Evaluating cell-of-origin subtype methods for predicting diffuse large B-cell lymphoma survival: a meta-analysis of gene expression profiling and immunohistochemistry algorithms

Randomized Phase II Study of R-CHOP With or Without Bortezomib in Previously Untreated Patients With Non-Germinal Center B-Cell-Like Diffuse Large B-Cell Lymphoma

Purpose To evaluate the impact of the addition of bortezomib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on outcomes in previously untreated patients with non-germinal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). Patients and Methods After real-time determination of non-GCB DLBCL using the Hans immunohistochemistry algorithm, 206 patients were randomly assigned (1:1; stratified by International Prognostic Index [IPI] score) to six 21-day cycles of standard R-CHOP alone or R-CHOP plus bortezomib 1.3 mg/m² intravenously on days 1 and 4 (VR-CHOP). The primary end point, progression-free survival (PFS), was evaluated in 183 patients with centrally confirmed non-GCB DLBCL who received one or more doses of study drug (91 R-CHOP, 92 VR-CHOP). Results After a median follow-up of 34 months, with 25% (R-CHOP) and 18% (VR-CHOP) of patients having had PFS events, the hazard ratio (HR) for PFS was 0.73 (90% CI, 0.43 to 1.24) with VR-CHOP ( P = .611). Two-year PFS rates were 77.6% with R-CHOP and 82.0% with VR-CHOP; they were 65.1% versus 72.4% in patients with high-intermediate/high IPI (HR, 0.67; 90% CI, 0.34 to 1.29), and 90.0% versus 88.9% (HR, 0.85; 90% CI, 0.35 to 2.10) in patients with low/low-intermediate IPI. Overall response rate with R-CHOP and VR-CHOP was 98% and 96%, respectively. The overall survival HR was 0.75 (90% CI, 0.38 to 1.45); 2-year survival rates were 88.4% and 93.0%, respectively. In the safety population (100 R-CHOP and 101 VR-CHOP patients), grade ≥ 3 adverse events included neutropenia (53% v 49%), thrombocytopenia (13% v 29%), anemia (7% v 15%), leukopenia (26% v 25%), and neuropathy (1% v 5%). Conclusion Outcomes for newly diagnosed, prospectively enrolled patients with non-GCB DLBCL were more favorable than expected with R-CHOP and were not significantly improved by adding bortezomib.

A Phase 2/3 Multicenter, Randomized, Open-Label Study to Compare the Efficacy and Safety of Lenalidomide Versus Investigator's Choice in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma

Purpose: Randomized, multicenter, open-label, phase 2/3 trial investigating lenalidomide versus investigator's choice (IC) in relapsed/refractory diffuse large B-cell lymphoma (DLBCL).Experimental Design: Patients with DLBCL who received ≥2 prior therapies were stratified by DLBCL subtype [germinal center B-cell (GCB) vs. non-GCB; determined by immunohistochemistry (IHC)] and then randomized 1:1 to lenalidomide (25 mg/day, 21 days of 28-day cycle) or IC (gemcitabine, rituximab, etoposide, or oxaliplatin). Crossover to lenalidomide was permitted for IC-treated patients with radiologically confirmed progressive disease. The primary endpoint was overall response rate (ORR). Progression-free survival (PFS), overall survival, and subtype analysis [GCB vs. activated B-cell (ABC)] using gene expression profiling (GEP) were exploratory endpoints.Results: Stage 1: 102 DLBCL patients (by IHC: non-GCB, n = 54; GCB, n = 48) received ≥1 dose of lenalidomide or IC. Hematologic treatment-emergent adverse events with lenalidomide versus IC included neutropenia (42.6%; 36.4%), anemia (33.3%; 47.3%), thrombocytopenia (24.1%; 43.6%), and leukopenia (5.6%; 12.7%), respectively. Overall, lenalidomide-treated patients had an ORR of 27.5% versus 11.8% in IC (ORRs were similar regardless of IHC-defined DLBCL subtype). Median PFS was increased in patients receiving lenalidomide (13.6 weeks) versus IC (7.9 weeks; P = 0.041), with greater improvements in non-GCB patients (15.1 vs. 7.1 weeks, respectively; P = 0.021) compared with GCB (10.1 vs. 9.0 weeks, respectively; P = 0.550).Conclusions: The clinical benefit of lenalidomide monotherapy in DLBCL patients was more evident in the non-GCB subtype. Exploratory analyses suggest that this preferential benefit was more pronounced in the GEP-defined ABC population, demonstrating a need for additional studies of lenalidomide in DLBCL using GEP subtyping. Clin Cancer Res; 23(15); 4127-37. ©2017 AACR.

Analysis of prognostic value of complete response by PET-CT and further stratification by clinical and biological markers in DLBCL patients

Positron emission tomography-computed tomography (PET-CT) is performed as the standard method for response assessment of diffuse large B cell lymphoma (DLBCL) patients. However, a substantial proportion of patients experience relapse even if they have achieved complete response (CR) defined by PET-CT. We validated the prognostic value of CR by PET-CT and applied the National Comprehensive Cancer Network-International Prognostic Index (NCCN-IPI) and cell of origin (COO) to patients with CR by PET-CT to evaluate their additional predictive ability for survival outcomes. We retrospectively analyzed DLBCL patients who were treated with R-CHOP or an R-CHOP-like regimen and who achieved CR by PET-CT or CT only. A total of 185 patients were analyzed: 114 patients achieved CR by PET-CT and 71 patients by CT only. Patients with CR by PET-CT had significantly better overall survival (OS) than those with CR by CT (5-year OS, 87.5 vs. 62.4%, P = 0.003). Patients with high risk according to the NCCN-IPI had a dismal outcome despite achieving CR by PET-CT (5-year OS, 61.8%). In contrast, low-, low-intermediate-, and high-intermediate-risk patients had excellent outcomes (5-year OS, 100, 89.7, and 93.5%, respectively). Among patients with CR by PET-CT, patients with germinal center B cell (GCB) DLBCL (n = 40) had significantly better survival than those with non-GCB DLBCL (n = 57) (5-year OS, 96.9 vs. 75.5%, P = 0.039). We demonstrated that CR by PET-CT was a better predictor of survival outcomes than CR by CT only. The NCCN-IPI and COO subtypes could identify a subpopulation of poor-risk patients among those who achieved CR by PET-CT.

CD109, a negative regulator of TGF-β signaling, is a putative risk marker in diffuse large B-cell lymphoma

CD109 is a glycosylphosphatidylinositol-anchored glycoprotein that negatively regulates TGF-β signaling. CD109 was originally identified in hematopoietic tumors; however, the significance of CD109 in hematopoietic malignancies remains unclear. Here, we study the association of CD109 with diffuse large B-cell lymphoma (DLBCL) prognosis. Eighty-four DLBCL specimens were immunohistochemically analyzed for CD109 expression, and 31 and 53 cases were classified into low- and high-CD109 expression groups, respectively. CD109 expression was not associated with overall survival using the Kaplan-Meier analysis and log-rank tests (P = 0.17); however, a significant association was observed between high-CD109 expression and low-1-year survival (P = 0.01). Moreover, in combination with the revised International Prognostic Index (R-IPI), R-IPI-poor/CD109-high was associated with poorer prognosis compared with R-IPI-poor alone. We assessed TGF-β signaling in CD109-depleted Nalm6 cells (a human B-lymphoblastic leukemia/lymphoma cell line), and found prolonged Smad2 phosphorylation compared with control cells after TGF-β1 stimulation, suggesting that CD109 attenuates TGF-β1 signaling in human B-cell tumors. These results suggest that CD109 is a putative biomarker for identifying a high-risk group among DLBCL patients.

ESMO consensus conference on malignant lymphoma: general perspectives and recommendations for prognostic tools in mature B-cell lymphomas and chronic lymphocytic leukaemia

The European Society for Medical Oncology (ESMO) consensus conference on mature B-cell lymphomas and chronic lymphocytic leukaemia (CLL) was held on 20 June 2015 in Lugano, Switzerland, and included a multidisciplinary panel of 25 leading experts. The aim of the conference was to develop recommendations on critical subjects difficult to consider in detail in the ESMO Clinical Practice Guidelines. The following areas were identified: (i) the elderly patient, (ii) prognostic factors suitable for clinical use and (iii) the 'ultra-high-risk' group. Before the conference, the expert panel was divided into three working groups; each group focused on one of these areas in order to address four clinically relevant questions relating to that topic. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, each working group developed recommendations to address each of the four questions assigned to their group. These recommendations were then presented to the entire panel and a consensus was reached. This manuscript presents recommendations dedicated to the second area of interest, i.e. prognostic factors suitable for clinical use. The four topics [i.e. interim positron emission tomography (PET), TP53 mutations, cell of origin (COO) and minimal residual disease (MRD)] were primarily chosen because of the bulk of available data together with the lack of clear guidance regarding their use in clinical practice and within clinical trials. Results, including a summary of evidence supporting each recommendation, are detailed in this manuscript. The panel acknowledged that detection of TP53 inactivation by deletion or mutation in CLL should be implemented in clinical practice (level of evidence I, strength of recommendation A). Due to their potentially high prognostic value, at least in some lymphoma entities, implementation of interim PET, COO and MRD was highly recommended in the context of clinical trials. All expert panel members approved this final article.

Advances in the molecular diagnosis of diffuse large B-cell lymphoma in the era of precision medicine

INTRODUCTION

The adoption of high-throughput technologies has led to a transformation in our ability to classify diffuse large B-cell lymphoma (DLBCL) into unique molecular subtypes. In parallel, the expansion of agents targeting key genetic and gene expression signatures has led to an unprecedented opportunity to personalize cancer therapies, paving the way for precision medicine. Areas covered: This review summarizes the key molecular subtypes of DLBCL and outlines the novel technology platforms in development to discriminate clinically relevant subtypes. Expert commentary: The application of emerging diagnostic tests into routine clinical practise is gaining momentum following the demonstration of subtype specific activity by novel agents. Co-ordinated efforts are required to ensure that these state of the art technologies provide reliable and clinically meaningful results accessible to the wider haematology community.

Lymph Node Fine-Needle Cytology: Beyond Flow Cytometry

Lymph node (LN) fine-needle cytology (FNC) coupled with flow cytometry immunophenotyping provides relevant information for the diagnosis of non-Hodgkin lymphoma (NHL). Numerous studies have shown FNC samples to be suitable for different molecular procedures; in this review, some of the molecular procedures most commonly employed for NHL are briefly described and evaluated in this perspective. Fluorescence in situ hybridization and chromogenic in situ hybridization are briefly described. Polymerase chain reaction (PCR)-based assays are used to identify and quantify mutations and translocations, namely immunoglobulin (IGH) and T-cell receptor rearrangements by clonality testing and IGVH somatic hypermutations either by Sanger sequencing, single-strand conformational polymorphisms or RT-PCR strategies. High-throughput technologies (HTT) encompass numerous and different diagnostic tools that share the capacity of multiple molecular investigation and sample processing in a fast and reproducible manner. HTT includes gene expression profiling, comparative genomic hybridization, single-nucleotide polymorphism arrays and next-generation sequencing technologies. A brief description of these tools and their potential application to LN FNC is reported. The challenge for FNC will be to achieve new knowledge and apply new technologies to FNC, exploiting its own basic qualities.

Primary cardiac diffuse large B-cell lymphoma in immunocompetent patients: clinical, histologic, immunophenotypic, and genotypic features of 3 cases

Primary cardiac lymphoma (PCL) is a rare extranodal lymphoma that involves only the heart and/or pericardium. Primary cardiac lymphoma is much less common in immunocompetent patients compared with those who are immunosuppressed. Patients with PCL have variable clinical manifestations that may lead to misdiagnosis and delay in treatment. Modern radiologic imaging now allows for earlier detection of these tumors. This study describes the clinical, histologic/cytologic, immunophenotypic, and molecular genetic findings for 3 immunocompetent patients with primary cardiac diffuse large B-cell lymphoma. All 3 patients had different initial clinical presentations. The neoplastic cells in all 3 cases were large in size, morphologically resembling diffuse large B-cell lymphoma. Neoplastic cells in 2 cases had non-germinal center (GC)-like (non-GC-like) and 1 case had GC-like immunophenotype. Neoplastic cells in all 3 cases showed C-MYC and BCL2 immunohistochemical protein coexpression. Neoplastic cells in 1 case showed double-hit MYC and BCL2 gene rearrangements, whereas another 1 case showed MYC gene rearrangement without BCL2 gene rearrangement. Epstein-Barr virus-encoded RNA was negative in the neoplastic cells in all 3 cases. All 3 patients received rituximab-based chemotherapy. Two patients subsequently had disease relapse at other extranodal sites at 10 and 24 months, respectively, whereas 1 patient was alive without disease at 9 months after diagnosis. If there is sufficient diagnostic tissue in these rare tumors, molecular studies should ideally be performed for prognostication and further patient management.

Molecular Profile and FDG-PET/CT Total Metabolic Tumor Volume Improve Risk Classification at Diagnosis for Patients with Diffuse Large B-Cell Lymphoma

PURPOSE

The prognostic impact of total metabolic tumor volume (TMTV) measured on pretreatment (18)F-FDG PET/CT and its added value to molecular characteristics was investigated in patients with diffuse large B-cell lymphoma (DLBCL).

EXPERIMENTAL DESIGN

For 81 newly diagnosed patients with DLBCL treated with rituximab and CHOP/CHOP-like regimen, TMTV was computed using the 41% SUVmax thresholding method. According to the gene expression profile, determined using DASL (cDNA-mediated Annealing, Selection, Ligation and extension) technology, a subset of 57 patients was classified in germinal center B (GCB) or activated B-cell (ABC) subtypes and MYC or BCL2 overexpressed.

RESULTS

Median follow-up was 64 months. Five-year progression-free survival (PFS) and overall survival (OS) were 60% and 63% in the whole population. Median pretherapy TMTV was 320 cm(3) (25th-75th percentiles 106-668 cm(3)). With a 300 cm(3) cutoff, patients with high TMTV (n = 43) had a 5-year PFS and OS of 43% and 46% compared with 76% and 78% for patients with a low TMTV (P = 0.0023, P = 0.0047). ABC status, MYC, or BCL2 overexpression and both overexpression ("dual expressor," DE) were significantly associated with a worse PFS and OS. TMTV combined with molecular data allowed a significant better risk substratification of ABC/GCB patients, on PFS and OS. High TMTV individualized in molecular-low-risk patients a group with a poor outcome (MYC, PFS=51%, OS=55% BCL2, PFS=49%, OS=49% or DE PFS=50%, OS=50%) and a group with a good outcome (MYC, PFS=93%, OS=93% BCL2, PFS=86%, OS=86%, or DE PFS=81%, OS=81%).

CONCLUSIONS

The combination of molecular and imaging characteristics at diagnosis could lead to a more accurate selection of patients, to increase tailor therapy. Clin Cancer Res; 22(15); 3801-9. ©2016 AACR.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.

miR-155 as a Biomarker in B-Cell Malignancies

MicroRNAs have the potential to be useful biomarkers in the development of individualized treatment since they are easy to detect, are relatively stable during sample handling, and are important determinants of cellular processes controlling pathogenesis, progression, and response to treatment of several types of cancers including B-cell malignancies. miR-155 is an oncomiR with a crucial role in tumor initiation and development of several B-cell malignancies. The present review elucidates the potential of miR-155 as a diagnostic, prognostic, or predictive biomarker in B-cell malignancies using a systematic search strategy to identify relevant literature. miR-155 was upregulated in several malignancies compared to nonmalignant controls and overexpression of miR-155 was further associated with poor prognosis. Elevated expression of miR-155 shows potential as a diagnostic and prognostic biomarker in diffuse large B-cell lymphoma and chronic lymphocytic leukemia. Additionally, in vitro and in vivo studies suggest miR-155 as an efficient therapeutic target, supporting its oncogenic function. The use of inhibiting anti-miR structures indicates promising potential as novel anticancer therapeutics. Reports from 53 studies prove that miR-155 has the potential to be a molecular tool in personalized medicine.

Current Role of Genetics in Hematologic Malignancies

Rapidly changing field of genetic technology and its application in the management of hematological malignancies has brought significant improvement in treatment and outcome of these disorders. Today, genetics plays pivotal role in diagnosis and prognostication of most hematologic neoplasms. The utilization of genetic tests in deciding specific treatment of various hematologic malignancies as well as for evaluation of depth of treatment response is rapidly advancing. Therefore, it is imperative for practitioners working in the field of hemato-oncology to have sufficient understanding of the basic concepts of genetics in order to comprehend upcoming molecular research in this area and to translate the same for patient care.

Cell-of-Origin in Diffuse Large B-Cell Lymphoma: Are the Assays Ready for the Clinic?

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma worldwide and consists of a heterogeneous group of cancers classified together on the basis of shared morphology, immunophenotype, and aggressive clinical behavior. It is now recognized that this malignancy comprises at least two distinct molecular subtypes identified by gene expression profiling: the activated B-cell-like (ABC) and the germinal center B-cell-like (GCB) groups-the cell-of-origin (COO) classification. These two groups have different genetic mutation landscapes, pathobiology, and outcomes following treatment. Evidence is accumulating that novel agents have selective activity in one or the other COO group, making COO a predictive biomarker. Thus, there is now a pressing need for accurate and robust methods to assign COO, to support clinical trials, and ultimately guide treatment decisions for patients. The "gold standard" methods for COO are based on gene expression profiling (GEP) of RNA from fresh frozen tissue using microarray technology, which is an impractical solution when formalin-fixed paraffin-embedded tissue (FFPET) biopsies are the standard diagnostic material. This review outlines the history of the COO classification before examining the practical implementation of COO assays applicable to FFPET biopsies. The immunohistochemistry (IHC)-based algorithms and gene expression-based assays suitable for the highly degraded RNA from FFPET are discussed. Finally, the technical and practical challenges that still need to be addressed are outlined before robust gene expression-based assays are used in the routine management of patients with DLBCL.

Serum nuclear magnetic resonance-based metabolomics and outcome in diffuse large B-cell lymphoma patients - a pilot study

The prognosis for diffuse large B-cell lymphoma (DLBCL) patients with early relapse or refractory disease is dismal. To determine if clinical outcome correlated to diverse serum metabolomic profiles, we used (1)H nuclear magnetic resonance (NMR) spectroscopy and compared two groups of DLBCL patients treated with immunochemotherapy: i) refractory/early relapse (REF/REL; n=27) and ii) long-term progression-free (CURED; n = 60). A supervised multivariate analysis showed a separation between the groups. Among discriminating metabolites higher in the REF/REL group were the amino acids lysine and arginine, the degradation product cadaverine and a compound in oxidative stress (2-hydroxybutyrate). In contrast, the amino acids aspartate, valine and ornithine, and a metabolite in the glutathione cycle, pyroglutamate, were higher in CURED patients. Together, our data indicate that NMR-based serum metabolomics can identify a signature for DLBCL patients with high-risk of failing immunochemotherapy, prompting for larger validating studies which could lead to more individualized treatment of this disease.

A phase II trial to evaluate the efficacy of fostamatinib in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL)

PURPOSE

To assess the safety and efficacy of fostamatinib in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL).

EXPERIMENTAL DESIGN

Relapsed or refractory DLBCL patients originally received the oral spleen tyrosine kinase inhibitor, fostamatinib in a two-arm, randomised, double-blinded manner at either 100 mg twice a day (BID) or 200 mg BID until disease progression or unacceptable toxicity. The primary objective was to assess the overall response rate (ORR). Preliminary analysis showed limited efficacy and all subsequent patients were treated at 200 mg BID. Previously randomised patients were unblinded and given the opportunity to receive 200 mg BID.

RESULTS

Sixty-eight patients were treated (47 at 200 mg BID, 21 at 100 mg BID). Cell of origin analysis showed 58% germinal B-cell (GCB) origin, 30% activated B-cell (ABC) origin and 12% with an intermediate cell of origin signature. The most common treatment-related adverse events of all patients were diarrhoea (21% total, 6% grade 3/4), nausea (19% total, 3% grade 3/4), and, fatigue (18% total, 9% grade 3/4). The ORR rate was 3% across both arms and clinical benefit (≥ stable disease) was achieved for 13% of all patients. The cell of origin for patients with clinical benefit was GCB (4 patients), intermediate (4 patients) or unknown (1 patient). None of the patients with clinical benefit had ABC genotype.

CONCLUSIONS

While fostamatinib was generally well tolerated in this patient population, efficacy at these doses and schedule was poor. Unlike data with other B-cell antigen receptor pathway inhibitors, responses were not observed in the ABC genotype.

Population-specific prognostic models are needed to stratify outcomes for African-Americans with diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) demonstrates significant racial differences in age of onset, stage, and survival. To examine whether population-specific models improve prediction of outcomes for African-American (AA) patients with DLBCL, we utilized Surveillance, Epidemiology, and End Results data and compared stratification by the international prognostic index (IPI) in general and AA populations. We also constructed and compared prognostic models for general and AA populations using multivariable logistic regression (LR) and artificial neural network approaches. While the IPI adequately stratified outcomes for the general population, it failed to separate AA DLBCL patients into distinct risk groups. Our AA LR model identified age ≥ 55 (odds ratio 0.45, [95% CI: 0.36, 0.56], male sex (0.75, [0.60, 0.93]), and stage III/IV disease (0.43, [0.34, 0.54]) as adverse predictors of 5-year survival for AA patients. In addition, general-population prognostic models were poorly calibrated for AAs with DLBCL, indicating a need for validated AA-specific prognostic models.

Clinical impact of molecular features in diffuse large B-cell lymphoma and follicular lymphoma

Our understanding of the pathogenesis and heterogeneity of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) has been dramatically enhanced by recent attempts to profile molecular features of these lymphomas. In this article, we discuss ways in which testing for molecular features may impact DLBCL and FL management if clinical trials are designed to incorporate such tests. Specifically, we discuss how distinguishing lymphomas on the basis of cell-of-origin subtypes or the presence of other molecular features is prognostically and therapeutically significant. Conversely, we discuss how the molecular similarities of DLBCL and FL have provided insight into the potential of both DLBCL and FL cases to respond to agents targeting alterations they have in common. Through these examples, we demonstrate how the translation of our understanding of cancer biology into improvements in patient outcomes depends on analyzing the molecular correlates of treatment outcomes in clinical trials and in routinely treated patients.

Next-generation prognostic assessment for diffuse large B-cell lymphoma

Current standard of care therapy for diffuse large B-cell lymphoma (DLBCL) cures a majority of patients with additional benefit in salvage therapy and autologous stem cell transplant for patients who relapse. The next generation of prognostic models for DLBCL aims to more accurately stratify patients for novel therapies and risk-adapted treatment strategies. This review discusses the significance of host genetic and tumor genomic alterations seen in DLBCL, clinical and epidemiologic factors, and how each can be integrated into risk stratification algorithms. In the future, treatment prediction and prognostic model development and subsequent validation will require data from a large number of DLBCL patients to establish sufficient statistical power to correctly predict outcome. Novel modeling approaches can augment these efforts.

Prognostic Significance of Diffuse Large B-Cell Lymphoma Cell of Origin Determined by Digital Gene Expression in Formalin-Fixed Paraffin-Embedded Tissue Biopsies

PURPOSE

To evaluate the prognostic impact of cell-of-origin (COO) subgroups, assigned using the recently described gene expression-based Lymph2Cx assay in comparison with International Prognostic Index (IPI) score and MYC/BCL2 coexpression status (dual expressers).

PATIENTS AND METHODS

Reproducibility of COO assignment using the Lymph2Cx assay was tested employing repeated sampling within tumor biopsies and changes in reagent lots. The assay was then applied to pretreatment formalin-fixed paraffin-embedded tissue (FFPET) biopsies from 344 patients with de novo diffuse large B-cell lymphoma (DLBCL) uniformly treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) at the British Columbia Cancer Agency. MYC and BCL2 protein expression was assessed using immunohistochemistry on tissue microarrays.

RESULTS

The Lymph2Cx assay provided concordant COO calls in 96% of 49 repeatedly sampled tumor biopsies and in 100% of 83 FFPET biopsies tested across reagent lots. Critically, no frank misclassification (activated B-cell-like DLBCL to germinal center B-cell-like DLBCL or vice versa) was observed. Patients with activated B-cell-like DLBCL had significantly inferior outcomes compared with patients with germinal center B-cell-like DLBCL (log-rank P < .001 for time to progression, progression-free survival, disease-specific survival, and overall survival). In pairwise multivariable analyses, COO was associated with outcomes independent of IPI score and MYC/BCL2 immunohistochemistry. The prognostic significance of COO was particularly evident in patients with intermediate IPI scores and the non-MYC-positive/BCL2-positive subgroup (log-rank P < .001 for time to progression).

CONCLUSION

Assignment of DLBCL COO by the Lymph2Cx assay using FFPET biopsies identifies patient groups with significantly different outcomes after R-CHOP, independent of IPI score and MYC/BCL2 dual expression.

Frontline rituximab, cyclophosphamide, doxorubicin, and prednisone with bortezomib (VR-CAP) or vincristine (R-CHOP) for non-GCB DLBCL

This phase 2 study evaluated whether substituting bortezomib for vincristine in frontline rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy could improve efficacy in non-germinal center B-cell-like diffuse large B-cell lymphoma (non-GCB DLBCL), centrally confirmed by immunohistochemistry (Hans method). In total, 164 patients were randomized 1:1 to receive six 21-day cycles of rituximab 375 mg/m(2), cyclophosphamide 750 mg/m(2), and doxorubicin 50 mg/m(2), all IV day 1, prednisone 100 mg/m(2) orally days 1-5, plus either bortezomib 1.3 mg/m(2) IV days 1, 4, 8, 11 (rituximab, cyclophosphamide, doxorubicin, and prednisone with bortezomib [VR-CAP]; n = 84) or vincristine 1.4 mg/m(2) (maximum 2 mg) IV day 1 (R-CHOP; n = 80). There were no significant differences between VR-CAP and R-CHOP in complete response rate (64.5%, 66.2%; odds ratio [OR], 0.91; P = .80), overall response rate (93.4%, 98.6%; OR, 0.21; P = .11), progression-free survival (hazard ratio [HR], 1.12; P = .76), or overall survival (HR, 0.89; P = .75). Rates of grade ≥3 adverse events (AEs; 88%, 89%), serious AEs (38%, 34%), discontinuations due to AEs (7%, 3%), and deaths due to AEs (2%, 5%) were similar with VR-CAP and R-CHOP. Grade ≥3 peripheral neuropathy rates were 6% and 3%, respectively. VR-CAP did not improve efficacy vs R-CHOP in non-GCB DLBCL. This trial was registered at www.clinicaltrials.gov as #NCT01040871.

Genetic lesions in diffuse large B-cell lymphomas

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in adults, accounting for 35%-40% of all cases. The combination of the anti-CD20 monoclonal antibody rituximab with anthracycline-based combination chemotherapy (R-CHOP, rituximab with cyclophosphamide, doxorubicin, vincristine and prednisone) lead to complete remission in most and can cure more than half of patients with DLBCL. The diversity in clinical presentation, as well as the pathologic and biologic heterogeneity, suggests that DLBCL comprises several disease entities that might ultimately benefit from different therapeutic approaches. In this review, we summarize the current literature focusing on the genetic lesions identified in DLBCL.