Nutrition Intervention Trials in Linxian Follow-up Study

April 17, 2024 updated by: National Cancer Institute (NCI)

Nutritional Intervention Trials in Linxian China- Continued Follow-up

Two large, nutritional intervention trials were conducted in Linxian, China between 1985-1991. These trials tested the effect of multiple vitamins and minerals in the prevention of esophageal cancer in a population with the highest known rate for this disease in the world. Results from the trials showed that Beta-carotene + Vitamin E + selenium reduced total mortality, total cancer mortality, and stomach cancer incidence and mortality. Multivitamins/minerals also showed reduction in premalignant lesions. Preliminary follow-up data obtained for the time period after cessation of intervention in 1991 suggests that the observed benefit for total and cancer mortality is reduced but that the benefit for stomach cancer remains.

The objectives of the follow-up study are: (1) to continue to determine cancer incidence and all causes of mortality in trial participants after intervention to permit examination of potential effects of the interventions on total and cause-specific mortality and cancer incidence in the post-intervention period; (2) to conduct a cross-sectional nutritional survey in a subsample of living trial participants to evaluate their nutritional status, asses the validity of dietary questionnaires, and relate neurologic status to vitamin B12 plasma levels; (3) to collect a blood sample from all living trial participants to permit further etiologic investigations of genetic and environmental hypotheses; and (4) to perform nested case-control studies of selected genetic and environmental hypotheses.

To accomplish the objectives of the follow-up study, we will: (1) determine updated vital status and cancer status data on all trial participants via monthly checks of village doctor records and quarterly checks of the Linxian Cancer Registry; conduct a Vital/Cancer Status Interview Survey among all (n-34,000 trial participants (or their surrogates); identify, collect, and store all available diagnostic materials for trial participants identified as having developed cancer or died with cancer during the follow-up period; (2) conduct a Nutritional Survey on a subsample (n-1000) of living trial participants that will include (a) a physical exam and brief medical history, (b) a neurologic history, (c) a cognitive function exam, (d) a hair/mouth skin exam, (e) a neurological exam, (f) a nutritional questionnaire, and (g) collection of a blood sample for hematologic/biochemical analyses; (3) conduct a Blood Collection Survey of all living trial participants (n-23,000) to obtain (a) a physical exam and brief medical history and (b) a single 10-ml blood sample for separation and preservation as WBCs (both viable and nonviable), RBCs, and plasma for genetic (e.g., xenobiotic polymorphisms) and environmental (e.g., plasma ascorbic acid) hypothesis testing; and (4) perform Nested Case-Control Studies of selected genetic and environmental hypothesis related to the etiology and prevention of esophageal cancer and stroke. These will be done using serum from the new cancer and stroke cases (-2500) and controls (-2500) previously identified from 1991-1996, as well as using new cancer and stroke cases and controls for the period 1996-2004 (-9000).

The followup for endpoints will continue monthly for an additional 5 years (through the year 2003). The Nutritional Survey and Blood Collection Survey will be conducted in the spring of 1999. The Nested Case-Control studies will be performed annually beginning in 2000, and the Vital/Cancer Interview Survey will be conducted in the Spring of 2001....

Study Overview

Status

Enrolling by invitation

Conditions

Detailed Description

Two large, nutritional intervention trials were conducted in Linxian, China between 1985-1991. These trials tested the effect of multiple vitamins and minerals in the prevention of esophageal cancer in a population with the highest known rate for this disease in the world. Results from the trials showed that Beta-carotene + Vitamin E + selenium reduced total mortality, total cancer mortality, and stomach cancer incidence and mortality. Multivitamins/minerals also showed reduction in premalignant lesions. Preliminary follow-up data obtained for the time period after cessation of intervention in 1991 suggests that the observed benefit for total and cancer mortality is reduced but that the benefit for stomach cancer remains.

The objectives of the follow-up study are: (1) to continue to determine cancer incidence and all causes of mortality in trial participants after intervention to permit examination of potential effects of the interventions on total and cause-specific mortality and cancer incidence in the post-intervention period; (2) to conduct a cross-sectional nutritional survey in a subsample of living trial participants to evaluate their nutritional status, asses the validity of dietary questionnaires, and relate neurologic status to vitamin B12 plasma levels; (3) to collect a blood sample from all living trial participants to permit further etiologic investigations of genetic and environmental hypotheses; and (4) to perform nested case-control studies of selected genetic and environmental hypotheses.

To accomplish the objectives of the follow-up study, we will: (1) determine updated vital status and cancer status data on all trial participants via monthly checks of village doctor records and quarterly checks of the Linxian Cancer Registry; conduct a Vital/Cancer Status Interview Survey among all (n approximately 34,000 trial participants (or their surrogates); identify, collect, and store all available diagnostic materials for trial participants identified as having developed cancer or died with cancer during the follow-up period; (2) conduct a Nutritional Survey on a subsample (n approximately 1000) of living trial participants that will include (a) a physical exam and brief medical history, (b) a neurologic history, (c) a cognitive function exam, (d) a hair/mouth skin exam, (e) a neurological exam, (f) a nutritional questionnaire, and (g) collection of a blood sample for hematologic/ biochemical analyses; (3) conduct a Blood Collection Survey of all living trial participants (n approximately 23,000) to obtain (a) a physical exam and brief medical history and (b) a single 10-ml blood sample for separation and preservation as WBCs (both viable and nonviable), RBCs, and plasma for genetic (e.g., xenobiotic polymorphisms) and environmental (e.g., plasma ascorbic acid) hypothesis testing; and (4) perform Nested Case-Control Studies of selected genetic and environmental hypothesis related to the etiology and prevention of esophageal cancer and stroke. These will be done using serum from the new cancer and stroke cases (approximately 2500) and controls (approximately 2500) previously identified from 1991-1996, as well as using new cancer and stroke cases and controls for the period 1996-2004 (approximately 9000).

The followup for endpoints will continue monthly for an additional 5 years (through the year 2003). The Nutritional Survey and Blood Collection Survey will be conducted in the spring of 1999. The Nested Case-Control studies will be performed annually beginning in 2000, and the Vital/Cancer Interview Survey will be conducted in the Spring of 2001.

Study Type

Observational

Enrollment (Estimated)

34000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
      • Beijing, China
        • Cancer Institute and Hospital, Chinese Academy of Medical Sciences

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 100 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Participants from two large, nutritional intervention trials that were conducted in Linxian, China between 1985-1991. These trials tested the effect of multiple vitamins and minerals in the prevention of esophageal cancer in a population with the highest known rate for this disease in the world.

Description

  • No eligibility criteria listed.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Other

Cohorts and Interventions

Group / Cohort
1
Participants from two large, nutritional intervention trials that were conducted in Linxian, China between 1985-1991.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Determine cancer incidence and all causes of mortality in trial participants in the post-intervention period and conduct studies ofselected genetic and environmental hypotheses related to the etiology and prevention of esophageal cancer and s...
Time Frame: Ongoing
analysis is ongoing
Ongoing

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Cancer Institute (NCI)

Investigators

  • Principal Investigator: Christian Abnet, Ph.D., National Cancer Institute (NCI)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 20, 1999

Primary Completion (Estimated)

December 1, 2024

Study Completion (Estimated)

December 1, 2024

Study Registration Dates

First Submitted

June 19, 2006

First Submitted That Met QC Criteria

June 19, 2006

First Posted (Estimated)

June 21, 2006

Study Record Updates

Last Update Posted (Actual)

April 18, 2024

Last Update Submitted That Met QC Criteria

April 17, 2024

Last Verified

October 31, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 999999031
  • OH99-C-N031

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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