Treatment Outcomes of Patients with Primary Mediastinal Diffuse Large B-CellLymphoma: A Single-Center Experience

Background: Primary mediastinal B-cell lymphoma (PMBCL) is a distinct clinicopathologic entity from diffuse large B-cell lymphoma. The optimal first-line therapy for PMBCL is subject of ongoing debate with no accepted standard of care. Patients and Methods: We searched retrospectively for adult patients with newly diagnosed PMBCL treated at our department between 2002 and 2014. Clinical, management and follow-up data were collected. Staging and response assessment of patients included PET and/or CT scan. Results: Twenty-nine patients with PMBCL (17 female and 12 male) were included. The median age at diagnosis was 36 years (18-79 years). Eighteen (62.1%) and 20 (69%) patients had limited-stage and bulky disease, respectively. All patients were treated with rituximab-based combination chemotherapy; 21 patients underwent consolidation radiotherapy. Seven patients (24.1%) were transplanted (six in first remission and the remaining in second remission). At the end of frontline therapy, 28 patients had responded (27 complete response and 1 partial response) and one patient showed progressive disease. Febrile neutropenia was the most frequent acute adverse event and three patients developed late toxicity. The median follow-up was 51,5 months. The 5-year overall progression-free survival was 83.8%. Four patients died, half of which died within the first year after diagnosis. Conclusion: Our study shows favorable prognosis of patients with PMBCL treated with rituximab-based chemotherapy and consolidation radiotherapy or autologous stem-cell transplant. While consolidation therapy continues to be commonly used, its role has become increasingly controversial.