Primary Urinary Tract Lymphoma: Rare but Aggressive

Background: Primary urinary tract lymphoma (PUTL) is an uncommon disease with only a few case reports in the literature. Materials and Methods: Information about 1,264 patients diagnosed between 1983 and 2013 with PUTL was extracted from the Surveillance, Epidemiology and End Results database. Kaplan-Meier curves and multivariable regression analysis were used to analyze the survival and identify prognostic factors. A comparison of nodal diffuse large B-cell lymphoma (DLBCL) with PUTL DLBCL was performed. In addition, we compared the characteristics of kidney and bladder lymphoma. Results: PUTL incidence was 1 case/1,000,000 people per year. DLBCL was found to be the predominant histology. Five-year overall survival and cancer-specific survival were 49% and 58%, respectively. DLBCL histology, male gender, stage III-IV disease, and advanced age were found to be poor prognostic factors. Surgery may be beneficial. Urinary tract DLBCL has a worse prognosis than nodal DLBCL. Conclusion: To our knowledge, this is the largest population-based study of PUTL in the literature. The survival of patients has not improved in the era of modern therapies therefore new treatments are needed.