Intravascular Large B Cell Lymphoma in the United States (US): A Population- Based Study Using Surveillance, Epidemiology, and End Results Program and National Cancer Data Base
Abstract Background: Intravascular large B cell lymphoma (IVLBCL) is a rare and aggressive non-Hodgkin lymphoma lacking any prior US based population studies. We aimed to conduct a population based study of IVLBCL in the US and compare characteristics and survival to diffuse large B cell lymphoma, not otherwise specified (DLBCL, NOS). Methods: We used Surveillance, Epidemiology, and End Results (SEER) registries from 2000 to 2013 to calculate incidence rates (case/1,000,000) and age-adjusted to the US 2000 standard population. We collected patient level data from the NCDB Participant User Files using ICD-O-3 histology code 9680 with ICD-O-3 primary site modifier C499 and analyzed for demographic and clinical characteristics as well as overall survival (2004-2013). Chi-Square test was used to compare the characteristics of patients with IVLBCL to that of DLBCL, NOS. Overall survival analysis was performed using Kaplan- Meier method and compared by log rank. Overall survival (OS) of IVLBCL was compared to propensity-matched cohort of DLBCL, NOS. Multivariate analysis was conducted using weighted Cox Proportional Hazard regression model. Results: In the years 2000-2013, the overall crude incidence rate of IVLBCL was 0.093 (case/1,000,000) and age-adjusted incidence rate of IVLBCL was 0.095 (case/1,000,000). A total of 388 IVLBCL patients were identified in NCDB database. Patients with IVLBCL (n=388), compared to DLBCL, NOS (n=155,436), were more likely to be of age ≥ 65 (64.2% vs 56.9%, p=0.0039), female (51.8% vs 46.5, p=0.036), diagnosed at advanced stage (stage IV, 51.5% vs 33.4%, p<0.0001) and less likely to receive chemotherapy (70.4% vs 78.9%, p = 0.0001).The median 1, 3 and 5-year OS rates for IVLBCL were 66.2%, 51.8% and 46.3% respectively. After propensity matching, the 5-year overall survival of IVLBCL was comparable to DLBCL, NOS (46.6% vs 45.4%, p=0.61). On multivariate analysis, advanced age (HR 1.03, 95% CI 1.032-1.034; p<0.0001), advanced stage (Stage III: HR 1.34, 95% CI 1.31-1.38; <0.0001, Stage IV: HR 1.81, 95% CI 1.77-1.85; p<0.0001), having Medicaid (HR 1.72, 95% CI 1.66-1.79; p<0.001) or Medicare (HR 1.24, 95% CI 1.20-1.26; p<0.0001) predicted worse OS, whereas female gender (HR 0.86, 95% CI 0.85-0.88; p<0.0001) and use of radiation therapy (HR 0.76, 95% CI 0.75-0.78; p<0.0001) predicted better OS. Conclusions: This is the largest series of IVLBCL reported to date. Our study provides characteristics and OS of a large cohort of this rare entity, which can be used for patient education and may provide background information for future research. In the Rituximab era, the OS of patients with IVLBCL is comparable to DLBCL, NOS. In addition, our study also reports predictors of OS in patients with IVLBCL. Disclosures No relevant conflicts of interest to declare.