Trends in survival of patients with primary plasma cell leukemia: A population-based analysis from 1973 to 2010.

8608 Background: Primary plasma cell leukemia (pPCL) is a rare plasma cell malignancy with a very aggressive course and poor outcome compared to multiple myeloma (MM). There has been significant improvement in the survival of MM patients over the past decade as a result of the incorporation of novel agents that are now also used in pPCL. The time period after 1995 represented adoption of autologous stem cell transplantation as a standard treatment modality and 2003 marked the wide availability of the novel agents in the relapsed and refractory setting due to accelerated FDA approval. However, it was not until 2006 that these novel agents were approved to be utilized in the first-line treatment of MM. The question remains whether the survival of pPCL has improved since the advent of these novel agents. Methods: We analysed the Surveillance, Epidemiology, and End Results (SEER) database for trends in survival of patients with pPCL (ICD-O: 9733) over the time period of 1973-2010 using the SEER Stat 8.1.2software. Kaplan-Meier analysis was used to analyze the overall survival (OS) and the Cox proportional hazards model was used to assess the influence of various prognostic factors on OS. Results: A total of 318 pPCL patients were identified in the SEER database. The median age at diagnosis was 62 years (range, 19-91) and 52% were females. The median follow up was 56 months (range, 39-102) and 83% of patients had died at the time of this analysis. The median 1, 2 and 5-year OS rates were 57%, 32% and 6% respectively. The median OS based on time periods of diagnosis of 1973-1995, 1996-2002, 2003-2005 and 2006-2010 were 9, 9, 8, and 19 months, respectively (P = 0.002). OS was similar regardless of subgroups based on age, gender, and marital status at diagnosis. Among patients <70 years age, the median OS was 11 months compared to 10 months in patients >70 years age (P = 0.378). Only diagnosis in the 2006-2010 era predicted for a better OS (HR: 0.65; 95% CI: 0.45-0.94; P = 0.0018, with reference to 1973-1995 era). Conclusions: Our study identifies a recent major improvement in survival amongst patients diagnosed with pPCL within a large US population. This suggests a positive impact of incorporating novel agents in the treatment of pPCL since 2006.