Epidemiology, Tumor Characteristics, and Survival in Patients With Primary Pancreatic Lymphoma: A Large Population-based Study Using the SEER Database.

INTRODUCTION: Primary pancreatic lymphoma (PPL) is an extranodal manifestation of non-Hodgkin lymphoma originating in the pancreas, which constitutes <1% of all pancreatic neoplasms. Because of the rarity of the disease, most data on PPL are derived from case reports and small case series. To provide better insight into the epidemiology, treatment, and outcomes of these patients, we conducted an analysis of patients with PPL from the Surveillance, Epidemiology and End Results (SEER) database, which is presented in this study.

METHODS: Patients with PPL were identified using the International Classification of Disease for Oncology, third edition histology codes for lymphoma (9590/3-9734/3), with pancreas (C25.0-C25.9) listed as the primary disease site. We collected data on patient demographics, year of diagnosis, primary tumor site, histology, first line of treatment received, and survival until death or last follow-up for the period 1973-2014.

RESULTS: Overall, 835 patients were included. The median (range) age of the study population was 67 (2 to 98) years. The median (95% confidence interval) overall survival for the cohort was 53 (37 to 73) months. On univariable analyses, age, stage, and use of chemotherapy were statistically associated with improved overall survival. Besides these factors, white race was associated with improved cause-specific survival on multivariable analysis.

CONCLUSIONS: This large population-based series describes PPL in detail. Younger age, white race, early stage, and initial treatment with chemotherapy are associated with improved survival in patients with PPL.