The Agricultural Health Study (AHS) is a long-term study of agricultural exposures (including pesticides) and chronic disease (especially cancer) among commercial or private pesticide applicators (and their spouses, if married) in Iowa and North Carolina. The study is funded through the National Cancer Institute (NCI) and involves several federal agencies. We are in the 25th year of the study.
In the first five years, 89,658 subjects (58,564 in Iowa and 31,094 in North Carolina) were enrolled in the study. The total for Iowa included 31,877 private applicators, 21,771 spouses of private applicators and 4,916 commercial applicators. Enrollment consisted of completing questionnaires about past exposures and health. The second phase of the study for private applicators and their spouses was completed at the end of 2003. It involved a telephone interview, a mailed dietary questionnaire, and collection of a cheek cell sample from all consenting cohort members. The telephone interview asked about pesticide use since enrollment, current farming and work practices and health changes.
The dietary health questionnaire asked about cooking practices and types of foods eaten, since cooking practices and diet may play a role in cancer and other health conditions. The cheek cells are being used to understand possible links between genetics, exposures and disease. For commercial applicators, the second phase of the study was completed at the end of 2005. The study’s third phase began in 2005 and ended in 2010. It involved updating information about exposures and health. The fourth phase of the study began in the fall of 2011 and for the University of Iowa research team primarily involved the collection of cheek cells from AHS participants diagnosed with cancer and the collection of blood, urine, cheek cells and dust samples from a select subgroup of AHS male participants. During this fourth phase health histories have also been updated.
Since 1997 cohort members have been linked annually or biennially to mortality and cancer registry incidence databases in both states. In addition mortality data on the cohort are being obtained from the National Death Index. More information about results from this study, the study background, frequently asked questions, other resources (internet & telephone) for agricultural health information, references for publications to date and information for scientific collaborators can be found here. This study’s data have also been pooled with data from other cohort studies and analyzed as collaborative activities. The titles for over 250 publications from this study linked to PubMed are available at the website. The cancer-related references for 2016 publications are provided in the last section of this report.
This study involves a statistical coordinating center, the ICR and five other primary data collection and research sites around the U.S. Across these sites we conducted population- based research in the areas of access to care and patterns of care for lung and colorectal cancer. We are evaluating the reasons for particular care decisions by patients and their physicians, including variation in disseminations of modern care protocols and practices in different geographic areas. We are also evaluating the effects of these decisions and practices on patient outcomes, including quality of life. In Iowa this
study was limited to lung cancer patients. Over 1,000 newly diagnosed lung cancer patients were enrolled between June 2003 and March 2005. Thereafter these patients provided consent for medical record abstraction and participated in follow-up interviews. Several publications have resulted from the findings and those that occurred in 2016 are provided in the last section of this report.
SEER Patterns of Care Studies are conducted to satisfy a U.S. Congressional directive to the NCI to “assess the incorporation of state-of-the-art cancer treatment into clinical practice and the extent to which cancer patients receive such treatments.” This year’s Patterns of Care Study will investigate state-of- the-art therapies for patients with the following cancers diagnosed during 2015: female breast, colorectum and lung. The objectives of the SEER Patterns of Care Study are to:
- Describe the use of adjuvant therapy, which, when applicable, will be verified with the treating physician or with a unified record
- Characterize the practice patterns in different communities
- Describe more completely the use of surgery as treatment
- Compare the patterns of treatment (surgery, radiation therapy, chemotherapy, immunotherapy, hormonal therapy) over time and by age, sex, race/ethnicity and insurance status
- Describe the co-morbidities and their effect on treatment
- Describe treatment by hospital characteristics (i.e., profit vs. not for profit, teaching vs. non-teaching, bed size, etc.)
- Describe the use of diagnostic tests and compare their use by demographic variables and geographic region
- Describe the use of biomarkers
- Match the Patterns of Care data with the SEER-Medicare linked files as appropriate by age
- Compare the outcomes in community practice to the outcomes obtained in clinical trials.
The ICR has been involved with these types of studies over the past 25 years.
In the early 1990s, the cancer incidence and survival data from the ICR was combined with other SEER Registry data and linked to Medicare data. This linked data set has been updated on several occasions since and has become an important data resource for cancer research involving epidemiologic and health services research related to the diagnosis and treatment procedures, costs and survival of cancer patients. Over 1,500 publications have resulted from this linked data set including over 200 during 2016, which are listed on the SEER Medicare website.
In 2003 the ICR obtained human subjects research approval for a new project to link SEER data with the Centers for Medicare and Medicaid (CMS) Medicare Health Outcomes Survey (MHOS). The SEER-MHOS linked data provided a wide range of potential research applications focused on health-related quality of life of cancer patients and cancer survivors. The first paper describing this data resource was published in 2008. Since then several more papers have followed. A listing of publications during 2016 is provided in the last section of this report.
This year the ICR and the Kentucky and Louisiana cancer registries will be collaborating with the Centers for Disease Prevention and Control (CDC) to obtain tissue for a project entitled, “Reassessment of Monitoring the Impact of a Prophylactic Human Papillomavirus (HPV) vaccine
on HPV Types in Cancers: Using Tissues from Central Cancer Registries.” Infection with selected types of human papillomavirus (HPV) is in the causal pathway of almost all cases of cervical cancer as well as a large proportion
of cancers at non-cervical sites including the oropharynx and anal regions. The objective of this project is to use the central cancer registries to identify HPV-related cases to determine the HPV vaccine impact (after implementation of the vaccine) in monitoring of HPV types, especially in areas with higher burden of disease and racial/ethnic diversity in the same registries that were part of a previous study that obtained tissue from cancers diagnosed prior to 2006.
Specifically, we will: 1) obtain tumor tissue for HPV typing on all or a sample of cervical, anal and rectal squamous cell carcinomas and oropharyngeal cancer cases; 2) re-establish an infrastructure for the systematic monitoring of HPV in incident cancers in representative samples of the United States; and 3) determine distribution of HPV types associated with the target cancers in the United States diagnosed in 2014 and 2015 in the post-HPV vaccine licensure era. The ICR will be seeking representative tumor tissue from over 400 cancers diagnosed among Iowans.
Today researchers are increasingly looking to obtain tissue to study molecular characteristics of cancers. Several studies that involve the ICR have included tissue. For example last year we began a three-year study to determine the capability of the ICR to obtain formalin-fixed, paraffin-embedded tissue to accompany data that already exists in the registry’s surveillance database for breast and pancreatic cancers meeting eligibility criteria for this study. The objectives of this SEER-linked virtual tissue repository project are to:
- Assess the ability of the ICR to serve as a resource for biospecimen research
- Locate cases with biospecimens in pathology labs and determine the requirements to retrieve those biospecimens for research purposes
- Provide custom annotation of specified data items for located cases
- Capture costs for objectives 2 and 3
This project involves other NCI SEER cancer registries and when completed will provide for an assessment of NCI SEER’s capabilities to perform this type of study. During 2016 a few articles involving tissue from Iowans were published, the references for which are provided in the last section of this report.
Solid organ transplantation provides life-saving treatment for end-stage organ disease but is associated with substantially elevated cancer risk, largely due to the need to maintain long-term immunosuppression. Important questions remain concerning the role of immunosuppression and other factors in causing cancer in this setting. Staff at two federal agencies, the NCI and the Health Resources and Services Administration (HRSA), are creating a database through linkage of information during 1987-2009 or beyond on over 200,000 U.S. transplant recipients, wait list candidates (over 120,000 in addition to those who were subsequently transplanted), and donors (over 60,000 deceased donors, over 50,000 living donors) with information on cancer from 15 U.S. cancer registries, including the ICR.
These data are being used to conduct research concerning the spectrum of cancer risk in transplant recipients. The data will also be used by HRSA in its public health role overseeing the U.S. solid organ transplant network to maintain and improve safety of organ transplantation, and will allow NCI to better characterize the burden of cancer in this population and discover additional factors associated with cancer among this population. Several publications have resulted from the findings and those that occurred in 2016 are provided in the last section of this report.
Over the past three decades, the ICR has participated in several second cancer studies. These have consisted of cohorts with a first cancer of the cervix, ovary, testis, uterus, female breast, non-Hodgkin lymphoma or Hodgkin lymphoma. They have been conducted primarily in collaboration with the Radiation Epidemiology Branch at the NCI and other registries in North America and Europe. Generally these studies evaluate the treatment received for the first cancer and the risk it places on the patient for development of a second cancer. They typically involve medical record review and pathology material retrieval. We are evaluating esophagus, pancreas and stomach as second cancer sites in several of these cohorts, mentioned above, with a first cancer.
The WECARE (Women’s Environmental Cancer and Radiation Epidemiology) Study is an example of a second cancer study. This study is designed to examine gene carrier status, demographic and lifestyle factors, as well as environmental and treatment factors reported to be associated with an initial breast cancer as they relate to the development of a second breast cancer in the opposite breast. Eligible cases were diagnosed with a first breast cancer between 1985 and 2009 that did not spread beyond the regional lymph nodes at diagnosis and a second primary contralateral breast cancer diagnosed at least one year after the first breast cancer diagnosis. Eligible controls were women with unilateral breast cancer who were individually matched to cases on year of birth, year of diagnosis, registry region and race. The controls must have survived without any subsequent diagnosis of cancer and with an intact contralateral breast during the interval that elapsed between their matched case’s first and second breast cancer diagnoses. Data collection not only involved medical record review, but also participant interviews and biosample collection, either cheek cells, saliva or blood. More recently the WECARE staff collected mammographic film data for its research subjects to evaluate breast density as another risk factor for a subsequent diagnosis of invasive breast cancer in the contralateral breast. A listing of publications during 2016 from second cancer studies, including the WECARE Study, is provided in the last section of this report.
In the Midwest the ICR maintains cooperative agreements with several hospital cancer registries and other agencies/entities. Some of the latter include:
- Iowa Department of Public Health
- Iowa Cancer Consortium
- The University of Iowa
- Center for Health Effects of Environmental Contamination
- Center for Health Policy and Research
- Center for Public Health Statistics
- Environmental Health Sciences Research Center
- Health Effectiveness Research Center
- Holden Comprehensive Cancer Center
- Iowa Center for Agricultural Safety and Health
- Iowa Center for Education and Research on Therapeutics (Iowa CERT)
- Injury Prevention Research Center
- Nutrition Center
- Prevention Research Center for Rural Health
- Preventive Intervention Center
- Reproductive Molecular Epidemiology Research & Education Program