Epstein-Barr virus-induced CD30-positive diffuse large B-cell lymphoma in a patient with mixed-phenotypic leukemia treated with clofarabine

Therapy for children and adults with mixed phenotype acute leukemia: a systematic review and meta-analysis

The rarity of mixed-phenotype acute leukemia (MPAL) has resulted in diffuse literature consisting of small case series, thus precluding a consensus treatment approach. We conducted a meta-analysis and systematic review to investigate the association of treatment type (acute lymphoblastic leukemia [ALL], acute myeloid leukemia [AML], or "hybrid" regimens), disease response, and survival. We searched seven databases from inception through June 2017 without age or language restriction. Included studies reported sufficient treatment detail for de novo MPAL classified according to the well-established European Group for Immunological Characterization of Acute Leukemias (EGIL) or World Health Organization (WHO2008) criteria. Meta-analyses and multivariable analyses of a patient-level compiled case series were performed for the endpoints of complete remission (CR) and overall survival (OS). We identified 97 reports from 33 countries meeting criteria, resulting in 1,499 unique patients with data, of whom 1,351 had sufficient detail for quantitative analysis of the study endpoints. Using either definition of MPAL, meta-analyses revealed that AML induction was less likely to achieve a CR as compared to ALL regimens, (WHO2008 odds ratio [OR] = 0.33, 95% confidence interval [95% CI] 0.18-0.58; EGIL, OR = 0.18, 95% CI 0.08-0.40). Multivariable analysis of the patient-level data supported poorer efficacy for AML induction (versus ALL: OR = 0.45 95% CI 0.27-0.77). Meta-analyses similarly found better OS for those beginning with ALL versus AML therapy (WHO2008 OR = 0.45, 95% CI 0.26-0.77; EGIL, OR = 0.43, 95% CI 0.24-0.78), but multivariable analysis of patient-level data showed only those starting with hybrid therapy fared worse (hazard ratio [HR] = 2.11, 95% CI 1.30-3.43). MPAL definition did not impact trends within each endpoint and were similarly predictive of outcome. Using either definition of MPAL, ALL-therapy is associated with higher initial remission rates for MPAL and is at least equivalent to more intensive AML therapy for long-term survival. Prospective trials are needed to establish a uniform approach to this heterogeneous disease.

Cancer Therapy-associated Lymphoproliferative Disorders: An Under-recognized Type of Immunodeficiency-associated Lymphoproliferative Disorder

We describe the clinicopathologic features of 17 patients who had a hematologic malignancy of various types, were treated, and subsequently developed a lymphoproliferative disorder (LPD). There were 10 men and 7 women with a median age of 59 years (range, 36 to 83 y). The primary hematologic neoplasms included: 5 chronic lymphocytic leukemia/small lymphocytic lymphoma, 3 plasma cell myeloma, 2 acute monoblastic leukemia, and 1 case each of mixed-phenotype acute leukemia, chronic myeloid leukemia, splenic marginal zone lymphoma, follicular lymphoma, mantle cell lymphoma, T-cell prolymphocytic leukemia, and peripheral T-cell lymphoma. All patients were treated with chemotherapy with or without therapeutic antibodies; 3 also underwent autologous stem cell transplantation. The mean interval from initiation of therapy for initial hematologic malignancy to onset of LPD was 66 months (range, 3 to 299 mo). Ten (59%) LPDs were extranodal and 7 (41%) involved nodal tissues. The histologic diagnoses included: 8 diffuse large B-cell lymphoma, 4 classical Hodgkin lymphoma, 3 polymorphic LPD, 1 lymphomatoid granulomatosis, and 1 Epstein-Barr virus (EBV) mucocutaneous ulcer. Fourteen cases were EBV. Following the onset of LPD, chemotherapy was administered to 10 (59%) patients. With a median follow-up of 100 months (range, 5 to 328 mo), 8 (47%) patients are alive and 9 (53%) died. One (6%) patient with lymphomatoid granulomatosis underwent spontaneous remission. On the basis of the clinicopathologic features and high prevalence of EBV infection in this cohort, we believe that these LPDs show similarities with other types of immunodeficiency-associated LPDs. We suggest that cancer therapy-associated LPD be included in future classification systems for immunodeficiency-associated LPDs.

EBV-driven B-cell lymphoproliferative disorders: from biology, classification and differential diagnosis to clinical management

Epstein–Barr virus (EBV) is a ubiquitous herpesvirus, affecting >90% of the adult population. EBV targets B-lymphocytes and achieves latent infection in a circular episomal form. Different latency patterns are recognized based on latent gene expression pattern. Latent membrane protein-1 (LMP-1) mimics CD40 and, when self-aggregated, provides a proliferation signal via activating the nuclear factor-kappa B, Janus kinase/signal transducer and activator of transcription, phosphoinositide 3-kinase/Akt (PI3K/Akt) and mitogen-activated protein kinase pathways to promote cellular proliferation. LMP-1 also induces BCL-2 to escape from apoptosis and gives a signal for cell cycle progression by enhancing cyclin-dependent kinase 2 and phosphorylation of retinoblastoma (Rb) protein and by inhibiting p16 and p27. LMP-2A blocks the surface immunoglobulin-mediated lytic cycle reactivation. It also activates the Ras/PI3K/Akt pathway and induces Bcl-xL expression to promote B-cell survival. Recent studies have shown that ebv-microRNAs can provide extra signals for cellular proliferation, cell cycle progression and anti-apoptosis. EBV is well known for association with various types of B-lymphocyte, T-lymphocyte, epithelial cell and mesenchymal cell neoplasms. B-cell lymphoproliferative disorders encompass a broad spectrum of diseases, from benign to malignant. Here we review our current understanding of EBV-induced lymphomagenesis and focus on biology, diagnosis and management of EBV-associated B-cell lymphoproliferative disorders.