Abstract
BACKGROUND
Primary central nervous system lymphoma (PCNSL) is an extranodal form of nonโHodgkin lymphoma arising in the craniospinal axis. The incidence of PCNSL appears to be increasing.
METHODS
PCNSL incidence data from 1973โ1997 were obtained from the nine Surveillance, Epidemiology and End Results (SEER) registries. To limit the influence of the human immunodeficiency virus on incidence rates, data of neverโmarried males and females and persons of unknown marital status were excluded. As a surrogate for new technology, SEER data were reviewed by dates of diagnosis (surrogate for imaging) and compared with glioma incidence (surrogate for stereotactic neurosurgery and improved diagnostic neuropathology). Ageโadjusted incidence rates were estimated and compared for the period prior to computed tomography (CT) (1973โ1984) and the magnetic resonance imaging (MRI) period (1985โ1997). The estimated annual percent change was calculated based on linear regression analyses using SEER*STAT.
RESULTS
The incidence of PCNSL appears to be increasing in all SEER registries examined. All age groups demonstrated an increase over time. This increase was observed both in the CT era as well as in the MRI era. PCNSL ageโadjusted incidence (0.15 to 0.48, a 3โfold increase) outpaced that of systemic lymphoma (14.1 to 18.5, a 33% increase) for the same registries over the same time periods. The rate of increase has begun to slow since 1985; the estimated annual percent change for PCNSL was threeโfold higher during the period 1973โ1985 compared with 1986โ1997.
CONCLUSION
The incidence rate of PCNSL continues to rise. The increase is evident in all age groups and in both genders. Data from the current study suggest that improved diagnostic tools, such as CT or MRI, cannot explain this increase. Cancer 2002;95:1504โ10. ยฉ 2002 American Cancer Society.
DOI 10.1002/cncr.10851