Relapsed or refractory primary mediastinal B-cell lymphoma: Evaluation of outcome of a minority from 125 patients treated at a single institution.

e19549 Background: Primary mediastinal B-cell lymphoma (PMBL) is a distinct entity of large B-cell lymphoma representing 2%–4% of non-Hodgkin’s lymphomas. The treatment based on rituximab (R) plus chemotherapy results in 78%-93% event free survival. Patients who do not respond to first-line treatment or relapse early are usually not cured. The aim of this study was to evaluate outcome of patients with PMBL after second-line therapy due to recurrent/refractory disease (rrPMBL). Methods: We retrospectively identified 18 (14%) rrPMBL from 125 PMBL patients treated at out institution between 2004 and 2013. Patients received salvage treatment including high-dose methotrexate and high-dose cytarabine (n=10), cisplatin-based regimens (n=4) or other chemotherapy (n=4). Eight patients underwent autologous stem cell transplantation (ASCT). Results: Median age (range) was 28 (20–42), clinical stage IVB - 15/18, pericardial effusion – 7, and all patients had IPI score 3-4 at diagnosis. Most patients received R-CHOP a...