Epigenome-wide association study of total nicotine equivalents in multiethnic current smokers from three prospective cohorts.

The impact of tobacco exposure on health varies by race and ethnicity and is closely tied to internal nicotine dose, a marker of carcinogen uptake. DNA methylation is strongly responsive to smoking status and may mediate health effects, but study of associations with internal dose is limited. We performed a blood leukocyte epigenome-wide association study (EWAS) of urinary total nicotine equivalents (TNEs; a measure of nicotine uptake) and DNA methylation measured using the MethylationEPIC v1.0 BeadChip (EPIC) in six racial and ethnic groups across three cohort studies. In the Multiethnic Cohort Study (discovery, n = 1994), TNEs were associated with differential methylation at 408 CpG sites across >250 genomic regions (p < 9 × 10-8). The top significant sites were annotated to AHRR, F2RL3, RARA, GPR15, PRSS23, and 2q37.1, all of which had decreasing methylation with increasing TNEs. We identified 45 novel CpG sites, of which 42 were unique to the EPIC array and eight annotated to genes not previously linked with smoking-related DNA methylation. The most significant signal in a novel gene was cg03748458 in MIR383;SGCZ. Fifty-one of the 408 discovery sites were validated in the Singapore Chinese Health Study (n = 340) and the Southern Community Cohort Study (n = 394) (Bonferroni corrected p < 1.23 × 10-4). Significant heterogeneity by race and ethnicity was detected for CpG sites in MYO1G and CYTH1. Furthermore, TNEs significantly mediated the association between cigarettes per day and DNA methylation at 15 sites (average 22.5%-44.3% proportion mediated). Our multiethnic study highlights the transethnic and ethnic-specific methylation associations with internal nicotine dose, a strong predictor of smoking-related morbidities.

Genome-wide association study identifies high-impact susceptibility loci for HCC in North America.

BACKGROUND AND AIMS: Despite the substantial impact of environmental factors, individuals with a family history of liver cancer have an increased risk for HCC. However, genetic factors have not been studied systematically by genome-wide approaches in large numbers of individuals from European descent populations (EDP). APPROACH AND RESULTS: We conducted a 2-stage genome-wide association study (GWAS) on HCC not affected by HBV infections. A total of 1872 HCC cases and 2907 controls were included in the discovery stage, and 1200 HCC cases and 1832 controls in the validation. We analyzed the discovery and validation samples separately and then conducted a meta-analysis. All analyses were conducted in the presence and absence of HCV. The liability-scale heritability was 24.4% for overall HCC. Five regions with significant ORs (95% CI) were identified for nonviral HCC: 3p22.1, MOBP , rs9842969, (0.51, [0.40-0.65]); 5p15.33, TERT , rs2242652, (0.70, (0.62-0.79]); 19q13.11, TM6SF2 , rs58542926, (1.49, [1.29-1.72]); 19p13.11 MAU2 , rs58489806, (1.53, (1.33-1.75]); and 22q13.31, PNPLA3 , rs738409, (1.66, [1.51-1.83]). One region was identified for HCV-induced HCC: 6p21.31, human leukocyte antigen DQ beta 1, rs9275224, (0.79, [0.74-0.84]). A combination of homozygous variants of PNPLA3 and TERT showing a 6.5-fold higher risk for nonviral-related HCC compared to individuals lacking these genotypes. This observation suggests that gene-gene interactions may identify individuals at elevated risk for developing HCC. CONCLUSIONS: Our GWAS highlights novel genetic susceptibility of nonviral HCC among European descent populations from North America with substantial heritability. Selected genetic influences were observed for HCV-positive HCC. Our findings indicate the importance of genetic susceptibility to HCC development.

Association of aflatoxin with gallbladder cancer in a case-control study nested within a Chinese cohort.

We evaluated whether aflatoxin B1 (AFB1 ) exposure was associated with later risk of developing gallbladder cancer (GBC). We measured AFB1 -lysine albumin adducts in baseline samples from the Shanghai Cohort Study of 18 244 men aged 45 to 64 years (recruited 1986-1989). We included 84 GBC cases with sufficient serum and 168 controls matched on age at sample collection, date of blood draw and residence. We calculated adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for detectable vs non-detectable AFB1 -lysine albumin adducts and gallbladder cancer. AFB1 -lysine albumin adducts were detected in 50.0% of GBC cases, and risk of GBC was twice as high in those with detectable vs undetectable levels (OR = 2.0, 95% CI = 1.0-3.9). ORs ranged from 1.8 (95% CI = 0.75-4.3) for 0.5 to <1.75 pg/mg vs undetectable adduct levels to 2.2 (95% CI = 0.91-5.6) for >3.36 pg/mg vs undetectable, suggesting a dose-response (Ptrend = .05). When restricted to cases diagnosed before the median time to diagnosis after blood draw (18.4 years), results were similar (OR = 2.2, 95% CI = 0.80-5.8) to those for the entire follow-up duration. The OR was 9.4 (95% CI = 1.7-51.1) for individuals with detectable AFB1 -lysine albumin adducts and self-reported gallstones compared to individuals with neither. Participants with detectable AFB1 -lysine albumin adducts at baseline had increased risk of developing GBC, replicating the previously observed association between AFB1 exposure and providing the first evidence of temporality.

Association between reproductive factors with lung cancer incidence and mortality: A pooled analysis of over 308,000 females in the Asia cohort consortium.

Previous studies have investigated the association between reproductive factors and lung cancer risk; however, findings have been inconsistent. In order to assess this association among Asian women, a total of 308,949 female participants from 11 prospective cohorts and four Asian countries (Japan, Korea, China, and Singapore) were included. Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CIs). A total of 3,119 primary lung cancer cases and 2247 lung cancer deaths were identified with a mean follow-up of 16.4 years. Parous women had a lower risk of lung cancer incidence and mortality as compared with nulliparous women, with HRs of 0.82 (95% CI = 0.70-0.96) and 0.78 (95% CI = 0.65-0.94). The protective association of parity and lung cancer incidence was greater among ever-smokers (HR = 0.66, 95% CI = 0.49-0.87) than in never-smokers (HR = 0.90, 95% CI = 0.74-1.09) (P-interaction = 0.029). Compared with age at first delivery ≤20 years, older age at first delivery (21-25, ≥26 years) was associated with a lower risk of lung cancer incidence and mortality. Women who ever used hormone replacements had a higher likelihood of developing non-small cell lung cancer (HR = 1.31, 95% CI = 1.02-1.68), compared to those who never used hormone replacements. Future studies are needed to assess the underlying mechanisms, the relationships within these female reproductive factors, and the potential changes in smoking habits over time.

Association of female reproductive and hormonal factors with gallbladder cancer risk in Asia: A pooled analysis of the Asia Cohort Consortium.

The female predominance of gallbladder cancer (GBC) has led to a hypothesis regarding the hormone-related aetiology of GBC. We aimed to investigate the association between female reproductive factors and GBC risk, considering birth cohorts of Asian women. We conducted a pooled analysis of 331,323 women from 12 cohorts across 4 countries (China, Japan, Korea, and Singapore) in the Asia Cohort Consortium. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) to assess the association between reproductive factors (age at menarche, parity, age at first delivery, breastfeeding, and age at menopause) and GBC risk. We observed that a later age at menarche was associated with an increased risk of GBC (HR 1.4, 95% CI 1.16-1.70 for 17 years and older vs. 13-14 years), especially among the cohort born in 1940 and later (HR 2.5, 95% CI 1.50-4.35). Among the cohort born before 1940, women with a later age at first delivery showed an increased risk of GBC (HR 1.56, 95% CI 1.08-2.24 for 31 years of age and older vs. 20 years of age and younger). Other reproductive factors did not show a clear association with GBC risk. Later ages at menarche and at first delivery were associated with a higher risk of GBC, and these associations varied by birth cohort.

Obesity is associated with biliary tract cancer mortality and incidence: A pooled analysis of 21 cohort studies in the Asia Cohort Consortium.

Body fatness is considered a probable risk factor for biliary tract cancer (BTC), whereas cholelithiasis is an established factor. Nevertheless, although obesity is an established risk factor for cholelithiasis, previous studies of the association of body mass index (BMI) and BTC did not take the effect of cholelithiasis fully into account. To better understand the effect of BMI on BTC, we conducted a pooled analysis using population-based cohort studies in Asians. In total, 905 530 subjects from 21 cohort studies participating in the Asia Cohort Consortium were included. BMI was categorized into four groups: underweight (<18.5 kg/m2 ); normal (18.5-22.9 kg/m2 ); overweight (23-24.9 kg/m2 ); and obese (25+ kg/m2 ). The association between BMI and BTC incidence and mortality was assessed using hazard ratios (HR) and 95% confidence intervals (CIs) by Cox regression models with shared frailty. Mediation analysis was used to decompose the association into a direct and an indirect (mediated) effect. Compared to normal BMI, high BMI was associated with BTC mortality (HR 1.19 [CI 1.02-1.38] for males, HR 1.30 [1.14-1.49] for females). Cholelithiasis had significant interaction with BMI on BTC risk. BMI was associated with BTC risk directly and through cholelithiasis in females, whereas the association was unclear in males. When cholelithiasis was present, BMI was not associated with BTC death in either males or females. BMI was associated with BTC death among females without cholelithiasis. This study suggests BMI is associated with BTC mortality in Asians. Cholelithiasis appears to contribute to the association; and moreover, obesity appears to increase BTC risk without cholelithiasis.

Diabetes is associated with increased liver cancer incidence and mortality in adults: A report from Asia Cohort Consortium.

There has been growing evidence suggesting that diabetes may be associated with increased liver cancer risk. However, studies conducted in Asian countries are limited. This project considered data of 968,738 adults pooled from 20 cohort studies of Asia Cohort Consortium to examine the association between baseline diabetes and liver cancer incidence and mortality. Cox proportional hazard model and competing risk approach was used for pooled data. Two-stage meta-analysis across studies was also done. There were 839,194 subjects with valid data regarding liver cancer incidence (5654 liver cancer cases [48.29/100,000 person-years]), follow-up time and baseline diabetes (44,781 with diabetes [5.3%]). There were 747,198 subjects with valid data regarding liver cancer mortality (5020 liver cancer deaths [44.03/100,000 person-years]), follow-up time and baseline diabetes (43,243 with diabetes [5.8%]). Hazard ratio (HR) (95% confidence interval [95%CI]) of liver cancer diagnosis in those with vs. without baseline diabetes was 1.97 (1.79, 2.16) (p < .0001) after adjusting for baseline age, gender, body mass index, tobacco smoking, alcohol use, and heterogeneity across studies (n = 586,072; events = 4620). Baseline diabetes was associated with increased cumulative incidence of death due to liver cancer (adjusted HR (95%CI) = 1.97 (1.79, 2.18); p < .0001) (n = 595,193; events = 4110). A two-stage meta-analytic approach showed similar results. This paper adds important population-based evidence to current literature regarding the increased incidence and mortality of liver cancer in adults with diabetes. The analysis of data pooled from 20 studies of different Asian countries and the meta-analysis across studies with large number of subjects makes the results robust.

Telomere length and clonal chromosomal alterations in peripheral blood of patients with severe aplastic anaemia.

Severe aplastic anaemia (SAA) is a rare and life-threatening bone marrow failure disorder. We used data from the transplant outcomes in aplastic anaemia study to characterize mosaic chromosomal alterations (mCAs) in the peripheral blood of 738 patients with acquired SAA and evaluate their associations with telomere length (TL) and survival post-haematopoietic cell transplant (HCT). The median age at HCT was 20.4 years (range = 0.2-77.4). Patients with SAA had shorter TL than expected for their age (median TL percentile for age: 35.7th; range <1-99.99). mCAs were detected in 211 patients (28.6%), with chr6p copy-neutral loss of heterozygosity (6p-CNLOH) in 15.9% and chr7 loss in 3.0% of the patients; chrX loss was detected in 4.1% of female patients. Negative correlations between mCA cell fraction and measured TL (r = -0.14, p = 0.0002), and possibly genetically predicted TL (r = -0.07, p = 0.06) were noted. The post-HCT 3-year survival probability was low in patients with chr7 loss (39% vs. 72% in patients with chr6-CNLOH, 60% in patients with other mCAs and 70% in patients with no mCAs; p-log rank = 0.001). In multivariable analysis, short TL (p = 0.01), but not chr7 loss (p = 0.29), was associated with worse post-HCT survival. TL may guide clinical decisions in patients with SAA.

Radiomics analysis to predict pulmonary nodule malignancy using machine learning approaches.

BACKGROUND: Low-dose CT screening can reduce lung cancer-related mortality. However, most screen-detected pulmonary abnormalities do not develop into cancer and it often remains challenging to identify malignant nodules, particularly among indeterminate nodules. We aimed to develop and assess prediction models based on radiological features to discriminate between benign and malignant pulmonary lesions detected on a baseline screen. METHODS: Using four international lung cancer screening studies, we extracted 2060 radiomic features for each of 16 797 nodules (513 malignant) among 6865 participants. After filtering out low-quality radiomic features, 642 radiomic and 9 epidemiological features remained for model development. We used cross-validation and grid search to assess three machine learning (ML) models (eXtreme Gradient Boosted Trees, random forest, least absolute shrinkage and selection operator (LASSO)) for their ability to accurately predict risk of malignancy for pulmonary nodules. We report model performance based on the area under the curve (AUC) and calibration metrics in the held-out test set. RESULTS: The LASSO model yielded the best predictive performance in cross-validation and was fit in the full training set based on optimised hyperparameters. Our radiomics model had a test-set AUC of 0.93 (95% CI 0.90 to 0.96) and outperformed the established Pan-Canadian Early Detection of Lung Cancer model (AUC 0.87, 95% CI 0.85 to 0.89) for nodule assessment. Our model performed well among both solid (AUC 0.93, 95% CI 0.89 to 0.97) and subsolid nodules (AUC 0.91, 95% CI 0.85 to 0.95). CONCLUSIONS: We developed highly accurate ML models based on radiomic and epidemiological features from four international lung cancer screening studies that may be suitable for assessing indeterminate screen-detected pulmonary nodules for risk of malignancy.

Age at menarche by birth cohort: A pooled analysis of half a million women in Asia.

OBJECTIVES: To evaluate changes in the age at menarche in Asian populations. STUDY DESIGN: Retrospective cohort study. METHODS: We included 548,830 women from six countries in Asia. The data were sourced from 20 cohorts participating in the Asia Cohort Consortium (ACC) and two additional cohort studies: Japan Multi-institutional Collaborative Cohorts (J-MICC), and Japan Nurse Health Study (JNHS) with data on age at menarche. Joinpoint regression was used to evaluate changes in age at menarche by birth year and by country. RESULTS: The study includes data from cohorts in six Asian countries namely, China, Iran, Japan, Korea, Malaysia and Singapore. Birth cohorts ranged from 1873 to 1995. The mean age of menarche was 14.0 years with a standard deviation (SD) of 1.4 years, ranged from 12.6 to 15.5 years. Over 100 years age at menarche showed an overall decrease in all six countries. China showed a mixed pattern of decrease, increase, and subsequent decrease from 1926 to 1960. Iran and Malaysia experienced a sharp decline between about 1985 and 1990, with APC values of -4.48 and -1.24, respectively, while Japan, South Korea, and Singapore exhibited a nearly linear decline since the 1980s, notably with an APC of -3.41 in Singapore from 1993 to 1995. CONCLUSIONS: Overall, we observed a declining age at menarche, while the pace of the change differed by country. Additional long-term observation is needed to examine the contributing factors of differences in trend across Asian countries. The study could serve as a tool to strengthen global health campaigns.

Circulating immune markers and risks of non-Hodgkin lymphoma subtypes: A pooled analysis.

Although prediagnostic circulating concentrations of the immune activation markers soluble CD27 (sCD27), sCD30 and chemokine ligand-13 (CXCL13) have been associated with non-Hodgkin lymphoma (NHL) risk, studies have been limited by sample size in associations with NHL subtypes. We pooled data from eight nested case-control studies to investigate subtype-specific relationships for these analytes. Using polytomous regression, we calculated odds ratios (ORs) with 95% confidence intervals (CIs) relating study-specific analyte tertiles to selected subtypes vs controls (n = 3310): chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; n = 623), diffuse large B cell lymphoma (DLBCL; n = 621), follicular lymphoma (FL; n = 398), marginal zone lymphoma (MZL; n = 138), mantle cell lymphoma (MCL; n = 82) and T cell lymphoma (TCL; n = 92). We observed associations with DLBCL for elevated sCD27 [OR for third vs first tertile (ORT3 ) = 2.2, 95% CI = 1.6-3.1], sCD30 (ORT3  = 2.0, 95% CI = 1.6-2.5) and CXCL13 (ORT3  = 2.3, 95% CI = 1.8-3.0). We also observed associations with sCD27 for CLL/SLL (ORT3  = 3.3, 95% CI = 2.4-4.6), MZL (ORT3  = 7.7, 95% CI = 3.0-20.1) and TCL (ORT3  = 3.4, 95% CI = 1.5-7.7), and between sCD30 and FL (ORT3  = 2.7, 95% CI = 2.0-3.5). In analyses stratified by time from phlebotomy to case diagnosis, the sCD27-TCL and all three DLBCL associations were equivalent across both follow-up periods (<7.5, ≥7.5 years). For other analyte-subtype comparisons, associations were stronger for the follow-up period closer to phlebotomy, particularly for indolent subtypes. In conclusion, we found robust evidence of an association between these immune markers and DLBCL, consistent with hypotheses that mechanisms related to immune activation are important in its pathogenesis. Our other findings, particularly for the rarer subtypes MZL and TCL, require further investigation.

High serum magnesium is associated with lower risk of hepatocellular carcinoma among patients with nonalcoholic fatty liver disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a major contributor to the rising incidence of hepatocellular carcinoma (HCC). Magnesium is a major cation in cellular activities. Epidemiological data on magnesium level and its relation to HCC are sparse. This study aimed to examine the associations between serum levels of magnesium and the risk of HCC among patients with NAFLD. METHODS: A total of 26,053 patients with NAFLD were identified in the University of Pittsburgh Medical Center Electronic Health Records from 2004 through 2018. After an average of 5.15 years of follow-up, 395 patients developed HCC after the first measurement of serum magnesium. Cox proportional hazards regression model was used to calculate hazard ratios (HRs) and 95% CIs of HCC incidence associated with quartile levels of serum magnesium after adjustment for age, sex, race, body mass index, diuretics use, history of type 2 diabetes, history of hypertension, history of hyperlipidemia, and tobacco smoking. RESULTS: Patients with NAFLD who developed HCC had a significantly lower mean (± standard deviation) serum magnesium (0.769 ± 0.131 mmol/L) than those who remained free of HCC (0.789 ± 0.125 mmol/L; p = .003). Compared with the lowest quartile, the HRs (95% CIs) of HCC second, third, and fourth quartiles of serum magnesium were 0.87 (0.67-1.12), 0.77 (0.57-1.04), and 0.73 (0.56-0.96), respectively, after adjustment for multiple potential confounders (P trend  = .02). CONCLUSION: This finding suggests higher levels of serum magnesium were significantly associated with decreased risk of HCC among patients with NAFLD.

Soluble CD137 and risk of hepatocellular carcinoma: nested case-control studies in cohorts in Shanghai and Singapore.

BACKGROUND: The majority of hepatocellular carcinoma (HCC) cases occur in the presence of cirrhosis. Biomarkers of cirrhosis-associated immune dysfunction such as CD8+ T cell cytokines could aid HCC risk assessment. METHODS: CD8+ T cell cytokines were determined in pre-diagnostic serum in two studies including 315 HCC case-control pairs in the Shanghai Cohort Study (SCS) and 197 pairs in the Singapore Chinese Health Study (SCHS). Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for HCC with levels of five cytokines-soluble CD137 (sCD137), soluble Fas (sFas), perforin, macrophage inflammatory protein 1-beta (MIP-1ß), and tumour necrosis factor alpha (TNF-α). RESULTS: sCD137 levels were significantly higher in HCC cases than controls in both cohorts (Ps < 0.001). Compared with the lowest quartile, multivariable-adjusted ORs (95% CI) of HCC for the highest sCD137 quartile were 3.79 (1.73, 8.30) in the SCS and 3.49 (1.44, 8.48) in the SCHS. The sCD137-HCC association was independent of hepatitis B seropositivity and follow-up time. No other cytokine was consistently associated with HCC risk. CONCLUSION: sCD137 was associated with higher risk of HCC in two studies nested in general population cohorts. sCD137 may be a long-term risk marker of HCC development.

Increased BMI and late-life mobility dysfunction; overlap of genetic effects in brain regions.

BACKGROUND: How obesity earlier in life impacts upon mobility dysfunctions in late life is not well understood. Pernicious effects of excess weight on the musculoskeletal system and mobility dysfunctions are well-recognized. However, increasingly more data support the link of obesity to overall motor defects that are regulated in the brain. OBJECTIVES: To assess the causal relationship between body mass index (BMI) at midlife and performance of the Timed Up-and-Go test (TUG) in late life among a population-based longitudinal cohort of Chinese adults living in Singapore. METHODS: We evaluated genetic predispositions for BMI in 8342 participants who were followed up from measurement of BMI at average 53 years, to TUG test (as a functional mobility measure) 20 years later. RESULTS: A robust 75.83% of genetically determined BMI effects on late-life TUG scores were mediated through midlife BMI (Pindirect-effect = 9.24 × 10-21). Utilizing Mendelian randomization, we demonstrated a causal effect between BMI and functional mobility in late life (ßIVW = 0.180, PIVW = 0.001). Secondary gene enrichment evaluations highlighted down-regulation of genes at BMI risk loci that were correlated with poorer functional mobility in the substantia nigra and amygdala regions as compared to all other tissues. These genes also exhibit differential expression patterns during human brain development. CONCLUSIONS: We report a causal effect of obesity on mobility dysfunction. Our findings highlight potential neuronal dysfunctions in regulating predispositions on the causal pathway from obesity to mobility dysfunction.

Circulating IL-10 is associated with reduced risk of prostate cancer in a prospective cohort of elderly men: the MrOS Study.

PURPOSE: Prostate cancer (PCa) is the most commonly diagnosed cancer in men, resulting in a large cancer burden given a relatively higher 5-year survival rate of patients after cancer diagnosis. The underlying etiology of prostate cancer is not well understood. Chronic inflammation plays a significant role in carcinogenesis overall and may be involved in the development of PCa, but immune-related biomarker studies in prostate cancer are limited. METHODS: The associations of serum concentrations of cytokines, systemic immune biomarkers, with risk of PCa were assessed in a randomly selected sub-cohort (n = 798, mean age = 73 years) of the Osteoporotic Fractures in Men (MrOS) study, a prospective cohort of older men. At baseline, we measured serum interleukin (IL)-6, C-reactive protein (CRP), tumor necrosis factor alpha (TNFα), soluble receptors (SR) of IL-6 (IL-6SR) and TNF (TNFαSR1 and TNFαSR2), and IL-10. The risk of PCa was calculated for higher tertile levels of measured individual cytokines relative to the lowest tertile using Cox proportional hazards regression models. RESULTS: After an average 6 years of follow-up, 59 men developed incident PCa. Men in the middle or highest tertile of IL-10 had a statistically significant 50% lower risk of PCa compared to the lowest tertile (hazard ratio = 0.50, 95% confidence interval = 0.30-0.84). There was no significant association between any of the other cytokines measured and PCa risk. CONCLUSION: IL-10, an anti-inflammatory cytokine, was associated with lower risk of PCa. Further research of IL-10 and inflammation in relation to PCa development is warranted.

Quantitation by Liquid Chromatography-Nanoelectrospray Ionization-High-Resolution Tandem Mass Spectrometry of Multiple DNA Adducts Related to Cigarette Smoking in Oral Cells in the Shanghai Cohort Study.

We developed a liquid chromatography-nanoelectrospray ionization-high-resolution tandem mass spectrometry (LC-NSI-HRMS/MS) method for simultaneous quantitative analysis of 5 oral cell DNA adducts associated with cigarette smoking: (8R/S)-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purine-10(3H)-one (γ-OH-Acr-dGuo, 1) from acrolein; (6S,8S and 6R,8R)-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxy-6-methylpyrimido[1,2-a]purine-10(3H)-one [(6S,8S)γ-OH-Cro-dGuo, 2; and (6R,8R)γ-OH-Cro-dGuo, 3] from crotonaldehyde; 1,N6-etheno-dAdo (4) from acrylonitrile, vinyl chloride, lipid peroxidation, and inflammation; and 8-oxo-dGuo (5) from oxidative damage. Oral cell DNA was isolated in the presence of glutathione to prevent artifact formation. Clear LC-NSI-HRMS/MS chromatograms were obtained allowing quantitation of each adduct using the appropriately labeled internal standards. The accuracy and precision of the method were validated, and the assay limit of quantitation was 5 fmol/µmol dGuo for adducts 1-4 and 20 fmol/µmol for adduct 5. The assay was applied to 80 buccal cell samples selected from those collected in the Shanghai Cohort Study: 40 from current smokers and 40 from never smokers. Significant differences were found in all adduct levels between smokers and nonsmokers. Levels of 8-oxo-dGuo (5) were at least 3000 times greater than those of the other adducts in both smokers and nonsmokers, and the difference between amounts of this adduct in smokers versus nonsmokers, while significant (P = 0.013), was not as great as the differences of the other DNA adducts between smokers and nonsmokers (P-values all less than 0.001). No significant relationship of adduct levels to risk of lung cancer incidence was found. This study provides a new LC-NSI-HRMS/MS methodology for the quantitation of diverse DNA adducts resulting from exposure to the α,ß-unsaturated aldehydes acrolein and crotonaldehyde, inflammation, and oxidative damage which are all associated with carcinogenesis. We anticipate application of this assay in ongoing studies of the molecular epidemiology of cancers of the lung and oral cavity related to cigarette smoking.

Re-scaling and small area estimation of behavioral risk survey guided by social vulnerability data.

BACKGROUND: Local governments and other public health entities often need population health measures at the county or subcounty level for activities such as resource allocation and targeting public health interventions, among others. Information collected via national surveys alone cannot fill these needs. We propose a novel, two-step method for rescaling health survey data and creating small area estimates (SAEs) of smoking rates using a Behavioral Risk Factor Surveillance System survey administered in 2015 to participants living in Allegheny County, Pennsylvania, USA. METHODS: The first step consisted of a spatial microsimulation to rescale location of survey respondents from zip codes to tracts based on census population distributions by age, sex, race, and education. The rescaling allowed us, in the second step, to utilize available census tract-specific ancillary data on social vulnerability for small area estimation of local health risk using an area-level version of a logistic linear mixed model. To demonstrate this new two-step algorithm, we estimated the ever-smoking rate for the census tracts of Allegheny County. RESULTS: The ever-smoking rate was above 70% for two census tracts to the southeast of the city of Pittsburgh. Several tracts in the southern and eastern sections of Pittsburgh also had relatively high (> 65%) ever-smoking rates. CONCLUSIONS: These SAEs may be used in local public health efforts to target interventions and educational resources aimed at reducing cigarette smoking. Further, our new two-step methodology may be extended to small area estimation for other locations and health outcomes.

Integration of multiomic annotation data to prioritize and characterize inflammation and immune-related risk variants in squamous cell lung cancer.

Clinical trial results have recently demonstrated that inhibiting inflammation by targeting the interleukin-1ß pathway can offer a significant reduction in lung cancer incidence and mortality, highlighting a pressing and unmet need to understand the benefits of inflammation-focused lung cancer therapies at the genetic level. While numerous genome-wide association studies (GWAS) have explored the genetic etiology of lung cancer, there remains a large gap between the type of information that may be gleaned from an association study and the depth of understanding necessary to explain and drive translational findings. Thus, in this study we jointly model and integrate extensive multiomics data sources, utilizing a total of 40 genome-wide functional annotations that augment previously published results from the International Lung Cancer Consortium (ILCCO) GWAS, to prioritize and characterize single nucleotide polymorphisms (SNPs) that increase risk of squamous cell lung cancer through the inflammatory and immune responses. Our work bridges the gap between correlative analysis and translational follow-up research, refining GWAS association measures in an interpretable and systematic manner. In particular, reanalysis of the ILCCO data highlights the impact of highly associated SNPs from nuclear factor-κB signaling pathway genes as well as major histocompatibility complex mediated variation in immune responses. One consequence of prioritizing likely functional SNPs is the pruning of variants that might be selected for follow-up work by over an order of magnitude, from potentially tens of thousands to hundreds. The strategies we introduce provide informative and interpretable approaches for incorporating extensive genome-wide annotation data in analysis of genetic association studies.

Composite dietary antioxidant index and the risk of colorectal cancer: Findings from the Singapore Chinese Health Study.

Colorectal cancer (CRC) is a major contributor to cancer death globally. Several studies showed some protections by certain individual dietary antioxidants against CRC development. Epidemiologic data on the composite dietary antioxidant index (CDAI) in relation to CRC risk are sparse. Using the Singapore Chinese Health Study, an ongoing prospective cohort consisting of 61 321 cancer-free participants aged 45 to 74 years at baseline, a food-based CDAI was calculated according to a previously established and validated method that included six food-sourced antioxidants including vitamins A, C and E, manganese, selenium and zinc. Cox proportional hazard regression method was used to estimate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for CRC associated with various levels of CDAI with adjustment for multiple potential confounders. After an average of 17.5 years of follow-up, 2140 participants developed CRC. HRs (95% CIs) of CRC for quartiles 2, 3 and 4 of CDAI were 0.94 (0.83-1.07), 0.86 (0.75-1.00) and 0.80 (0.66-0.98), respectively, compared to the lowest quartile (Ptrend  = .02). This inverse association between CDAI and CRC risk was more apparent in women or those without a history of diabetes, without family history of CRC, never smokers or overweight/obese individuals. However, none of the heterogeneity tests for the CDAI-CRC risk association reached statistical significance. Our findings suggest that food-based antioxidants may be beneficial for reducing the risk of CRC in the general population.

Overlap of high-risk individuals predicted by family history, and genetic and non-genetic breast cancer risk prediction models: implications for risk stratification.

BACKGROUND: Family history, and genetic and non-genetic risk factors can stratify women according to their individual risk of developing breast cancer. The extent of overlap between these risk predictors is not clear. METHODS: In this case-only analysis involving 7600 Asian breast cancer patients diagnosed between age 30 and 75 years, we examined identification of high-risk patients based on positive family history, the Gail model 5-year absolute risk [5yAR] above 1.3%, breast cancer predisposition genes (protein-truncating variants [PTV] in ATM, BRCA1, BRCA2, CHEK2, PALB2, BARD1, RAD51C, RAD51D, or TP53), and polygenic risk score (PRS) 5yAR above 1.3%. RESULTS: Correlation between 5yAR (at age of diagnosis) predicted by PRS and the Gail model was low (r=0.27). Fifty-three percent of breast cancer patients (n=4041) were considered high risk by one or more classification criteria. Positive family history, PTV carriership, PRS, or the Gail model identified 1247 (16%), 385 (5%), 2774 (36%), and 1592 (21%) patients who were considered at high risk, respectively. In a subset of 3227 women aged below 50 years, the four models studied identified 470 (15%), 213 (7%), 769 (24%), and 325 (10%) unique patients who were considered at high risk, respectively. For younger women, PRS and PTVs together identified 745 (59% of 1276) high-risk individuals who were not identified by the Gail model or family history. CONCLUSIONS: Family history and genetic and non-genetic risk stratification tools have the potential to complement one another to identify women at high risk.