Primary esophageal non-Hodgkin's lymphoma: demographics, clinical characteristics, histopathologic types, and survival in 179 patients from the SEER program and systematic review of the literature.

BACKGROUND The most frequent site for the extranodal appearance of primary non-Hodgkin's lymphomas (NHL) is the gastrointestinal (G.I.) tract. However, primary esophageal lymphoma is extremely rare. The purpose of the present study was to describe and analyze the demographics, clinical characteristics, histopathologic types, and long-term survival of patients with primary esophageal NHL registered in the surveillance, epidemiology, and end results (SEER) database. METHODS Retrospective cohort study. Individuals with primary esophageal lymphoma (PEL) were identified using the international classification of disease for oncology, third edition histology codes. Patients were excluded if there was no microscopic confirmation of the neoplasm or if the diagnosis was made by autopsy or death certificate. Data on demographics, clinical characteristics, histopathology and survival were analyzed using the Kaplan-Meier method, life table, and cox proportional hazard models. RESULTS 179 patients were included (68% males, median age 66 years [IQR 46-79]). The overall survival at 1, 5 and 10 years was 65% (95% CI 57.9-72.3%), 49% (95% CI 42.1-57.3%), and 31% (95% CI 24.5-38.6%), respectively. On univariate analyses, individuals with extranodal marginal zone lymphoma (MZL) had a significantly higher overall survival when compared to patients with diffuse large B cell lymphoma (HR 0.29; 95% CI 0.11-0.73. p = 0.008). Furthermore, patients whose cancer was diagnosed after 1997 showed an improved overall survival (HR 0.40; 95% CI 0.26-0.61. p < 0.001) when compared to those diagnosed before 1997. CONCLUSIONS In this large population-based series, diagnosis after 1997 (year of rituximab approval by the FDA) and MZL subtype were associated with improved survival outcomes in patients with PEL.