Decreasing incidence rates of primary central nervous system lymphoma

BACKGROUND Incidence rates of primary central nervous system lymphomas (PCNSL) in the U.S. were reported to have increased dramatically during the 1980s and early 1990s. Recent reports portray a continuation of this trend. With potential etiologic factors related to immunosuppression changing, the authors hypothesized that the incidence of PCNSL would be stabilizing. METHODS The authors analyzed age specific, gender specific, and race specific PCNSL incidence rates from 1973–1998 using data from the Surveillance, Epidemiology, and End Results (SEER) program. To estimate the impact of the acquired immunodeficiency syndrome (AIDS) and organ transplantation on PCNSL trends, the authors evaluated incidence data from the Centers for Disease Control and Prevention HIV [human immunodeficiency virus]/AIDS Surveillance Report, and the United Network for Organ Sharing. RESULTS PCNSL incidence rates decreased from a peak of 10.2 per 1 million person‐years in 1995 to 5.1 per 1 million person‐years in 1998, a decrease that was largely attributable to a decrease in the incidence of the disease in males age ≤ 59 years. The annual rate among those age ≥ 60 years essentially has remained unchanged since 1994, at approximately 16 per 1 million person‐years. Since the early 1980s, regardless of age, PCNSL incidence rates were higher in males than in females, and higher in blacks than in whites. Concordant with PCNSL trends, AIDS rates have decreased since their peak in 1993. However, the rate of solid organ transplantations has increased steadily since 1990. CONCLUSIONS In contrast to recent reports of a progressively increasing incidence, the authors found that PCNSL rates have been decreasing in the majority of demographic groups in the U.S since the mid‐1990s. A notable exception was observed in the highest PCNSL risk group, those age ≥ 60 years. Cancer 2002;95:193–202. © 2002 American Cancer Society. DOI 10.1002/cncr.10643