Cancer Markers Associated With Occupational Exposure to Trichloroethylene
30 ottobre 2020 aggiornato da: 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.
Panoramica dello studio
Stato
Completato
Condizioni
Descrizione dettagliata
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 di studio
Osservativo
Iscrizione (Effettivo)
125
Contatti e Sedi
Questa sezione fornisce i recapiti di coloro che conducono lo studio e informazioni su dove viene condotto lo studio.
Luoghi di studio
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Guangzhou, Cina
- Guangdong National Poison Control Center (NPCC)
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Criteri di partecipazione
I ricercatori cercano persone che corrispondano a una certa descrizione, chiamata criteri di ammissibilità. Alcuni esempi di questi criteri sono le condizioni generali di salute di una persona o trattamenti precedenti.
Criteri di ammissibilità
Età idonea allo studio
Da 18 anni a 50 anni (Adulto)
Accetta volontari sani
No
Sessi ammissibili allo studio
Tutto
Metodo di campionamento
Campione di probabilità
Popolazione di studio
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.
Descrizione
- 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.
Piano di studio
Questa sezione fornisce i dettagli del piano di studio, compreso il modo in cui lo studio è progettato e ciò che lo studio sta misurando.
Come è strutturato lo studio?
Dettagli di progettazione
Cosa sta misurando lo studio?
Misure di risultato primarie
Misura del risultato |
Misura Descrizione |
Lasso di tempo |
|---|---|---|
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Hematotoxicity change
Lasso di tempo: 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
Lasso di tempo: 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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Collaboratori e investigatori
Qui è dove troverai le persone e le organizzazioni coinvolte in questo studio.
Sponsor
Studiare le date dei record
Queste date tengono traccia dell'avanzamento della registrazione dello studio e dell'invio dei risultati di sintesi a ClinicalTrials.gov. I record degli studi e i risultati riportati vengono esaminati dalla National Library of Medicine (NLM) per assicurarsi che soddisfino specifici standard di controllo della qualità prima di essere pubblicati sul sito Web pubblico.
Studia le date principali
Inizio studio (Effettivo)
15 giugno 2006
Completamento primario (Effettivo)
30 ottobre 2020
Completamento dello studio (Effettivo)
30 ottobre 2020
Date di iscrizione allo studio
Primo inviato
1 giugno 2007
Primo inviato che soddisfa i criteri di controllo qualità
1 giugno 2007
Primo Inserito (Stima)
4 giugno 2007
Aggiornamenti dei record di studio
Ultimo aggiornamento pubblicato (Effettivo)
3 novembre 2020
Ultimo aggiornamento inviato che soddisfa i criteri QC
30 ottobre 2020
Ultimo verificato
1 ottobre 2020
Maggiori informazioni
Termini relativi a questo studio
Parole chiave
Altri numeri di identificazione dello studio
- 999906176
- 06-C-N176
Queste informazioni sono state recuperate direttamente dal sito web clinicaltrials.gov senza alcuna modifica. In caso di richieste di modifica, rimozione o aggiornamento dei dettagli dello studio, contattare register@clinicaltrials.gov. Non appena verrà implementata una modifica su clinicaltrials.gov, questa verrà aggiornata automaticamente anche sul nostro sito web .