Cancer Markers Associated With Occupational Exposure to Trichloroethylene
30 de outubro de 2020 atualizado por: National Cancer Institute (NCI)
A Cross-Sectional Study of Occupational Exposure to Trichloroethylene, Chromosomal Aberrations, and Related Biomarkers in Guangdong, China
Background:
- Trichloroethylene (TCE) is a solvent used in many medical and industrial processes.
- TCE is a carcinogen (causes cancer) in rats, but its carcinogenicity in humans is unclear. There is some evidence of increased liver and kidney cancers and of an association with non-Hodgkin lymphoma in studies of workers exposed to TCE.
- The carcinogenicity and regulation of TCE is a matter of continuing debate.
Objectives:
- To determine if TCE exposure is associated with higher levels of genetic aberrations in certain white blood cells called lymphocytes.
- To determine if TCE exposure affects lymphocyte subsets and levels of certain hormones called cytokines.
Eligibility: Workers exposed to two different levels of exposure to TCE and unexposed workers in Guangdong Province, China.
Design:
- 45 workers exposed to more than 25 parts per million (ppm) TCE, 30 workers exposed to from 10 to less than 25 ppm TCE and 45 unexposed workers will be enrolled.
- Subjects wear small instruments at work that measure chemicals in the air for 1 or 2 days during the 2-week study period. Exposed workers also wear several small skin patches on one of the two days.
- Subjects provide blood and urine samples.
- Subjects answer a questionnaire about work, smoking and drinking, use of medicines, medical history, general health, hobbies, and exposure to radiation and exposure to various substances at home.
Visão geral do estudo
Status
Concluído
Condições
Descrição detalhada
Trichloroethylene (TCE) is an industrial solvent used in degreasing, dry cleaning, and numerous other medical and industrial processes.
It is a ubiquitous environmental contaminant of drinking water and is present in many EPA Superfund sites.
TCE is a rodent carcinogen but its carcinogenicity in humans is unclear.
There is some evidence for an elevation in liver and kidney cancers and somewhat more convincing evidence of an association with non-Hodgkin lymphoma (NHL) in epidemiological studies of occupationally exposed cohorts.
Overall, the carcinogenicity of TCE and its regulation is a matter of continuing debate despite an extensive database of in vitro and in vivo animal studies and several cohort and case-control studies.
IARC categorizes TCE as a probable human carcinogen.
In order to address questions about TCE's potential carcinogenicity and mechanism of action in humans, we propose to conduct a cross-sectional study of early biologic effect biomarkers of genotoxicity and immunotoxicity in 45 workers exposed to greater than 25 ppm TCE, 30 workers exposed to 10-25 ppm TCE, and 45 unexposed controls in Guangdong Province, China.
We will assess TCE exposure level quantitatively, collect other exposure information through a questionnaire, collect biological samples, and assay a series of biomarkers of susceptibility, intermediate and early biologic effects.
Our primary goal is to determine if TCE exposure increases chromosomal aberrations in peripheral lymphocytes, with a secondary goal of determining if TCE alters levels of key cytokines in plasma and changes lymphocyte subset ratios.
In addition, our collaborators at UC Berkeley will apply a new generation of cytogenetic and molecular techniques to study TCE's ability to cause specific types of chromosomal aberrations that have been associated with NHL and related hematological malignancies as well as the impact of TCE on mRNA expression and the proteome.
The work will compliment previous and ongoing OEEB studies of populations exposed to TCE and has the potential to make an important contribution to what little is known about the early biologic effects of TCE in humans.
Tipo de estudo
Observacional
Inscrição (Real)
125
Contactos e Locais
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Locais de estudo
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Guangzhou, China
- Guangdong National Poison Control Center (NPCC)
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Critérios de participação
Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.
Critérios de elegibilidade
Idades elegíveis para estudo
18 anos a 50 anos (Adulto)
Aceita Voluntários Saudáveis
Não
Gêneros Elegíveis para o Estudo
Tudo
Método de amostragem
Amostra de Probabilidade
População do estudo
We carried out a cross-sectional study of workers currently exposed to TCE in the six study factories with TCE cleaning operations and unexposed controls.
Control workers were enrolled from two clothes manufacturing factories, one food production factory and a hospital that did not use TCE and were in the same geographic region as the factories that used TCE.
Exclusion criteria for both TCE-exposed and control workers were history of cancer, chemotherapy and radiotherapy, as well as previous occupations with notable exposure to benzene, butadiene, styrene and/or ionizing radiation.
Descrição
- INCLUSION CRITERIA:
A total of 45 workers exposed to greater than 25 ppm TCE, 30 workers exposed from 10 to less than 25 ppm TCE, and 45 unexposed workers will be enrolled.
We will identify 45 workers from 3 factories who are exposed to greater than 25 ppm TCE. Our colleagues at the Guangdong NPCC will visit potential study factories and carry out air measurements for TCE, epichlorhydrin, methylene chloride, perchloroethylene and benzene. Factories will be selected that use only TCE for degreasing processes, have minimal co-exposures present in the same part of the workplace where TCE is used, and have used a stable manufacturing process for the past five years.
Workers will be chosen who work in part of the factory with TCE exposure, have worked for at least one year in the factory doing the same job in the same part of the manufacturing process, and have not been exposed to other genotoxic, hematotoxic, or immunotoxic compounds in any workplace. We will enroll 45 controls, who have no history of occupational exposure to TCE or to any other genotoxic, hematotoxic or immunotoxic chemicals.
EXCLUSION CRITERIA:
History of cancer, chemotherapy with DNA-damaging or immunotoxic agents, and medical treatment with ionizing radiation.
Plano de estudo
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Como o estudo é projetado?
Detalhes do projeto
O que o estudo está medindo?
Medidas de resultados primários
Medida de resultado |
Descrição da medida |
Prazo |
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Hematotoxicity change
Prazo: 2006-2034
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The primary goal of the study is to determine if TCE exposure is associated with higher levels of chromosomal aberrations in peripherallymphocytes.
The additional goals of the study, to be funded by extramural collaborators, are to evaluate TCE urinary metabolite patterns, alterations in specific types of chromosomal aberrations that have been detected in NHL and other hematopoietic malignancies, and alterations in mRNA expression and the proteome.
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2006-2034
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Immune function
Prazo: 2006-2034
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A secondary goal of the study is to determine if TCE exposure alters plasma cytokine levels and lymphocyte subsets.
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2006-2034
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Colaboradores e Investigadores
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Patrocinador
Datas de registro do estudo
Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.
Datas Principais do Estudo
Início do estudo (Real)
15 de junho de 2006
Conclusão Primária (Real)
30 de outubro de 2020
Conclusão do estudo (Real)
30 de outubro de 2020
Datas de inscrição no estudo
Enviado pela primeira vez
1 de junho de 2007
Enviado pela primeira vez que atendeu aos critérios de CQ
1 de junho de 2007
Primeira postagem (Estimativa)
4 de junho de 2007
Atualizações de registro de estudo
Última Atualização Postada (Real)
3 de novembro de 2020
Última atualização enviada que atendeu aos critérios de controle de qualidade
30 de outubro de 2020
Última verificação
1 de outubro de 2020
Mais Informações
Termos relacionados a este estudo
Palavras-chave
Outros números de identificação do estudo
- 999906176
- 06-C-N176
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