1. Trans Divisional Research Program, Division of Cancer Epidemiology and Genetics, National Cancer Institute , Bethesda, Maryland , USA
2. Central Brain Tumor Registry of the United States , Hinsdale, Illinois , USA
3. Department of Neurosurgery, Duke University School of Medicine , Durham, North Carolina , USA
4. The Preston Robert Tisch Brain Tumor Center, Duke University School of Medicine , Durham, North Carolina , USA
5. Center for Biomedical Informatics and Information Technology, National Cancer Institute , Bethesda, Maryland , USA