Objectives: Primary mediastinal large B-cel l lymphoma (PMBCL) is a rare subtype of B-cell lymphoma that is not yet fully understood. This population-based study aimed to assess the latest survival and treatment strategies for patients with PMBCL.
Methods: The study used the dataset from the Surveillance, Epidemiology, and End Results Program registry to retrospectively analyze adult patients diagnosed with PMBCL between 2001 and 2018. The primary outcome measures included overall survival (OS) and disease-specific survival (DSS).
Results: Among the 814 identified cases, the study revealed a 5-year OS rate of 86.7% and a 5-year DSS rate of 88.2% after a median follow-up of 54 months. Cox regression analysis indicated that age over 60 years, pre-2010 diagnosis, non-White ethnicity, advanced stage, and absence of chemotherapy significantly reduced both OS and DSS. It also found that chemotherapy has remained the primary therapeutic protocol for PMBCL over the last 20 years, whereas the utilization of surgery and radiation declined significantly. Patients diagnosed with PMBCL between 2010 and 2018 had a significantly reduced mortality risk (∼50%) compared to those diagnosed between 2001 and 2009. Notably, in the era of rituximab's widespread usage, recipients of radiotherapy exhibited a poorer OS rate than non-recipients.
Conclusion: Survival outcomes for patients with PMBCL have significantly improved in the current era, possibly due to the evolving treatment paradigm. The value of radiotherapy in PMBCL is still debated and requires further prospective evaluation.
Keywords: SEER program; lymphoma; mediastinum; radiotherapy; survival.