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

Summary 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 CD 30‐expressing cells. However, CD 30 ( TNFRSF 8) expression patterns in DLBCL are not well described thus far. Here, we examined CD 30 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 CD 30+ tumour cells. Using a > 0% cut‐off, CD 30 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 CD 30 expression (10/11) ( P < 0·001). We conclude CD 30 is expressed in a substantial proportion of DLBCL and CD 30 immunohistochemistry may be a useful prognostic marker in R‐ CHOP treated GCB ‐ DLBCL . The significant association of CD 30 with EBV ‐positive non‐ GCB DLBCL suggests a distinct pathobiology for these cases.