Jack Siemiatycki

Publications of Jack Siemiatycki

• Comparison of exposure estimates in the Finnish job-exposure matrix FINJEM with a JEM derived from expert assessments performed in Montreal.

  Authors: Jérôme Lavoué, Javier Pintos, Martie Van Tongeren, Laurel Kincl, Lesley Richardson, T Kauppinen, Elisabeth Cardis, Jack Siemiatycki

  Occupational and environmental medicine. 04/2012;

  ContextRetrospective exposure assessment in population-based case-control studies poses a major challenge due to the wide range of occupations and industries involved. The FINJEM is a genericContextRetrospective exposure assessment in population-based case-control studies poses a major challenge due to the wide range of occupations and industries involved. The FINJEM is a generic job-exposure matrix (JEM) developed in Finland, which represents a potentially cost-effective exposure assessment tool. While FINJEM has been used in several studies outside Finland, little is known of its applicability in other countries.MethodsWe compared prevalence and intensity of exposure in FINJEM with a JEM developed from expert assessments of occupational histories obtained in a population-based case-control study in Montreal. Agreement for prevalence of exposure was measured by weighted κ coefficients between prevalence categories. Agreement for exposure intensity was measured by Spearman correlation coefficients between cells with non-null exposure.ResultsThe comparison involved 27 chemicals, the time period 1945-1995 and included 4743 jobs initially assessed by the Montreal experts. 4293 combinations of agent, occupational title and period were available for comparison of prevalence. Agent-specific prevalence was consistently higher in the Montreal JEM (median difference 1.7%). Agent-specific κ values between prevalence categories varied from 0.89 (welding fumes) to 0.07 (flour dust). The comparison of exposure levels involved 14 agents and 198 cells with non-null exposure in both sources. Agent-specific Spearman correlation varied from 0.89 (flour dust) to -0.35 (benzo(a)pyrene).ConclusionOur observations suggest that information concerning several agents (eg, metals, welding fumes) can be successfully transported from Finland to Canada and probably other countries. However, for other agents, there was considerable disagreement, and hence, transportability of FINJEM cannot be assumed by default.

• Socioeconomic Position and Lung Cancer Risk: How Important is the Modeling of Smoking?

  Authors: Thomas Matukala Nkosi, Marie-Élise Parent, Jack Siemiatycki, Marie-Claude Rousseau

  Epidemiology (Cambridge, Mass.). 03/2012; 23(3):377-85.

  : Although it has been reported that low socioeconomic position (SEP) is associated with lung cancer, the extent to which this reflects SEP differences in cigarette smoking is unclear. We: Although it has been reported that low socioeconomic position (SEP) is associated with lung cancer, the extent to which this reflects SEP differences in cigarette smoking is unclear. We investigated how various modeling approaches for smoking might influence this observed association. : We used data from a case-control study conducted in Montreal, Canada (1996-2002), comprising 1203 subjects with incident lung cancer and 1513 population controls. SEP was measured by census-based and self-reported income, residential value, education level, and occupational class. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression, and Akaike's Information Criterion (AIC) was used to compare model fit. : Associations were observed between SEP indicators and lung cancer, but gradually disappeared with more comprehensive adjustment for smoking. For comparisons of the highest to lowest categories of census-based income, the OR for lung cancer was 0.58 (95% CI = 0.32-1.05) when adjusting only for smoking status (never, former, current), but 0.97 (0.51-1.86) when adjusting for smoking status, cigarette-years, and time since cessation. For comparisons of highest to lowest levels of education, the ORs for lung cancer were 0.50 (0.38-0.65) and 0.76 (0.57-1.02), when making the least and most comprehensive adjustments for smoking, respectively. Similarly, comparing highly skilled with unskilled manual workers, the ORs were 0.78 (0.54-1.12) and 1.00 (0.68-1.47), respectively. With thorough smoking adjustment, associations between SEP indicators and lung cancer virtually disappeared, and SEP did not improve model fit. : Previously reported associations of SEP with lung cancer may be attributable to incomplete adjustment for smoking. Our findings underline the importance of adjusting for several dimensions of smoking behavior to make correct inferences.

• Cigarette smoking and lung cancer-relative risk estimates for the major histological types from a pooled analysis of case-control studies.

  Authors: Beate Pesch, Benjamin Kendzia, Per Gustavsson, Karl-Heinz Jöckel, Georg Johnen, Hermann Pohlabeln, Ann Olsson, Wolfgang Ahrens, Isabelle Mercedes Gross, Irene Brüske [......] Eleonora Fabianova, Rodica Stanescu Dumitru, Vladimir Bencko, Lenka Foretova, Vladimir Janout, Charles M Rudin, Paul Brennan, Paolo Boffetta, Kurt Straif, Thomas Brüning

  International journal of cancer. Journal international du cancer. 11/2011;

  Lung cancer is mainly caused by smoking, but the quantitative relations between smoking and histologic subtypes of lung cancer remain inconclusive. By using one of the largest lung cancer datasetsLung cancer is mainly caused by smoking, but the quantitative relations between smoking and histologic subtypes of lung cancer remain inconclusive. By using one of the largest lung cancer datasets ever assembled, we explored the impact of smoking on risks of the major cell types of lung cancer. This pooled analysis included 13,169 cases and 16,010 controls from Europe and Canada. Studies with population controls comprised 66.5% of the subjects. Adenocarcinoma (AdCa) was the most prevalent subtype in never smokers and in women. Squamous cell carcinoma (SqCC) predominated in male smokers. Age-adjusted odds ratios (ORs) were estimated with logistic regression. ORs were elevated for all metrics of exposure to cigarette smoke and were higher for SqCC and small cell lung cancer (SCLC) than for AdCa. Current male smokers with an average daily dose of >30 cigarettes had ORs of 103.5 (95% confidence interval (CI): 74.8-143.2) for SqCC, 111.3 (95% CI: 69.8-177.5) for SCLC and 21.9 (95% CI: 16.6-29.0) for AdCa. In women, the corresponding ORs were 62.7 (95% CI: 31.5-124.6), 108.6 (95% CI: 50.7-232.8) and 16.8 (95% CI: 9.2-30.6), respectively. Although ORs started to decline soon after quitting, they did not fully return to the baseline risk of never smokers even 35 years after cessation. The major result that smoking exerted a steeper risk gradient on SqCC and SCLC than on AdCa is in line with previous population data and biological understanding of lung cancer development.

• Occupational exposure to organic dust increases lung cancer risk in the general population.

  Authors: Susan Peters, Hans Kromhout, Ann C Olsson, Heinz-Erich Wichmann, Irene Brüske, Dario Consonni, Maria Teresa Landi, Neil Caporaso, Jack Siemiatycki, Lorenzo Richiardi [......] Vladimir Janout, Isabelle Stücker, Rodica Stanescu Dumitru, Simone Benhamou, Bas Bueno-de-Mesquita, Benjamin Kendzia, Beate Pesch, Kurt Straif, Thomas Brüning, Roel Vermeulen

  Thorax. 08/2011; 67(2):111-6.

  Organic dust is a complex mixture of particulate matter from microbial, plant or animal origin. Occupations with exposure to animal products have been associated with an increased lung cancer risk,Organic dust is a complex mixture of particulate matter from microbial, plant or animal origin. Occupations with exposure to animal products have been associated with an increased lung cancer risk, while exposure to microbial components (eg, endotoxin) has been associated with a decreased risk. To date there has not been a comprehensive evaluation of the possible association between occupational organic dust exposure (and its specific constituents) and lung cancer risk in the general population. The SYNERGY project has pooled information on lifetime working and smoking from 13 300 lung cancer cases and 16 273 controls from 11 case-control studies conducted in Europe and Canada. A newly developed general population job-exposure matrix (assigning no, low or high exposure to organic dust, endotoxin, and contact with animals or fresh animal products) was applied to determine level of exposure. ORs for lung cancer were estimated by logistic regression, adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. Occupational organic dust exposure was associated with increased lung cancer risk. The second to the fourth quartile of cumulative exposure showed significant risk estimates ranging from 1.12 to 1.24 in a dose-dependent manner (p<0.001). This association remained in the highest quartile after restricting analyses to subjects without chronic obstructive pulmonary disease or asthma. No association was observed between lung cancer and exposure to endotoxin or contact with animals or animal products. Occupational exposure to organic dust was associated with increased lung cancer risk in this large pooled case-control study.

• Exposures in painting-related occupations and risk of lung cancer among men: results from two case-control studies in Montreal.

  Authors: Agnihotram V Ramanakumar, Marie-Élise Parent, Lesley Richardson, Jack Siemiatycki

  Occupational and environmental medicine. 01/2011; 68(1):44-51.

  Evidence that painters may be at risk for lung cancer comes mainly from analyses on job titles rather than on specific exposures found in the environments of painters. In the context of two largeEvidence that painters may be at risk for lung cancer comes mainly from analyses on job titles rather than on specific exposures found in the environments of painters. In the context of two large population-based case-control studies of lung cancer carried out in Montreal, we were able to assess possible relationships between lung cancer and the occupation of painter as well as exposure to paints, varnishes and stains. Interviews for study I were conducted in 1979-1986 (857 cases, 533 population controls, 1349 cancer controls) and interviews for study II were conducted in 1996-2001 (765 cases and 899 controls). Detailed lifetime job histories were elicited; a team of hygienists and chemists evaluated the evidence of exposure to many occupational substances including paint-related substances. The relative risk of lung cancer was estimated, adjusting for several potential confounders, including smoking, in a three-variable parameterisation. In analyses pooling the two studies, painters had an OR of lung cancer of 1.3 (95% CI 0.9 to 2.2). Regarding exposures, ORs were: for wood varnishes and stains, 1.6 (95% CI 1.0 to 2.3); for wood and gypsum paints, 1.3 (95% CI 0.9 to 1.7); and for metal coatings, 1.1 (95% CI 0.8 to 1.6). Small numbers hampered evaluation of dose-response relationships. While our results cannot exclude chance or residual confounding by smoking or concomitant occupational exposures, they provide further evidence that some exposures in paint-related occupations, most notably wood varnishes and stains, increase the risk of lung cancer.

• Comparison of indicators of material circumstances in the context of an epidemiological study.

  Authors: Thomas Matukala Nkosi, Marie-Elise Parent, Jack Siemiatycki, Javier Pintos, Marie-Claude Rousseau

  BMC medical research methodology. 01/2011; 11:108.

  Since individual-level income is difficult to collect, investigators often rely on group-based measures derived from census data. No study has assessed the use of residential property values as anSince individual-level income is difficult to collect, investigators often rely on group-based measures derived from census data. No study has assessed the use of residential property values as an indicator of individual material circumstances. We aimed to compare two proxy indicators of material circumstances, one based on residential value and the other on median census tract income, to self-reported household income. We used data from a case-control study (1996-2002), restricting analyses to 676 residents of the Island of Montreal for whom the three indicators were available. The degree of discrepancy between the residential value index, census income, and self-reported household income--each in 5 categories--was estimated, along with overall and weighted Kappas. When comparing residential value index and census income to self-reported household income, perfect concordance was observed for 38% and 30% of subjects, respectively; very good concordance, defined as ≤1 category difference, was observed for 76% and 69% of subjects, respectively. When compared to self-reported household income, overall and weighted Kappas showed stronger agreement with residential value index (weighted Kappa=0.37, 95% CI: 0.32, 0.42) than with census income (weighted Kappa=0.25, 95% CI: 0.20, 0.30). A residential value index may provide a measure of material circumstances that is closer to self-reported household income than the commonly used census income. Each indicator presents advantages and disadvantages, and their choice may depend on study objectives and feasibility.

• Occupational and recreational physical activity during adult life and the risk of cancer among men.

  Authors: Marie-Élise Parent, Marie-Claude Rousseau, Mariam El-Zein, Benoit Latreille, Marie Désy, Jack Siemiatycki

  Cancer epidemiology. 10/2010; 35(2):151-9.

  There is a strong evidence for a protective role of physical activity (PA) on cancers of the colon, breast (postmenopausal) and endometrium, but data are less consistent or scarce for other cancerThere is a strong evidence for a protective role of physical activity (PA) on cancers of the colon, breast (postmenopausal) and endometrium, but data are less consistent or scarce for other cancer types. This study assessed the relationship between occupational and recreational PA and cancer risk among men in a population-based case-control study conducted in Montreal, Canada. Incident cases of cancer of the lung (n=857), colon (n=496), bladder (n=484), prostate (n=449), stomach (n=251), rectum (n=248), non-Hodgkin's lymphoma (n=215), kidney (n=177), pancreas (n=116), melanoma (n=103), esophagus (n=99), Hodgkin's lymphoma (n=54), and 533 population controls, were interviewed. Detailed lifetime occupational PAs were translated into metabolic equivalents. Participation in sports and outdoor activities was elicited. Compared to those with low lifetime occupational PA levels, men with high occupational PA levels had decreased odds ratios (OR) for all cancer types. The strongest evidence was for cancers of the colon [OR: 0.58, 95% confidence interval (CI): 0.34-0.99] and the prostate (OR: 0.54, 95% CI: 0.31-0.95). Men engaging in sports and outdoor activities had lower risks of lung (OR: 0.69, 95% CI: 0.52-0.91), esophageal (OR: 0.54, 95% CI: 0.30-0.97) and bladder (OR: 0.78, 95% CI: 0.59-1.05) cancers, and somewhat increased risks of melanoma (OR: 1.24, 95% CI: 0.73-2.12). A protective effect of high lifetime occupational PA levels was observed for colon and prostate cancers. A tendency for inverse associations was also noted for several other cancer types. Recreational PA was inversely related with smoking-related cancers including lung, esophageal and bladder cancers.

• Exposure to diesel motor exhaust and lung cancer risk in a pooled analysis from case-control studies in Europe and Canada.

  Authors: Ann C Olsson, Per Gustavsson, Hans Kromhout, Susan Peters, Roel Vermeulen, Irene Brüske, Beate Pesch, Jack Siemiatycki, Javier Pintos, Thomas Brüning [......] Peter Rudnai, Eleonora Fabianova, Rodica Stanescu Dumitru, Isabelle M Gross, Benjamin Kendzia, Francesco Forastiere, Bas Bueno-de-Mesquita, Paul Brennan, Paolo Boffetta, Kurt Straif

  American journal of respiratory and critical care medicine. 10/2010; 183(7):941-8.

  Diesel motor exhaust is classified by the International Agency for Research on Cancer as probably carcinogenic to humans. The epidemiologic evidence is evaluated as limited because most studies lackDiesel motor exhaust is classified by the International Agency for Research on Cancer as probably carcinogenic to humans. The epidemiologic evidence is evaluated as limited because most studies lack adequate control for potential confounders and only a few studies have reported on exposure-response relationships. Investigate lung cancer risk associated with occupational exposure to diesel motor exhaust, while controlling for potential confounders. The SYNERGY project pooled information on lifetime work histories and tobacco smoking from 13,304 cases and 16,282 controls from 11 case-control studies conducted in Europe and Canada. A general population job exposure matrix based on ISCO-68 occupational codes, assigning no, low, or high exposure to diesel motor exhaust, was applied to determine level of exposure. Odds ratios of lung cancer and 95% confidence intervals were estimated by unconditional logistic regression, adjusted for age, sex, study, ever-employment in an occupation with established lung cancer risk, cigarette pack-years, and time-since-quitting smoking. Cumulative diesel exposure was associated with an increased lung cancer risk highest quartile versus unexposed (odds ratio 1.31; 95% confidence interval, 1.19-1.43), and a significant exposure-response relationship (P value < 0.01). Corresponding effect estimates were similar in workers never employed in occupations with established lung cancer risk, and in women and never-smokers, although not statistically significant. Our results show a consistent association between occupational exposure to diesel motor exhaust and increased risk of lung cancer. This association is unlikely explained by bias or confounding, which we addressed by adjusted models and subgroup analyses.

• Occupational exposure to silica and lung cancer: pooled analysis of two case-control studies in Montreal, Canada.

  Authors: Stephen Vida, Javier Pintos, Marie-Elise Parent, Jerome Lavoué, Jack Siemiatycki

  Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 06/2010; 19(6):1602-11.

  Respirable crystalline silica is a highly prevalent occupational exposure and a recognized lung carcinogen. Most previous studies have focused on selected high-exposure occupational groups. ThisRespirable crystalline silica is a highly prevalent occupational exposure and a recognized lung carcinogen. Most previous studies have focused on selected high-exposure occupational groups. This study examines the relationship between occupational exposure to silica and lung cancer in an occupationally diverse male population. Two large population-based case-control studies of lung cancer were conducted in Montreal, one in 1979-1986 (857 cases, 533 population controls, 1,349 cancer controls) and the second in 1996-2001 (738 cases and 899 controls). Interviews provided descriptive lifetime job histories, smoking histories, and other information. Industrial hygienists translated job histories into histories of exposure to a host of occupational substances, including silica. Relative risk was estimated, adjusting for several potential confounders, including smoking. The odds ratio for substantial exposure to silica was 1.67 (95% confidence interval, 1.21-2.31) and for any exposure was 1.31 (95% confidence interval, 1.08-1.59). Joint effects between silica and smoking were between additive and multiplicative, perhaps closer to the latter. In this population, it is estimated that approximately 3% of lung cancers were attributable to substantial silica exposure. The carcinogenicity of inhaled crystalline silica was observed in a population with a wide variety of exposure circumstances. The finding of carcinogenicity across a wide range of occupations complements prior studies of specific high-exposure occupations. This suggests that the burden of cancer induced by silica may be much greater than previously thought.

• History of asthma or eczema and cancer risk among men: a population-based case-control study in Montreal, Quebec, Canada.

  Authors: Mariam El-Zein, Marie-Elise Parent, Khady Kâ, Jack Siemiatycki, Yves St-Pierre, Marie-Claude Rousseau

  Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology. 05/2010; 104(5):378-84.

  Epidemiologic evidence regarding the association between a history of allergic diseases and different cancer types has been inconsistent. To examine whether a history of asthma or eczema isEpidemiologic evidence regarding the association between a history of allergic diseases and different cancer types has been inconsistent. To examine whether a history of asthma or eczema is associated with various cancers among Canadian men in a population based case-control study conducted in the 1980s. Questionnaire-based interviews were performed by a team of trained interviewers from August 1979 to March 1986. Information collected included self-reported history of a prior medical diagnosis of asthma and of eczema, medication use, and several covariates among 3,300 cancer cases and 512 population controls. Logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between asthma or eczema and more than 20 cancer types combined, as well as for each of the 8 most common cancer types (stomach, colon, rectum, lung, prostate, bladder, skin, and lymph nodes). Considering study participants who reported a prior medical diagnosis of the disease and medication use, a history of asthma was negatively associated with all cancer types combined (OR, 0.72; 95% CI, 0.5-1.1) and similarly for a history of eczema (OR, 0.66; 95% CI, 0.4-1.1). Although ORs between asthma and eczema and most individual types were below 1.0, only 2 ORs were significantly below 1.0: that between asthma and stomach cancer (OR, 0.27; 95% CI, 0.1-0.9) and that between eczema and lung cancer (OR, 0.34; 95% CI, 0.2-0.7). Allergic conditions that result from a hyperreactive immune system might lead to a more efficient elimination of abnormal cells, thus lowering cancer risks.

• A weighted Cox model for modelling time-dependent exposures in the analysis of case-control studies.

  Authors: Karen Leffondre, Willy Wynant, Zhirong Cao, Michal Abrahamowicz, Georg Heinze, Jack Siemiatycki

  Statistics in medicine. 03/2010; 29(7-8):839-50.

  Many exposures investigated in epidemiological case-control studies may vary over time. The effects of these exposures are usually estimated using logistic regression, which does not directly accountMany exposures investigated in epidemiological case-control studies may vary over time. The effects of these exposures are usually estimated using logistic regression, which does not directly account for changes in covariate values over time within individuals. By contrast, the Cox model with time-dependent covariates directly accounts for these changes over time. However, the over-sampling of cases in case-control studies, relative to controls, requires manipulating the risk sets in the Cox partial likelihood. A previous study showed that simple inclusion or exclusion of future cases in each risk set induces an under- or over-estimation bias in the regression parameters, respectively. We investigate the performance of a weighted Cox model that weights subjects according to age-conditional probabilities of developing the disease of interest in the source population. In a simulation study, the lifetime experience of a source population is first generated and a case-control study is then simulated within each population. Different characteristics of exposure are generated, including time-varying intensity. The results show that the estimates from the weighted Cox model are much less biased than the Cox models that simply include or exclude future cases, and are superior to logistic regression estimates in terms of bias and mean-squared error. An application to frequency-matched population-based case-control data on lung cancer illustrates similar differences in the estimated effects of different smoking variables. The investigated weighted Cox model is a potential alternative method to analyse matched or unmatched population-based case-control studies with time-dependent exposures.

• Lung cancer risk associated with occupational exposure to nickel, chromium VI, and cadmium in two population-based case-control studies in Montreal.

  Authors: Rachelle Beveridge, Javier Pintos, Marie-Elise Parent, Jérome Asselin, Jack Siemiatycki

  American journal of industrial medicine. 02/2010; 53(5):476-85.

  Nickel, chromium VI, and cadmium have been identified as lung carcinogens in highly exposed cohorts. The purpose of this study was to examine the etiological link between lung cancer and these metalsNickel, chromium VI, and cadmium have been identified as lung carcinogens in highly exposed cohorts. The purpose of this study was to examine the etiological link between lung cancer and these metals in occupations, that usually entail lower levels of exposure than those seen in historical cohorts. Two population-based case-control studies were conducted in Montreal, from 1979 to 1986 and from 1996 to 2001, comprising 1,598 cases and 1,965 controls. A detailed job history was obtained to evaluate lifetime occupational exposure to many agents, including nickel, chromium VI, and cadmium compounds. Lung cancer odds ratios were increased only among former or non-smokers: 2.5 (95% CI: 1.3-4.7) for nickel exposure, 2.4 (95% CI: 1.2-4.8) for chromium VI, and 4.7 (95% CI: 1.5-14.3) for cadmium. The metals did not increase risk among smokers. While excess risks due to these metal compounds were barely discernable among smokers, carcinogenic effects were seen among non-smokers.

• Analysis of multiple exposures: an empirical comparison of results from conventional and semi-bayes modeling strategies.

  Authors: Franco Momoli, Michal Abrahamowicz, Marie-Elise Parent, Dan Krewski, Jack Siemiatycki

  Epidemiology (Cambridge, Mass.). 01/2010; 21(1):144-51.

  BACKGROUND: Analysts of epidemiologic data often contend with the problem of estimating the independent effects of many correlated exposures. General approaches include assessing each exposureBACKGROUND: Analysts of epidemiologic data often contend with the problem of estimating the independent effects of many correlated exposures. General approaches include assessing each exposure separately, adjusting for some subset of other exposures, or assessing all exposures simultaneously in a single model such as semi-Bayes modeling. The optimal strategy remains uncertain, and it is unclear to what extent different reasonable approaches influence findings. We provide an empirical comparison of results from several modeling strategies. METHODS: In an occupational case-control study of lung cancer with 184 exposure substances, we implemented 6 modeling strategies to estimate odds ratios for each exposure-cancer association. These included one-exposure-at-a-time models with various confounder selection criteria (such as a priori selection or a change-in-the-estimate criterion) and semi-Bayes models, one version of which integrated information on previous evidence and chemical properties. RESULTS: While distributions of odds ratios were broadly similar across the 6 analytic strategies, there were some differences in point estimates and in substances manifesting statistically significant odds ratios, particularly between strategies with few or no occupational covariates and those with many. Semi-Bayes models produced fewer statistically significant odds ratios than other methods. A simple semi-Bayes model that shrank all the 184 estimates to a common mean yielded nearly identical results to one that integrated considerable prior information. CONCLUSION: Different modeling strategies can lead to different results. Considering the conceptual and pragmatic difficulties of identifying confounders, these results suggest that it would be unwise to place uncritical reliance on any single strategy.

• Risk of Mesothelioma and Occupational Exposure to Asbestos and Man-Made Vitreous Fibers: Evidence From Two Case-Control Studies in Montreal, Canada.

  Authors: Javier Pintos, Marie-Elise Parent, Bruce Case, Marie-Claude Rousseau, Jack Siemiatycki

  Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine. 09/2009;

  OBJECTIVE:: To examine the effects of exposure to occupational asbestos and man-made vitreous fibers (MMVF) across a wide range of occupations on risk of mesothelioma. METHODOLOGY:: TwoOBJECTIVE:: To examine the effects of exposure to occupational asbestos and man-made vitreous fibers (MMVF) across a wide range of occupations on risk of mesothelioma. METHODOLOGY:: Two population-based case-control studies (1979-1986 and 1996-2001) provided 35 histologically confirmed mesothelioma cases and 1965 controls. A detailed job history was obtained to evaluate occupational exposure to many agents, including asbestos and MMVF. RESULTS:: The mesothelioma odds ratio for exposure to any asbestos type was 3.7 (95% confidence interval = 1.7 to 7.8). The subset exposed to amphibole fibers experienced an odds ratio = 7.0 (95% confidence interval = 2.7 to 18.5). Effects of MMVF could not be disentangled from those of asbestos. DISCUSSION:: In workers with exposure levels lower than in most historical cohort studies and across a wide range of industries, a strong association was found between asbestos, especially when it was amphibole, and mesothelioma.

• Characteristics of menstruation and pregnancy and the risk of lung cancer in women.

  Authors: Anita Koushik, Marie-Élise Parent, Jack Siemiatycki

  International journal of cancer. Journal international du cancer. 06/2009;

  Lung tissue, both normal and cancerous, has been found to express estrogen receptors and patterns of expression have differed between men and women, suggesting a possible role for hormone-relatedLung tissue, both normal and cancerous, has been found to express estrogen receptors and patterns of expression have differed between men and women, suggesting a possible role for hormone-related factors in lung carcinogenesis in women. Few epidemiological studies have examined hormone-related variables and lung cancer risk and the findings have not been consistent. We investigated the association between characteristics of menstruation and pregnancy in relation to lung cancer risk in a population-based case-control study carried out in Montreal, Canada, including 422 women with lung cancer and 577 controls. For each variable, odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression modeling. Associations were also examined according to level of smoking and by lung cancer histology. All statistical tests were two-sided. Most characteristics of menstruation and pregnancy were not associated with lung cancer risk. However, an increased risk was observed for women who had had a non-natural menopause, which predominantly included women who had had a bilateral oophorectomy, compared with women who had had a natural menopause (OR = 1.92, 95% CI: 1.22-3.01). An inverse association with age at menopause was suggested. These results did not vary by level of smoking and they were similar for adenocarcinomas compared with other histological types. Our results suggest that hormonal factors, related to early menopause and/or ovary removal, may play a role in the risk of lung cancer. Further studies are needed to confirm these findings, and to assess the possible contribution of hormone replacement therapy. (c) 2009 UICC.

• Quantifying the Impact of Selection Bias Caused by Nonparticipation in a Case-Control Study of Mobile Phone Use.

  Authors: Martine Vrijheid, Lesley Richardson, Bruce K Armstrong, Anssi Auvinen, Gabriele Berg, Matthew Carroll, Angela Chetrit, Isabelle Deltour, Maria Feychting, Graham G Giles [......] Siegal Sadetzki, Tina Salminen, Marie Sanchez, Birgitte Schlehofer, Joachim Schüz, Jack Siemiatycki, Tore Tynes, Alistair Woodward, Naohito Yamaguchi, Elisabeth Cardis

  Annals of epidemiology. 02/2009; 19(1):33-41.e1.

  PURPOSE: To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor. METHODS: Non-responsePURPOSE: To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor. METHODS: Non-response questionnaires (NRQ) were completed by a sub-set of nonparticipants. Selection bias factors were calculated based on the prevalence of mobile phone use reported by nonparticipants with NRQ data, and on scenarios of hypothetical exposure prevalence for other nonparticipants. RESULTS: Regular mobile phone use was reported less frequently by controls and cases who completed the NRQ (controls, 56%; cases, 50%) than by those who completed the full interview (controls, 69%; cases, 66%). This relationship was consistent across study centers, sex, and age groups. Lower education and more recent start of mobile phone use were associated with refusal to participate. Bias factors varied between 0.87 and 0.92 in the most plausible scenarios. CONCLUSIONS: Refusal to participate in brain tumor case-control studies seems to be related to less prevalent use of mobile phones, and this could result in a downward bias of around 10% in odds ratios for regular mobile phone use. The use of simple selection bias estimation methods in case-control studies can give important insights into the extent of any bias, even when nonparticipant information is incomplete.

• Lifetime consumption of alcoholic beverages and risk of 13 types of cancer in men: results from a case-control study in Montreal.

  Authors: Andrea Benedetti, Marie-Elise Parent, Jack Siemiatycki

  Cancer detection and prevention. 02/2009; 32(5-6):352-62.

  BACKGROUND: The aim of the study was to investigate the association between lifetime consumption of alcoholic beverages and cancer risk. METHODS: Data were collected in a population-basedBACKGROUND: The aim of the study was to investigate the association between lifetime consumption of alcoholic beverages and cancer risk. METHODS: Data were collected in a population-based case-control study, conducted in Montreal in the mid-1980s, designed to assess the associations between hundreds of non-occupational and occupational exposures and multiple cancer sites in men. We present results for 13 cancer sites: oesophagus (n = 78), stomach (n = 215), colon (n = 427), rectum (n = 239), liver (n = 28), pancreas (n = 83), lung (n = 700), melanoma (n = 107), prostate (n = 374), bladder (n = 425), kidney (n = 156), Hodgkin's lymphoma (n = 42), and non-Hodgkin's lymphoma (n = 190), in comparison to population controls (n = 507). Odds ratios (OR) were estimated for the associations between lifetime consumption of total alcoholic beverages, beer, wine, and/or spirits, altogether and separately, and each cancer site, while carefully adjusting for smoking and other covariates using polytomous logistic regression. RESULTS: For several cancers (oesophagus, stomach, colon, liver, pancreas, lung, prostate) there was evidence of increased risk among alcohol consumers compared with abstainers and occasional drinkers. For most sites, it was beer and to a lesser extent spirits consumption that drove the excess risks. CONCLUSIONS: Our results support the hypothesis that moderate and high alcohol intake levels over the lifetime might increase cancer risk at several sites.

• Does Exposure to Agricultural Chemicals Increase the Risk of Prostate Cancer among Farmers?

  Authors: Marie-Elise Parent, Marie Désy, Jack Siemiatycki

  McGill journal of medicine : MJM : an international forum for the advancement of medical sciences by students. 01/2009; 12(1):70-7.

  Several studies suggest that farmers may be at increased risk of prostate cancer. The present analysis, based on a large population-based case-control study conducted among men in the Montreal areaSeveral studies suggest that farmers may be at increased risk of prostate cancer. The present analysis, based on a large population-based case-control study conducted among men in the Montreal area in the early 1980's, aim at identifying occupational chemicals which may be responsible for such increases. The original study enrolled 449 prostate cancer cases, nearly 4,000 patients with other cancers, as well as 533 population controls. Subjects were interviewed about their occupation histories, and a team of industrial hygienists assigned their past exposures using a checklist of some 300 chemicals. The present analysis was restricted to a study base of men who had worked as farmers earlier in their lives. There were a total of 49 men with prostate cancers, 127 with other cancers and 56 population controls. We created a pool of 183 controls combining the patients with cancers at sites other than the prostate and the population controls. We then estimated the odds ratio for prostate cancer associated with exposure to each of 10 agricultural chemicals, i.e., pesticides, arsenic compounds, acetic acid, gasoline engine emissions, diesel engine emissions, polycyclic aromatic hydrocarbons from petroleum, lubricating oils and greases, alkanes with >/=18 carbons, solvents, and mononuclear aromatic hydrocarbons. Based on a model adjusting for age, ethnicity, education, and respondent status, there was evidence of a two-fold excess risk of prostate cancer among farmers with substantial exposure to pesticides [odds ratio (OR)=2.3, 95% confidence interval (CI) 1.1-5.1], as compared to unexposed farmers. There was some suggestion, based on few subjects, of increased risks among farmers ever exposed to diesel engine emissions (OR=5.7, 95% CI 1.2-26.5). The results for pesticides are particularly noteworthy in the light of findings from previous studies. Suggestions of trends for elevated risks were noted with other agricultural chemicals, but these are largely novel and need further confirmation in larger samples.

• Occupational Exposure to Asbestos and Man-Made Vitreous Fibers, and Risk of Lung Cancer: Evidence From Two Case-Control Studies in Montreal, Canada.

  Authors: Javier Pintos, Marie-Elise Parent, Marie-Claude Rousseau, Bruce Case, Jack Siemiatycki

  Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine. 12/2008; 50(11):1273-1281.

  OBJECTIVE:: To examine the effects of occupational asbestos and man-made vitreous fibers (MMVF) on the risk of lung cancer in two population-based case-control studies entailing exposure at lowerOBJECTIVE:: To examine the effects of occupational asbestos and man-made vitreous fibers (MMVF) on the risk of lung cancer in two population-based case-control studies entailing exposure at lower levels than in historic cohort studies. METHODOLOGY:: Study I (1979 to 1986) comprised 857 cases and 1066 population and cancer controls. Study II (1996 to 2001) comprised 858 cases and 1295 population controls. A detailed job history was obtained to evaluate lifetime occupational exposure to 294 agents, including asbestos and MMVF. RESULTS:: We found increased risks for substantial exposure to asbestos (odds ratio = 1.78; 95% confidence interval: 0.94 to 3.36). The corresponding odds ratio for substantial exposure to MMVF was 1.10 (95% confidence interval: 0.37 to 3.22). DISCUSSION:: Low and moderate levels of exposure to asbestos, as encountered in this population, were associated with some excess risk of lung cancer. Results for MMVF were inconclusive.

• Exposures in painting related occupations and risk of selected cancers: results from a case-control study in Montreal.

  Authors: Agnihotram V Ramanakumar, Louise Nadon, Jack Siemiatycki

  American journal of industrial medicine. 07/2008; 51(6):419-27.

  BACKGROUND: Painters are considered to be at increased risk of lung cancer. The objective was to evaluate risk of several cancers, apart from lung, in painting-related professions. Most previousBACKGROUND: Painters are considered to be at increased risk of lung cancer. The objective was to evaluate risk of several cancers, apart from lung, in painting-related professions. Most previous studies have focused on the job title rather than on exposures incurred. METHODS: A large population based case-control study was carried out during 1979-1986 in Montreal including several types of cancer and focusing on occupational exposures. Interviews elicited detailed lifetime job histories; those were evaluated by a team of industrial hygienists to assign exposure. The exposure checklist included three paint-related substances: metal coatings, wood varnishes and stains, and wood and gypsum paints. Seven types of cancer were analyzed (numbers interviewed): esophagus (97), stomach (248), colorectal (754), prostate (438), bladder (478), kidney (174) and non-Hodgkin's lymphoma (215). For each cancer type, a pooled control group was constituted from 533 population controls and 533 cancer patients selected from other types of cancer. Odds ratios (ORs) were estimated between each of the paint-related agents and each of the seven cancer types, adjusting for several potential confounders, including smoking. RESULTS: The job title of "painters" was not associated with risk of any of the cancers under study. Most of the ORs between the three agents and the seven cancers were close to null. However, there was a tendency for ORs to be above 1.0 for subjects who had substantial exposure to metal coatings, with noteworthy associations for cancers of the esophagus (OR = 4.2; 95% CI: 1.1-17.0; n = 4), prostate (OR = 2.7; 95% CI: 1.0-7.7; n = 13), and bladder (OR = 1.7; 95% CI: 0.7-4.4; n = 13). CONCLUSION: These results are compatible with an absence of risk among painting-related professions; they are also compatible with excess risk of certain cancers, especially among those exposed to metal coatings.