The etiology of brain tumors is poorly understood. Due, in part, to public concern about a postulated relationship between the use of cellular telephones or other increasingly prevalent environmental exposures and the incidence of brain cancer in adults, the National Cancer Institute is collaborating with three U.S. hospitals in a comprehensive case-control study of malignant and benign brain tumors. Factors under consideration include use of cellular phones and other wireless communication devices, workplace exposures to chemical agents and electromagnetic fields, dietary factors, family history of tumors, genetic determinants of susceptibility, home appliance use, reproductive history and hormonal exposures, viruses, medical and dental exposure to ionizing radiation, and other aspects of medical history.
Approximately 800 newly diagnosed brain tumor cases and 800 controls have been enrolled at hospitals in Boston, Phoenix and Pittsburgh. Cases include all adults (age greater than or equal to 18 years) newly diagnosed with a histologically confirmed intracranial glioma, intracranial meningioma or acoustic neuroma. Controls are patients admitted to the same hospitals as the cases, and treated for any of a variety of non-malignant conditions. Participating cases and controls were interviewed in the hospital by a research nurse and asked to complete a self-administered questionnaire and donate a sample of blood. Key features of the study include its large size, the emphasis on rapid ascertainment of incident cases and interview of study subjects rather than surrogate respondents, the use of detailed, job-specific questions developed by industrial hygienists to ascertain occupational exposures, and the storage of blood samples for future evaluation of inherited susceptibility, biomarkers of exposure and gene-environment interactions.
Implementation of the study protocol proceeded without serious problems. There have been no harmful effects on study participants. There have been no complaints from participants or breaches of confidentiality. Continuation of this research involves analysis and reporting of results. As there will be many papers, this process is expected to extend over the next several years.
| Estimated Enrollment: |
1600 |
| Study Start Date: |
August 1994 |
The etiology of brain cancer is largely unknown, although several chemicals and occupations have been associated with the disease. Occupations in the agricultural industry have shown associations with brain cancer in several studies, and pesticides and fertilizers have been suggested as the etiologic agent. This case-control study will accrue 798 cases and 1175 controls form four Midwestern states to investigate this hypothesis. This study was initiated and completed by the National Institute for Occupational Safety and Health (NIOSH), an agency of the CDC. Investigators at NCI have since been asked to join the study to allow merging of the NCI brain cancer study data with the NIOSH study data to provide more power in the analyses.
Cases will be identified from hospitals and neurosurgeon offices in these states. Controls will be frequency matched and obtained from state driver's license records and HCFA Medicare records. A questionnaire will be administered to collect information on occupational exposures, residential history, and other variables. Water samples will be collected from subjects with private wells. Tissue will be collected from the cases and blood from both cases and controls. An industrial hygienist will identify possible chemical agents and estimate levels to those agents based on the literature and her experience. Levels of disinfection by-products in municipal and private wells will be estimated from state records. The biologic tissues will be evaluated for markers for exposure, mutation, DNA repair, or metabolic polymorphisms.
Purpose
