CD30 expression in de novo diffuse large B-cell lymphoma: a population-based study from British Columbia.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with variable therapeutic responses and alternative therapies are needed for patients with unfavourable treatment outcomes after standard treatment with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). One promising candidate is brentuximab vedotin, an antibody-drug conjugate targeting CD30-expressing cells. However, CD30 (TNFRSF8) expression patterns in DLBCL are not well described thus far. Here, we examined CD30 expression in a population-based cohort of immunocompetent patients from British Columbia with de novo DLBCL using immunohistochemistry. 385 cases of formalin-fixed paraffin-embedded DLBCL in tissue microarrays were evaluated. 95 cases (25%) harboured CD30+ tumour cells. Using a > 0% cut-off, CD30 expression was predictive of superior 5-year progression-free survival within R-CHOP treated germinal centre B-cell-like (GCB) DLBCL (86% vs. 64%, P = 0·020), which was independent of the International Prognostic Index. Epstein-Barr virus (EBV) was identified in 11 (3%) cases, all of which were non-GCB (P = 0·001) and almost exclusively positive for CD30 expression (10/11) (P < 0·001). We conclude CD30 is expressed in a substantial proportion of DLBCL and CD30 immunohistochemistry may be a useful prognostic marker in R-CHOP treated GCB-DLBCL. The significant association of CD30 with EBV-positive non-GCB DLBCL suggests a distinct pathobiology for these cases.