Impact of treatment variability and clinicopathological characteristics on survival in patients with Epstein-Barr-Virus positive diffuse large B cell lymphoma.

Patients with EBV-positive diffuse large B cell lymphoma not otherwise specified (EBV DLBCL (NOS)) recurrently present with advanced age and reduced performance status. They are therefore insufficiently represented in clinical trials and treatment is likely to differ. Here we assess clinicopathological characteristics, therapeutic variability and clinical outcome in the largest consecutively diagnosed EBV DLBCL (NOS) cohort published to date (n = 80; median age 70 years; range 19-90). Centralized and systematic haematopathological panel review was performed. By immunohistochemistry 60/80 patients were CD30-positive. Further, we identified nine EBV DLBCL (NOS) patients with associated or composite peripheral T cell lymphoma at diagnosis or relapse (preceded by clonal T cell populations within the initial DLBCL biopsy in 4/5 cases). Most patients (80%) were treated with R-CHOP-type therapy and 16 patients received none or less intensiveprotocols. Upon univariate analysis both R-CHOP-type therapy (OS: P < 0.0001; PFS: P = 0.0617) and negativity for CD30 (OS: P = 0.0002; PFS: P = 0.0002) showed a protective 66 effect, maintained upon multivariate analysis. In a propensity-score matched analysis with a cohort of non-EBV DLBCL (NOS) patients, balanced for all revised-international prognostic index factors, we found an EBV-association to hold no significant impact on progression-free and overall survival whilst exhibiting a trend favouring EBV-negativity (OS: P = 0.116; PFS: P = 0.269). Our findings provide insight into the clinical course of EBV DLBCL (NOS), highlight the ramifications of CD30-expression and underline the superior therapeutic efficacy of R-CHOP immunochemotherapy. Alternative therapies, incorporating tumour biology (e.g. CD30 directed therapies) need to be explored in EBV DLBCL (NOS) patients. Moreover our data advert to the close relationship between EBV DLBCL (NOS) and peripheral T cell lymphomas.