Epidemiology of primary central nervous system tumors

The descriptive epidemiology of primary central nervous system (CNS) tumors is based on population-based cancer registries that include tumors of the brain, cranial nerves, cerebral meninges, spinal cord, and spinal meninges. Malignant CNS tumors in adults account for 1.7% of new cancers and 2.1% of cancer deaths. In Europe, Australia/New Zealand, and North America there are 7.5-14 new cases per 100. 000 population per year in males, and 4-11 new cases in females. Incidence rates of benign and borderline CNS tumors are available from the Surveillance, Epidemiology, and End Results (SEER) Program for the time period 1975-2004: incidence was 8.1 new cases per 100. 000 population per year in males, and 12.1 in females. Incidence and mortality significantly increased in white males and females from 1975-1991; subsequently, the incidence remained steady, and mortality decreased significantly from 1992-2004. In population-based studies less than 5% of glioma risk is hereditary. Well-identified genetic syndromes that include primary brain tumors (PBTs) are most often autosomal dominant, and have variable penetrance. The most common syndrome is neurofibromatosis type 1. Ionizing radiation has a proven etiological role in experimental studies in monkeys and primates and, as a late complication of therapeutic X-irradiation, in humans. Extensive epidemiological research conducted during the past 20 years on occupational electromagnetic field exposure did not indicate strong or consistent associations with adult PBTs. The WHO/IARC has classified RF electromagnetic fields as possibly carcinogenic to humans (Group 2B) based on an increased risk for glioma associated with wireless phone use. Additional research needs to be conducted into the long-term use of mobile phones.