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Lung CancerNCT00559065

A Case-Cohort Study of Hematopoietic Malignancies and Related Disorders and Lung Cancer in Benzene-Exposed Workers in China

An observational study of Lung Cancer and Lymphoma, run by National Cancer Institute (NCI) at 1 site in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study will examine the risks of workplace exposure to benzene, a substance known to lead to cancer of the blood and possibly of the lungs. It is used widely in industries and is a contaminant in the environment. Read more about this study

Who is it for?
Ages 21 to 90 years
How many people
3,260 participants
Where
1 siteChina
Study dates
11 Jul 2006to 6 Nov 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 21 to 90 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: From a cohort of 74,827 benzene-exposed and 35,804 unexposed workers employed (Bullet) one month in several industries and followed up during 1972-99, we identified a case-cohort population that included incident and deceased cases with hematopoietic malignancies diagnosed during those same years among exposed and unexposed workers and a 1,500 worker subcohort (1,100 exposed, 400 unexposed). The subcohort was selected by stratified random sampling (by sex, exposure status, and age at start of follow-up) from 106,641 of the cohort members. Other outcomes to be evaluated include incident cases with benzene hematotoxicity and deaths from lung cancer.

Who may be able to join

  • The study subjects are Chinese. Gender is not an important consideration as a risk factor in benzene-exposed workers. Subjects will be recruited by on - site collaborators in each of the 12 study cities. Participation is voluntary. Subjects may withdra from the study at any time.

Who cannot join

  • Based on the available data, no cases (an , thus no controls) will be less than 18 years of age. Any subject under 18 would be excluded from the study. Otherwise, no exclusions of potential study subjects are planned.

Trial locations and contacts

1 site in 1 country.

China1 site
  • China Center for Disease Control (CDC)

    Beijing

Other trials in China

About this study

Official title: A Case - Cohort Study of Hematopoietic Malignancies and Related Disorders and Lung Cancer in Benzene-Exposed Workers in China

This study will examine the risks of workplace exposure to benzene, a substance known to lead to cancer of the blood and possibly of the lungs. It is used widely in industries and is a contaminant in the environment. Researchers from the National Cancer Institute and the China Center for Disease Control (formerly Chinese Academy of Preventive Medicine) had done previous studies of workers in manufacturing industries in China of people who worked at least 1 day from 1972 to 1987 in 12 cities in that country. Data were collected of approximately 75,000 workers exposed to benzene and 35,000 who were not, with the purpose of investigating the relationship between benzene exposure and cancer risk. For workers exposed to benzene, there was a significant risk of cancer affecting the blood cells and a 1.8-fold excess of lung cancer among them. This study will expand those findings and also identify the effects of benzene amounts and whether there is a genetic tendency for benzene poisoning. About 3,860 benzene-exposed workers from the 12 cities will be interviewed. Next-of-kin of deceased workers, and a subcohort (additional grouping) of participants will serve as a control group in the research.

Patients who have worked at places where there was exposure to benzene will have a brief physical exam and samples of cells from a mouth rinse and samples from blood will be collected to study the genetic influence on developing blood diseases from workplace exposures.

All participants or next-of-kin, for deceased, will be given a questionnaire about their work history, use of cigarettes and hair dyes, medications they take, and family history of cancer. Interviews of about 40 minutes long will be conducted at participants homes or workplaces, at a time convenient to them, and the interviews will be audiotaped.

Read the detailed description

Benzene is a known leukemogen and may cause lymphoma as well, but its ability to , cause these conditions below 10 parts per million (ppm) in air are unclear. It is currently regulated in the United States at 1 ppm as an 8-hour time-weighted average and at a 5 ppm short-term exposure level for 15 minutes. There is a critical need to assess risks related to benzene exposure under 10 ppm because it is widely used industrially and a ubiquitous contaminant in the environment.

The National Cancer Institute (NCI) and the Chinese Academy of Preventive Medicine (CAPM), whose name was recently changed to the China Center for Disease Control (CDC) previously established a cohort of 75,000 workers exposed to benzene in 12 cities in China and 35,000 unexposed comparison workers, to investigate the relationship between benzene exposure and cancer risk, from 1972 to 1987. We followed up each worker using factory records and reported results suggesting that benzene exposure under 10 ppm may be associated with increased risk of acute non-lymphocytic cancer and could also be associated with increased risk of lymphoma and lung cancer. We have now laid the groundwork for a further epidemiologic investigation in China to evaluate health risks from lower levels of benzene exposure, particularly as present in the factories during the 1990s. The cohort was followed up through 1999, and through this effort we have identified 3260 subjects for study, including cases (HLD malignancies, n= 161; benzene poisoning, n= 1040; lung cancer, n= 560) and 1500 subjects in a cohort sub-sample to be used as the comparison group. In addition, we have identified a series of cases with benzene poisoning and controls from the same factories outside of the cohort (n = 600).

We propose to contact next-of-kin of deceased subjects (essentially all cancer cases and some members of the sub-cohort are deceased), for questionnaire-based evaluation of benzene and other exposures, and to contact living subjects (primarily the benzene poisoning cases and the sub-cohort sample) for collection of questionnaires and biologic samples. The questionnaires (formatted for direct interview of living subjects or for next-of-kin) will collect information on potential confounders needed in the analysis of benzene's effects and information on work experience outside of the study cohort factories. The biologic sample collection (13 ml blood and buccal cell rinse) will provide material primarily for study of genetic polymorphisms potentially associated with benzene metabolism and disease status. The polymorphisms being studied are relatively common in the Chinese population and may be associated with a relatively modest increase in risk (1.5 to 2-fold). Written informed consent will be obtained from all next-of-kin and all live study subjects. We will attempt to enroll 3,860 study subjects or next-of-kin. The study will be carried out with Drs. Gui-Lan Li and Song-Nian Yin and colleagues from the China CDC, Beijing, China.

Keywords
Case-Cohort Study, Leukemia, Lymphoma, Benzene, Blood Disorders, Solvent Exposure, Cancer Risk
Medical subject headings
Lung Neoplasms, Lymphoma, Leukemia, Myeloid, Acute, Leukemia, Hematologic Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT00559065
Study groupRoleWhat they receive
Benzene CohortBenzene exposed and unexposed workers.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Benzene poisoning, Hemapoietic Malignancies and related disorders, Lung cancer

    Benzene poisoning, Hemapoietic Malignancies and related disorders, Lung cancer

    Measured: 1972-1999

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Nov 2007 (estimated)
  2. Study start11 Jul 2006
  3. Primary completion31 Dec 2016
  4. Study completion6 Nov 2020

Resources

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
Cohort
Time perspective
Retrospective
Enrolment
3,260 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00559065
Sponsor's protocol ID
999906205
Other IDs
06-C-N205
Status last verified
Nov 2020
First submitted
15 Nov 2007
Last updated
12 May 2021
Results posted
No

Publications

  • Aksoy M. Malignancies due to occupational exposure to benzene. Am J Ind Med. 1985;7(5-6):395-402. doi: 10.1002/ajim.4700070506.

    PubMed 4003402
  • Aksoy M, Erdem S. Followup study on the mortality and the development of leukemia in 44 pancytopenic patients with chronic exposure to benzene. Blood. 1978 Aug;52(2):285-92. No abstract available.

    PubMed 667356
  • Arp EW Jr, Wolf PH, Checkoway H. Lymphocytic leukemia and exposures to benzene and other solvents in the rubber industry. J Occup Med. 1983 Aug;25(8):598-602.

    PubMed 6886869

Questions about this trial

What is this clinical trial studying?

An observational study of Lung Cancer and Lymphoma, 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 1 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 12 May 2021. 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?

Benzene poisoning, Hemapoietic Malignancies and related disorders, Lung cancer (time frame: 1972-1999). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00559065, which also lists 3 linked publications.

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 12 May 2021.

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