). A positive association with nitrogen dioxide ([Formula: see text]) was also observed (OR: 2.06; 95% CI: 1.19, 3.49). By contrast, neither benzo(a)pyrene (BaP) nor fine particulate matter with aerodynamic diameter [Formula: see text] ([Formula: see text]) were associated with lung cancer in the multipollutant models.

CONCLUSIONS

To our knowledge, this is the first study to comprehensively evaluate the association between lung cancer and household air pollution (HAP) constituents estimated over the entire life course. Given the global ubiquity of coal use domestically for indoor cooking and heating and commercially for electric power generation, our study suggests that more extensive monitoring of coal combustion products, including methylated PAHs, may be warranted to more accurately assess health risks and develop prevention strategies from this exposure. https://doi.org/10.1289/EHP4913.

Serum ghrelin and esophageal and gastric cancer in two cohorts in China

Ghrelin is a hormone produced in the oxyntic glands of the stomach. Previous work by our group has suggested that serum ghrelin concentrations are inversely associated with gastric and esophageal cancer risk. We measured ghrelin concentrations in the Linxian General Population Nutrition Intervention Trial (NIT), and the Shanghai Women's Health Study (SWHS). In NIT, we analyzed serum samples from 298 esophageal squamous cell carcinoma (ESCC) cases, 518 gastric cardia adenocarcinoma (GCA) cases, 258 gastric noncardia adenocarcinoma (GNCA) cases and 770 subcohort controls (case-cohort). In SWHS, we measured ghrelin in plasma samples from 249 GNCA cases and 498 matched controls (nested case-control). Ghrelin was measured using radioimmunoassay. In NIT and SWHS, low ghrelin concentrations were associated with an increased risk of developing GNCA and GCA. The hazard ratio (HR _Q1:Q4 ) for GNCA in NIT was 1.35 (95% CI: 0.89-2.05; p-trend = 0.02); the odds ratio in SWHS was 1.66 (95% CI: 1.02-2.70; p-trend = 0.06). Low ghrelin was associated with a twofold increase of GCA (HR _Q1:Q4 = 2.00, 95% CI: 1.45-2.77; p-trend<0.001). In contrast, a lower risk of ESCC (NIT ESCC HR _Q1:Q4 = 0.65, 95% CI: 0.45-0.92; p-trend = 0.02) was found in NIT. Low baseline ghrelin concentrations were associated with an increased risk for GNCA and GCA in the NIT and the SWHS. In contrast, low ghrelin concentrations at baseline were associated with a reduced risk of developing ESCC in the NIT. Ghrelin may be an early marker of future cancer risk for developing upper gastrointestinal cancer in regions of high incidence.

Tuberculosis infection and lung adenocarcinoma: Mendelian randomization and pathway analysis of genome-wide association study data from never-smoking Asian women

We investigated whether genetic susceptibility to tuberculosis (TB) influences lung adenocarcinoma development among never-smokers using TB genome-wide association study (GWAS) results within the Female Lung Cancer Consortium in Asia. Pathway analysis with the adaptive rank truncated product method was used to assess the association between a TB-related gene-set and lung adenocarcinoma using GWAS data from 5512 lung adenocarcinoma cases and 6277 controls. The gene-set consisted of 31 genes containing known/suggestive associations with genetic variants from previous TB-GWAS. Subsequently, we followed-up with Mendelian Randomization to evaluate the association between TB and lung adenocarcinoma using three genome-wide significant variants from previous TB-GWAS in East Asians. The TB-related gene-set was associated with lung adenocarcinoma (p = 0.016). Additionally, the Mendelian Randomization showed an association between TB and lung adenocarcinoma (OR = 1.31, 95% CI: 1.03, 1.66, p = 0.027). Our findings support TB as a causal risk factor for lung cancer development among never-smoking Asian women.

Abstract 5043: Pre-diagnostic blood levels of organochlorines and risk of non-Hodgkin lymphoma in three population-based cohorts in China and Singapore

Background: Organochlorines (OCs) are environmentally persistent compounds that have been extensively used as pesticides and for other industrial applications. Residues of OCs have been detected at hazardous waste sites and in various environmental media worldwide and serum levels of OCs continue to be detectable in the general population. Specific OCs have been associated with non-Hodgkin lymphoma (NHL) risk with varying degrees of evidence. These associations have not been evaluated in Asia, where the exposure patterns of substantially high levels of certain OC pesticides and lower levels of polychlorinated biphenyls (PCBs) are different from Western populations. China accounted for nearly 20% of the worldwide production of dichlorodiphenyltrichloroethane (DDT) through 1983 when it was restricted, and historical usage of hexachlorocyclohexane (HCH) in China has been among the highest in the world.

Methods: We evaluated the risk of NHL in relation to pre-diagnostic blood levels of five OC pesticides/metabolites (hexachlorobenzene, β-HCH, oxychlordane, trans-nonachlor, and p,p’-DDE, the primary metabolite of DDT) and four PCB congeners (118, 138-158, 153, 180) in a case-control study of 167 NHL cases and 167 controls matched on age, sex, and blood collection date. The study was nested within three population-based cohorts of Chinese men and women in Shanghai and Singapore. Associations between lipid-adjusted OC concentrations and NHL risk were analyzed using conditional logistic regression.

Results: Median levels of p,p’-DDE and β-HCH were up to 12 and 65 times higher, respectively, in Shanghai (blood collected between 1986-2000) compared to reported levels in population-based cohorts in the United States (CLUE; Nurse’s Health Study) and Norway (Janus) with blood collected between 1972-1990. Median levels of p,p’-DDE and β-HCH were more comparable in Singapore (blood collected between 2000-2004) relative to the Western cohorts (1-2 fold concentration differences). Levels of β-HCH were associated with increased risk of overall NHL (3rd vs. 1st tertile OR=1.78, 95%CI=0.98-3.23; ptrend =0.049) in the pooled analysis of three cohorts. No significant associations were observed for other OCs and NHL risk, including for p,p’-DDE. Results for β-HCH and p,p’-DDE were consistent across cohorts.

Discussion: Associations between β-HCH and NHL risk have not been consistent in studies of Western populations. Our findings provide the first evidence suggesting associations between blood levels of β-HCH and NHL risk in a population in Asia that experienced far higher exposures. Although there is limited evidence that DDT (IARC Group 2A) is associated with NHL based on studies in Western populations, our findings among Asians, who had higher p,p’-DDE levels than reported in the general population in the West, do not support an association with environmental exposure.

Citation Format: Bryan A. Bassig, Xiao-Ou Shu, Andreas Sjodin, Woon-Puay Koh, Yu-Tang Gao, Jennifer Adams-Haduch, Mark Davis, Renwei Wang, Yong-Bing Xiang, Mark Purdue, Bu-Tian Ji, Gong Yang, Richard Jones, H. Dean Hosgood, Wei Jie Seow, Wei Hu, Wei Zheng, Jian-Min Yuan, Qing Lan, Nathaniel Rothman. Pre-diagnostic blood levels of organochlorines and risk of non-Hodgkin lymphoma in three population-based cohorts in China and Singapore [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5043.

Association between occupational exposure to trichloroethylene and serum levels of microRNAs: a cross-sectional molecular epidemiology study in China

OBJECTIVES

The objective of our study was to evaluate the association between occupational exposure to trichloroethylene (TCE), a suspected lymphomagen, and serum levels of miRNAs in a cross-sectional molecular epidemiology study of TCE-exposed workers and comparable unexposed controls in China.

METHODS

Serum levels of 40 miRNAs were compared in 74 workers exposed to TCE (median: 12 ppm) and 90 unexposed control workers. Linear regression models were used to test for differences in serum miRNA levels between exposed and unexposed workers and to evaluate exposure-response relationships across TCE exposure categories using a three-level ordinal variable [i.e., unexposed, < 12 ppm, the median value among workers exposed to TCE) and ≥ 12 ppm)]. Models were adjusted for sex, age, current smoking, current alcohol use, and recent infection.

RESULTS

Seven miRNAs showed significant differences between exposed and unexposed workers at FDR (false discovery rate) < 0.20. miR-150-5p and let-7b-5p also showed significant inverse exposure-response associations with TCE exposure (P_trend= 0.002 and 0.03, respectively). The % differences in serum levels of miR-150-5p relative to unexposed controls were - 13% and - 20% among workers exposed to < 12 ppm and ≥ 12 ppm TCE, respectively.

CONCLUSIONS

miR-150-5p is involved in B cell receptor pathways and let-7b-5p plays a role in the innate immune response processes that are potentially important in the etiology of non-Hodgkin lymphoma (NHL). Further studies are needed to replicate these findings and to directly test the association between serum levels of these miRNAs and risk of NHL in prospective studies.

Lung cancer risk by geologic coal deposits: A case-control study of female never-smokers from Xuanwei and Fuyuan, China

Coal types vary around the world because of geochemical differences in their source deposits; however, the influence of coal emissions from different deposits on human health remains unexplored. To address this issue, we conducted the first study of the relationship between coal use from various deposits and lung cancer risk in Xuanwei and Fuyuan, counties in China where lung cancer rates are among the highest in the world among female never-smokers due to use of bituminous ("smoky") coal for heating and cooking. We conducted a population-based case-control study of 1031 lung cancer cases and 493 controls among never-smoking women in Xuanwei and Fuyuan. Logistic regression models were used to estimate associations between coal use from various deposits across the lifecourse and lung cancer risk. There was substantial heterogeneity in risks by coal deposit (p = 7.8E-05). Compared to non-smoky coal users, risks by smoky coal deposit ranged from OR = 7.49 (95% CI: 3.43-16.38) to OR = 33.40 (95% CI: 13.07-85.34). Further, women born into homes that used smoky coal and subsequently changed to non-smoky coal had a higher risk (OR = 10.83 (95% CI: 4.61-25.46)) than women born into homes that used non-smoky coal and changed to smoky coal (OR = 4.74 (95% CI: 2.03-11.04, p_difference = 0.04)). Our study demonstrates that various sources of coal have considerably different impact on lung cancer in this population and suggests that early-life exposure to carcinogenic emissions may exert substantial influence on health risks later in life. These factors should be considered when evaluating the health risks posed by exposure to coal combustion emissions.

Household coal combustion, indoor air pollutants, and circulating immunologic/inflammatory markers in rural China

The study aim was to investigate whether household bituminous ("smoky") coal use and personal exposure to combustion emissions were associated with immunologic/inflammatory marker levels. A cross-sectional study of healthy never-smoking women from rural Xuanwei and Fuyuan, China was conducted, which included 80 smoky coal and 14 anthracite ("smokeless") coal users. Personal exposure to fine particulate matter (PM_2.5) and benzo[a]pyrene (BaP) was assessed using portable devices, while 67 circulating plasma immunologic/inflammatory markers were measured using multiplex bead-based assays. Multivariable linear regression models were employed to estimate associations between smoky coal versus smokeless coal use, indoor air pollutants, and immunologic/inflammatory markers. Six markers were altered among smoky coal users compared to smokeless coal, including significantly decreased interferon-inducible T-cell alpha chemoattractant (CXCL11/I-TAC), and increased serum amyloid P component (SAP). CXCL11/I-TAC was previously found to be reduced in workers exposed to high levels of diesel engine exhaust, which exhibits similar constituents as coal combustion emissions. Further, there was evidence that elevated PM_2.5 and BaP exposure was associated with significantly diminished levels of the serum amyloid A (SAA); however, the false discovery rates (FDRs) were >0.2 after accounting for multiple comparisons. Inflammatory processes may thus mediate the carcinogenic effects attributed to smoky coal emissions.

Green tea consumption and risk of type 2 diabetes in Chinese adults: the Shanghai Women's Health Study and the Shanghai Men's Health Study

Background

Epidemiological evidence on the association between tea consumption and the risk of type 2 diabetes (T2D) is inconsistent. This study prospectively investigated whether green tea drinking affects the risk of T2D.

Methods

This study included participants from the Shanghai Women's Health Study (N = 67 058) and the Shanghai Men's Health Study (N  =  52 315) without diabetes at study enrolment. Details of tea consumption, including types and amounts, were collected at the baseline and follow-up survey. Incident T2D was identified through follow-up surveys. Plasma level of caffeine metabolite was measured in a nested case-control study involving 592 diabetes case-control pairs. Cox regression analysis, with tea drinking as a time-dependent variable and covariates adjusted for by a propensity score, was applied to estimate the hazard ratio (HR) and 95% confidence interval (CI) for T2D risk. Logistic regression analysis was applied to evaluate the association between caffeine metabolites and T2D risk.

Results

Current green tea drinkers had an increased risk of T2D compared with non-current drinkers [HR = 1.20 (95% CI = 1.14-1.27)], and a dose-response relationship was observed for duration of drinking tea and the amount of tea consumed [P for trend <0.001]. The increased risk associated with green tea drinking was observed in both women and men, across the entire period of follow-up, with HR (95% CI) of 1.08 (0.97-1.19) within 5 years of follow-up, 1.22 (1.12-1.32) during the period of 5-10 years of follow-up and 1.16 (1.03-1.30) after 10 years of follow-up. This association did not vary significantly by body mass index, waist-to-hip circumference ratio or smoking status. Plasma level of caffeine was also associated with increased diabetes risk (P  =  0.03), confirming the results based on self-reported tea drinking.

Conclusions

Green tea drinking was associated with an increased risk of T2D in Chinese adults. The mechanisms underlying the association need to be elucidated.

Serologic markers of viral infection and risk of non-Hodgkin lymphoma: A pooled study of three prospective cohorts in China and Singapore

Incidence rates of non-Hodgkin lymphoma (NHL) and distributions of certain viruses differ between East Asian and Western populations. There are limited data on associations between serologic markers of multiple viral infections in pre-diagnostic blood and NHL risk in East Asians. We conducted a nested case-control study of 214 NHL cases and 214 matched controls from three population-based prospective cohorts in Shanghai and Singapore. Antibodies against antigens from herpesviruses, Hepatitis B (HBV) and C (HCV) virus and polyomaviruses were measured in plasma or serum using fluorescent bead-based multiplex assays. Conditional logistic regression was used to evaluate associations between antibody levels and NHL risk. An increased risk of NHL was observed for higher compared to lower EA-D (Odds Ratio (OR) = 2.04, 95% Confidence Interval (CI) = 1.10-3.81; ptrend  = 0.005) and ZEBRA (OR = 2.17, 95% CI = 0.96-4.89; ptrend  = 0.008) Epstein-Barr Virus (EBV) antibodies, as well as for antibody seropositivity against the IE1A human herpesvirus-6 (HHV-6) antigen (OR = 1.85, 95% CI = 1.04-3.29). An increased NHL risk was also observed for higher compared to lower antibodies against the HBV-HBc and HBe antigens. An increased risk of NHL in relation to EBV and HBV infection in East Asians is consistent with findings in several studies of Western populations, suggesting similar viral risk factors for NHL in these diverse populations with distinct patterns of NHL. The association between HHV-6 antibodies and NHL has not previously been reported in a prospective study in this population and will require replication.

Variants in genes encoding small GTPases and association with epithelial ovarian cancer susceptibility

Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer mortality in American women. Normal ovarian physiology is intricately connected to small GTP binding proteins of the Ras superfamily (Ras, Rho, Rab, Arf, and Ran) which govern processes such as signal transduction, cell proliferation, cell motility, and vesicle transport. We hypothesized that common germline variation in genes encoding small GTPases is associated with EOC risk. We investigated 322 variants in 88 small GTPase genes in germline DNA of 18,736 EOC patients and 26,138 controls of European ancestry using a custom genotype array and logistic regression fitting log-additive models. Functional annotation was used to identify biofeatures and expression quantitative trait loci that intersect with risk variants. One variant, ARHGEF10L (Rho guanine nucleotide exchange factor 10 like) rs2256787, was associated with increased endometrioid EOC risk (OR = 1.33, p = 4.46 x 10-6). Other variants of interest included another in ARHGEF10L, rs10788679, which was associated with invasive serous EOC risk (OR = 1.07, p = 0.00026) and two variants in AKAP6 (A-kinase anchoring protein 6) which were associated with risk of invasive EOC (rs1955513, OR = 0.90, p = 0.00033; rs927062, OR = 0.94, p = 0.00059). Functional annotation revealed that the two ARHGEF10L variants were located in super-enhancer regions and that AKAP6 rs927062 was associated with expression of GTPase gene ARHGAP5 (Rho GTPase activating protein 5). Inherited variants in ARHGEF10L and AKAP6, with potential transcriptional regulatory function and association with EOC risk, warrant investigation in independent EOC study populations.

Abstract 5313: Occupational exposure to trichloroethylene and DNA methylation: a cross-sectional study

Trichloroethylene (TCE) is a chlorinated solvent that is often used in occupational settings for vapor degreasing of metal parts. In 2012, TCE was classified as a known human carcinogen (Group 1) by the International Agency for Research on Cancer, largely based on evidence for kidney cancer. Animal studies have suggested that TCE may modulate DNA methylation. We performed a cross-sectional study to examine the associations of DNA methylation of individual CpG sites with TCE exposure. We enrolled 80 workers from factories where TCE was used, as well as 96 unexposed controls from food and clothes manufacturing factories in the same region, and 69 exposed workers and 77 controls were available for analyses in this study. Personal exposure measurements (2-3 per subject) were collected for a full work shift using a 3MTM badge in both exposed workers and a subgroup of the control workers. Blood samples were collected from each subject and CpG methylation was assayed on the Illumina Infinium HumanMethylation450 BeadChip. After quality controls procedures, 485,512 CpG probes were available for analyses. We used separate multivariable linear regression models to examine the associations of TCE exposure and the methylation level at each single CpG site. All models were adjusted for age, sex, current smoking status, current alcohol consumption, recent infection, and body mass index. The median TCE exposure level in exposed subjects was 12 ppm (10th percentile: 2 ppm; 90th percentile: 45 ppm). We found 29 CpG probes that achieved genome-wide significance (p &lt; 1.04x10-7) when comparing TCE exposed workers with controls. TCE exposure was associated with hypomethylation at nearly all (28/29) of those CpG probes. Of these 29 CpG probes, 6 CpGs showed a significant (p &lt; 1.04x10-7) exposure-response relationship across the categories of controls and lower- (&lt;12ppm) and higher-exposed (≥12 ppm) workers, and were mapped to 6 different chromosomes. To our knowledge, this is the first report that TCE exposure is associated with alterations in DNA methylation in a molecular epidemiologic study. Our findings may provide insight into potential biological mechanisms linking exposure to TCE and adverse health outcomes.

Citation Format: Jinming Zhang, Luoping Zhang, Roel Vermeulen, Wei Hu, Bryan A. Bassig, Jason Y. Wong, Min Shen, Bu-Tian Ji, Boris Reiss, Mark Purdue, Martyn T. Smith, Qing Lan, Nathaniel Rothman. Occupational exposure to trichloroethylene and DNA methylation: a cross-sectional study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5313.

Abstract 4974: Prospective study of untargeted urinary metabolomics and risk of lung cancer among female never-smokers in Shanghai, China

The lung cancer rate among never-smokers is the highest among Asian women, however its etiology and any relevant non-smoking related biomarkers are still unclear. Pre-diagnostic lung cancer-related metabolic biomarkers may provide novel insights into lung cancer mechanisms, and may contribute to the discovery of etiologic factors for the high lung cancer prevalence among Asian women. We evaluated the role of the urinary metabolome in lung cancer development among female never-smokers in China by conducting a nested case-control study of 275 lung cancer cases and 289 healthy controls from the Shanghai Women's Health Study, a prospective cohort comprised of 73,363 Chinese female never-smokers. Metabolic profiling of urinary chemical features was conducted using ultrahigh-performance liquid chromatography - tandem mass spectrometry (UPLC-MS) (39,409 spectral features) and 600 MHz 1H nuclear magnetic resonance (NMR) spectroscopy (386 features). Unconditional logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the association between each log-transformed metabolite level and lung cancer risk, adjusting for potential confounders such as age, body mass index, history of respiratory disease and passive smoking. Spearman correlation and linear regression were used to estimate associations between the most significant metabolites and pre-diagnosis dietary factors. Three detected UPLC-MS urinary metabolites were negatively associated with lung cancer risk with a false discovery rate of less than 10%: pos_2.61_127.0382m/z (OR = 0.57, 95% CI = 0.46-0.72, P = 1.98 x 10-6), neg_2.60_369.0408m/z (OR = 0.97, 95% CI = 0.96-0.98, P = 1.36 x 10-6), and pos_2.61_184.0325n (OR = 0.55, 95% CI = 0.43-0.71, P = 4.91 x 10-6). These were strongly correlated with each other (rho &gt; 0.65, p &lt; 0.0001). The significant metabolite (pos_2.61_127.0382m/z) was identified as 5-methyl-2-furoic acid and was moderately correlated with self-reported dietary intake of soy (rho = 0.21, p &lt; 0.001). In conclusion, we identified a metabolite in urine (5-methyl-2-furoic acid) that provides support for the protective association of soy-based foods on lung cancer risk that was previously observed in this population of never-smoking women. Further studies are warranted to replicate these findings.

Citation Format: Wei Jie Seow, Xiao-Ou Shu, Jeremy Nicholson, Elaine Holmes, Wei Hu, Qiuyin Cai, Yu-Tang Gao, Yong-Bing Xiang, Steve Moore, Bryan A. Bassig, Jason Yy Wong, Jinming Zhang, Bu-Tian Ji, Claire Boulange, Manuja Kaluarachchi, Kyrillos F. Adesina-Georgiadis, Anisha Wijeyesekera, Wei Zheng, Paul Elliot, Nathaniel Rothman, Qing Lan. Prospective study of untargeted urinary metabolomics and risk of lung cancer among female never-smokers in Shanghai, China [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4974.

Helicobacter pylori Blood Biomarkers and Gastric Cancer Survival in China

Background: Infection with Helicobacter pylori is the leading risk factor for noncardia gastric cancer, yet its influence on prognosis of gastric cancer is largely unknown. Thus, exploring the role of Helicobacter pylori (H. pylori) in survival could lead to a greater understanding of the high mortality associated with gastric cancer.Methods: Seropositivity to 15 H. pylori antigens was assessed using a multiplex assay in two prospective cohorts, the Shanghai Men's Health Study and the Shanghai Women's Health Study. Multivariable-adjusted Cox proportional hazards regression was used to examine the association between prediagnostic H. pylori antigen levels and gastric cancer-specific survival.Results: Prediagnostic levels of H. pylori serum antibodies that were previously associated with gastric cancer incidence in this population were not associated with gastric cancer survival, whether assessed in a 6-antigen panel [HR = 1.29; 95% confidence interval (CI), 0.78-2.13 for men; HR = 0.93; 95% CI, 0.57-1.52 for women], focused on CagA⁺H. pylori (HR = 0.73; 95% CI, 0.44-1.20 forwomen; HR = 1.27; 95% CI, 0.70-2.31 for men) or on the high-risk biomarkers of dual Omp and HP 0305 seropositivity (HR = 0.97; 95% CI, 0.72-1.30 for women; HR = 1.37; 95% CI, 0.97-1.94 for men).Conclusions: Prediagnostic H. pylori antigen levels are not associated with gastric cancer survival in East Asian populations.Impact: Identification of additional factors associated with gastric cancer survival would further our understanding of the high mortality associated with this malignancy. Cancer Epidemiol Biomarkers Prev; 27(3); 342-4. ©2017 AACR.

A prospective study of immune and inflammation markers and risk of lung cancer among female never smokers in Shanghai

There is a paucity of data on risk factors for lung cancer among never smokers. Here, we have carried out the first large study of circulating inflammation markers and lung cancer risk among female never smokers in Shanghai. A study of 248 lung cancer cases in female never smokers and 263 controls was nested within the Shanghai Women's Health Study (n = 75221), matched by dates of birth and blood collection (mean follow-up time = 7.5 years). Prediagnostic plasma levels of 65 inflammation markers were measured using a Luminex bead-based assay. Odds ratios (ORs) were estimated with multivariable logistic regression. Nine of 61 evaluable markers were statistically significantly associated with lung cancer risk among never smoking Chinese women (P-trend across categories <0.05). Soluble interleukin-6 receptor [sIL-6R; highest versus lowest category OR = 2.37; 95% confidence interval (CI) 1.40-4.02) and chemokine (C-C motif) ligand 2/monocyte chemotactic protein 1; (OR = 1.62; 95% CI 0.94-2.80) were associated with an increased risk of lung cancer, whereas interleukin (IL)-21 (OR = 0.53; 95%CI 0.31-0.93), chemokine (C-X3-C motif) ligand 1/fractalkine (OR = 0.54; 95% CI 0.30-0.96), soluble vascular endothelial growth factor receptor 2 (sVEGFR2, OR = 0.45; 95% CI 0.26-0.76), sVEGFR3 (OR = 0.53; 95% CI 0.32-0.90), soluble tumor necrosis factor receptor I (OR = 0.49; 95% CI 0.29-0.83), IL-10 (OR = 0.60; 95% CI 0.34-1.05) and C-reactive protein (OR = 0.63; 95% CI 0.37-1.06) were associated with a decreased risk. sIL-6R remained significantly associated with lung cancer risk >7.5 years prior to diagnosis. Markers involved in various aspects of the immune response were associated with subsequent lung cancer risk, implicating inflammation in the etiology of lung cancer among female never smokers.

Association of sleep duration and incidence of diabetes modified by tea consumption: a report from the Shanghai men's health study

OBJECTIVES

To evaluate the association between sleep duration and the incidence of diabetes stratified by sleep-related factors among Chinese men.

METHODS

This study included 34,825 men who provided information on sleep-related questions in the Shanghai Men's Health Study, a population-based cohort study conducted in Shanghai, China from 2002 to 2011. Participants were excluded who had a history of diabetes or who were diagnosed with diabetes within 2 years of recruitment. Cox regression was employed to evaluate the influence of sleep duration and its interaction with sleep-related factors on diabetes risk.

RESULTS

A total of 1521 incident cases were documented during a median of 5.6 follow-up years. Adjusted hazard ratios and 95% confidence intervals were 1.0 (0.9-1.1) and 1.2 (1.0-1.3) for men who slept <7 and ≥8 h per day, respectively, compared with those who slept 7 h per day (p_trend = 0.01). Stratified analyses revealed that the association between sleep duration and risk of diabetes was only statistically significant among current smokers and regular drinkers, never tea drinkers, men with a high body mass index, hypertension or comorbidity, and men who did not work nightshift or who snored. A statistically significant interaction between tea drinking and sleep duration was observed (p_interaction = 0.01). The above association patterns remained when daytime nappers were excluded from the analyses.

CONCLUSIONS

The data suggested that longer sleep duration, particularly among individuals already exhibiting factors linked to poor quality of sleep, was associated with diabetes. The association between sleep duration and diabetes may be modified by tea drinking, especially in older men or men with more sleep-related factors.

Personal exposure to fine particulate matter and benzo[a]pyrene from indoor air pollution and leukocyte mitochondrial DNA copy number in rural China

Households in Xuanwei and Fuyuan, China, possess hazardous levels of fine particulate matter with an aerodynamic diameter <2.5 microns (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) from coal combustion. Previous studies found that increased exposure to PM2.5 and benzo[a]pyrene (BaP; a PAH) were associated with decreased mitochondrial DNA copy number (mtDNAcn), a marker of oxidative stress. We further evaluated these associations in a cross-sectional study of 148 healthy non-smoking women from Xuanwei and Fuyuan. Personal exposure to PM2.5 and BaP was measured using portable devices. MtDNAcn was measured using qPCR amplification of leukocyte DNA that was collected after air measurements. Linear regression models were used to estimate the associations between personal exposure to PM2.5 and BaP, and mtDNAcn adjusted for age, body mass index (BMI) and fuel type. We found inverse associations between exposure to PM2.5 and BaP, and mtDNAcn. Each incremental log-μg/m3 increase in PM2.5 was associated with a significant decrease in mtDNAcn of -10.3 copies per cell [95% confidence interval (95% CI): -18.6, -2.0; P = 0.02]. Additionally, each log-ng/m3 increase in BaP was associated with a significant decrease in mtDNAcn of -5.4 copies per cell (95% CI: -9.9, -0.8, P = 0.02). Age, BMI, fuel type and coal mine type were not significantly associated with mtDNAcn. Exposure to PM2.5 and BaP may alter mitochondrial dynamics in non-smoking Chinese women. MtDNAcn may be a potential mediator of indoor air pollution on chronic disease development.

Abstract 4245: Serologic markers of infection and risk of non-Hodgkin lymphoma in a pooled prospective study of three Chinese cohorts

Background: Infections with some viruses, including HIV and Epstein-Barr Virus (EBV) in immunocompromised individuals, are known risk factors for specific subtypes of non-Hodgkin lymphoma (NHL). Epidemiological studies have also provided evidence that hepatitis viruses, and EBV in immunocompetent individuals, may also be associated with NHL. There are limited population-based prospective studies with pre-diagnostic blood samples that have comprehensively evaluated viral biomarkers and NHL risk in East Asians, in whom the descriptive characteristics of NHL and the prevalence of certain viral infections differ compared to Western populations.

Methods: We conducted a nested case-control study of 214 NHL cases and 214 controls from three population-based prospective cohorts in Shanghai and Singapore. Cases and controls were individually matched by age, sex, date of blood draw, and cohort. Antibodies to 21 antigens associated with the evaluated viruses (herpesviruses, Hepatitis B (HBV) and C (HCV), and polyomaviruses) were measured in plasma/serum using fluorescent bead-based multiplex serology. Conditional logistic regression was used to evaluate associations between viral antibody levels measured as median fluorescence intensity and NHL.

Results: For herpesviruses, an increased risk of NHL was observed for higher compared to lower early antigen diffuse (EA-D) (OR = 2.2, 95% CI = 1.2-4.1) and BZLF1-encoded replication activator (ZEBRA) (OR = 2.2, 95% CI = 1.0-4.9) antibodies (rsp = +0.5) associated with EBV. An increased risk of NHL was also observed among those seropositive for the intermediate-early 1A antigen (OR = 1.9, 95% CI = 1.0-3.3; rsp with EBV antibodies = +0.2) associated with human herpesvirus-6 (HHV-6). For hepatitis viruses, a significant NHL risk was observed for higher compared to lower antibodies to the HBV-associated core (HBc) antigen (OR = 1.8, 95% CI = 1.1-3.1), and this risk was particularly apparent in those with the highest HBc and EBV EA-D antibody levels (OR = 4.2, 95% CI = 1.4-12.7) compared to the lowest. Seropositivity to HCV was low (1.4% cases; 0.9% controls). No associations with NHL risk were observed for individual polyomaviruses (BK, JC, TSV, MCV). Discussion: Our study of serologic markers of infection and NHL risk in three prospective population-based studies of Chinese individuals suggests a role of specific viral agents in lymphomagenesis. The findings for EBV are consistent with some data from Western cohorts and indicate that EBV reactivation may be associated with NHL risk in the Chinese general population. HHV-6 is a lymphotropic virus that has been observed in some retrospective studies to be associated with lymphoma, but to our knowledge has not previously been associated with NHL prospectively in the general population. HBV is endemic to regions of East Asia, including China, and our data suggest that high levels of antibodies to the HBc antigen may be a marker for NHL risk.

Citation Format: Bryan A. Bassig, Angelika Michel, Xiao-Ou Shu, Woon-Puay Koh, Yu-Tang Gao, Lesley M. Butler, Mark Purdue, Yong-Bing Xiang, Jennifer Adams-Haduch, Renwei Wang, Nicole Brenner, Tim Waterboer, Martina Willhauck-Fleckenstein, Bu-Tian Ji, H. Dean Hosgood, Charles S. Rabkin, Jason Y.Y. Wong, Jinming Zhang, Wei Hu, Gong Yang, Wong-Ho Chow, Michael Pawlita, Wei Zheng, Jian-Min Yuan, Qing Lan, Nathaniel Rothman. Serologic markers of infection and risk of non-Hodgkin lymphoma in a pooled prospective study of three Chinese cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4245. doi:10.1158/1538-7445.AM2017-4245

Abstract 2297: Household stove improvement and risk of chronic obstructive pulmonary disease in Xuanwei, China: a cohort study

Background: In Xuanwei County, China, chronic obstructive pulmonary disease (COPD) rates are over twice the national average. Patients with COPD have higher risks of both lung cancer and poor treatment outcomes after lung cancer diagnosis. In a prior retrospective cohort study (1976-1992), household stove improvement was found to be associated with decreased COPD incidence among lifetime smoky (bituminous) coal users. However, whether the protective effects persist over time is unclear. Our objective was to evaluate the associations between risk of COPD, and vented and portable stove use with extended follow-up (1976-2011).

Methods: The study population comprised 22,833 residents who were born between 1917 and 1951 and lived in Xuanwei as of January 1, 1976. Participants were followed retrospectively from 1976 to 1992, and then followed prospectively through 2011. We conducted two surveys in 1992 and 2011. During each survey, we collected comprehensive information on household stove type, fuel use, family size and number of rooms in each residence during the lifetime, smoking, education, age started cooking food and time spent indoor from each subject. Participants were also asked to report any medically diagnosed chronic bronchitis or emphysema, age and place of diagnosis, which we combined into a single category of COPD. COPD cases diagnosed before January 1, 1976 were excluded. Sex-specific time-dependent Cox regression models were used to estimate the hazard ratio (HR) of stove improvement for COPD incidence among lifetime smoky coal users.

Results: The analysis was restricted to lifetime smoky coal users. A significant reduction in COPD incidence was found after change to vented stoves (Men’s model: HR=0.66, 95% confidence interval(CI): 0.59-0.75; Women’s model: HR=0.63, 95% CI: 0.55-0.72) and portable stoves (Men’s model: HR=0.77, 95% CI: 0.67-0.88; Women’s model: HR=0.63, 95% CI: 0.54-0.74). There was a downward trend of COPD incidence over time after change to vented stove or portable stove (p-trend&lt;0.01). Similar findings were noted in both men and women.

Conclusion: Consistent with prior research, our findings suggest that household stove improvement was associated with a substantially decreased risk of COPD, a strong risk factor for lung cancer. Domestic smoky coal use and unvented coal combustion are important risk factors for COPD. Our findings support the need for replacing smoky coal with less carcinogenic fuels in areas where domestic coal use is common for cooking and heating, especially in the developing countries.

Citation Format: Jinming Zhang, Bryan A. Bassig, Roel Vermeulen, Wei Jie Seow, Jason Y.Y. Wong, Wei Hu, Bofu Ning, George S. Downward, Hormuzd A. Katki, Bu-Tian Ji, Nathaniel Rothman, Robert S. Chapman, Qing Lan. Household stove improvement and risk of chronic obstructive pulmonary disease in Xuanwei, China: a cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2297. doi:10.1158/1538-7445.AM2017-2297

Lung cancer risk in welders and foundry workers with a history of heavy smoking in the USA: The National Lung Screening Trial

OBJECTIVES

Foundry work is a risk factor for lung cancer; however, the association with welding is unclear, as smoking is common among metalworkers and may mask the relationship. We evaluated whether history of welding and foundry work, independently and jointly, and employment duration were associated with lung cancer risk in heavy smokers.

METHODS

We analysed data from the National Lung Screening Trial, a prospective randomised trial of 53 454 heavy smokers (>30 pack-years) in the USA. Cox regression models were used to estimate the HRs and 95% CIs of medically/histologically confirmed incident lung cancer during the follow-up period (2002-2009) in relation to history and duration of welding and foundry work assessed via questionnaires, adjusted for screening arm, component study, sex, age, race/ethnicity, education, smoking status and pack-years, body mass index and personal/family medical history.

RESULTS

There were 2034 incident lung cancer cases throughout the follow-up. Increasing years of employment in welding (p-trend =0.039) and foundry work (p-trend =0.005) were related to increased lung cancer risk among heavy smokers. Having ever been employed (≥1 yr) as either a welder or foundry worker alone was associated with non-significant increased risks of lung cancer (HR=1.12 (95% CI 0.91 to 1.37) and HR=1.09 (95% CI 0.85 to 1.39), respectively). Further, there was a joint-effect in that those who were ever employed in both occupations had significantly increased risks (HR=1.48 (95% CI 1.08 to 2.04)).

CONCLUSIONS

Our findings provide further evidence that exposure to welding/metal fumes may be associated with elevated lung cancer risk.

TRIAL REGISTRATION NUMBER

NCT00047385.

Sleep Duration across the Adult Lifecourse and Risk of Lung Cancer Mortality: A Cohort Study in Xuanwei, China

Sufficient sleep duration is crucial for maintaining normal physiological function and has been linked to cancer risk; however, its contribution to lung cancer mortality is unclear. Therefore, we evaluated the relationship between average sleep duration in various age-periods across the adult lifecourse, and risk of lung cancer mortality in Xuanwei, China. An ambidirectional cohort study was conducted in 42,422 farmers from Xuanwei, China. Participants or their surrogates were interviewed in 1992 to assess average sleep hours in the age periods of 21-30, 31-40, 41-50, 51-60, 61-70, and ≥71 years, which were categorized as ≤7, 8 (reference), 9, and ≥10 hours/day. Vital status was followed until 2011. Sex-specific Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for lung cancer mortality in 1994-2011, adjusted for demographic, anthropometric, medical, and household characteristics. J-shaped relationships were found between average sleep duration and lung cancer mortality. The patterns were consistent across sex, age periods, and fuel usage. Compared with sleeping 8 hours/day on average, ≤7 hours/day was associated with significantly increased HRs ranging from 1.39 to 1.58 in ages ≥41 years in men, and 1.29 to 2.47 in ages ≥51 years in women. Furthermore, sleeping ≥10 hours/day was associated with significantly increased HRs ranging from 2.44 to 3.27 in ages ≥41 year in men, and 1.31 to 2.45 in ages ≤60 years in women. Greater and less than 8 hours/day of sleep in various age-periods may be associated with elevated risk of lung cancer mortality in Xuanwei, China. Cancer Prev Res; 10(6); 327-35. ©2017 AACR.

Association between GWAS-identified lung adenocarcinoma susceptibility loci and EGFR mutations in never-smoking Asian women, and comparison with findings from Western populations

To evaluate associations by EGFR mutation status for lung adenocarcinoma risk among never-smoking Asian women, we conducted a meta-analysis of 11 loci previously identified in genome-wide association studies (GWAS). Genotyping in an additional 10,780 never-smoking cases and 10,938 never-smoking controls from Asia confirmed associations with eight known single nucleotide polymorphisms (SNPs). Two new signals were observed at genome-wide significance (P < 5 × 10-8), namely, rs7216064 (17q24.3, BPTF), for overall lung adenocarcinoma risk, and rs3817963 (6p21.3, BTNL2) which is specific to cases with EGFR mutations. In further sub-analyses by EGFR status, rs9387478 (ROS1/DCBLD1) and rs2179920 (HLA-DPB1) showed stronger estimated associations in EGFR-positive compared to EGFR-negative cases. Comparison of the overall associations with published results in Western populations revealed that the majority of these findings were distinct, underscoring the importance of distinct contributing factors for smoking and non-smoking lung cancer. Our results extend the catalogue of regions associated with lung adenocarcinoma in non-smoking Asian women and highlight the importance of how the germline could inform risk for specific tumour mutation patterns, which could have important translational implications.

Evaluating Exposure-Response Associations for Non-Hodgkin Lymphoma with Varying Methods of Assigning Cumulative Benzene Exposure in the Shanghai Women's Health Study

Objectives

To provide insight into the contributions of exposure measurements to job exposure matrices (JEMs), we examined the robustness of an association between occupational benzene exposure and non-Hodgkin lymphoma (NHL) to varying exposure assessment methods.

Methods

NHL risk was examined in a prospective population-based cohort of 73087 women in Shanghai. A mixed-effects model that combined a benzene JEM with >60000 short-term, area benzene inspection measurements was used to derive two sets of measurement-based benzene estimates: 'job/industry-specific' estimates (our presumed best approach) were derived from the model's fixed effects (year, JEM intensity rating) and random effects (occupation, industry); 'calibrated JEM' estimates were derived using only the fixed effects. 'Uncalibrated JEM' (using the ordinal JEM ratings) and exposure duration estimates were also calculated. Cumulative exposure for each subject was calculated for each approach based on varying exposure definitions defined using the JEM's probability ratings. We examined the agreement between the cumulative metrics and evaluated changes in the benzene-NHL associations.

Results

For our primary exposure definition, the job/industry-specific estimates were moderately to highly correlated with all other approaches (Pearson correlation 0.61-0.89; Spearman correlation > 0.99). All these metrics resulted in statistically significant exposure-response associations for NHL, with negligible gain in model fit from using measurement-based estimates. Using more sensitive or specific exposure definitions resulted in elevated but non-significant associations.

Conclusions

The robust associations observed here with varying benzene assessment methods provide support for a benzene-NHL association. While incorporating exposure measurements did not improve model fit, the measurements allowed us to derive quantitative exposure-response curves.

Menstrual and Reproductive Factors, Hormone Use, and Risk of Pancreatic Cancer: Analysis From the International Pancreatic Cancer Case-Control Consortium (PanC4)

OBJECTIVES

We aimed to evaluate the relation between menstrual and reproductive factors, exogenous hormones, and risk of pancreatic cancer (PC).

METHODS

Eleven case-control studies within the International Pancreatic Cancer Case-control Consortium took part in the present study, including in total 2838 case and 4748 control women. Pooled estimates of odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using a 2-step logistic regression model and adjusting for relevant covariates.

RESULTS

An inverse OR was observed in women who reported having had hysterectomy (ORyesvs.no, 0.78; 95% CI, 0.67-0.91), remaining significant in postmenopausal women and never-smoking women, adjusted for potential PC confounders. A mutually adjusted model with the joint effect for hormone replacement therapy (HRT) and hysterectomy showed significant inverse associations with PC in women who reported having had hysterectomy with HRT use (OR, 0.64; 95% CI, 0.48-0.84).

CONCLUSIONS

Our large pooled analysis suggests that women who have had a hysterectomy may have reduced risk of PC. However, we cannot rule out that the reduced risk could be due to factors or indications for having had a hysterectomy. Further investigation of risk according to HRT use and reason for hysterectomy may be necessary.

Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with risk of clear cell ovarian cancer

BACKGROUND

Regulatory T (Treg) cells, a subset of CD4+ T lymphocytes, are mediators of immunosuppression in cancer, and, thus, variants in genes encoding Treg cell immune molecules could be associated with ovarian cancer.

METHODS

In a population of 15,596 epithelial ovarian cancer (EOC) cases and 23,236 controls, we measured genetic associations of 1,351 SNPs in Treg cell pathway genes with odds of ovarian cancer and tested pathway and gene-level associations, overall and by histotype, for the 25 genes, using the admixture likelihood (AML) method. The most significant single SNP associations were tested for correlation with expression levels in 44 ovarian cancer patients.

RESULTS

The most significant global associations for all genes in the pathway were seen in endometrioid ( p = 0.082) and clear cell ( p = 0.083), with the most significant gene level association seen with TGFBR2 ( p = 0.001) and clear cell EOC. Gene associations with histotypes at p < 0.05 included: IL12 ( p = 0.005 and p = 0.008, serous and high-grade serous, respectively), IL8RA ( p = 0.035, endometrioid and mucinous), LGALS1 ( p = 0.03, mucinous), STAT5B ( p = 0.022, clear cell), TGFBR1 ( p = 0.021 endometrioid) and TGFBR2 ( p = 0.017 and p = 0.025, endometrioid and mucinous, respectively).

CONCLUSIONS

Common inherited gene variation in Treg cell pathways shows some evidence of germline genetic contribution to odds of EOC that varies by histologic subtype and may be associated with mRNA expression of immune-complex receptor in EOC patients.