Incidence, clinical features, treatment and outcome of primary central nervous system lymphoma in Norway.

The incidence of primary central nervous system lymphoma (PCNSL) has been reported to increase in some parts of the world, while being stable in other regions. In an attempt to characterize the incidence rate, clinical features, treatment, outcome, and prognostic factors of PCNSL in Norway, we report our experience in a large unselected series of patients. Clinical features, histological diagnosis, radiological findings, treatment, and outcome of all patients diagnosed with PCNSL in Norway in the years 1989-1998 were registered. During the 10-year period 58 new cases of histologically verified PCNSL were registered in Norway. The annual incidence rate of PCNSL was on average 1.34 cases per million people with a non-significant increasing trend (p=0.069). For patients diagnosed before death (n=45) the estimated survival following histological diagnosis was 55%, 47%, and 23% at 1, 2, and 5 years, respectively. In Cox-regression analysis age, WHO performance status and treatment had independent prognostic impact on survival. In the studied decade, there was a non-significant trend towards increased incidence of PCNSL, perhaps due to increased availability of diagnostic imaging, especially magnetic resonance imaging.