Plasma cell leukemia: A SEER database analysis

Abstract

8605 Background: Primary plasma cell leukemia (PCL) is a rare plasma cell disorder with clinical information limited to small series of patients. Methods: We analyzed the Surveillance Epidemiology and End Results (SEER) database to evaluate the patient characteristic and survival data for patients with PCL. Patients were divided into cohorts based upon age, gender, race and time period of diagnosis. Kaplan-Meier product limit method was used to estimate survival functions for group in each risk factor. Demographics and survival over different periods of time from 1973 and 2004 were compared with multiple myeloma. Results: Among the 291 patients with PCL, median age was 67 years (range 19–98), and the male/female distribution was equal and the most common race was white (79.4%). Median overall survival (OS) and disease specific survivals (DSS, defined by interval from diagnosis to the event of death from PCL) were 4 months and 6 months respectively. The 1 year, 2 year and 5 year overall survival rates were 22.7%, 10.2% and 3.8% respectively. The survival did not differ between gender and race. Patients ≤60 years had a better median overall survival compared to older patients (median OS: 7 months Vs 3 months, p=0.007), although 5-year overall survival was equally poor for either group (6.9% Vs 6.7%). During the same period, we identified 49,106 patients with MM. Demographics for MM showed a slightly increased median age of 70 years, but similar race and gender distribution. Unlike MM, where there has been a modest but statistically significant survival improvement over time, both OS and DSS remained stable in PCL ( Table ). Conclusions: This is the largest study to analyze demographic and survival data on patients with PCL. The poor long term outcome and the lack of improvement in survival of patients with PCL despite small gains in MM suggest a more aggressive disease, for which further therapeutic agents are needed. [Table: see text] No significant financial relationships to disclose.