Co-expression of MYC and BCL2 predicts poorer outcomes for relapsed/refractory diffuse large B-cell lymphoma with R-ICE and intent to transplant

Abstract

Diffuse large B-cell lymphoma (DLBCL) with co-expression of MYC and BCL2 protein by immunohistochemistry (IHC) – that is, double-expresser lymphoma (DEL) – is associated with poor outcomes after standard frontline therapy. Less is known about the prognostic impact of DEL in patients with relapsed/refractory disease treated with salvage therapy and autologous stem cell transplantation (ASCT). We analyzed the outcomes of 167 patients with relapsed/refractory DLBCL treated with R-ICE (rituximab, ifosfamide, carboplatin and etoposide), of whom 111 patients (66%) underwent ASCT. Using predefined cutoffs for positivity by IHC at relapse for MYC and BCL2 of ⩾40% and ⩾50% of positive tumor cells, respectively, 26 patients (16%) were categorized as DEL and the rest as non-DEL. Overall and complete response rates to R-ICE did not differ between DEL and non-DEL. With a median follow up of 20 months, the 3-year progression-free survival (PFS) and overall survival (OS) rates for DEL were inferior compared to non-DEL (for PFS: 6% versus 33%, p = 0.044, for OS: 39% versus 56%, p = 0.03). The negative impact of DEL on PFS and OS remained significant on multivariable analysis. In conclusion, positive DEL status predicts poorer outcomes following salvage therapy.