The rationale for standardized registration and reporting of brain and central nervous system tumors in population-based cancer registries.

Most population-based statistical reports of brain and central nervous system (CNS) tumors are limited to data of primary malignant tumors and to summary estimates of all tumor locations and histologies. We argue that data of benign brain and CNS tumors should also be included in registry reports and that standard definitions for the reporting of all brain and CNS tumors by site and histology should exist. We demonstrate current inconsistencies in the definitions of brain and CNS tumor sites used in reports. Grouping of brain and CNS tumors by subtype--which integrates the current World Health Organization classification scheme with the International Classification of Diseases for Oncology coding system used in cancer registries--is proposed. Adoption of standard tumor site and behavior codes for annual reports would aid the comparison of rates of brain and CNS tumors between geographic regions, allow for the evaluation of trends over time, and provide new estimates of tumor subtypes in a more clinically relevant format. A consensus among cancer registries and neuroscientists is needed to adopt standard definitions so that accurate and clinically relevant brain and CNS tumor data are available.