Clinical trial NCT00352924: Agriculture Health Study
Official title: The Main Agricultural Health Study - A Prospective Study of Cancer and Other Diseases Among Men and Women in Agriculture
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Prostate Cancer
Pesticide Exposures
Lymphoma
Multiple Myeloma
Keywords: Cancer
Pesticides
Agriculture
Natural History
Lead sponsor: National Institutes of Health Clinical Center (CC)
Sponsor class: NIH
Collaborators: name: Environmental Protection Agency (EPA)
First posted: 2006-07-17
Enrollment: 89655
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: A prospective cohort of 89,655 registered pesticide applicators and spouses (57,310 applicators and 32,346 spouses of private applicators) with sufficient personal identifiers to conduct follow up activities has been assembled during the first four years of recruitment in the Agricultural Health Study, 1993-1997. The majority of applicators were asked to enroll in the AHS as they obtained or renewed their pesticide registration/licenses through the agricultural extension services of the states of North Carolina and Iowa. In the last year of enrollment, applicators who received or renewed their pesticide licenses, but were never given the opportunity to enroll due to added requirements in the testing/training class, were called and asked to complete the enrollment questionnaire over the phone. Spouses of the private applicators were also given the opportunity to enroll via the telephone.

Brief summary: The "Agricultural Health Study" (AHS) is a collaborative effort between the National Cancer Institute and the National Institute of Environmental Health Sciences. The U.S. Environmental Protection Agency and the National Institute for Occupational Safety and Health are providing support for a limited exposure assessment effort.

Initial data collection on a prospective cohort of 89,658 study subjects has been completed as of December 1997. Participants completed questionnaires that included items on pesticides used, other agricultural exposures, and work practices that modify exposure as well as on other activities that may affect either exposure or disease risks (e.g., diet, exercise, alcohol consumption, medical conditions, family history of cancer, other occupations and smoking history). Phase II of the study (1998-2003) updated information on occupational exposures, diet, work practices and medical history by means of a computer assisted telephone interview. We also collected buccal cells on sample of 34,000 study participants to assess the effect of inheritable polymorphisms and the interaction of environment and genomic predisposition.

The stimulus for this prospective investigation comes from the growing evidence that, despite a low mortality overall, farmers experience an excess of several cancers. These excesses have been observed in retrospective epidemiological studies among agricultural workers in several countries. Excess cancers are observed for the lymphatic and hematopoietic system, connective tissue, skin, brain, prostate, stomach and lips. Several of these tumors (brain, NHL, multiple myeloma, and prostate) are also increasing in the general population in many of these countries. This suggests a common set of exposures may explain the high rates in farmers and rising rates in the general population.

Farmers, their families, and other pest control workers may have contact with a variety of potentially hazardous substances including pesticides, solvents, fuels and oils, engine exhaust, dust and zoonotic viruses and other microbes. Our cohort study includes all registered pesticide applicators in Iowa and North Carolina and the spouse of applicators who are farmers. The health effects of pesticide use are the primary focus of the study. The influence of other farm exposures are also being evaluated.

The focus of the phase II follow-up period (2004-2008) is to update exposure information and health histories by means of a computer assisted interview and also following the cohort to determine disease incidence and mortality. The cohort is being followed through the cancer registries within Iowa and North Carolina, the Social Security Administration database, state vital statistics offices, National Death Index, and various in-state databases, such as the listing of registered pesticide applicators. Individuals who enrolled into the study but who are no longer at the address given during enrollment (based on subsequent attempts at follow up) have been submitted and will continue to be submitted (through NIOSH) in the standard format to the IRS under their Project 057 Taxpayer Address Request Program. Identifying data provided to the IRS include only SSN and the first four letters of last name of cohort member. IRS provides in return the most current address in IRS records if a match (SSN + all four letter of last name) is found. The purpose of this effort is to identify members of the cohort who have moved out of state, to enable adjustment of person-years for incidence and mortality calculations. Persons who have moved out of state can be followed for vital status and cause of death, but not for cancer incidence.

Continuation of the protocol will provide a valuable epidemiologic resource to help prevent cancers in the future by identifying risk factors in the rural/agricultural environment. Because more cases of important cancer outcomes occur in this cohort every year, potential cancer causes can be evaluated with increased statistical power. Larger number of cases also allows for statistical control of confounding factors, making more meaningful conclusions about cancer risk, and, for some relatively infrequent cancers, such as the lyphomas and leukemias, greater follow-up time is necessary to make any meaningful observations.

Detailed description: The "Agricultural Health Study" (AHS) is a collaborative effort between the National Cancer Institute and the National Institute of Environmental Health Sciences. The U.S. Environmental Protection Agency and the National Institute for Occupational Safety and Health are providing support for a limited exposure assessment effort. Initial data collection on a prospective cohort of 89,655 study subjects has been completed as of December 1997. Participants completed questionnaires that included items on pesticides used, other agricultural exposures, and work practices that modify exposure as well as on other activities that may affect either exposure or disease risks (e.g., diet, exercise, alcohol consumption, medical conditions, family history of cancer, other occupations and smoking history). Phase II of the study (1998-2003) updated information on occupational exposures, diet, work practices and medical history by means of a computer assisted telephone interview. We also collected buccal cells on sample of 34,000 study participants to assess the effect of inheritable polymorphisms and the interaction of environment and genomic predisposition. The stimulus for this prospective investigation comes from the growing evidence that, despite a low mortality overall, farmers experience an excess of several cancers. These excesses have been observed in retrospective epidemiological studies among agricultural workers in several countries. Excess cancers are observed for the lymphatic and hematopoietic system, connective tissue, skin, brain, prostate, stomach and lips. Several of these tumors (brain, NHL, multiple myeloma, and prostate) are also increasing in the general population in many of these countries. This suggests a common set of exposures may explain the high rates in farmers and rising rates in the general population.

Farmers, their families, and other pest control workers may have contact with a variety of potentially hazardous substances including pesticides, solvents, fuels and oils, engine exhaust, dust and zoonotic viruses and other microbes. Our cohort study includes all registered pesticide applicators in Iowa and North Carolina and the spouse of applicators who are farmers. The health effects of pesticide use are the primary focus of the study. The influence of other farm exposures are also being evaluated.

Eligibility criteria: * INCLUSION CRITERIA:

All registered pesticide applicators in Iowa and North Carolina and the spouse and children of applicators who are farmers.

Primary outcomes:
measure: Non-cancer disease incidence in pesticide applicators
timeFrame: Follow-up was every 5 years (to date); now to be every 3-5 years (CMS linkage)
measure: measurement of pesticide and other agricultural exposures
timeFrame: Follow-up was every 5 years (to date)
measure: Disease risk and dietary exposures
timeFrame: Baseline and first follow-up only
measure: Disease in spouses and children of farmers
timeFrame: Cancer as annual; now semi annual; other diseases, about 3-5 years
measure: Cancer incidence in pesticide applicators
timeFrame: Was annual; now semi annually (cancer linkages)
measure: Agricultural exposures and biomarkers of exposure, biological effect, and biomarkers of pre-clinical disease and genetic susceptibility factors
timeFrame: Follow-up was every 5 years (to date); now to be every 3-5 years (CMS linkage)
Secondary outcomes:
Other outcomes:
Locations:
city: Research Triangle Park
country: United States
facility: Research Triangle Institute
state: North Carolina
Study officials:
affiliation: National Cancer Institute (NCI)
name: Laura E Beane Freeman, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Alavanja MC, Blair A, Merkle S, Teske J, Eaton B. Mortality among agricultural extension agents. Am J Ind Med. 1988;14(2):167-76. doi: 10.1002/ajim.4700140207.
citation: Barthel E. Increased risk of lung cancer in pesticide-exposed male agricultural workers. J Toxicol Environ Health. 1981 Nov-Dec;8(5-6):1027-40. doi: 10.1080/15287398109530135.
citation: Bjeldanes LF, Morris MM, Timourian H, Hatch FT. Effects of meat composition and cooking conditions on mutagen formation in fried ground beef. J Agric Food Chem. 1983 Jan-Feb;31(1):18-21. doi: 10.1021/jf00115a005. No abstract available.
citation: Lebov JF, Engel LS, Richardson D, Hogan SL, Hoppin JA, Sandler DP. Pesticide use and risk of end-stage renal disease among licensed pesticide applicators in the Agricultural Health Study. Occup Environ Med. 2016 Jan;73(1):3-12. doi: 10.1136/oemed-2014-102615. Epub 2015 Jul 15.