1,722,856 research outputs found
Malignant mesothelioma: Epidemiology
No full textPrimary malignant neoplasms of the pleura and peritoneum originate from the mesothelial cells that line the respective cavities. The majority of these tumors are mesotheliomas. Mesothelioma is a relatively rare but very severe neoplasm, Exposure to asbestos (primarily on the workplace) is the main cause of mesothelioma. All types of asbestos fibers cause mesothelioma, but the potency of amphiboles is greater than that of chrysotile. The main determinant of mesothelioma risk is time since first asbestos exposure; duration and level of exposure play a minorrole. © Springer-Verlag London 2014
Mechanistic considerations in the molecular epidemiology of head and neck cancer
No full textHead and neck cancer occurs through a complex multistage process that is likely to involve a combination of carcinogen exposure and genetic susceptibility. The primary cause of head and neck cancer are alcohol consumption and cigarette smoking, although the carcinogenic mechanism for these agents is unclear. Molecular epidemiological studies of head and neck cancer can help to clarify the carcinogenic process in several ways, including identification of metabolizing genes which increase the risk of head and neck cancer, identification of DNA adducts in target cells and analysis of specific gene mutations and their relationship with exposure. This review summarizes current knowledge on the molecular epidemiology of head and neck cancer and attempts to identify those areas where future studies may prove fruitful
Lung cancer (exposure assessment, pathology, and epidemiology)
No full textLung cancer is the most common malignancy worldwide and the most common cause of a cancer-related death. Tobacco smoking is the most important cause of lung cancer in most populations although occupational exposures cause an increased risk of lung cancer more than any other malignancy. This chapter will review the histomorphology and classification of carcinoma of the lung and the evidence for specific occupational exposures reported to cause lung cancer. © Springer-Verlag London 2014
Multiple primary cancers as clues to environmental and heritable causes of cancer and mechanisms of carcinogenesis
No full textSuccesses in cancer therapy are leading to an increasing incidence of second cancers, which may be due to the same factors that cause first cancers or to the effect of therapy for the first cancer. There are also a number of specific methodological and sampling problems that have to be controlled before informative studies can be embarked upon. The risk of a second cancer is higher than that for the first one, which may be an indication of a particular exposure, an inherited set of genes, or both. We show clustering of multiple cancers caused by tobacco, alcohol and infections. We discuss familial aggregation of cancer as one of the causes of multiple primary cancers. However, multiple primary cancers may particularly be a manifestation of polygenic susceptibility, which cannot easily be recognized as familial clustering, and multiple cancers may offer a model for understanding the complex etiology of human cancer and for generating and testing hypotheses on mechanisms of carcinogenesis
Biomarkers in cancer epidemiology: An integrative approach
No full textThere are different reasons for the increase in the use of biomarkers in cancer epidemiology which is as follows: (i) the fact that the identification of new carcinogens, characterized by complex exposure circumstances and weak effects, has become increasingly difficult with traditional epidemiological approaches; (ii) the increasing understanding of mechanisms of carcinogenesis and (iii) technical developments in molecular biology and genetics. While a distinction is made between biomarkers of exposure, intermediate events, disease, outcome and susceptibility, their integration in a unique conceptual model is needed. The use of exposure biomarkers in cancer epidemiology aims at measuring the biologically relevant exposure more validly and precisely. In some instances, there is an obvious improvement in using an exposure biomarker, as in the case of urinary markers of aflatoxin and tobacco-specific nitrosamines. Intermediate (effect) biomarkers measure early-in general non-persistent-biological events that take place in the continuum between exposure and cancer development. These include cellular or tissue toxicity, chromosomal alterations, changes in DNA, RNA and protein expression and alterations in functions relevant to carcinogenesis (e.g. DNA repair, immunological response, etc.). The analysis of acquired TP53 mutations is an example of the potentially important. Biomarkers should be validated and consideration of sources of bias and confounding in molecular epidemiology studies should be no less stringent than in other types of epidemiological studies. The overarching goal is the integration of different types of biomarkers to derive risk and outcome profiles for healthy individuals as well as patients. © The Author 2009. Published by Oxford University Press
The contribution of molecular epidemiology to the identification of human carcinogens: Current status and future perspectives
No full textBackground: The use of biological-based markers of exposure, intermediate effect, outcome, and susceptibility has become standard practice in cancer epidemiology, which has contributed to identification of several carcinogenic agents. Nevertheless, with the exception of biological agents, this contribution, in terms of providing sufficiently strong evidence as required by the International Agency for Research on Cancer (IARC) monographs, has been modest. Materials and methods: We discuss the overall contribution of molecular epidemiology to identification of carcinogens, with focus on IARC monographs. Results: For many carcinogens, valid biological markers of exposure and mechanisms of actions are not available. Molecular markers are usually assessed in single biological samples, which may not represent the actual exposure or biological events related to carcinogens. The contribution of molecular epidemiology to identification of carcinogens has mainly been limited to the carcinogens acting through a genotoxic mechanism, i.e. when carcinogens induce DNA damage. A number of factors, including certain hormones and overweight/obesity, may show carcinogenic effects through nongenotoxic pathways, for which mechanisms of carcinogenicity are not well identified and their biomarkers are sparse. Conclusion: Longitudinal assessment of biomarkers may provide more informative data in molecular epidemiology studies. For many carcinogens and mechanistic pathways, in particular nongenotoxic carcinogenicity, valid biological markers still need to be identified. © The Author 2012
Response to: Pleural mesothelioma, and occupational and non-occupational asbestos exposure: A case-control study with quantitative risk assessment
No full textNo abstrac
Research on cancer prevention, detection and management in low- and medium-income countries
No full textThe burden of cancer in low- and medium-income countries (LMIC) is expected to increase in the next decades. The application of current knowledge and results of research in key areas would contribute to limit the impact of this phenomenon. Opportunities for research on cancer prevention in LMIC include investigating specific circumstances of exposure to known carcinogens and to agents which are not prevalent in other regions, as well as interactions among carcinogens and between genetic and environmental factors. Early detection both by screening and early clinical diagnosis represents an important component of cancer control in LMIC. Research has been carried out to identify effective and sustainable approaches for early detection of cervical cancer through human papillomavirus testing and visual tests and of oral cancer through visual inspection. For other important neoplasms such as breast cancer, on the other hand, no effective low-cost screening methods are currently available. Downstaging represents a potentially important approach for cancer control and a priority area for future research. Studies addressing the efficacy of treatment protocols, country-specific cost-effectiveness of various interventions and the clinical utility and cost-effectiveness of innovative heath care and communication technologies represent the priority for clinical cancer research. © The Author 2010. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved
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