Primary pancreatic lymphoma: a population-based analysis using the SEER program.

Background: Primary pancreatic lymphoma (PPL) is a rare disease, accounting for only 0.5% of all pancreatic masses. A paucity of literature exists on the epidemiology and outcomes of PPL. Here, we present a series of 523 cases of PPL obtained from the Surveillance, Epidemiology, and End Results database. Methods: Patients diagnosed with a PPL from 1973 to 2007 were identified. Data on patient and tumor characteristics as well as initial treatment with surgery or radiation were extracted. Survival rates were calculated using the Kaplan-Meier method. A multivariate analysis was performed to determine independent prognostic factors predicting mortality hazard ratios using Cox proportional hazards modeling. Results: Fifty-eight percent of patients identified were male. The median age range at diagnosis was 65 to 69 years. The most common histologic subtype in the present series was diffuse large B-cell lymphoma, which accounted for 56% of all patients. The 5-year overall survival for the group was 45%. Multivariate analysis suggests that age more than 60 years at diagnosis, race of "other" (compared with "white"), and marital status of single or widowed were predictive of increased all-cause mortality (P < 0.05). Conclusions: This represents the largest published series of patients with PPL. Age more than 60 years, female sex, and marital status of married were identified as independent prognostic factors predicting for decreased all-cause mortality.