Brain tumors have been the subject of controversy, both with respect to patterns of occurrence and with respect to potential causes. While progress is being made in discovering the biology of these tumors, the contribution of epidemiology to understanding the importance of these advances in human populations is just emerging. Better definitions and descriptions of the occurrence of these complex tumors have been achieved in the last decade. As a result, a new consensus on surveillance of these tumors is being implemented on a broad scale and will eventually improve the ability to document the burden of disease worldwide. Improving the accuracy and standardization of descriptive data will increase the likelihood that rates consistently reflect disease occurrence. Hypotheses based on accurate variations in rates will be more fruitful in directing efforts towards identifying causes of these tumors. The process of describing patterns of disease by person (for example by age, gender, ethnicity), place, and time also provides an underpinning of data to support policy and planning activities. The objectives of this chapter are to:
● outline the availability of population based incidence data and discuss issues which affect the use of these data;
● describe the current patterns of brain tumor occurrence and survival on a population level;
● summarize current knowledge on risk factors for brain tumors.