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Pahwa P.,University of Saskatchewan | Karunanayake C.P.,University of Saskatchewan | Dosman J.A.,University of Saskatchewan | Spinelli J.J.,University of British Columbia | And 4 more authors.
Journal of Agromedicine | Year: 2012

The objective of this study was to investigate the putative associations of specific pesticides with multiple myeloma. A matched, population-based, case-control study was conducted among men residing in six Canadian provinces (Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia). Data were collected on 342 multiple myelome cases and 1506 age and province of residence matched controls. Data were collected by mailed questionnaires to capture demographic characteristics, antecedent medical history, detailed lifetime occupational history, smoking history, family history of cancer, and exposure to broadly characterized pesticides at home, work, and practicing hobbies. Details of pesticide exposures were collected by telephone interview for those who reported 10 hours or more per year of exposure. Exposure to pesticides grouped into major chemical classes resulted in increased risk being detected only for carbamate insecticides [odds ratio (OR) and 95% confidence interval (CI) 1.90 (1.11, 3.27) adjusted for potential confounders]. An exposure to fungicide captan [2.35 (1.03, 5.35)] was positively associated with the incidence of multiple myeloma. While an exposure to carbaryl [1.89 (0.98, 3.67)] was associated with the incidence of multiple myelome with borderline significance. The authors further suggest that certain pesticide exposures may have a role in multiple myeloma etiology, and identify specific factors warranting investigation in other populations. © 2012 Taylor and Francis Group, LLC. Source

Jang J.-H.,University of Toronto | Cotterchio M.,Prevention and Cancer Control | Borgida A.,Dr Zane Cohen Digestive Diseases Clinical Research Center | Liu G.,University of Toronto | And 4 more authors.
Molecular Carcinogenesis | Year: 2013

Mitotic regulator genes have been associated with several cancers, however little is known about their possible association with pancreatic cancer. Smoking and family history are the strongest risk factors for this highly fatal disease. The main purpose of this study was to determine if polymorphisms of mitotic regulator genes are associated with pancreatic cancer and whether they modify the association between cigarette smoking and pancreatic cancer risk. A population-based case-control study was conducted in Ontario with 455 pathology-confirmed pancreatic cancer cases and 893 controls. Cigarette smoking history was collected using questionnaires and DNA obtained from blood samples. Genotypes were determined by mass-spectrometry. Odds ratio estimates were obtained using multivariate logistic regression. Interactions between genetic variant and smoking were assessed using stratified analyses and the likelihood ratio statistic (significance P<0.05). Variants of MCPH1, FYN, APC, PRKCA, NIN, TopBP1, RIPK1, and SNW1 were not independently associated with pancreatic cancer risk. A significant interaction was observed between pack-years and MCPH1-2550-C>T (P=0.02). Compared to never smokers, individuals with 10-27 pack-years and MCPH1-2550-CC genotype were at increased risk for pancreatic cancer (MVOR=2.49, 95% confidence interval [95% CI]: 1.55, 4.00) as were those with >27 pack-years and MCPH1-2550-TC genotype (MVOR=2.42, 95% CI: 1.45, 4.05). A significant interaction was observed between smoking status and TopBP1-3257-A>G (P=0.04) using a dominant model. Current smokers with the TopBP1-3257 A allele were at increased risk for pancreatic cancer (MVOR=2.55, 95% CI: 1.77, 3.67). MCPH1-2550-C>T and TopBP1-3257-A>G modify the association between smoking and pancreatic cancer. These findings provide insights into the potential molecular mechanisms behind smoking-associated pancreatic cancer. © 2013 Wiley Periodicals, Inc. Source

Hamidi M.,A+ Network | Hamidi M.,University of Toronto | Boucher B.A.,Prevention and Cancer Control | Boucher B.A.,University of Toronto | And 6 more authors.
Osteoporosis International | Year: 2011

Summary: High fruit and vegetable intake may be associated with improved bone status among women aged ≥45 years. This is the first systematic review that specifically assessed this association and identified research gaps. The benefits of fruit and vegetables (F&V) on bone health remain unclear. Further studies are needed. Introduction: F&V have several components that are beneficial to bones. Some studies report that high F&V intake is associated with improved bone status in middle aged and aged women; however, findings are inconsistent. The objective was to systematically review observational and interventional studies that investigated the effects of F&V intake on incidence of osteoporotic fractures, bone mineral density (BMD), and bone turnover markers (BTM) in women aged ≥45 years and to identify potential research gaps. Methods: Electronic databases were searched, and peerreviewed manuscripts published in English, with F&V intake as a main dietary exposure, were included. Data selection, extraction, and evaluation of risk of bias were performed independently by two reviewers. Results: Eight studies were included. One cohort study reported cross-sectional as well as longitudinal data. There was significant between-study heterogeneity in design, definition, and amount of F&V intake, outcomes, analyses, and reporting of results. Two studies had low, two had moderate, and four had high risk of bias. Among reports with low or moderate risk of bias, two cross-sectional analyses reported positive associations between F&V intake and BMD of the forearm, lumbar spine, or total hip, whereas one randomized controlled trial and two prospective cohort analyses reported no effects. One trial reported no associations between F&V and BTM. Conclusions: Based on limited evidence, the benefits of F&V on bone health remain unclear for women aged ≥45 years. Further studies with low risk of bias are needed. © International Osteoporosis Foundation and National Osteoporosis Foundation 2010. Source

Nguyen P.,Prevention and Cancer Control | Brown P.E.,University of Toronto | Stafford J.,University of Toronto
Biometrics | Year: 2012

Mapping disease risk often involves working with data that have been spatially aggregated to census regions or postal regions, either for administrative reasons or confidentiality. When studying rare diseases, data must be collected over a long time period in order to accumulate a meaningful number of cases. These long time periods can result in spatial boundaries of the census regions changing over time, as is the case with the motivating example of exploring the spatial structure of mesothelioma lung cancer risk in Lambton County and Middlesex County of southwestern Ontario, Canada. This article presents a local-EM kernel smoothing algorithm that allows for the combining of data from different spatial maps, being capable of modeling risk for spatially aggregated data with time-varying boundaries. Inference and uncertainty estimates are carried out with parametric bootstrap procedures, and cross-validation is used for bandwidth selection. Results for the lung cancer study are shown and discussed. © 2012, The International Biometric Society. Source

Barisic A.,Prevention and Cancer Control | Leatherdale S.T.,University of Waterloo | Burkhalter R.,University of Waterloo | Ahmed R.,The Care Registry
Chronic Diseases and Injuries in Canada | Year: 2014

Introduction: The objective of this manuscript is to examine the prevalence of youth exposed to second-hand smoke (SHS) in homes and cars, changes in SHS exposure over time, and factors associated with beliefs youth hold regarding SHS exposure among a nationally representative sample of Canadian youth. Methods: Descriptive analysis of SHS exposure in homes and cars was conducted using data from the Canadian Youth Smoking Survey (2004, 2006 and 2008). Logistic regression was conducted to examine factors associated with beliefs youth had about SHS exposure in 2008. Results: In 2008, 21.5% of youth reported being exposed to SHS in their home on a daily or almost daily basis, while 27.3% reported being exposed to SHS while riding in a car at least once in the previous week. Between 2004 and 2008, the prevalence of daily SHS exposure in the home and cars decreased by 4.7% and 18.0% respectively. Conclusion: Despite reductions in SHS exposure over time, a substantial number of Canadian youth continue to be exposed to SHS in homes and cars. Further effort is required to implement and evaluate policies designed to protect youth from SHS. Source

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