A Case-Referent Study of Brain Tumors in Adults

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.