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Cancer Res ; 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33472890


Lung cancer is the leading cause of cancer death globally. An improved risk stratification strategy can increase efficiency of low-dose computed tomography (LDCT) screening. Here we assessed whether individual's genetic background has clinical utility for risk stratification in the context of LDCT screening. Based on 13,119 lung cancer patients and 10,008 controls with European ancestry in the International Lung Cancer Consortium, we constructed a polygenic risk score (PRS) via 10-fold cross-validation with regularized penalized regression. The performance of risk model integrating PRS, including calibration and ability to discriminate, was assessed using UK biobank data (N=335,931). Absolute risk was estimated based on age-specific lung cancer incidence and all-cause mortality as competing risk. To evaluate its potential clinical utility, the PRS distribution was simulated in the National Lung Screening Trial, N=50,772 participants). The lung cancer odds ratio (ORs) for individuals at the top decile of the PRS distribution versus those at bottom 10% was 2.39 (95%CI=1.92-3.00, P=1.80x10-14) in the validation set (trend p-value of 5.26 x 10-20). The OR per standard deviation of PRS increase was 1.26 (95%CI=1.20-1.32, P=9.69x10-23) for overall lung cancer risk in the validation set. When considering absolute risks, individuals at different PRS deciles showed differential trajectories of 5-year and cumulative absolute risk. The age reaching the LDCT screening recommendation threshold can vary by 4 to 8 years, depending on the individual's genetic background, smoking status and family history. Collectively, these results suggest that Individual's genetic background may inform the optimal lung cancer LDCT screening strategy.

Nat Commun ; 11(1): 27, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31911640


Impaired lung function is often caused by cigarette smoking, making it challenging to disentangle its role in lung cancer susceptibility. Investigation of the shared genetic basis of these phenotypes in the UK Biobank and International Lung Cancer Consortium (29,266 cases, 56,450 controls) shows that lung cancer is genetically correlated with reduced forced expiratory volume in one second (FEV1: rg = 0.098, p = 2.3 × 10-8) and the ratio of FEV1 to forced vital capacity (FEV1/FVC: rg = 0.137, p = 2.0 × 10-12). Mendelian randomization analyses demonstrate that reduced FEV1 increases squamous cell carcinoma risk (odds ratio (OR) = 1.51, 95% confidence intervals: 1.21-1.88), while reduced FEV1/FVC increases the risk of adenocarcinoma (OR = 1.17, 1.01-1.35) and lung cancer in never smokers (OR = 1.56, 1.05-2.30). These findings support a causal role of pulmonary impairment in lung cancer etiology. Integrative analyses reveal that pulmonary function instruments, including 73 novel variants, influence lung tissue gene expression and implicate immune-related pathways in mediating the observed effects on lung carcinogenesis.

Neoplasias Pulmonares/genética , Pulmão/fisiopatologia , Adulto , Idoso , Feminino , Volume Expiratório Forçado , Predisposição Genética para Doença , Humanos , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/fisiopatologia , Masculino , Análise da Randomização Mendeliana , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Testes de Função Respiratória , Capacidade Vital
EBioMedicine ; 47: 58-64, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31495719


BACKGROUND: Impaired lung health represents a significant burden on global health, including chronic obstructive pulmonary disease (COPD) and lung cancer. Given its global health impact, it is important to understand the determinants of impaired lung function and its relation to lung cancer risk independent of smoking. However, to date, no study has evaluated determinants of impaired lung function in a cohort exclusively of never-smokers, who also represent a growing proportion of all lung cancers. METHODS: A total of 222,274 never-smokers with reproducible spirograms were identified in the UK Biobank population-based cohort and included in the analysis. Baseline volumetric measures of lung function, including forced expiratory volume in 1-s (FEV1) and forced vital capacity (FVC), were used to define lung function impairment. Determinants of impaired lung function were evaluated using Poisson regression with robust variance estimation. The added value of lung function in lung cancer prediction was evaluated using Fine and Gray regression accounting for the competing risk of all-cause mortality. FINDINGS: Lung function impairment was associated with low birthweight, ambient air pollution (PM2·5 µg/mm3), and overweight, after adjustment for other important risk factors. We observed modest improvement in discrimination by adding lung function to our lung cancer prediction model for never-smokers. The highest optimism-corrected AUC at 3 (0·700, 95% CI: 0·654-0·734) and 5 years (0·694, 95% CI: 0·658-0·736) included FEV1 (% of GLI predicted FEV1), while the highest AUC at 7 years was based on the inclusion of FEV1/FVC (0·722, 95% CI: 0·687-0·762). INTERPRETATION: We identified several modifiable risk factors associated with increased risk of lung function impairment among lifetime never-smokers in UKB. We achieved moderate discrimination for lung cancer risk-prediction for never-smokers, and found modest improvement with the inclusion of lung function. FUND: This study was supported by a Canada Research Chair to RJH.

Neoplasias Pulmonares/epidemiologia , Testes de Função Respiratória , Fumantes , Adulto , Idoso , Bancos de Espécimes Biológicos , Biomarcadores , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Testes de Função Respiratória/métodos , Testes de Função Respiratória/estatística & dados numéricos , Tomografia Computadorizada por Raios X
Cancer Epidemiol ; 53: 12-20, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29353151


PURPOSE: Regular recreational moderate to vigorous physical activity (rMVPA) has been previously associated with a reduced risk of colorectal cancer (CRC), however, few studies have examined the association of rMVPA with colorectal polyps, the pre-malignant precursor lesions. The objective of this study was to examine the associations between physical activity and sitting time and polyps at the time of screening. METHODS: We conducted a cross-sectional study of 2496 individuals undergoing screening-related colonoscopy in Calgary, Alberta, Canada. Physical activity and sitting time were characterized using hours of rMVPA, meeting physical activity recommendations and hours of sitting time using self-reported data obtained from the International Physical Activity Questionnaire. Logistic regression models were used to estimate the crude and adjusted odds ratios (OR) for presence of polyps associated with rMVPA and sitting time. RESULTS: Meeting physical activity guidelines of ≥150 min/week was non-significantly associated with a modest decrease in odds of having ≥1 polyp at screening (ORadj = 0.95, 95% CI: 0.80-1.14). In males, threshold effects for sitting time were observed for up to 20 h/week (ORadj per hour sitting = 1.07, 95% CI: 1.01-1.13). In stratified analysis, larger inverse associations were observed between physical activity and the presence of polyps in females, obese individuals, and ever smokers, compared to pooled findings. CONCLUSIONS: In this large CRC screening population, there was a suggestive association between increased rMVPA and reduced prevalence of polyps at screening, particularly among females. Even low amounts of regular sitting time (0-20 h/day) were associated with the presence of polyps, particularly among males. Further research on rMVPA and sitting time is necessary to better inform strategies to reduce the frequency of pre-malignant colorectal lesions.

Pólipos do Colo/epidemiologia , Exercício Físico/fisiologia , Idoso , Canadá/epidemiologia , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Razão de Chances , Prevalência , Fatores de Risco
JNCI Cancer Spectr ; 2(1): pkx010, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31360836


Background: A small proportion of non-small cell lung cancers (NSCLCs) have been observed to spread to distant lymph nodes (N3) or metastasize (M1) or both, while the primary tumor is small (≤3 cm, T1). These small aggressive NSCLCs (SA-NSLSC) are important as they are clinically significant, may identify unique biologic pathways, and warrant aggressive follow-up and treatment. This study identifies factors associated with SA-NSCLC and attempts to validate a previous finding that women with a family history of lung cancer are at particularly elevated risk of SA-NSCLC. Methods: This study used a case-case design within the National Cancer Institute's National Lung Screening Trial (NLST) cohort. Case patients and "control" patients were selected based on TNM staging parameters. Case patients (n = 64) had T1 NSCLCs that were N3 or M1 or both, while "control" patients (n = 206) had T2 or T3, N0 to N2, and M0 NSCLCs. Univariate and multivariable logistic regression were used to identify factors associated with SA-NSCLC. Results: In bootstrap bias-corrected multivariable logistic regression models, small aggressive adenocarcinomas were associated with a positive history of emphysema (odds ratio [OR] = 5.15, 95% confidence interval [CI] = 1.63 to 23.00) and the interaction of female sex and a positive family history of lung cancer (OR = 6.55, 95% CI = 1.06 to 50.80). Conclusions: Emphysema may play a role in early lung cancer progression. Females with a family history of lung cancer are at increased risk of having small aggressive lung adenocarcinomas. These results validate previous findings and encourage research on the role of female hormones interacting with family history and genetic factors in lung carcinogenesis and progression.

J Epidemiol Community Health ; 71(10): 961-969, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28847844


BACKGROUND: There is suggestive evidence that increased intake of dietary fibre and the use of non-steroidal anti-inflammatory drugs (NSAIDs) are generally associated with decreased colorectal cancer risk. However, the effects on precursors of colorectal cancer, such as adenomatous polyps, are mixed. We present the associations between dietary fibre intake and NSAID use on the presence and type of colorectal polyps in a screening population. METHODS: A cross-sectional study of 2548 individuals undergoing colonoscopy at the Forzani & MacPhail Colon Cancer Screening Centre (Calgary, Canada) was conducted. Dietary fibre intake and NSAID use were assessed using the Diet History Questionnaire I or II and the Health and Lifestyle Questionnaire. Colorectal outcomes were documented as a polyp or high-risk adenomatous polyp (HRAP; villous histology, high-grade dysplasia, ≥10 mm or ≥3 adenomas). Crude and ORs and 95% CIs were estimated using unconditional logistic regression. RESULTS: There were 1450 negative colonoscopies and 1098 patients with polyps, of which 189 patients had HRAPs. Total dietary fibre intake was associated with a decreased presence of HRAPs (OR=0.50, 95% CI: 0.29 to 0.86) when comparing the highest to lowest quartiles and was observed with both soluble (OR=0.51, 95% CI: 0.30 to 0.88) and insoluble (OR=0.51, 95% CI: 0.30 to 0.86) fibres. Ever use of NSAIDs was also inversely associated with HRAPs (OR=0.65, 95% CI: 0.47 to 0.89), observed with monthly (OR=0.60, 95% CI: 0.37 to 0.95) and daily (OR=0.53, 95% CI: 0.32 to 0.86) use. CONCLUSIONS: Dietary fibre intake and NSAID use were associated with a decreased risk of having a HRAP at screening.

Adenoma/prevenção & controle , Pólipos Adenomatosos/prevenção & controle , Anti-Inflamatórios não Esteroides/administração & dosagem , Neoplasias Colorretais/prevenção & controle , Fibras na Dieta , Pólipos Adenomatosos/epidemiologia , Pólipos Adenomatosos/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios não Esteroides/uso terapêutico , Canadá/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/etiologia , Estudos Transversais , Relação Dose-Resposta a Droga , Feminino , Humanos , Incidência , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e Questionários