Primary pancreatic lymphoma: A population-based analysis using the Surveillance, Epidemiology and End Results database.
303 Background: Primary pancreatic lymphoma (PPL) is a rare disease, accounting for only 0.5% of all pancreatic masses. The clinical presentation of PPL is similar to that of pancreatic adenocarcinoma and the two are difficult to distinguish radiographically. A paucity of literature exists on the epidemiology and outcomes of PPL. Given the limited case reports published on PPL, a comparison of the different treatment modalities has previously not been possible. Here, we present a series of 523 cases of PPL obtained from the Surveillance, Epidemiology, and End Results (SEER) database to investigate the tumor characteristics and compare the different treatment modalities. Methods: Patients diagnosed with a primary pancreatic lymphoma from 1973-2007 were identified. Data on patient and tumor characteristics as well as initial treatment with surgery or radiation was extracted. Chemotherapy information is not available through SEER. Overall survival was calculated using the Kaplan-Meier method. A multivariate analysis was performed to determine independent prognostic factors predicting for survival using a Cox proportional hazards model. Results: Fifty-eight percent of patients identified were male. The median age range at diagnosis was 65-69 years (range, 10-14 years – greater than 85 years). The most common histologic subtype in the present series was diffuse large B-cell lymphoma (DLBCL), which accounted for 71% of all patients. The 5-year overall survival for the group was 47%. Multivariate analysis indicates that age >60 and a marital status of single were predictive of a decreased cause-specific and overall-survival specific survival (p<0.05). Radiation therapy, but not surgery, was predictive of an improved overall survival (p<0.05). Conclusions: PPL is a rare form of extra-nodal NHLs of the GI tract. Adjuvant radiation therapy for patients with a PPL should be strongly considered and a surgical treatment should be avoided if an early diagnosis is established. A prospective study evaluating this patient population will be difficult given the rarity PPL. We hope that this case series will provide a context in evaluating and treating patients with PPL. No significant financial relationships to disclose.