Long-Term Outcomes and Management Strategies With DA-R-EPOCH in Primary Mediastinal B-Cell Lymphoma: Insights From a Single-Center Experience

Immunochemotherapy has demonstrated high cure rates in primary mediastinal large B-cell lymphoma (PMBCL). Recent findings from the IELSG 37 study show that certain specific dose-dense treatment regimens are more likely to eliminate the need for consolidative radiation therapy, thereby reducing long-term toxicity. Here, we report our experience with DA-R-EPOCH in a cohort of 70 patients treated at our cancer center. This retrospective, observational, single-center study includes patients treated between 2013 and 2021. Treatment response was evaluated using positron emission tomography-computed tomography (PET-CT) scans and assessed according to the Deauville Score. With a median follow-up of 36.4 months, 29% of patients achieved a complete metabolic response (CMR) on interim PET-CT, while 71% achieved CMR at the end of treatment. Despite these results, 3-year overall survival (OS) and progression-free survival (PFS) rates were 99% and 93%, respectively. Our findings highlight the importance of tailoring treatment regimens, allowing for reduced reliance on consolidative therapies in line with recent advancements. Notably, none of the patients who achieved CMR on interim PET-CT experienced relapse, and no disease progression was observed beyond 1 year after completing DA-R-EPOCH. Additionally, our results indicate that dose intensification beyond level 2 does not appear to improve survival, emphasizing the important implications for minimizing treatment-related toxicity. We also analyzed the management and outcomes of refractory and relapsed cases, underscoring the challenges in treating non-responding patients identified by interim PET-CT, the limited efficacy of salvage immunochemotherapy, and the interesting role of radiation therapy in these cases.