Occupational exposures and risk of lung cancer among women

Contexte: Le cancer du poumon est la deuxième cause de décès par cancer chez les femmes mondialement. Peu d'études ont examiné les facteurs de risque professionnel potentiel de ce cancer chez celles-ci. Objectif: Cette thèse vise à déterminer si certaines expositions professionnelles sont associées au risque de cancer du poumon chez les femmes. L’objectif principal est composé de trois sous-objectifs: 1) Étudier les associations entre les expositions professionnelles prévalentes telles qu'évaluées par des experts et le risque de cancer du poumon chez les femmes dans une étude cas-témoin Montréalaise. 2) Comparer la concordance des attributions d'exposition entre la matrice emploi-exposition canadienne (CANJEM) et l'évaluation d'experts pour les emplois occupés par des femmes. 3) Étudier les associations entre des expositions professionnelles prévalentes et le risque de cancer du poumon chez les femmes dans un ensemble de données internationales combinées de dix études cas-témoins de ce cancer, en utilisant CANJEM pour évaluer les expositions des femmes Méthodes : Pour le sous-objectif 1, nous avons utilisé des modèles de régression logistique multivariée pour examiner les associations entre les expositions professionnelles prévalentes et le risque de cancer du poumon chez les femmes (361 cas et 521 témoins) dans l'étude de Montréal. Pour le sous-objectif 2, nous avons comparé la concordance des expositions entre CANJEM et les experts pour 69 expositions professionnelles en utilisant les données de la même étude montréalaise. Pour le sous-objectif 3, nous avons utilisé une approche méta-analytique pour examiner les associations entre des expositions professionnelles prévalentes et le risque de cancer du poumon chez les femmes (3040 cas et 4187 témoins) à partir de dix études cas-témoins menées en Europe, au Canada et en Nouvelle-Zélande. En l'absence de la disponibilité de données sur les expositions des femmes, nous avons appliqué CANJEM pour estimer les expositions professionnelles. Résultats: Nous n'avons pas observé de risque accru de cancer du poumon chez les femmes exposées professionnellement à 22 agents prévalents évalués dans l'étude de Montréal. Nous avons constaté que la capacité de CANJEM à reproduire l'évaluation des expositions par des experts variait selon l'agent. 2 Compte tenu de ces résultats, nous avons sélectionné 15 agents susceptibles d'être évaluables à l'aide de CANJEM qui étaient également répandus dans l'ensemble de données internationales. Il n'y avait aucune association entre la plupart des agents examinés et le cancer pulmonaire; cependant, les expositions à la poussière métallique, aux composés de fer, à l'isopropanol et aux solvants organiques étaient associées à des risques légèrement élevés. Conclusions: Cette thèse a estimé l'exposition professionnelle des femmes à un large éventail d'agents et a examiné leurs associations avec le cancer du poumon. Dans l'étude de Montréal, aucun des agents évalués par les experts n'était associé à ce cancer. CANJEM s'est avéré capable de reproduire des évaluations d'exposition similaires à celles des experts, bien que sa fiabilité dépende de l'agent. Les expositions professionnelles évaluées par CANJEM ont suggéré des risques plus élevés de cancer du poumon chez les femmes exposées à la poussière métallique, aux composés de fer, à l'isopropanol et aux solvants organiques.Background: Worldwide, lung cancer is the second leading cause of cancer death among women. Few studies have examined possible occupational risk factors for lung cancer in women. Objective: This thesis aims to investigate whether selected occupational exposures are associated with lung cancer risk among women. The main objective consists of three sub-objectives: 1) To investigate associations between prevalent occupational exposures as assessed by experts and lung cancer risk among women in a Montreal lung cancer case-control study 2) To compare exposure assignment concordance between the Canadian Job-Exposure Matrix (CANJEM) and expert assessment for jobs held by women 3) To investigate associations between prevalent occupational exposures and lung cancer risk among women in a combined international dataset of ten lung cancer case-control studies, with exposure assessed by CANJEM. Methods: For sub-objective 1, we used multivariate logistic regression models to examine the associations between prevalent occupational exposures as assessed by experts and lung cancer risk among women (361 cases and 521 controls) in the Montreal study. For sub-objective 2, we compared exposure assignment concordance between CANJEM and expert assessments for 69 occupational exposures using data from the same Montreal study. For sub-objective 3, we used meta-analysis to examine the associations between prevalent occupational exposures and lung cancer risk among women (3040 cases and 4187 controls) from ten case-control studies conducted in Europe, Canada, and New Zealand. In the absence of available expert-assessed exposures, we applied CANJEM to estimate occupational exposures. Results: We did not observe a clearly increased risk of lung cancer among women occupationally exposed to 22 prevalent agents assessed by experts in the Montreal study. We found that CANJEM’s ability to replicate expert assessment of exposures varied by agent and by specific configurations of CANJEM. Considering these findings, we selected 15 agents suitable to evaluate using CANJEM — which were also prevalent in the international dataset of ten studies — and examined their risks for lung cancer. There was no association between most agents examined in this analysis and lung cancer; however, exposures to metallic dust, iron compounds, isopropanol, and organic solvents were associated with suggestive higher risks. 4 Conclusions: This thesis estimated women's occupational exposure to a wide range of agents and examined their associations with lung cancer. In the Montreal study, none of the expert-assessed prevalent agents was associated with lung cancer. CANJEM was shown to be able to reproduce exposure assessments similar to those of the experts, although its reliability was agent dependent. Occupational exposures assessed by CANJEM in the international dataset of ten studies indicated slightly higher risks of lung cancer among women exposed to metallic dust, iron compounds, isopropanol, and organic solvents

Subject response rates in case-control studies of cancer : time trends, study design determinants, and quality of reporting

Objectifs: Examiner les tendances temporelles, les déterminants en lien avec le design des études et la qualité des taux de réponse rapportés dans des études cas-témoins sur le cancer publiées lors des 30 dernières années. Méthodes: Une revue des études cas-témoins sur le cancer a été menée. Les critères d'inclusion étaient la publication (i) dans l’un de 15 grands périodiques ciblés et (ii) lors de quatre périodes de publication (1984-1986, 1995, 2005 et 2013) couvrant trois décennies. 370 études ont été sélectionnées et examinées. La méthodologie en lien avec le recrutement des sujets et la collecte de données, les caractéristiques de la population, les taux de participation et les raisons de la non-participation ont été extraites de ces études. Des statistiques descriptives ont été utilisées pour résumer la qualité des taux de réponse rapportés (en fonction de la quantité d’information disponible), les tendances temporelles et les déterminants des taux de réponse; des modèles de régression linéaire ont été utilisés pour analyser les tendances temporelles et les déterminants des taux de participation. Résultats: Dans l'ensemble, les qualités des taux de réponse rapportés et des raisons de non-participation étaient très faible, particulièrement chez les témoins. La participation a diminué au cours des 30 dernières années, et cette baisse est plus marquée dans les études menées après 2000. Lorsque l'on compare les taux de réponse dans les études récentes a ceux des études menées au cours de 1971 à 1980, il y a une plus grande baisse chez les témoins sélectionnés en population générale ( -17,04%, IC 95%: -23,17%, -10,91%) que chez les cas (-5,99%, IC 95%: -11,50%, -0,48%). Les déterminants statistiquement significatifs du taux de réponse chez les cas étaient: le type de cancer examiné, la localisation géographique de la population de l'étude, et le mode de collecte des données. Le seul déterminant statistiquement significatif du taux de réponse chez les témoins hospitaliers était leur localisation géographique. Le seul déterminant statistiquement significatif du taux de participation chez les témoins sélectionnés en population générale était le type de répondant (sujet uniquement ou accompagné d’une tierce personne). Conclusion: Le taux de participation dans les études cas-témoins sur le cancer semble avoir diminué au cours des 30 dernières années et cette baisse serait plus marquée dans les études récentes. Afin d'évaluer le niveau réel de non-participation et ses déterminants, ainsi que l'impact de la non-participation sur la validité des études, il est nécessaire que les études publiées utilisent une approche normalisée pour calculer leurs taux de participation et qu’elles rapportent ceux-ci de façon transparente.Objectives: To examine the time trends, study design determinants, and quality of reporting of response rates in published case-control studies of cancer over the past 30 years. Methods: A review was conducted of case-control studies of cancer. Inclusion criteria required publications in 15 major journals, during four publication periods spanning three decades (1984-86, 1995, 2005 and 2013). 370 studies were selected and reviewed. Information on study base ascertainment, data collection methods, population characteristics, response rates, and reasons for non-participation was extracted. Quality of response rate reporting was assessed based on the amount of information reported. Descriptive statistics were used to summarize the quality of the reporting, time trends and the determinants of response rates; linear regression models were used to analyse time trends and determinants of response rates. Results: Overall, the quality of reporting of response rates and reasons for non-participation was very poor, especially for control series. Participation has declined over the past 30 years, and this decline was steeper in studies conducted after 2000. When comparing the response rates in recent studies to that in studies conducted during 1971-1980, there was a greater decline of this rate in population controls (-17.04%, 95% CI: -23.17%, -10.91%) than in cases (-5.99%, 95% CI: -11.50%, -0.48%). Statistically significant determinants of response rates among cases were: cancer type examined, location of the study population, and mode of data collection. The only statistically significant determinant of response rates among medical source controls was location of the study population. The only statistically significant determinant of response rates among population controls was type of respondent (self only or self and proxy) accepted by studies. Conclusion: Response rates in case-control studies of cancer seem to have declined and this decline has accelerated in recent studies. In order to appreciate the true level of non-participation and its determinants, as well as the impact of non-participation on validity of studies, there is a need for more transparent reporting and standardized calculation of response rates in published studies

Trusting those who trust you: A study on trust and privacy on Facebook

Over more than a decade, IS research has examined the role of trust in the context of technology adoption such as website acceptance(Gefen et al. 2003), successful online interactions(Coppola et al. 2004) and recommendation agents usage(Wang and Benbasat 2005). The primary antecedent of trust in the line of research is often trustee’s trustworthiness. However, Dashiti et al. (2011) articulated the role of trust- received(trustor’s felt trust from trustee) will cause trust-given(trustor’s trust in trustee) and later the trusting behaviors in the e-government context. Drawing on the recent development, this study aims to investigate the context of online social networks (OSNs) and to test whether trust-received plays a similar role in forming the interpersonal trust among Facebook user’s interactions. We aim to find out (i) whether users are more willing to trust others and share their personal information with them when individuals experienced trust-received and (ii) what IT features influence trust-received

Complementary Labels Learning with Augmented Classes

Complementary Labels Learning (CLL) arises in many real-world tasks such as private questions classification and online learning, which aims to alleviate the annotation cost compared with standard supervised learning. Unfortunately, most previous CLL algorithms were in a stable environment rather than an open and dynamic scenarios, where data collected from unseen augmented classes in the training process might emerge in the testing phase. In this paper, we propose a novel problem setting called Complementary Labels Learning with Augmented Classes (CLLAC), which brings the challenge that classifiers trained by complementary labels should not only be able to classify the instances from observed classes accurately, but also recognize the instance from the Augmented Classes in the testing phase. Specifically, by using unlabeled data, we propose an unbiased estimator of classification risk for CLLAC, which is guaranteed to be provably consistent. Moreover, we provide generalization error bound for proposed method which shows that the optimal parametric convergence rate is achieved for estimation error. Finally, the experimental results on several benchmark datasets verify the effectiveness of the proposed method

Influence Maximization in Social Networks: A Survey

Online social networks have become an important platform for people to communicate, share knowledge and disseminate information. Given the widespread usage of social media, individuals' ideas, preferences and behavior are often influenced by their peers or friends in the social networks that they participate in. Since the last decade, influence maximization (IM) problem has been extensively adopted to model the diffusion of innovations and ideas. The purpose of IM is to select a set of k seed nodes who can influence the most individuals in the network. In this survey, we present a systematical study over the researches and future directions with respect to IM problem. We review the information diffusion models and analyze a variety of algorithms for the classic IM algorithms. We propose a taxonomy for potential readers to understand the key techniques and challenges. We also organize the milestone works in time order such that the readers of this survey can experience the research roadmap in this field. Moreover, we also categorize other application-oriented IM studies and correspondingly study each of them. What's more, we list a series of open questions as the future directions for IM-related researches, where a potential reader of this survey can easily observe what should be done next in this field

CRIT:Identifying RNA-binding protein regulator in circRNA life cycle via non-negative matrix factorization

Circular RNAs (circRNAs) are endogenous non-coding RNAs that regulate gene expression and participate in carcinogenesis. However, the RNA-binding proteins (RBPs) involved in circRNAs biogenesis and modulation remain largely unclear. We developed the circRNA regulator identification tool (CRIT), a non-negative matrix-factorization-based pipeline to identify regulating RBPs in cancers. CRIT uncovered 73 novel regulators across thousands of samples by effectively leveraging genomics data and functional annotations. We demonstrated that known RBPs involved in circRNA control are significantly enriched in these predictions. Analysis of circRNA-RBP interactions using two large cross-linking immunoprecipitation (CLIP) databases, we validated the consistency between CRIT prediction and the CLIP experiments. Furthermore, newly discovered RBPs are functionally connected with authentic circRNA regulators by various biological associations, such as physical interaction, similar binding motifs, common transcription factor modulation, and co-expression. When analyzing RNA sequencing (RNA-seq) datasets after short hairpin RNA (shRNA)/small interfering RNA (siRNA) knockdown, we found several novel RBPs that can affect global circRNA expression, which strengthens their role in the circRNA life cycle. The above evidence provided independent confirmation that CRIT is a useful tool to capture RBPs in circRNA processing. Finally, we show that authentic regulators are more likely the core splicing proteins and peripheral factors and usually harbor more alterations in the vast majority of cancers