Outdoor particulate matter (PM10) exposure and lung cancer risk in the EAGLE study.

OBJECTIVE: Cohort studies in Europe, but not in North-America, showed an association between exposure to outdoor particulate matter with aerodynamic diameter ≤10 µm (PM10) and lung cancer risk. Only a case-control study on lung cancer and PM10 in South Korea has so far been performed. For the first time in Europe we analyzed quantitatively this association using a case-control study design in highly polluted areas in Italy. METHODS: The Environment And Genetics in Lung cancer Etiology (EAGLE) study, a population-based case-control study performed in the period 2002-2005 in the Lombardy Region, north-west Italy, enrolled 2099 cases and 2120 controls frequency-matched for area of residence, gender, and age. For this study we selected subjects with complete active and passive smoking history living in the same municipality since 1980 until study enrollment. Fine resolution annual PM10 estimates obtained by applying land use regression modeling to satellite data calibrated with fixed site monitor measurements were used. We assigned each subject the PM10 average estimates for year 2000 based on enrollment address. We used logistic regression models to calculate odds ratios (OR) and 95% confidence intervals (CI) adjusted for matching variables, education, smoking, and dietary and occupational variables. RESULTS: We included 3473 subjects, 1665 cases (1318 men, 347 women) and 1808 controls (1368 men, 440 women), with PM10 individual levels ranging from 2.3 to 53.8 µg/m3 (mean: 46.3). We found increasing lung cancer risk with increasing PM10 category (P-value for trend: 0.04). The OR per 10 µg/m3 was 1.28 (95% CI: 0.95-1.72). The association appeared stronger for squamous cell carcinoma (OR 1.44, 95% CI: 0.90-2.29). CONCLUSION: In a population living in highly polluted areas in Italy, our study added suggestive evidence of a positive association between PM10 exposure and lung cancer risk. This study emphasizes the need to strengthen policies to reduce airborne pollution.

Large-scale association analysis identifies new lung cancer susceptibility loci and heterogeneity in genetic susceptibility across histological subtypes.

Although several lung cancer susceptibility loci have been identified, much of the heritability for lung cancer remains unexplained. Here 14,803 cases and 12,262 controls of European descent were genotyped on the OncoArray and combined with existing data for an aggregated genome-wide association study (GWAS) analysis of lung cancer in 29,266 cases and 56,450 controls. We identified 18 susceptibility loci achieving genome-wide significance, including 10 new loci. The new loci highlight the striking heterogeneity in genetic susceptibility across the histological subtypes of lung cancer, with four loci associated with lung cancer overall and six loci associated with lung adenocarcinoma. Gene expression quantitative trait locus (eQTL) analysis in 1,425 normal lung tissue samples highlights RNASET2, SECISBP2L and NRG1 as candidate genes. Other loci include genes such as a cholinergic nicotinic receptor, CHRNA2, and the telomere-related genes OFBC1 and RTEL1. Further exploration of the target genes will continue to provide new insights into the etiology of lung cancer.

Nut Consumption and Lung Cancer Risk: Results from Two Large Observational Studies.

Background: Epidemiologic evidence on the association between nut consumption and lung cancer risk is limited.Methods: We investigated this relationship in the Environment and Genetics in Lung Cancer Etiology (EAGLE) study, a population-based case-control study, and the National Institutes of Health (NIH) American Association of Retired Persons (AARP) Diet and Health Study, a prospective cohort. We identified 2,098 lung cases for EAGLE and 18,533 incident cases in AARP. Diet was assessed by food frequency questionnaire for both studies. Multivariable ORs and HRs and respective 95% confidence intervals (CI) were calculated using unconditional logistic regression and Cox proportional hazards regression for EAGLE and AARP, respectively.Results: Higher frequency of intake of nut consumption was inversely associated with overall lung cancer risk (highest vs. lowest quintile, OREAGLE = 0.74; 95% CI, 0.57-0.95; HRAARP = 0.86; 95% CI, 0.81-0.91), regardless of smoking status. Results from the prospective cohort showed similar associations across histologic subtypes and a more pronounced benefits from nut consumption for those who smoked 1 to 20 cigarettes/day (OREAGLE = 0.61; 95% CI, 0.39-0.95; HRAARP = 0.83; 95% CI, 0.74-0.94).Conclusions: Nut consumption was inversely associated with lung cancer in two large population-based studies, and associations were independent of cigarette smoking and other known risk factors.Impact: To our knowledge, this is the first study that examined the association between nut consumption and lung cancer risk by histologic subtypes and smoking intensity. Cancer Epidemiol Biomarkers Prev; 26(6); 826-36. ©2017 AACR.

Somatic Genomics and Clinical Features of Lung Adenocarcinoma: A Retrospective Study.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most common histologic subtype of lung cancer and has a high risk of distant metastasis at every disease stage. We aimed to characterize the genomic landscape of LUAD and identify mutation signatures associated with tumor progression. METHODS AND FINDINGS: We performed an integrative genomic analysis, incorporating whole exome sequencing (WES), determination of DNA copy number and DNA methylation, and transcriptome sequencing for 101 LUAD samples from the Environment And Genetics in Lung cancer Etiology (EAGLE) study. We detected driver genes by testing whether the nonsynonymous mutation rate was significantly higher than the background mutation rate and replicated our findings in public datasets with 724 samples. We performed subclonality analysis for mutations based on mutant allele data and copy number alteration data. We also tested the association between mutation signatures and clinical outcomes, including distant metastasis, survival, and tumor grade. We identified and replicated two novel candidate driver genes, POU class 4 homeobox 2 (POU4F2) (mutated in 9 [8.9%] samples) and ZKSCAN1 (mutated in 6 [5.9%] samples), and characterized their major deleterious mutations. ZKSCAN1 was part of a mutually exclusive gene set that included the RTK/RAS/RAF pathway genes BRAF, EGFR, KRAS, MET, and NF1, indicating an important driver role for this gene. Moreover, we observed strong associations between methylation in specific genomic regions and somatic mutation patterns. In the tumor evolution analysis, four driver genes had a significantly lower fraction of subclonal mutations (FSM), including TP53 (p = 0.007), KEAP1 (p = 0.012), STK11 (p = 0.0076), and EGFR (p = 0.0078), suggesting a tumor initiation role for these genes. Subclonal mutations were significantly enriched in APOBEC-related signatures (p < 2.5×10-50). The total number of somatic mutations (p = 0.0039) and the fraction of transitions (p = 5.5×10-4) were associated with increased risk of distant metastasis. Our study's limitations include a small number of LUAD patients for subgroup analyses and a single-sample design for investigation of subclonality. CONCLUSIONS: These data provide a genomic characterization of LUAD pathogenesis and progression. The distinct clonal and subclonal mutation signatures suggest possible diverse carcinogenesis pathways for endogenous and exogenous exposures, and may serve as a foundation for more effective treatments for this lethal disease. LUAD's high heterogeneity emphasizes the need to further study this tumor type and to associate genomic findings with clinical outcomes.

Incidence of mesothelioma in Lombardy, Italy: exposure to asbestos, time patterns and future projections.

OBJECTIVES: In Italy, asbestos has been extensively used from 1945 to 1992. We evaluated the impact of exposure to asbestos on occurrence of malignant mesothelioma (MM) in the Lombardy Region, Northwest Italy, the most populated and industrialised Italian region. METHODS: From the Lombardy Mesothelioma Registry, we selected all incident cases of MM diagnosed between 2000 and 2012. We described sources of exposure to asbestos and examined time trends of MM rates. Using Poisson age-cohort models, we derived projections of burden of MM in the Lombardy population for the period 2013-2029. RESULTS: In 2000-2012, we recorded 4442 cases of MM (2850 men, 1592 women). Occupational exposure to asbestos was more frequent in men (73.6%) than in women (38.2%). Non-occupational exposure was found for 13.6% of women and 3.6% of men. The average number of cases of MM per year was still increasing (+3.6% in men, +3.3% in women). Incidence rates were still increasing in individuals aged 65+ years and declining in younger people. A maximum of 417 cases of MM (267 men, 150 women) are expected in 2019. We forecast there will be 6832 more cases (4397 in men, 2435 in women) in the period 2013-2029, for a total of 11 274 cases of MM (7247 in men, 4027 in women) in 30 years. CONCLUSIONS: This study documented a high burden of MM in both genders in the Lombardy Region, reflecting extensive occupational (mainly in men) and non-occupational (mainly in women) exposure to asbestos in the past. Incidence rates are still increasing; a downturn in occurrence of MM is expected to occur after 2019.

Determinants of active and environmental exposure to tobacco smoke and upper reference value of urinary cotinine in not exposed individuals.

The aims of this study were (1) to explore the behavioral and sociodemographic factors influencing urinary cotinine (COT-U) levels in active smokers and in environmental tobacco smoke (ETS)-exposed individuals, (2) to assess the specificity and sensitivity of the questionnaire for identifying active smokers and nonsmokers, and (3) to derive the upper reference value of COT-U in non-ETS exposed individuals. The COT-U levels of 495 adults (age range 18-69 years) who classified themselves as active smokers (29%) or as nonsmokers with (17%) or without (83%) ETS exposure were quantified by LC-MS-MS (quantification limit: 0.1µg/L, range of linearity: 0.1-4000µg/L). Median COT-U levels in these groups were 883, 1.38, and 0.39µg/L, respectively. Significant determinants of COT-U levels in active smokers were the number of cigarettes per day, type of smoking product, smoking environment, as well as time between the last cigarette and urine collection. Among ETS-exposed nonsmokers, significant determinants were living with smokers, being exposed to smoke at home, ETS exposure duration, as well as time between the last exposure and urine collection. When a 30-µg/L COT-U cut-off value was used to identify active daily smoking, the sensitivity and specificity of the questionnaire were 94% and 98%, respectively. For ETS exposure, the COT-U value of 1.78 (0.90 confidence interval 1.75-1.78) µg/L, corresponding to the 95th percentiles of the COT-U distribution in non-ETS-exposed participants, is proposed as upper reference value to identify environmental exposure.

[Malignant mesotheliomas with unknown exposure to asbestos: a re-examination]. / Mesoteliomi maligni con esposizione ad amianto ignota: un riesame a distanza.

INTRODUCTION: Malignant Mesothelioma (MM) is a rare neoplasm associated with asbestos exposure. In 24,5% of MM cases reported to the Lombardy Mesothelioma Registry (LMR), asbestos exposure has been defined as "unknown". OBJECTIVE: To evaluate the cases with "unknown exposure to asbestos" diagnosed in 2000-2004 in agreement with new knowledge about source of asbestos exposure. METHODS: Information regarding exposure has been reviewed in order to select the cases susceptible of further investigations, including: interview of relatives and/or colleagues; further evaluations by local PSAL (Prevention and Security in workplace) services; contact of industrial hygienists; analysis of production processes. The same procedure has been followed for extra-occupational exposure. These cases have been subjected to the LMR evaluation group. RESULTS: Fourthy four out of 364 (12,1%) MM have been reclassified. In 47,7% of the cases, a "possible occupational exposure" has been recognized, 15,9% have been attributed a "certain occupational exposure", while 36,4% an extra-occupational (domestic, environmental and leisure-time) exposure. No significant differences between age, sex, cancer site, diagnostic certainty, residence, year of diagnosis, interviewed subjects were detected. The occupational sector with the highest amount of reclassifications was the clothing production. CONCLUSIONS: The detailed reconstruction of clinical and occupational history and of lifestyle habits of patients affected by MM, close cooperation with Local Services of Occupational Medicine and literature review make it possible for previously overlooked asbestos exposure to be acknowledged.

The role of haplotype in 15q25.1 locus in lung cancer risk: results of scanning chromosome 15.

The role of haplotypes and the interaction of haplotypes and smoking in lung cancer risk have not been well characterized. We analyzed data from an Italian population-based, case-control study with 1815 lung cancer patients and 1959 healthy controls in discovery, and performed a validation using a case-control study with 2983 lung cancer patients and 3553 healthy controls of European ancestry for replication. Sliding window haplotype analysis within chromosome 15, evaluating 4722250 haplotypes and pair-wise haplotype analysis identified that CHRNA5 rs588765-rs16969968 was the most significant haplotype associated with lung cancer risk (omnibus P = 8.35×10(-15) in discovery and 7.26×10(-14) in replication), and improved the prediction of case status over that provided by the individual SNPs rs16969968 or rs588765 (likelihood ratio test P = 0.006 for rs16969968 and 3.83×10(-14) for rs588765 in discovery, 0.009 for rs16969968 and 4.62×10(-13) for rs588765 in replication, compared with rs588765-rs16969968). Compared with the wild-type homozygous diplotype, CA/CA homozygote exhibited an approximately 2-fold increase risk for lung cancer (OR = 2.12; 95% CI 1.46-3.07 in discovery, and OR = 2.01; 95% CI 1.51-2.67 in replication). Even among never-smokers, CA/CA homozygote showed an increased risk of lung cancer with borderline significance in discovery (adjusted OR = 1.75, 95% CI 0.96-3.19) and statistical significance in replication (adjusted OR = 2.10, 95% CI 1.12-3.96), compared with combined genotypes (CG/CG + CG/TG). Accordingly, rs588765-rs16969968 may be a genetic marker to lung cancer risk, even among never-smokers.

Lung cancer prognosis before and after recurrence in a population-based setting.

BACKGROUND: Population-based estimates of absolute risk of lung cancer recurrence, and of mortality rates after recurrence, can inform clinical management. METHODS: We evaluated prognostic factors for recurrences and survival in 2098 lung cancer case patients from the general population of Lombardy, Italy, from 2002 to 2005. We conducted survival analyses and estimated absolute risks separately for stage IA to IIIA surgically treated and stage IIIB to IV non-surgically treated patients. RESULTS: Absolute risk of metastases exceeded that of local recurrence in every stage and cell type, highlighting the systemic threat of lung cancer. In stage I, the probability of dying within the first year after diagnosis was 2.7%, but it was 48.3% within first year after recurrence; in stage IV, the probabilities were 57.3% and 80.6%, respectively. Over half the patients died within one year of first metastasis. Although in stages IA to IB about one-third of patients had a recurrence, stage IIA patients had a recurrence risk (61.2%) similar to stage IIB (57.9%) and IIIA (62.8%) patients. Risk of brain metastases in stage IA to IIIA surgically treated non-small cell lung cancer patients increased with increasing tumor grade. Absolute risk of recurrence was virtually identical in adenocarcinoma and squamous cell carcinoma patients. CONCLUSIONS: This population-based study provides clinically useful estimates of risks of lung cancer recurrence and mortality that are applicable to the general population. These data highlight the need for more effective adjuvant treatments overall and within specific subgroups. The estimated risks of various endpoints are useful for designing clinical trials, whose power depends on absolute numbers of events.

IARC monographs: 40 years of evaluating carcinogenic hazards to humans.

BACKGROUND: Recently, the International Agency for Research on Cancer (IARC) Programme for the Evaluation of Carcinogenic Risks to Humans has been criticized for several of its evaluations, and also for the approach used to perform these evaluations. Some critics have claimed that failures of IARC Working Groups to recognize study weaknesses and biases of Working Group members have led to inappropriate classification of a number of agents as carcinogenic to humans. OBJECTIVES: The authors of this Commentary are scientists from various disciplines relevant to the identification and hazard evaluation of human carcinogens. We examined criticisms of the IARC classification process to determine the validity of these concerns. Here, we present the results of that examination, review the history of IARC evaluations, and describe how the IARC evaluations are performed. DISCUSSION: We concluded that these recent criticisms are unconvincing. The procedures employed by IARC to assemble Working Groups of scientists from the various disciplines and the techniques followed to review the literature and perform hazard assessment of various agents provide a balanced evaluation and an appropriate indication of the weight of the evidence. Some disagreement by individual scientists to some evaluations is not evidence of process failure. The review process has been modified over time and will undoubtedly be altered in the future to improve the process. Any process can in theory be improved, and we would support continued review and improvement of the IARC processes. This does not mean, however, that the current procedures are flawed. CONCLUSIONS: The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public's health.

Impact of an asbestos cement factory on mesothelioma incidence: global assessment of effects of occupational, familial, and environmental exposure.

Few studies have examined the incidence of malignant mesothelioma (MM) associated with distinct sources of asbestos exposure (occupational, familial, or environmental). We assessed the impact of asbestos exposure-global and by source-on the incidence of MM in Broni, an Italian town in which an asbestos cement factory once operated (1932-1993). Based on data collected by the Lombardy Mesothelioma Registry, we calculated the number of observed and expected MM cases among workers, their cohabitants, and people living in the area in 2000-2011. We identified 147 MM cases (17.45 expected), 138 pleural and nine peritoneal, attributable to exposure to asbestos from the factory. Thirty-eight cases had past occupational exposure at the factory (2.33 expected), numbering 32 men (26 pleural, six peritoneal) and six women (four pleural, two peritoneal). In the families of the workers, there were 37 MM cases (4.23 expected), numbering five men (all pleural) and 32 women (31 pleural, one peritoneal). Among residents in Broni or in the adjacent/surrounding towns, there were 72 cases of pleural MM (10.89 expected), numbering 23 men and 49 women. The largest MM excess was found in the towns of Broni (48 observed, 3.68 expected) and Stradella (16 observed, 1.85 expected). This study documents the large impact of the asbestos cement factory, with about 130 excess MM cases in a 12-year period. The largest MM burden was among women, from non-occupational exposure. Almost half of the MM cases were attributable to environmental exposure.

Associated Links Among Smoking, Chronic Obstructive Pulmonary Disease, and Small Cell Lung Cancer: A Pooled Analysis in the International Lung Cancer Consortium.

BACKGROUND: The high relapse and mortality rate of small-cell lung cancer (SCLC) fuels the need for epidemiologic study to aid in its prevention. METHODS: We included 24 studies from the ILCCO collaboration. Random-effects panel logistic regression and cubic spline regression were used to estimate the effects of smoking behaviors on SCLC risk and explore their non-linearity. Further, we explored whether the risk of smoking on SCLC was mediated through COPD. FINDINGS: Significant dose-response relationships of SCLC risk were observed for all quantitative smoking variables. Smoking pack-years were associated with a sharper increase of SCLC risk for pack-years ranged 0 to approximately 50. The former smokers with longer cessation showed a 43%quit_for_5-9 years to 89%quit_for_≥ 20 years declined SCLC risk vs. subjects who had quit smoking < 5 years. Compared with non-COPD subjects, smoking behaviors showed a significantly higher effect on SCLC risk among COPD subjects, and further, COPD patients showed a 1.86-fold higher risk of SCLC. Furthermore, smoking behaviors on SCLC risk were significantly mediated through COPD which accounted for 0.70% to 7.55% of total effects. INTERPRETATION: This is the largest pooling study that provides improved understanding of smoking on SCLC, and further demonstrates a causal pathway through COPD that warrants further experimental study.

Lung cancer risk among bricklayers in a pooled analysis of case-control studies.

Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies that analyzed lung cancer risk among these workers had several study design limitations. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case-control studies on lung cancer and the joint effects of occupational carcinogens. For men ever employed as bricklayers we estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for study center, age, lifetime smoking history and employment in occupations with exposures to known or suspected lung carcinogens. Among 15,608 cases and 18,531 controls, there were 695 cases and 469 controls who had ever worked as bricklayers (OR: 1.47; 95% CI: 1.28-1.68). In studies using population controls the OR was 1.55 (95% CI: 1.32-1.81, 540/349 cases/controls), while it was 1.24 (95% CI: 0.93-1.64, 155/120 cases/controls) in hospital-based studies. There was a clear positive trend with length of employment (p < 0.001). The relative risk was higher for squamous (OR: 1.68, 95% CI: 1.42-1.98, 309 cases) and small cell carcinomas (OR: 1.78, 95% CI: 1.44-2.20, 140 cases), than for adenocarcinoma (OR: 1.17, 95% CI: 0.95-1.43, 150 cases) (p-homogeneity: 0.0007). ORs were still elevated after additional adjustment for education and in analyses using blue collar workers as referents. This study provided robust evidence of increased lung cancer risk in bricklayers. Although non-causal explanations cannot be completely ruled out, the association is plausible in view of the potential for exposure to several carcinogens, notably crystalline silica and to a lesser extent asbestos.

Nutrients intake is associated with DNA methylation of candidate inflammatory genes in a population of obese subjects.

The aim of the present study was to evaluate the potential association between dietary nutrients and alterations in DNA methylation in a set of five candidate genes, including CD14, Et-1, iNOS, HERV-w and TNFα, in a population of overweight/obese subjects. We evaluated possible associations between gene methylation and clinical blood parameters, including total cholesterol (TC), low- and high-density lipoprotein cholesterol (LDL-C and HDL-C), triglyceride and homocysteine levels. We employed validated methods to assess anthropometric, clinical and dietary data, as well as pyrosequencing to evaluate DNA methylation of the five candidate genes in 165 overweight/obese subjects. There was no association between body mass index and DNA methylation of the five candidate genes in this group of subjects. Positive associations were observed between TNFα methylation and blood levels of LDL-C (ß = 0.447, p = 0.002), TC/HDL-C (ß = 0.467, p = 0.001) and LDL-C/HDL-C (ß = 0.445, p = 0.002), as well as between HERV-w methylation and dietary intakes of ß-carotene (ß = 0.088, p = 0.051) and carotenoids (ß = 0.083, p = 0.029). TNFα methylation showed negative associations with dietary intakes of cholesterol (ß = -0.278, p = 0.048), folic acid (ß = -0.339, p = 0.012), ß-carotene (ß = -0.332, p = 0.045), carotenoids (ß = -0.331, p = 0.015) and retinol (ß = -0.360, p = 0.008). These results suggest a complex relationship among nutrient intake, oxidative stress and DNA methylation.

Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33.

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.

Time to smoke first morning cigarette and lung cancer in a case-control study.

BACKGROUND: Targeting smokers at higher lung cancer risk can improve efficiency and reduce false-positive detection in lung cancer screening. We evaluated whether time to first cigarette after waking (TTFC), a single-item measure of nicotine dependency, could improve stratification of lung cancer risk beyond standard smoking metrics (intensity, duration, and pack-years). METHODS: In 3249 ever-smokers (n = 1812 case subjects; n = 1437 control subjects) from a population-based case-control study in Italy, we examined the association between TTFC and lung cancer using logistic regression and estimated lung cancer incidence by levels of TTFC, and intensity, duration, and pack-years using absolute risk regression. Significance tests were two-sided. RESULTS: Compared with smokers with TTFC greater than 60 minutes, the lung cancer odds ratios for TTFC of 31 to 60 minutes, 6 to 30 minutes, and 5 or fewer minutes (by increasing dependency) were 2.57 (95% confidence interval [CI] = 2.03 to 3.26), 2.27 (95% CI = 1.79 to 2.88), and 3.50 (95% CI = 2.64 to 4.64), respectively (P trend < .0001). The average lung cancer incidence rates for smokers of 1 to 10, 11 to 20, 21 to 30 and more than 30 cigarettes per day were consistently higher among smokers with TTFC of 60 or fewer minutes vs more than 60 minutes (64.1 vs 11.7; 125.6 vs 28.6; 130.1 vs 40.7; and 260.8 vs 108.9 per 100000 person-years, respectively). The slopes of increase in lung cancer rates with smoking duration and pack-years were statistically significantly greater among smokers with higher dependency (P interaction < .001). CONCLUSIONS: Lung cancer risk increases with shorter TTFC; this simple nicotine dependency measure increases lung cancer risk stratification beyond standard smoking measures. Assessing TTFC may improve lung cancer risk prediction and could be useful in lung cancer screening and smoking cessation programs.

Relevance of telomere/telomerase system impairment in early stage chronic lymphocytic leukemia.

Several studies have proposed telomere length and telomerase activity as prognostic factors in chronic lymphocytic leukemia (CLL), whereas information addressing the role of telomere-associated genes is limited. We measured relative telomere length (RTL) and TERT expression levels in purified peripheral CD19(+) B-cells from seven healthy donors and 77 untreated CLLs in early stage disease (Binet A). Data were correlated with the major biological and cytogenetic markers, global DNA methylation (Alu and LINE-1), and clinical outcome. The expression profiles of telomere-associated genes were also investigated. RTL was decreased in CLLs as compared with controls (P < 0.001); within CLL, a progressive and significant RTL shortening was observed in patients from 13q- through +12, 11q-, and 17p- alterations; short telomeres were significantly associated with unmutated IGHV configuration and global DNA hypomethylation. Decreased RTL was associated with a shorter time to first treatment. A significant upregulation of POT1, TRF1, RAP1, MRE11A, RAD50, and RPA1 transcript levels was observed in CLLs compared with controls. Our study suggests that impairment of telomere/telomerase system represents an early event in CLL pathogenesis. Moreover, the correlation between telomere shortening and global DNA hypomethylation supports the involvement of DNA hypomethylation to increase chromosome instability. © 2014 Wiley Periodicals, Inc.

Characterizing the genetic basis of methylome diversity in histologically normal human lung tissue.

The genetic regulation of the human epigenome is not fully appreciated. Here we describe the effects of genetic variants on the DNA methylome in human lung based on methylation-quantitative trait loci (meQTL) analyses. We report 34,304 cis- and 585 trans-meQTLs, a genetic-epigenetic interaction of surprising magnitude, including a regulatory hotspot. These findings are replicated in both breast and kidney tissues and show distinct patterns: cis-meQTLs mostly localize to CpG sites outside of genes, promoters and CpG islands (CGIs), while trans-meQTLs are over-represented in promoter CGIs. meQTL SNPs are enriched in CTCF-binding sites, DNaseI hypersensitivity regions and histone marks. Importantly, four of the five established lung cancer risk loci in European ancestry are cis-meQTLs and, in aggregate, cis-meQTLs are enriched for lung cancer risk in a genome-wide analysis of 11,587 subjects. Thus, inherited genetic variation may affect lung carcinogenesis by regulating the human methylome.

Heme-related gene expression signatures of meat intakes in lung cancer tissues.

Lung cancer causes more deaths worldwide than any other cancer. In addition to cigarette smoking, dietary factors may contribute to lung carcinogenesis. Epidemiologic studies, including the environment and genetics in lung cancer etiology (EAGLE), have reported increased consumption of red/processed meats to be associated with higher risk of lung cancer. Heme-iron toxicity may link meat intake with cancer. We investigated this hypothesis in meat-related lung carcinogenesis using whole genome expression. We measured genome-wide expression (HG-U133A) in 49 tumor and 42 non-involved fresh frozen lung tissues of 64 adenocarcinoma EAGLE patients. We studied gene expression profiles by high-versus-low meat consumption, with and without adjustment by sex, age, and smoking. Threshold for significance was a false discovery rate (FDR) ≤ 0.15. We studied whether the identified genes played a role in heme-iron related processes by means of manually curated literature search and gene ontology-based pathway analysis. We found that gene expression of 232 annotated genes in tumor tissue significantly distinguished lung adenocarcinoma cases who consumed above/below the median intake of fresh red meats (FDR = 0.12). Sixty-three (∼ 28%) of the 232 identified genes (12 expected by chance, P-value < 0.001) were involved in heme binding, absorption, transport, and Wnt signaling pathway (e.g., CYPs, TPO, HPX, HFE, SLCs, and WNTs). We also identified several genes involved in lipid metabolism (e.g., NCR1, TNF, and UCP3) and oxidative stress (e.g., TPO, SGK2, and MTHFR) that may be indirectly related to heme-toxicity. The study's results provide preliminary evidence that heme-iron toxicity might be one underlying mechanism linking fresh red meat intake and lung cancer.