Dual institution experience of extranodal marginal zone lymphoma reveals excellent long-term outcomes

Extranodal marginal zone lymphoma (EMZL) is a B-cell lymphoma arising from mucosa-associated lymphoid tissue (MALT). The disease characteristics, clinical course and treatment vary considerably based on site of involvement. Because long-term outcome data for EMZL are limited, we sought to describe the clinical details of a large number of patients with EMZL evaluated at the Case Comprehensive Cancer Center over a 12-year period to identify prognostic markers including the impact of site of involvement. We identified 211 cases of EMZL involving the stomach (30%), ocular adnexa (19%), lungs (16%) and intestines (9%). Initial treatment included antibiotics (18%), radiation (21%), rituximab (20%), chemotherapy (3%), rituximab + chemotherapy (7%), surgery (17%) or observation (8%). After a median follow-up of 44·3 months (range 2·2-214·9), median progression-free survival (PFS) was 68·2 months (95% confidence interval [CI] 54·5-111·3) and median overall survival (OS) has not been reached. Age >60 years, elevated lactate dehydrogenase level (LDH), ≥4 lymph node groups involvement, and high follicular lymphoma international prognostic index (FLIPI) were associated with inferior PFS/OS. In summary, patients with EMZL have excellent prognosis with median OS in excess of 10 years. Age, elevated LDH, advanced disease, and high FLIPI score are associated with worse outcomes.