Industrial HygieneNCT00481611
Cancer Markers Associated With Occupational Exposure to Trichloroethylene
An observational study of Industrial Hygiene and Epidemiology, run by National Cancer Institute (NCI) at 1 site in China.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Industrial Hygiene, Epidemiology, Neoplasms
- How many people
- 125 participants
- Where
- 1 siteChina
- Study dates
- 15 Jun 2006to 30 Oct 2020
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- All sexes
- No healthy volunteers
- Adult
Study population: 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.
Who may be able to join
- 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.
Who cannot join
- History of cancer, chemotherapy with DNA-damaging or immunotoxic agents, and medical treatment with ionizing radiation.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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.
Read more
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.
Read the detailed description
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.
- Conditions
- Industrial Hygiene, Epidemiology, Neoplasms
- Keywords
- Industry Hygiene, Molecular Epidemiology, Cancer Susceptibility, Genotoxicity, Immune Function, Cancer Susceptability
- Medical subject headings
- Neoplasms
What is being measured
The primary outcome is the main question the study is designed to answer.
Hematotoxicity change
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.
Measured: 2006-2034
Immune function
A secondary goal of the study is to determine if TCE exposure alters plasma cytokine levels and lymphocyte subsets.
Measured: 2006-2034
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2007 (estimated)
- Study start15 Jun 2006
- Primary completion30 Oct 2020
- Study completion30 Oct 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Industrial HygieneStudies of the same condition, open and under way.
- More trials run by National Cancer Institute (NCI)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 125 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Cancer Institute (NCI)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Qing Lan, M.D., Principal investigator, National Cancer Institute (NCI)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00481611
- Sponsor's protocol ID
- 999906176
- Other IDs
- 06-C-N176
- Status last verified
- Oct 2020
- First submitted
- 1 Jun 2007
- Last updated
- 3 Nov 2020
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Cross-Sectional Study of Occupational Exposure to Trichloroethylene, Chromosomal Aberrations, and Related Biomarkers in Guangdong, China
- ClinicalTrials.gov ID
- NCT00481611
- Acronym / sponsor ID
- 999906176
- Conditions
- Industrial Hygiene, Epidemiology, Neoplasms
- Keywords
- Industry Hygiene, Molecular Epidemiology, Cancer Susceptibility, Genotoxicity, Immune Function, Cancer Susceptability
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 125 participants (actual)
- Lead sponsor
- National Cancer Institute (NCI)US National Institutes of Health
- Study start
- 15 Jun 2006 (actual)
- Primary completion
- 30 Oct 2020 (actual)
- Study completion
- 30 Oct 2020 (actual)
- First posted
- 4 Jun 2007 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- 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.
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (1 listed)
- History of cancer, chemotherapy with DNA-damaging or immunotoxic agents, and medical treatment with ionizing radiation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Hematotoxicity change
Time frame: 2006-2034
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.
Immune function
Time frame: 2006-2034
A secondary goal of the study is to determine if TCE exposure alters plasma cytokine levels and lymphocyte subsets.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2020.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Qing Lan, M.D. principal investigator
National Cancer Institute (NCI)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Industrial Hygiene and Epidemiology, run by National Cancer Institute (NCI) at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 3 Nov 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Hematotoxicity change (time frame: 2006-2034). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2020.