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1.
J Epidemiol Glob Health ; 14(2): 420-432, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38598163

ABSTRACT

Body shape phenotypes combining multiple anthropometric traits have been linked to postmenopausal breast cancer (BC). However, underlying biological pathways remain poorly understood. This study investigated to what extent the associations of body shapes with postmenopausal BC risk is mediated by biochemical markers. The study included 176,686 postmenopausal women from UK Biobank. Four body shape phenotypes were derived from principal component (PC) analysis of height, weight, body mass index, waist and hip circumferences, and waist-to-hip ratio (WHR). The four-way decomposition of the total effect was used to estimate mediation and interaction effects simultaneously as well as the mediated proportions. After 10.9 years median follow-up, 6,396 incident postmenopausal BC were diagnosed. There was strong evidence of positive associations between PC1 (general obesity) and PC2 (tall, low WHR), and BC risk. The association of PC1 with BC risk was positively mediated by testosterone and negatively by insulin-like growth factor-1 (IGF-1), with the overall proportion mediated (sum of the mediated interaction and pure indirect effect (PIE)) accounting for 11.4% (95% confidence intervals: 5.1 to 17.8%) and -12.2% (-20.5% to -4.0%) of the total effect, respectively. Small proportions of the association between PC2 and BC were mediated by IGF-1 (PIE: 2.8% (0.6 to 4.9%)), and sex hormone-binding globulin (SHBG) (PIE: -6.1% (-10.9% to -1.3%)). Our findings are consistent with differential pathways linking different body shapes with BC risk, with a suggestive mediation through testosterone and IGF-1 in the relationship of a generally obese body shape and BC risk, while IGF-1 and SHBG may mediate a tall/lean body shape-BC risk association.


Subject(s)
Biological Specimen Banks , Breast Neoplasms , Phenotype , Postmenopause , Humans , Female , Breast Neoplasms/epidemiology , United Kingdom/epidemiology , Middle Aged , Aged , Mediation Analysis , Risk Factors , Cohort Studies , Body Mass Index , Waist-Hip Ratio , Somatotypes , Insulin-Like Growth Factor I/metabolism , Insulin-Like Growth Factor I/analysis , UK Biobank
2.
Environ Pollut ; 351: 124043, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38679129

ABSTRACT

Studies suggested that exposure to air pollutants, with endocrine disrupting (ED) properties, have a key role in breast cancer (BC) development. Although the population is exposed simultaneously to a mixture of multiple pollutants and ED pollutants may act via common biological mechanisms leading to synergic effects, epidemiological studies generally evaluate the effect of each pollutant separately. We aimed to assess the complex effect of exposure to a mixture of four xenoestrogen air pollutants (benzo-[a]-pyrene (BaP), cadmium, dioxin (2,3,7,8-Tétrachlorodibenzo-p-dioxin TCDD)), and polychlorinated biphenyl 153 (PCB153)) on the risk of BC, using three recent statistical methods, namely weighted quantile sum (WQS), quantile g-computation (QGC) and Bayesian kernel machine regression (BKMR). The study was conducted on 5222 cases and 5222 matched controls nested within the French prospective E3N cohort initiated in 1990. Annual average exposure estimates to the pollutants were assessed using a chemistry transport model, at the participants' residence address between 1990 and 2011. We found a positive association between the WQS index of the joint effect and the risk of overall BC (adjusted odds ratio (OR) = 1.10, 95% confidence intervals (CI): 1.03-1.19). Similar results were found for QGC (OR = 1.11, 95%CI: 1.03-1.19). Despite the association did not reach statistical significance in the BKMR model, we observed an increasing trend between the joint effect of the four pollutants and the risk of BC, when fixing other chemicals at their median concentrations. BaP, cadmium and PCB153 also showed positive trends in the multi-pollutant mixture, while dioxin showed a modest inverse trend. Despite we found a clear evidence of a positive association between the joint exposure to pollutants and BC risk only from WQS and QGC regression, we observed a similar suggestive trend using BKMR. This study makes a major contribution to the understanding of the joint effects of air pollution.


Subject(s)
Air Pollutants , Breast Neoplasms , Cadmium , Endocrine Disruptors , Environmental Exposure , Polychlorinated Biphenyls , Humans , Breast Neoplasms/epidemiology , Breast Neoplasms/chemically induced , Female , Air Pollutants/analysis , Environmental Exposure/statistics & numerical data , Middle Aged , Bayes Theorem , Benzo(a)pyrene , Aged , Polychlorinated Dibenzodioxins , France/epidemiology , Adult
3.
Cancers (Basel) ; 15(3)2023 Feb 01.
Article in English | MEDLINE | ID: mdl-36765887

ABSTRACT

Current evidence of an association of breast cancer (BC) risk with air pollution exposure, in particular from traffic exhaust, remains inconclusive, and the exposure assessment methodologies are heterogeneous. This study aimed to conduct a systematic review and meta-analysis on the association between traffic-related air pollution (TRAP) and BC incidence (PROSPERO CRD42021286774). We systematically reviewed observational studies assessing exposure to TRAP and BC risk published until June 2022, available on Medline/PubMed and Web of Science databases. Studies using models for assessing exposure to traffic-related air pollutants or using exposure proxies (including traffic density, distance to road, etc.) were eligible for inclusion. A random-effects meta-analysis of studies investigating the association between NO2/NOx exposure and BC risk was conducted. Overall, 21 studies meeting the inclusion criteria were included (seven case-control, one nested case-control, 13 cohort studies); 13 studies (five case-control, eight cohort) provided data for inclusion in the meta-analyses. Individual studies provided little evidence of an association between TRAP and BC risk; exposure assessment methods and time periods of traffic emissions were different. The meta-estimate on NO2 exposure indicated a positive association (pooled relative risk per 10 µg/m3 of NO2: 1.015; 95% confidence interval, CI: 1.003; 1.028). No association between NOx exposure and BC was found (three studies). Although there was limited evidence of an association for TRAP estimated with proxies, the meta-analysis showed a significant association between NO2 exposure, a common TRAP pollutant marker, and BC risk, yet with a small effect size. Our findings provide additional support for air pollution carcinogenicity.

4.
Environ Pollut ; 317: 120719, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36435283

ABSTRACT

Nitrogen dioxide (NO2) is an important air pollutant due to its adverse effects on human health. Yet, current evidence on the association between NO2 and the risk of breast cancer lacks consistency. In this study, we investigated the association between long-term exposure to NO2 and breast cancer risk in the French E3N cohort study. Association of breast cancer risk with NO2 exposure was assessed in a nested case-control study within the French E3N cohort including 5222 breast cancer cases identified over the 1990-2011 follow-up period and 5222 matched controls. Annual mean concentrations of NO2 at participants' residential addresses for each year from recruitment 1990 through 2011, were estimated using a land use regression (LUR) model. Multivariable conditional logistic regression models were used to compute odds ratios (ORs) and their 95% confidence intervals (CIs). Additional analyses were performed using NO2 concentrations estimated by CHIMERE, a chemistry transport model. Overall, the mean NO2 exposure was associated with an increased risk of breast cancer. In all women, for each interquartile range (IQR) increase in NO2 levels (LUR: 17.8 µg/m3), the OR of the model adjusted for confounders was 1.09 (95% CI: 1.01-1.18). The corresponding OR in the fully adjusted model (additionally adjusted for established breast cancer risk factors) was 1.07 (95% CI: 0.98-1.15). By menopausal status, results for postmenopausal women were comparable to those for all women, while no association was observed among premenopausal women. By hormone receptor status, the OR of estrogen receptor positive breast cancer = 1.07 (95% CI: 0.97-1.19) in the fully adjusted model. Additional analyses using the CHIMERE model showed slight differences in ORs estimates. The results of this study indicate an increased risk of breast cancer associated with long-term exposure to NO2 air pollution. Observing comparable effects of NO2 exposure estimated by two different models, reinforces these findings.


Subject(s)
Air Pollutants , Air Pollution , Breast Neoplasms , Humans , Female , Nitrogen Dioxide/analysis , Cohort Studies , Breast Neoplasms/chemically induced , Breast Neoplasms/epidemiology , Case-Control Studies , Environmental Exposure/adverse effects , Environmental Exposure/analysis , Air Pollution/adverse effects , Air Pollution/analysis , Air Pollutants/analysis , Particulate Matter/analysis
5.
Br J Cancer ; 128(4): 594-605, 2023 02.
Article in English | MEDLINE | ID: mdl-36460776

ABSTRACT

BACKGROUND: Classical anthropometric traits may fail to fully represent the relationship of weight, adiposity, and height with cancer risk. We investigated the associations of body shape phenotypes with the risk of overall and site-specific cancers. METHODS: We derived four distinct body shape phenotypes from principal component (PC) analysis on height, weight, body mass index (BMI), waist (WC) and hip circumferences (HC), and waist-to-hip ratio (WHR). The study included 340,152 men and women from 9 European countries, aged mostly 35-65 years at recruitment (1990-2000) in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: After a median follow-up of 15.3 years, 47,110 incident cancer cases were recorded. PC1 (overall adiposity) was positively associated with the risk of overall cancer, with a HR per 1 standard deviation (SD) increment equal to 1.07 (95% confidence interval 1.05 to 1.08). Positive associations were observed with 10 cancer types, with HRs (per 1 SD) ranging from 1.36 (1.30-1.42) for endometrial cancer to 1.08 (1.03-1.13) for rectal cancer. PC2 (tall stature with low WHR) was positively associated with the risk of overall cancer (1.03; 1.02-1.04) and five cancer types which were not associated with PC1. PC3 (tall stature with high WHR) was positively associated with the risk of overall cancer (1.04; 1.03-1.05) and 12 cancer types. PC4 (high BMI and weight with low WC and HC) was not associated with overall risk of cancer (1.00; 0.99-1.01). CONCLUSIONS: In this multi-national study, distinct body shape phenotypes were positively associated with the incidence of 17 different cancers and overall cancer.


Subject(s)
Rectal Neoplasms , Somatotypes , Humans , Female , Cohort Studies , Prospective Studies , Risk Factors , Waist Circumference , Obesity/epidemiology , Adiposity , Body Mass Index , Waist-Hip Ratio , Phenotype , Proportional Hazards Models
6.
World J Hepatol ; 14(9): 1767-1777, 2022 Sep 27.
Article in English | MEDLINE | ID: mdl-36185725

ABSTRACT

BACKGROUND: Primary liver cancer is common in West Africa due to endemic risk factors. However, epidemiological studies of the global burden and trends of liver cancer are limited. We report changes in trends of the incidence of liver cancer over a period of 28 years using the population-based cancer registry of Bamako, Mali. AIM: To assess the trends and patterns of liver cancer by gender and age groups by analyzing the cancer registration data accumulated over 28 years (1987-2015) of activity of the population-based registry of the Bamako district. METHODS: Data obtained since the inception of the registry in 1987 through 2015 were stratified into three periods (1987-1996, 1997-2006, and 2007-2015). Age-standardized rates were estimated by direct standardization using the world population. Incidence rate ratios and the corresponding 95% confidence intervals (CI) were estimated using the early period as the reference (1987-1996). Joinpoint regression models were used to assess the annual percentage change and highlight trends over the entire period (from 1987 to 2015). RESULTS: Among males, the age-standardized incidence rates significantly decreased from 19.41 (1987-1996) to 13.12 (1997-2006) to 8.15 (2007-2015) per 105 person-years. The incidence rate ratio over 28 years was 0.42 (95%CI: 0.34-0.50), and the annual percentage change was -4.59 [95%CI: (-6.4)-(-2.7)]. Among females, rates dropped continuously from 7.02 (1987-1996) to 2.57 (2007-2015) per 105 person-years, with an incidence rate ratio of 0.37 (95%CI: 0.28-0.45) and an annual percentage change of -5.63 [95%CI: (-8.9)-(-2.3)]. CONCLUSION: The population-based registration showed that the incidence of primary liver cancer has steadily decreased in the Bamako district over 28 years. This trend does not appear to result from biases or changes in registration practices. This is the first report of such a decrease in an area of high incidence of liver cancer in Africa. This decrease may be explained by the changes and diversity of diet that could reduce exposure to aflatoxins through dietary contamination in this population.

7.
Eur J Epidemiol ; 37(1): 79-93, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34254231

ABSTRACT

In epidemiology, left-truncated data may bias exposure effect estimates. We analyzed the bias induced by left truncation in estimating breast cancer risk associated with exposure to airborne dioxins. Simulations were run with exposure estimates from a Geographic Information System (GIS)-based metric and considered two hypotheses for historical exposure, three scenarios for intra-individual correlation of annual exposures, and three exposure-effect models. For each correlation/model combination, 500 nested matched case-control studies were simulated and data fitted using a conditional logistic regression model. Bias magnitude was assessed by estimated odds-ratios (ORs) versus theoretical relative risks (TRRs) comparisons. With strong intra-individual correlation and continuous exposure, left truncation overestimated the Beta parameter associated with cumulative dioxin exposure. Versus a theoretical Beta of 4.17, the estimated mean Beta (5%; 95%) was 73.2 (67.7; 78.8) with left-truncated exposure and 4.37 (4.05; 4.66) with lifetime exposure. With exposure categorized in quintiles, the TRR was 2.0, the estimated ORQ5 vs. Q1 2.19 (2.04; 2.33) with truncated exposure versus 2.17 (2.02; 2.32) with lifetime exposure. However, the difference in exposure between Q5 and Q1 was 18× smaller with truncated data, indicating an important overestimation of the dose effect. No intra-individual correlation resulted in effect dilution and statistical power loss. Left truncation induced substantial bias in estimating breast cancer risk associated with exposure with continuous and categorical models. With strong intra-individual exposure correlation, both models detected associations, but categorical models provided better estimates of effect trends. This calls for careful consideration of left truncation-induced bias in interpreting environmental epidemiological data.


Subject(s)
Breast Neoplasms , Dioxins , Breast Neoplasms/chemically induced , Breast Neoplasms/epidemiology , Case-Control Studies , Dioxins/toxicity , Female , Humans , Odds Ratio , Risk
8.
Sci Rep ; 11(1): 23088, 2021 11 29.
Article in English | MEDLINE | ID: mdl-34845239

ABSTRACT

Molecular studies suggest that cadmium due to its estrogenic properties, might play a role in breast cancer (BC) progression. However epidemiological evidence is limited. This study explored the association between long-term exposure to airborne cadmium and risk of BC by stage, grade of differentiation, and histological types at diagnosis. A nested case-control study of 4401 cases and 4401 matched controls was conducted within the French E3N cohort. A Geographic Information System (GIS)-based metric demonstrated to reliably characterize long-term environmental exposures was employed to evaluate airborne exposure to cadmium. Multivariable adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression models. There was no relationship between cadmium exposure and stage of BC. Also, no association between cadmium exposure and grade of differentiation of BC was observed. However, further analyses by histological type suggested a positive association between cadmium and risk of invasive tubular carcinoma (ITC) BC [ORQ5 vs Q1 = 3.4 (95% CI 1.1-10.7)]. The restricted cubic spline assessment suggested a dose-response relationship between cadmium and ITC BC subtype. Our results do not support the hypothesis that airborne cadmium exposure may play a role in advanced BC risk, but suggest that cadmium may be associated with an increased risk of ITC.


Subject(s)
Air Pollutants/adverse effects , Breast Neoplasms/etiology , Cadmium/adverse effects , Adult , Aged , Alcohol Drinking , Breast Neoplasms/diagnosis , Breast Neoplasms/epidemiology , Carcinoma, Ductal, Breast/diagnosis , Carcinoma, Ductal, Breast/epidemiology , Carcinoma, Ductal, Breast/etiology , Case-Control Studies , Cell Differentiation , Dose-Response Relationship, Drug , Environmental Exposure , Female , Geographic Information Systems , Humans , Middle Aged , Multivariate Analysis , Neoplasm Metastasis , Neoplasm Staging , Odds Ratio , Risk , Risk Factors
9.
Br J Cancer ; 124(11): 1882-1890, 2021 05.
Article in English | MEDLINE | ID: mdl-33772152

ABSTRACT

BACKGROUND: We investigated whether associations between prevalent diabetes and cancer risk are pertinent to older adults and whether associations differ across subgroups of age, body weight status or levels of physical activity. METHODS: We harmonised data from seven prospective cohort studies of older individuals in Europe and the United States participating in the CHANCES consortium. Cox proportional hazard regression was used to estimate the associations of prevalent diabetes with cancer risk (all cancers combined, and for colorectum, prostate and breast). We calculated summary risk estimates across cohorts using pooled analysis and random-effects meta-analysis. RESULTS: A total of 667,916 individuals were included with an overall median (P25-P75) age at recruitment of 62.3 (57-67) years. During a median follow-up time of 10.5 years, 114,404 total cancer cases were ascertained. Diabetes was not associated with the risk of all cancers combined (hazard ratio (HR) = 0.94; 95% confidence interval (CI): 0.86-1.04; I2 = 63.3%). Diabetes was positively associated with colorectal cancer risk in men (HR = 1.17; 95% CI: 1.08-1.26; I2 = 0%) and a similar HR in women (1.13; 95% CI: 0.82-1.56; I2 = 46%), but with a confidence interval including the null. Diabetes was inversely associated with prostate cancer risk (HR = 0.81; 95% CI: 0.77-0.85; I2 = 0%), but not with postmenopausal breast cancer (HR = 0.96; 95% CI: 0.89-1.03; I2 = 0%). In exploratory subgroup analyses, diabetes was inversely associated with prostate cancer risk only in men with overweight or obesity. CONCLUSIONS: Prevalent diabetes was positively associated with colorectal cancer risk and inversely associated with prostate cancer risk in older Europeans and Americans.


Subject(s)
Aging/physiology , Diabetes Mellitus/epidemiology , Neoplasms/epidemiology , Aged , Aged, 80 and over , Breast Neoplasms/epidemiology , Cohort Studies , Colorectal Neoplasms/epidemiology , Europe/epidemiology , Female , Humans , Male , Middle Aged , Prevalence , Prostatic Neoplasms/epidemiology , Risk Factors , United States/epidemiology
10.
Environ Int ; 149: 106399, 2021 04.
Article in English | MEDLINE | ID: mdl-33503556

ABSTRACT

BACKGROUND: Benzo[a]pyrene (BaP) is an endocrine-disrupting pollutant formed during incomplete combustion of organic materials. It has been recognized as a reproductive and developmental toxicant, however epidemiological evidence of the long-term effect of ambient air BaP on breast cancer (BC) is limited. Thus we evaluated associations between ambient air BaP exposure and risk of BC, overall and according to menopausal status and molecular subtypes (estrogen receptor negative/positive (ER-/ER+) and progesterone receptor negative/positive (PR-/PR+)), stage and grade of differentiation of BC in the French E3N cohort study. METHODS: Within a nested case-control study of 5222 incident BC cases and 5222 matched controls, annual BaP exposure was estimated using a chemistry-transport model (CHIMERE) and was assigned to the geocoded residential addresses of participants for each year during the 1990-2011 follow-up period. Multivariable conditional logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Overall, cumulative airborne BaP exposure was significantly associated with the overall risk of BC, for each 1 interquartile range (IQR) increase in the concentration levels of BaP (1.42 ng/m3), the OR = 1.15 (95% CI: 1.04-1.27). However, by menopausal status, the significant positive association remained only in women who underwent menopausal transition (i.e. premenopausal women at inclusion who became postmenopausal at diagnosis), OR per 1 IQR = 1.20 (95% CI: 1.03-1.40). By hormone receptor status, positive associations were observed for ER+, PR + and ER + PR + BC, with ORs = 1.17 (95% CI: 1.04-1.32), 1.16 (95% CI: 1.01-1.33), and 1.17 (95% CI: 1.01-1.36) per 1 IQR, respectively. There was also a borderline positive association between BaP and grade 3 BC (OR per 1 IQR = 1.15 (95% CI: 0.99-1.34). CONCLUSIONS: We provide evidence of increased risk of BC associated with cumulative BaP exposure, which varied according to menopausal status, hormone receptor status, and grade of differentiation of BC. Our results add further epidemiological evidence to the previous experimental studies suggesting the adverse effects of BaP.


Subject(s)
Air Pollution , Breast Neoplasms , Air Pollution/adverse effects , Benzo(a)pyrene/toxicity , Breast Neoplasms/chemically induced , Breast Neoplasms/epidemiology , Case-Control Studies , Cohort Studies , Female , Humans , Risk Factors
11.
Environ Res ; 195: 110743, 2021 04.
Article in English | MEDLINE | ID: mdl-33450235

ABSTRACT

BACKGROUND: Although the genetic and hormonal risk factors of breast cancer are well identified, they cannot fully explain the occurrence of all cases. Epidemiological and experimental studies have suggested that exposure to environmental pollutants, especially those with potential estrogenic properties, as polychlorinated biphenyls (PCBs) may have a role in breast cancer development. Being the most abundantly detected in human tissues and in the environment, congener 153 (PCB153) is widely used in epidemiological studies as indicator for total PCBs exposure. OBJECTIVES: We aimed to estimate the association between cumulative atmospheric exposure to PCB153 and breast cancer risk. METHODS: We conducted a case-control study of 5222 cases and 5222 matched controls nested within the French E3N cohort from 1990 to 2011. Annual atmospheric PCB153 concentrations were simulated with the deterministic chemistry-transport model (CHIMERE) and were assigned to women using their geocoded residential history. Their cumulative PCB153 exposure was calculated for each woman from their cohort inclusion to their index date. Breast cancer odds ratios (ORs) associated with cumulative PCB153 exposure and their 95% confidence intervals (95% CIs) were estimated using multivariate conditional logistic regression models. RESULTS: Overall, our results showed a statistically significant linear increase in breast cancer risk related to cumulative atmospheric exposure to PCB153 as a continuous variable (adjusted OR = 1.19; 95% CI: 1.08-1.31, for an increment of one standard deviation among controls (55 pg/m3)). Among women who became postmenopausal during follow-up, the association remained statistically significant (adjusted OR = 1.23; 95% CI: 1.09-1.39). In analyses by hormone receptors status, the positive association remained significant only for ER-positive breast cancer (adjusted OR = 1.18; 95% CI: 1.05-1.33). DISCUSSION: This study is the first to have estimated the impact of atmospheric exposure to PCB153 on breast cancer risk. Our results showed a statistically significant increase in breast cancer risk, which may be limited to ER-positive breast cancer. These results warrant confirmation in further independent studies but raise the possibility that exposure to PCB153 increase breast cancer risk.


Subject(s)
Breast Neoplasms , Polychlorinated Biphenyls , Breast/chemistry , Breast Neoplasms/chemically induced , Breast Neoplasms/epidemiology , Case-Control Studies , Cohort Studies , Female , Humans , Polychlorinated Biphenyls/analysis , Polychlorinated Biphenyls/toxicity , Risk Factors
12.
JMIR Res Protoc ; 9(9): e15167, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32930673

ABSTRACT

BACKGROUND: Breast cancer is the most frequent cancer in women in industrialized countries. Lifestyle and environmental factors, particularly endocrine-disrupting pollutants, have been suggested to play a role in breast cancer risk. Current epidemiological studies, although not fully consistent, suggest a positive association of breast cancer risk with exposure to several International Agency for Research on Cancer Group 1 air-pollutant carcinogens, such as particulate matter, polychlorinated biphenyls (PCB), dioxins, Benzo[a]pyrene (BaP), and cadmium. However, epidemiological studies remain scarce and inconsistent. It has been proposed that the menopausal status could modify the relationship between pollutants and breast cancer and that the association varies with hormone receptor status. OBJECTIVE: The XENAIR project will investigate the association of breast cancer risk (overall and by hormone receptor status) with chronic exposure to selected air pollutants, including particulate matter, nitrogen dioxide (NO2), ozone (O3), BaP, dioxins, PCB-153, and cadmium. METHODS: Our research is based on a case-control study nested within the French national E3N cohort of 5222 invasive breast cancer cases identified during follow-up from 1990 to 2011, and 5222 matched controls. A questionnaire was sent to all participants to collect their lifetime residential addresses and information on indoor pollution. We will assess these exposures using complementary models of land-use regression, atmospheric dispersion, and regional chemistry-transport (CHIMERE) models, via a Geographic Information System. Associations with breast cancer risk will be modeled using conditional logistic regression models. We will also study the impact of exposure on DNA methylation and interactions with genetic polymorphisms. Appropriate statistical methods, including Bayesian modeling, principal component analysis, and cluster analysis, will be used to assess the impact of multipollutant exposure. The fraction of breast cancer cases attributable to air pollution will be estimated. RESULTS: The XENAIR project will contribute to current knowledge on the health effects of air pollution and identify and understand environmental modifiable risk factors related to breast cancer risk. CONCLUSIONS: The results will provide relevant evidence to governments and policy-makers to improve effective public health prevention strategies on air pollution. The XENAIR dataset can be used in future efforts to study the effects of exposure to air pollution associated with other chronic conditions. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/15167.

13.
Int J Cancer ; 146(2): 341-351, 2020 01 15.
Article in English | MEDLINE | ID: mdl-30851122

ABSTRACT

Cadmium, due to its estrogen-like activity, has been suspected to increase the risk of breast cancer; however, epidemiological studies have reported inconsistent findings. We conducted a case-control study (4,059 cases and 4,059 matched controls) nested within the E3N French cohort study to estimate the risk of breast cancer associated with long-term exposure to airborne cadmium pollution, and its effect according to molecular subtype of breast cancer (estrogen receptor negative/positive [ER-/ER+] and progesterone receptor negative/positive [PR-/PR+]). Atmospheric exposure to cadmium was assessed using a Geographic Information System-based metric, which included subject's residence-to-cadmium source distance, wind direction, exposure duration and stack height. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. Overall, there was no significant association between cumulative dose of airborne cadmium exposure and the risk of overall, premenopausal and postmenopausal breast cancer. However, by ER and PR status, inverse associations were observed for ER- (ORQ5 vs. Q1 = 0.63; 95% CI: 0.41-0.95, ptrend = 0.043) and for ER-/PR- breast tumors (ORQ4 vs. Q1 = 0.62; 95% CI: 0.40-0.95, ORQ5 vs. Q1 = 0.68; 95% CI: 0.42-1.07, ptrend = 0.088). Our study provides no evidence of an association between exposure to cadmium and risk of breast cancer overall but suggests that cadmium might be related to a decreased risk of ER- and ER-/PR- breast tumors. These observations and other possible effects linked to hormone receptor status warrant further investigations.


Subject(s)
Air Pollutants/adverse effects , Air Pollution/adverse effects , Breast Neoplasms/epidemiology , Cadmium/adverse effects , Adult , Aged , Air Pollution/statistics & numerical data , Breast/pathology , Breast Neoplasms/chemically induced , Breast Neoplasms/pathology , Case-Control Studies , Female , Follow-Up Studies , France/epidemiology , Humans , Incidence , Middle Aged , Postmenopause , Premenopause , Prospective Studies , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Risk Factors
14.
Ecancermedicalscience ; 13: 949, 2019.
Article in English | MEDLINE | ID: mdl-31552122

ABSTRACT

Liver cancer (mostly hepatocellular carcinoma, HCC) is both common and highly lethal throughout Africa, in particular in western and middle Africa where HCC is the first cause of cancer death in men and the third in women. In these high-incidence areas, HCC develops mostly early (<50 years), with an aggressive clinical course and frequently without prior diagnosis of liver cirrhosis. The dynamics of African populations predict that the burden of liver cancers will be multiplied by three to four in the next decades unless effective prevention and therapy is achieved. This article outlines a path for significantly curbing the mortality of liver cancer in Africa by combining primary prevention, improved early detection and introduction of innovative and appropriate management strategies.

15.
Nat Rev Gastroenterol Hepatol ; 16(10): 589-604, 2019 10.
Article in English | MEDLINE | ID: mdl-31439937

ABSTRACT

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-related death worldwide. Risk factors for HCC include chronic hepatitis B and hepatitis C, alcohol addiction, metabolic liver disease (particularly nonalcoholic fatty liver disease) and exposure to dietary toxins such as aflatoxins and aristolochic acid. All these risk factors are potentially preventable, highlighting the considerable potential of risk prevention for decreasing the global burden of HCC. HCC surveillance and early detection increase the chance of potentially curative treatment; however, HCC surveillance is substantially underutilized, even in countries with sufficient medical resources. Early-stage HCC can be treated curatively by local ablation, surgical resection or liver transplantation. Treatment selection depends on tumour characteristics, the severity of underlying liver dysfunction, age, other medical comorbidities, and available medical resources and local expertise. Catheter-based locoregional treatment is used in patients with intermediate-stage cancer. Kinase and immune checkpoint inhibitors have been shown to be effective treatment options in patients with advanced-stage HCC. Together, rational deployment of prevention, attainment of global goals for viral hepatitis eradication, and improvements in HCC surveillance and therapy hold promise for achieving a substantial reduction in the worldwide HCC burden within the next few decades.


Subject(s)
Carcinoma, Hepatocellular/epidemiology , Liver Neoplasms/epidemiology , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/prevention & control , Carcinoma, Hepatocellular/therapy , Global Health/trends , Humans , Liver Neoplasms/etiology , Liver Neoplasms/prevention & control , Liver Neoplasms/therapy , Risk Factors
17.
Hum Mutat ; 40(1): 97-105, 2019 01.
Article in English | MEDLINE | ID: mdl-30352134

ABSTRACT

Reports of variable cancer penetrance in Li-Fraumeni syndrome (LFS) have raised questions regarding the prevalence of pathogenic germline TP53 variants. We previously reported higher-than-expected population prevalence estimates in sequencing databases composed of individuals unselected for cancer history. This study aimed to expand and further evaluate the prevalence of pathogenic and likely pathogenic germline TP53 variants in the gnomAD dataset (version r2.0.2, n = 138,632). Variants were selected and classified based on our previously published algorithm and compared with alternative estimates based on three different classification databases: ClinVar, HGMD, and the UMD_TP53 database. Conservative prevalence estimates of pathogenic and likely pathogenic TP53 variants were within the range of one carrier in 3,555-5,476 individuals. Less stringent classification increased the approximate prevalence to one carrier in every 400-865 individuals, mainly due to the inclusion of the controvertible p.N235S, p.V31I, and p.R290H variants. This study shows a higher-than-expected population prevalence of pathogenic and likely pathogenic germline TP53 variants even with the most conservative estimates. However, these estimates may not necessarily reflect the prevalence of the classical LFS phenotype, which is based upon family history of cancer. Comprehensive approaches are needed to better understand the interplay of germline TP53 variant classification, prevalence estimates, cancer penetrance, and LFS-associated phenotype.


Subject(s)
Databases, Genetic , Genetics, Population , Germ-Line Mutation/genetics , Molecular Sequence Annotation , Tumor Suppressor Protein p53/genetics , Humans , Middle Aged
18.
Curr Opin Oncol ; 30(1): 23-29, 2018 01.
Article in English | MEDLINE | ID: mdl-29076966

ABSTRACT

PURPOSE OF REVIEW: Germline pathogenic TP53 mutation may predispose to multiple cancers but penetrance and cancer patterns remain incompletely documented. We have analyzed international agency for research on cancer TP53 database to reevaluate age and variant-dependent tumor patterns. RECENT FINDINGS: Genome-wide studies suggest that germline variants are more frequent than estimated prevalence of Li-Fraumeni syndrome (LFS), suggesting that many carriers of potentially pathogenic mutations may not develop the syndrome. Carriers of a germline TP53 mutation who are detected in a clinical context have a penetrance of 80% at age 70. Penetrance varies according to age, sex and mutation type. Temporal tumor patterns show distinct phases, with childhood phase (0-15 years, 22% of all cancers) characterized by adrenal cortical carcinoma, choroid plexus carcinoma, rhabdomyosarcoma and medulloblastoma; early adulthood phase (16-50 years, 51%) including breast cancer, osteosarcoma, soft tissue sarcomas, leukemia, astrocytoma and glioblastoma, colorectal and lung cancer; late adulthood phase (51-80 years, 27%) including pancreatic and prostate cancer. SUMMARY: Germline pathogenic variants in TP53 gene have different consequences according to cell, tissue, context and age. The occurrence of frequent variants in patients with no criteria suggestive of LFS calls for attention in predicting individual risk and highlights the need of additional predictors for assigning carriers to appropriate surveillance programs.


Subject(s)
Genes, p53 , Germ-Line Mutation , Li-Fraumeni Syndrome/genetics , Tumor Suppressor Protein p53/genetics , Animals , Humans
19.
Eur J Nutr ; 57(2): 751-760, 2018 Mar.
Article in English | MEDLINE | ID: mdl-28004270

ABSTRACT

PURPOSE: Impaired B vitamin status has been identified as a risk factor for major chronic diseases. This study aims at examining the determinants of plasma folate and vitamin B12 concentrations, considering lifestyle factors and MTHFR polymorphisms. METHODS: A total of 988 women aged 40-65 years from the French E3N cohort were investigated. Intakes of folate and vitamin B12 were assessed using food frequency questionnaires, and plasma concentrations were measured by microbiological assay. Dietary scores were computed to summarize folate and vitamin B12 dietary sources. MTHFR-C677T and MTHFR-A1298C were determined by Kaspar assay. Pearson's partial correlation coefficients and multivariable linear regression models were used to assess correlations between main determinants and plasma folate and vitamin B12 levels. RESULTS: The partial correlation coefficient between dietary intakes and plasma folate was 0.19 (p value <0.001) and 0.08 (p value = 0.008) for vitamin B12. Dietary scores were the main determinant of B vitamin plasma concentrations with a percent change per unit increase of 12.64% (p value <0.001) for folate and 7.6% (p value <0.001) for vitamin B12. Homozygous (T/T) or heterozygous (C/T) women for MTHFR-C677T had lower plasma folate concentrations [C/T: -6.48% (p value = 0.038) and T/T: -15.89% (p value <0.001)] compared to women carrying the C/C genotype. Other determinants of B vitamin plasma concentration include: smoking status for folate, and age and hormone replacement therapy for vitamin B12. CONCLUSIONS: We confirmed previous findings on the role of diet as main determinant of folate and vitamin B12 plasma concentrations. However, the impact of genetic polymorphisms and lifestyle factors on plasma B vitamin concentrations should not be neglected.


Subject(s)
Diet/adverse effects , Folic Acid Deficiency/etiology , Folic Acid/blood , Nutritional Status , Vitamin B 12 Deficiency/etiology , Vitamin B 12/blood , Amino Acid Substitution , Biomarkers/blood , Case-Control Studies , Cohort Studies , Diet, Healthy , Female , Folic Acid Deficiency/blood , Folic Acid Deficiency/genetics , Folic Acid Deficiency/prevention & control , France/epidemiology , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Middle Aged , Patient Compliance , Polymorphism, Single Nucleotide , Prospective Studies , Self Report , Vitamin B 12 Deficiency/blood , Vitamin B 12 Deficiency/genetics , Vitamin B 12 Deficiency/prevention & control
20.
PLoS One ; 11(8): e0161686, 2016.
Article in English | MEDLINE | ID: mdl-27564705

ABSTRACT

Low circulating levels of vitamin D and high mammographic density (MD) have been associated with higher risk of breast cancer. Although some evidence suggested an inverse association between circulating vitamin D and MD, no studies have investigated this association among Mexican women. We examined whether serum 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with MD in a cross-sectional study nested within the large Mexican Teacher's Cohort. This study included 491 premenopausal women with a mean age of 42.9 years. Serum 25(OH)D3 levels were measured by liquid chromatography/tandem mass spectrometry. Linear regression and non-linear adjusted models were used to estimate the association of MD with serum 25(OH)D3. Median serum 25(OH)D3 level was 27.3 (23.3-32.8) (ng/ml). Forty one (8%) women had 25(OH)D3 levels in the deficient range (< 20 ng/ml). Body mass index (BMI) and total physical activity were significantly correlated with 25(OH)D3 (r = -0.109, P = 0.019 and r = 0.095, P = 0.003, respectively). In the multivariable linear regression, no significant association was observed between 25(OH)D3 levels and MD overall. However, in stratified analyses, higher serum 25(OH)D3 levels (≥27.3 ng/ml) were significantly inversely associated with percent MD among women with BMI below the median (ß = -0.52, P = 0.047). Although no significant association was observed between serum 25(OH)D3 and percent MD in the overall population, specific subgroups of women may benefit from higher serum 25(OH)D3 levels.


Subject(s)
Breast Density , Calcifediol/blood , Homocysteine/blood , Adult , Aged , Body Mass Index , Cross-Sectional Studies , Exercise , Female , Humans , Longitudinal Studies , Male , Mammography , Mexico/epidemiology , Middle Aged , Regression Analysis , Risk Factors , Vitamin D Deficiency/blood
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