Prognosis and Treatment of Plasmablastic Lymphoma in the United States: A Multicenter Retrospective Study

Plasmablastic lymphoma (PBL) is a rare, aggressive AIDS-related lymphoma observed in patients with immunosuppressed states as well as in immunocompetent individuals. We sought to determine survival outcomes, prognostic factors, and optimal treatment regimens in a large, contemporary cohort of patients with PBL in the United States. We performed a multicenter, retrospective cohort study, including 344 patients diagnosed with PBL between 2005 and 2022. Patients were stratified into cohorts according to underlying immune status. Survival outcomes were calculated using Kaplan-Meier statistics, with cohort-specific survival outcomes adjusted using propensity score-based weighting. Factors associated with outcomes were assessed via multivariable models using multiple imputation. The median age at diagnosis was 53 years, most patients were male (n = 270), and many had HIV (n = 164). The median OS was 5.0 years, with a median PFS of 1.4 years. Patients living with HIV had the best outcomes, whereas patients with prior organ transplantation had the worst outcomes. Use of higher intensity chemotherapy regimens and use of a proteasome inhibitor in the frontline setting did not show survival benefit. While there was no clear optimal treatment approach in the frontline setting, the median OS of 5.0 years is dramatically improved compared with historical controls.