Splenic marginal zone lymphoma: a population-based study on the 2001-2008 incidence and survival in the United States.

The epidemiology of splenic marginal zone lymphoma (SMZL) in the United States has not been addressed. Eight years of data (2001-2008) from 17 registries of the Surveillance, Epidemiology and End Results (SEER) program were used for this study. Of the 116,411 cases of non-Hodgkin lymphoma (NHL) in the registries, 763 (0.6%) were SMZL. The overall annual age-adjusted incidence was 0.13 per 100,000 persons per year. The annual percent change in age-adjusted incidence was 4.81% overall (p < 0.05), and significantly increasing trends were found for patients who were white, male or aged 70 years and older (p < 0.05). The relative 5-year overall survival rate for patients with SMZL was 81% (95% confidence interval 75-86%). The incidence of SMZL was highest among whites, males and older patients. A steadily increasing trend in incidence was observed for SMZL. The relative 5-year overall survival rate was high.