Motive and Opportunity: MYC rearrangements in high-grade B-cell lymphoma with MYC and BCL2 rearrangements-an LLMPP study

Rearrangements that place the oncogenes MYC, BCL2, or BCL6 adjacent to superenhancers are common in mature B-cell lymphomas. Lymphomas with diffuse large B-cell lymphoma (DLBCL) or high-grade morphology with both MYC and BCL2 rearrangements are classified as high-grade B-cell lymphoma with MYC and BCL2 rearrangements ("double hit": HGBCL-DH-BCL2) and are associated with aggressive disease and poor outcomes. Although it is established that MYC rearrangements involving immunoglobulin (IG) loci are associated with inferior outcomes relative to those involving other non-IG superenhancers, the frequency of, and mechanisms driving, IG vs non-IG MYC rearrangements have not been elucidated. Here we used custom targeted capture and/or whole genome sequencing to characterize oncogene rearrangements across 883 mature B-cell lymphomas including Burkitt lymphoma, follicular lymphoma, DLBCL, and HGBCL-DH-BCL2 tumors. We demonstrate that, while BCL2 rearrangement topology is consistent across entities, HGBCL-DH-BCL2 have distinct MYC rearrangement architecture relative to tumors with single MYC rearrangements or with both MYC and BCL6 rearrangements (HGBCL-DH-BCL6), including both a higher frequency of non-IG rearrangements and different architecture of MYC::IGH rearrangements. The distinct MYC rearrangement patterns in HGBCL-DH-BCL2 occur on the background of high levels of somatic hypermutation across MYC partner loci in HGBCL-DH-BCL2, creating more opportunity to form these rearrangements. Furthermore, because one IGH allele is already disrupted by the existing BCL2 rearrangement, the MYC rearrangement architecture in HGBCL-DH-BCL2 likely reflects selective pressure to preserve both BCL2 and B cell receptor expression. These data provide new mechanistic explanations for the distinct patterns of MYC rearrangements observed across different lymphoma entities.

Integrative analysis of clinicopathological features defines novel prognostic models for mantle cell lymphoma in the immunochemotherapy era: a report from The North American Mantle Cell Lymphoma Consortium

BACKGROUND

Patients with mantle cell lymphoma (MCL) exhibit a wide variation in clinical presentation and outcome. However, the commonly used prognostic models are outdated and inadequate to address the needs of the current multidisciplinary management of this disease. This study aims to investigate the clinical and pathological features of MCL in the immunochemotherapy era and improve the prognostic models for a more accurate prediction of patient outcomes.

METHODS

The North American Mantle Cell Lymphoma Project is a multi-institutional collaboration of 23 institutions across North America to evaluate and refine prognosticators for front-line therapy. A total of 586 MCL cases diagnosed between 2000 and 2012 are included in this study. A comprehensive retrospective analysis was performed on the clinicopathological features, treatment approaches, and outcomes of these cases. The establishment of novel prognostic models was based on in-depth examination of baseline parameters, and subsequent validation in an independent cohort of MCL cases.

RESULTS

In front-line strategies, the use of hematopoietic stem cell transplantation was the most significant parameter affecting outcomes, for both overall survival (OS, p < 0.0001) and progression-free survival (PFS, p < 0.0001). P53 positive expression was the most significant pathological parameter correlating with inferior outcomes (p < 0.0001 for OS and p = 0.0021 for PFS). Based on the baseline risk factor profile, we developed a set of prognostic models incorporating clinical, laboratory, and pathological parameters that are specifically tailored for various applications. These models, when tested in the validation cohort, exhibited strong predictive power for survival and showed a stratification resembling the training cohort.

CONCLUSIONS

The outcome of patients with MCL has markedly improved over the past two decades, and further enhancement is anticipated with the evolution of clinical management. The innovative prognostic models developed in this study would serve as a valuable tool to guide the selection of more suitable treatment strategies for patients with MCL.

Physical activity and the risk of non-Hodgkin lymphoma subtypes: A pooled analysis

Non-Hodgkin lymphoma (NHL) is composed of a heterogeneous collection of subtypes with considerable differences in genetics, biology and aetiology. Studies to date on physical activity and NHL risk have not had sufficient sample size to evaluate whether associations differ by subtype. We pooled data from nine case-control studies to examine the association between moderate-to-vigorous intensity physical activity (MVPA) and risk of NHL overall and by subtype (diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukaemia/small lymphocytic lymphoma, marginal zone lymphoma and mature T-cell lymphoma). A total of 5653 cases and 9115 controls were included in the pooled analysis. Physical activity was harmonised across nine studies and modelled as study-specific tertiles. Multinomial logistic regression was used to estimate the association between physical activity and NHL, adjusting for confounders. The overall odds of NHL was 13% lower among participants in the most active tertile of MVPA compared to the least active tertile (adjusted odds ratio = 0.87, 95% CI = 0.80, 0.95). Similar decreases were observed across NHL subtypes. In summary, in this pooled analysis of case-control studies, physical activity was associated with a modest risk reduction for each NHL subtype examined and with overall NHL.

Low T-cell proportion in the tumor microenvironment is associated with immune escape and poor survival in diffuse large B-cell lymphoma

The tumor microenvironment (TME) is important in the pathogenesis and prognosis of lymphoma. Previous studies have demonstrated that features of the diffuse large B-cell lymphoma (DLBCL) TME can be associated with prognosis, but questions remain about the mechanisms underlying these TME features and the interplay between tumor cells and the local TME. Therefore, we performed multispectral immunofluorescence (mIF) using two 6-color panels to interrogate the cellular proportions of T-cell subsets, macrophages, and NK-cells in 57 cases of de novo DLBCL treated with R-CHOP chemotherapy. We found that very low CD3+ T-cell proportion and low CD4+PD1+ and CD8+PD1+ T-cells have poor survival compared to those with a high T-cell proportion. Also, cases with concurrently low TIM3 and PD1 have a poor prognosis. This poor prognosis with low T-cell proportion was validated using immune deconvolution of gene expression profiling data from 351 cases of DLBCL and an additional cohort of 53 cases of DLBCL using routine immunohistochemistry. In addition, cases with loss of B2M, HLA I and/or HLA II protein expression on the tumor cells also had a low T-cell proportion, providing evidence that lack of these proteins allows for immune evasion. Overall, our results show that patients with DLBCL with a low T-cell proportion in the TME have a poor survival when treated with R-CHOP and exhibit mechanisms of immune escape.

Gene Expression Signatures for the Accurate Diagnosis of Peripheral T-Cell Lymphoma Entities in the Routine Clinical Practice

PURPOSE

Peripheral T-cell lymphoma (PTCL) includes heterogeneous clinicopathologic entities with numerous diagnostic and treatment challenges. We previously defined robust transcriptomic signatures that distinguish common PTCL entities and identified two novel biologic and prognostic PTCL-not otherwise specified subtypes (PTCL-TBX21 and PTCL-GATA3). We aimed to consolidate a gene expression-based subclassification using formalin-fixed, paraffin-embedded (FFPE) tissues to improve the accuracy and precision in PTCL diagnosis.

MATERIALS AND METHODS

We assembled a well-characterized PTCL training cohort (n = 105) with gene expression profiling data to derive a diagnostic signature using fresh-frozen tissue on the HG-U133plus2.0 platform (Affymetrix, Inc, Santa Clara, CA) subsequently validated using matched FFPE tissues in a digital gene expression profiling platform (nCounter, NanoString Technologies, Inc, Seattle, WA). Statistical filtering approaches were applied to refine the transcriptomic signatures and then validated in another PTCL cohort (n = 140) with rigorous pathology review and ancillary assays.

RESULTS

In the training cohort, the refined transcriptomic classifier in FFPE tissues showed high sensitivity (> 80%), specificity (> 95%), and accuracy (> 94%) for PTCL subclassification compared with the fresh-frozen-derived diagnostic model and showed high reproducibility between three independent laboratories. In the validation cohort, the transcriptional classifier matched the pathology diagnosis rendered by three expert hematopathologists in 85% (n = 119) of the cases, showed borderline association with the molecular signatures in 6% (n = 8), and disagreed in 8% (n = 11). The classifier improved the pathology diagnosis in two cases, validated by clinical findings. Of the 11 cases with disagreements, four had a molecular classification that may provide an improvement over pathology diagnosis on the basis of overall transcriptomic and morphological features. The molecular subclassification provided a comprehensive molecular characterization of PTCL subtypes, including viral etiologic factors and translocation partners.

CONCLUSION

We developed a novel transcriptomic approach for PTCL subclassification that facilitates translation into clinical practice with higher precision and uniformity than conventional pathology diagnosis.

DNMT3A mutations define a unique biological and prognostic subgroup associated with cytotoxic T cells in PTCL-NOS

Peripheral T-cell lymphomas (PTCLs) are heterogenous T-cell neoplasms often associated with epigenetic dysregulation. We investigated de novo DNA methyltransferase 3A (DNMT3A) mutations in common PTCL entities, including angioimmunoblastic T-cell lymphoma and novel molecular subtypes identified within PTCL-not otherwise specified (PTCL-NOS) designated as PTCL-GATA3 and PTCL-TBX21. DNMT3A-mutated PTCL-TBX21 cases showed inferior overall survival (OS), with DNMT3A-mutated residues skewed toward the methyltransferase domain and dimerization motif (S881-R887). Transcriptional profiling demonstrated significant enrichment of activated CD8+ T-cell cytotoxic gene signatures in the DNMT3A-mutant PTCL-TBX21 cases, which was further validated using immunohistochemistry. Genomewide methylation analysis of DNMT3A-mutant vs wild-type (WT) PTCL-TBX21 cases demonstrated hypomethylation in target genes regulating interferon-γ (IFN-γ), T-cell receptor signaling, and EOMES (eomesodermin), a master transcriptional regulator of cytotoxic effector cells. Similar findings were observed in a murine model of PTCL with Dnmt3a loss (in vivo) and further validated in vitro by ectopic expression of DNMT3A mutants (DNMT3A-R882, -Q886, and -V716, vs WT) in CD8+ T-cell line, resulting in T-cell activation and EOMES upregulation. Furthermore, stable, ectopic expression of the DNMT3A mutants in primary CD3+ T-cell cultures resulted in the preferential outgrowth of CD8+ T cells with DNMT3AR882H mutation. Single-cell RNA sequencing(RNA-seq) analysis of CD3+ T cells revealed differential CD8+ T-cell subset polarization, mirroring findings in DNMT3A-mutated PTCL-TBX21 and validating the cytotoxic and T-cell memory transcriptional programs associated with the DNMT3AR882H mutation. Our findings indicate that DNMT3A mutations define a cytotoxic subset in PTCL-TBX21 with prognostic significance and thus may further refine pathological heterogeneity in PTCL-NOS and suggest alternative treatment strategies for this subset.

B-Cell NHL Subtype Risk Associated with Autoimmune Conditions and PRS

BACKGROUND

A previous International Lymphoma Epidemiology (InterLymph) Consortium evaluation of joint associations between five immune gene variants and autoimmune conditions reported interactions between B-cell response-mediated autoimmune conditions and the rs1800629 genotype on risk of B-cell non-Hodgkin lymphoma (NHL) subtypes. Here, we extend that evaluation using NHL subtype-specific polygenic risk scores (PRS) constructed from loci identified in genome-wide association studies of three common B-cell NHL subtypes.

METHODS

In a pooled analysis of NHL cases and controls of Caucasian descent from 14 participating InterLymph studies, we evaluated joint associations between B-cell-mediated autoimmune conditions and tertile (T) of PRS for risk of diffuse large B-cell lymphoma (DLBCL; n = 1,914), follicular lymphoma (n = 1,733), and marginal zone lymphoma (MZL; n = 407), using unconditional logistic regression.

RESULTS

We demonstrated a positive association of DLBCL PRS with DLBCL risk [T2 vs. T1: OR = 1.24; 95% confidence interval (CI), 1.08-1.43; T3 vs. T1: OR = 1.81; 95% CI, 1.59-2.07; P-trend (Ptrend) < 0.0001]. DLBCL risk also increased with increasing PRS tertile among those with an autoimmune condition, being highest for those with a B-cell-mediated autoimmune condition and a T3 PRS [OR = 6.46 vs. no autoimmune condition and a T1 PRS, Ptrend < 0.0001, P-interaction (Pinteraction) = 0.49]. Follicular lymphoma and MZL risk demonstrated no evidence of joint associations or significant Pinteraction.

CONCLUSIONS

Our results suggest that PRS constructed from currently known subtype-specific loci may not necessarily capture biological pathways shared with autoimmune conditions.

IMPACT

Targeted genetic (PRS) screening among population subsets with autoimmune conditions may offer opportunities for identifying those at highest risk for (and early detection from) DLBCL.

Bone Marrow Collection: Comparison of Unassisted vs Assisted Bedside Collections by a Laboratory Technologist

OBJECTIVES

Bone marrow collections are often difficult, and creating quality smears and touch preparations at the bedside can prove challenging. The objective of this study is to compare the quality of bone marrow specimens between unassisted and assisted bone marrow collections by a bone marrow technologist.

METHODS

Data for this study were collected from 422 hematopathology reports over 14 months. We recorded the bone marrow quality of the different parts (aspirate smears, touch imprints, core biopsy, and clot/particle sections) as adequate, suboptimal, or inadequate. Student t test statistical analysis was performed between the corresponding parts in the two groups.

RESULTS

Our results demonstrate that the quality of assisted bone marrow specimens is significantly better compared with unassisted specimens, particularly for the aspirate smears (P < .0001) and touch imprints (P < .0001). Notably, the quality of aspirate smears was improved, which is important for cytologic evaluation.

CONCLUSIONS

We conclude that assistance by a bone marrow technologist resulted in a significant improvement in the quality of bone marrow collection.

Expression of Immune Checkpoint Molecules PD1, PD-L1 and ICOS in Mycosis Fungoides and Sézary Syndrome: Association with Disease Stage and Clinical Outcome

Background

The relationship between immune checkpoint status and disease outcome is a major focus of research in cutaneous T‐cell lymphoma (CTCL), a disfiguring neoplastic dermatological disorder. Mycosis fungoides (MF) and Sézary syndrome (SS) are the two most common types of CTCL.

Objectives

The aim was to evaluate the immune checkpoint markers programmed death protein 1 (PD1), inducible T‐cell co‐stimulator (ICOS) and programmed death‐ligand 1 (PD‐L1) in skin biopsies from patients with CTCL relative to disease stage and overall survival.

Methods

This consecutive case series enrolled 47 patients: 57% had stage IA–IIA disease and 43% had stage IIB–IVA2 disease (including seven with SS).

Results

PD1, PD‐L1 and ICOS expression was seen in all biopsies. Notably, PD‐L1 was predominantly expressed on histiocytes/macrophages, but focal expression on CTCL cells was seen. High expression of either ICOS or PD‐L1 was associated with advanced‐stage disease (P = 0·007 for both) and with the appearance of large‐cell transformation (LCT), a histopathological feature associated with a poor prognosis (ICOS: P = 0·02; PD‐L1: P = 0·002). PD1 expression was not significantly associated with disease stage (P = 0·12) or LCT (P = 0·49), but expression was high in SS biopsies. A high combined checkpoint marker score (PD1, PD‐L1 and ICOS) was associated with advanced‐stage disease (P = 0·001), LCT (P = 0·021) and lower overall survival (P = 0·014).

Conclusions

These findings demonstrate the existence of a complex immunoregulatory microenvironment in CTCL and support the development of immunotherapies targeting ICOS and PD‐L1 in advanced disease.

Metagenomic analysis to identify novel infectious agents in systemic anaplastic large cell lymphoma

Systemic anaplastic large cell lymphoma (ALCL) is a rare CD30-expressing T-cell non-Hodgkin lymphoma. Risk of systemic ALCL is highly increased among immunosuppressed individuals. Because risk of cancers associated with viruses is increased with immunosuppression, we conducted a metagenomic analysis of systemic ALCL to determine whether a known or novel pathogen is associated with this malignancy. Total RNA was extracted and sequenced from formalin-fixed paraffin-embedded tumor specimens from 19 systemic ALCL cases (including one case from an immunosuppressed individual with human immunodeficiency virus infection), 3 Epstein-Barr virus positive diffuse large B-cell lymphomas (DLBCLs) occurring in solid organ transplant recipients (positive controls), and 3 breast cancers (negative controls). We used a pipeline based on the Genome Analysis Toolkit (GATK)-PathSeq algorithm to subtract out human RNA reads and map the remaining RNA reads to microbes. No microbial association with ALCL was identified, but we found Epstein-Barr virus in the DLBCL positive controls and determined the breast cancers to be negative. In conclusion, we did not find a pathogen associated with systemic ALCL, but because we analyzed only one ALCL tumor from an immunosuppressed person, we cannot exclude the possibility that a pathogen is associated with some cases that arise in the setting of immunosuppression.

Genome-Wide miRNA Expression Profiling of Molecular Subgroups of Peripheral T-cell Lymphoma

PURPOSE

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of non-Hodgkin lymphomas with aggressive clinical behavior. We performed comprehensive miRNA profiling in PTCLs and corresponding normal CD4⁺ Th1/2 and TFH-like polarized subsets to elucidate the role of miRNAs in T-cell lymphomagenesis.

EXPERIMENTAL DESIGN

We used nCounter (NanoString Inc) for miRNA profiling and validated using Taqman qRT-PCR (Applied Biosystems, Inc). Normal CD4⁺ T cells were polarized into effector Th subsets using signature cytokines, and miRNA significance was revealed using functional experiments.

RESULTS

Effector Th subsets showed distinct miRNA expression with corresponding transcription factor expression (e.g., BCL6/miR-19b, -106, -30d, -26b, in IL21-polarized; GATA3/miR-155, miR-337 in Th2-polarized; and TBX21/miR-181a, -331-3p in Th1-polarized cells). Integration of miRNA signatures suggested activation of TCR and PI3K signaling in IL21-polarized cells, ERK signaling in Th1-polarized cells, and AKT-mTOR signaling in Th2-polarized cells, validated at protein level. In neoplastic counterparts, distinctive miRNAs were identified and confirmed in an independent cohort. Integrative miRNA-mRNA analysis identified a decrease in target transcript abundance leading to deregulation of sphingolipid and Wnt signaling and epigenetic dysregulation in angioimmunoblastic T-cell lymphoma (AITL), while ERK, MAPK, and cell cycle were identified in PTCL subsets, and decreased target transcript abundance was validated in an independent cohort. Elevated expression of miRNAs (miR-126-3p, miR-145-5p) in AITL was associated with poor clinical outcome. In silico and experimental validation suggest two targets (miR-126→ SIPR2 and miR-145 → ROCK1) resulting in reduced RhoA-GTPase activity and T-B-cell interaction.

CONCLUSIONS

Unique miRNAs and deregulated oncogenic pathways are associated with PTCL subtypes. Upregulated miRNA-126-3p and miR-145-5p expression regulate RhoA-GTPase and inhibit T-cell migration, crucial for AITL pathobiology.

A Review and Update with Perspective of Evidence that the Herbicide Glyphosate (Roundup) is a Cause of Non-Hodgkin Lymphoma

Glyphosate-based formulations (GBFs), such as Roundup, are the most heavily used herbicides in the world. In 2015, the International Agency for Research on Cancer (IARC) concluded that glyphosate and GBFs are probably carcinogenic to humans (group 2A), mainly for non-Hodgkin lymphoma (NHL). However, this finding has been controversial, and most pesticide regulatory agencies have not followed their lead. The purpose of this review was to examine the scientific literature linking exposure to glyphosate and GBFs to the development of NHL, with emphasis on new findings since publication of the IARC report. The epidemiologic studies provide ample evidence for an association between exposure to GBFs and an increased risk of NHL. Animal studies have shown that glyphosate is carcinogenic in rodents and causes NHL in mice. Mechanistic studies have demonstrated that glyphosate and GBFs are genotoxic to human lymphocytes, the normal cell of origin of NHL, both in vitro and in vivo. Genotoxic and other biological effects have also been shown in various animal and cell models with these agents even at low doses. A novel mechanism underlying the specificity of glyphosate for NHL, that is upregulation of the B-cell genome mutator enzyme activation-induced cytidine deaminase, has recently been demonstrated. These findings were evaluated holistically using the guidelines for evaluation of general causation set forth by Bradford Hill. This evaluation provides coherent and compelling evidence that glyphosate and GBFs are a cause of NHL in humans exposed to these agents. These findings should prompt new reviews by pesticide regulatory agencies around the world.

Relative frequency and clinicopathologic characteristics of MYC-rearranged follicular lymphoma

MYC rearrangement is a relatively rare genetic abnormality in follicular lymphoma (FL). In this study, we evaluated the relative frequency of MYC rearrangement in 522 cases of FL and studied their clinicopathologic, cytogenetic, and molecular characteristics. Fluorescence in situ hybridization studies for MYC (break-apart probe), MYC/IGH, IGH/BCL2, and BCL6 rearrangements were performed on tissue microarrays. Immunohistochemical stains for CD10, BCL2, BCL6, and MYC were performed and scored on MYC-rearranged cases. On 4 FL cases, a custom targeted panel of 356 genes was used for mutation analysis. Ten cases (1.9%) were positive for MYC rearrangement. Histologically, 6 of 10 cases were grade 1-2, and 4 cases were grade 3A. By immunohistochemistry, 9 of 9 tested cases were CD10+, all cases were BCL6+, and 9/10 cases were BCL2+. MYC protein staining was low in all cases tested. IGH/BCL2 rearrangement was detected in 5 of 9 cases, whereas BCL6 rearrangement was detected in 3 of 7 tested cases and 4 of 10 cases showed MYC/IGH rearrangement. The most commonly detected mutations in the MYC-positive cases included HLA-B, TNFRSF14, and KMT2D. MYC and/or B2M abnormalities were detected in 2 cases. In conclusion, MYC rearrangement is uncommon in FL and these cases do not appear to have specific histologic characteristics. Molecular analysis showed abnormalities in genes associated with transformation, namely MYC and B2M. Larger studies are needed to evaluate if MYC-rearrangement in FL has prognostic significance.

Validation of the Double-Hit Gene Expression Signature (DLBCL90) in an Independent Cohort of Patients with Diffuse Large B-Cell Lymphoma of Germinal Center Origin

The prognosis of diffuse large B-cell lymphoma (DLBCL) has been associated with clinical parameters, cell of origin, and various genetic aberrations. Recently, a NanoString gene expression assay (DLBCL90) was developed, which identifies DLBCL cases with an outcome similar to those with double- or triple-hit DLBCL with both MYC and BCL2 rearrangements. This study validates the predictive ability of the DLBCL90 assay in an independent cohort of patients with the germinal center B-cell subtype DLBCL. A customized targeted sequencing panel was used to analyze the mutational profile in these patients. Cases with a double or triple hit by conventional fluorescence in situ hybridization cytogenetic analysis are known to have a poor prognosis, and the DLBCL90 gene expression signature identified these cases, as well as additional cases that would have otherwise been missed by fluorescence in situ hybridization analysis. Our findings validate use of the DLBCL90 assay for identifying high-risk patients for new and innovative therapies.

Double-hit Signature with TP53 Abnormalities Predicts Poor Survival in Patients with Germinal Center Type Diffuse Large B-cell Lymphoma Treated with R-CHOP

PURPOSE

We performed detailed genomic analysis on 87 cases of de novo diffuse large B-cell lymphoma of germinal center type (GCB DLBCL) to identify characteristics that are associated with survival in those treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone).

EXPERIMENTAL DESIGN

The cases were extensively characterized by combining the results of IHC, cell-of-origin gene expression profiling (GEP; NanoString), double-hit GEP (DLBCL90), FISH cytogenetic analysis for double/triple-hit lymphoma, copy-number analysis, and targeted deep sequencing using a custom mutation panel of 334 genes.

RESULTS

We identified four distinct biologic subgroups with different survivals, and with similarities to the genomic classifications from two large retrospective studies of DLBCL. Patients with the double-hit signature, but no abnormalities of TP53, and those lacking EZH2 mutation and/or BCL2 translocation, had an excellent prognosis. However, patients with an EZB-like profile had an intermediate prognosis, whereas those with TP53 inactivation combined with the double-hit signature had an extremely poor prognosis. This latter finding was validated using two independent cohorts.

CONCLUSIONS

We propose a practical schema to use genomic variables to risk-stratify patients with GCB DLBCL. This schema provides a promising new approach to identify high-risk patients for new and innovative therapies.

Insecticide use and risk of non-Hodgkin lymphoma subtypes: A subset meta-analysis of the North American Pooled Project

Insecticide use has been linked to increased risk of non-Hodgkin lymphoma (NHL), however, findings of epidemiologic studies have been inconsistent, particularly for NHL subtypes. We analyzed 1690 NHL cases and 5131 controls in the North American Pooled Project (NAPP) to investigate self-reported insecticide use and risk of NHL overall and by subtypes: follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL) and small lymphocytic lymphoma (SLL). Odds ratios (OR) and 95% confidence intervals for each insecticide were estimated using logistic regression. Subtype-specific associations were evaluated using ASSET (Association analysis for SubSETs). Increased risks of multiple NHL subtypes were observed for lindane (OR = 1.60, 1.20-2.10: FL, DLCBL, SLL), chlordane (OR = 1.59, 1.17-2.16: FL, SLL) and DDT (OR = 1.36, 1.06-1.73: DLBCL, SLL). Positive trends were observed, within the subsets with identified associations, for increasing categories of exposure duration for lindane (P_trend = 1.7 × 10^-4 ), chlordane (P_trend = 1.0 × 10^-3 ) and DDT (P_trend = 4.2 × 10^-3 ), however, the exposure-response relationship was nonlinear. Ever use of pyrethrum was associated with an increased risk of FL (OR = 3.65, 1.45-9.15), and the relationship with duration of use appeared monotonic (OR for >10 years: OR = 5.38, 1.75-16.53; P_trend = 3.6 × 10^-3 ). Our analysis identified several novel associations between insecticide use and specific NHL subtypes, suggesting possible etiologic heterogeneity in the context of pesticide exposure.

Anaplastic large cell lymphoma in human immunodeficiency virus-infected people and solid organ transplant recipients

Human immunodeficiency virus (HIV)-infected people and solid organ transplant recipients have elevated risk of anaplastic large cell lymphoma (ALCL). Little is known regarding ALCL risk factors in immunosuppressed populations. We used data from US cancer registries linked to HIV registries (1996-2016) and to the national transplant registry (1992-2017). ALCL risk in HIV-infected people and transplant recipients relative to the general population was calculated as a standardized incidence ratio (SIR). ALCL risk factors were evaluated using Poisson regression. We identified 121 incident ALCL cases in the HIV (n = 86) and transplant (n = 35) populations. We reviewed pathology reports for 45 cases and most (86·7%) were confirmed as ALCL. Epstein-Barr virus tested positive in 1/8 (12·5%) cases. Compared to the general population, ALCL risk was strongly elevated among HIV-infected people [SIR 5·43; 95% confidence interval (CI) 4·27-6·81] and transplant recipients (5·96; 4·03-8·49). Among HIV-infected people, ALCL incidence was strongly related to CD4 count [adjusted incidence rate ratio (aIRR) 0·15 for ≥500 vs. <200 cells/μl; P trend < 0·001]. Among transplant recipients, risk was highest within the first year (aIRR 6·82) and 10+ years post-transplant (5·99). In conclusion, ALCL risk is strongly increased in these immunosuppressed populations but may be unrelated to EBV infection based on limited reports.

Follicular lymphoma polygenic risk score is associated with increased disease risk but improved overall survival among women in a population based case-control in Los Angeles County California

INTRODUCTION

Although clinical prognostic indicators exist for follicular lymphoma(FL), patient outcomes remain heterogeneous.

MATERIAL AND METHODS

We evaluated the association between survival and a polygenic risk score(PRS) composed of five previously identified FL susceptibility loci(rs12195582, rs13254990, rs17749561, rs4245081, rs4938573) among women who participated in a case-control study of non-Hodgkin lymphoma in Los Angeles County between 2004-2008. Risk associations were estimated through logistic regression, calculating the odds ratios(OR) and 95 % confidence intervals(95 % CI). Survival was estimated under a Cox proportional hazards model and hazard ratios(HR) and 95 % CI were calculated.

RESULTS

Among 437 non-Hispanic White controls and 100 non-Hispanic White FL patients, we confirmed a 2.6-fold increased risk of FL associated with the highest PRS tertile (95 % CI:1.35-4.86). After accounting for clinical indicators, the PRS was associated with improved overall survival in non-Hispanic women (HR:0.31; 95 % CI:0.10-0.96).

CONCLUSION

PRS was associated with increased risk of FL, but improved overall survival.

Reproducing the molecular subclassification of peripheral T-cell lymphoma-NOS by immunohistochemistry

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of mature T-cell malignancies; approximately one-third of cases are designated as PTCL-not otherwise specified (PTCL-NOS). Using gene-expression profiling (GEP), we have previously defined 2 major molecular subtypes of PTCL-NOS, PTCL-GATA3 and PTCL-TBX21, which have distinct biological differences in oncogenic pathways and prognosis. In the current study, we generated an immunohistochemistry (IHC) algorithm to identify the 2 subtypes in paraffin tissue using antibodies to key transcriptional factors (GATA3 and TBX21) and their target proteins (CCR4 and CXCR3). In a training cohort of 49 cases of PTCL-NOS with corresponding GEP data, the 2 subtypes identified by the IHC algorithm matched the GEP results with high sensitivity (85%) and showed a significant difference in overall survival (OS) (P = .03). The IHC algorithm classification showed high interobserver reproducibility among pathologists and was validated in a second PTCL-NOS cohort (n = 124), where a significant difference in OS between the PTCL-GATA3 and PTCL-TBX21 subtypes was confirmed (P = .003). In multivariate analysis, a high International Prognostic Index score (3-5) and the PTCL-GATA3 subtype identified by IHC were independent adverse predictors of OS (P = .0015). Additionally, the 2 IHC-defined subtypes were significantly associated with distinct morphological features (P < .001), and there was a significant enrichment of an activated CD8+ cytotoxic phenotype in the PTCL-TBX21 subtype (P = .03). The IHC algorithm will aid in identifying the 2 subtypes in clinical practice, which will aid the future clinical management of patients and facilitate risk stratification in clinical trials.

Glyphosate use and associations with non-Hodgkin lymphoma major histological sub-types: findings from the North American Pooled Project

Objectives Some epidemiological studies have suggested positive associations between glyphosate use and non-Hodgkin lymphoma (NHL), but evidence is inconsistent and few studies could evaluate histological sub-types. Here, associations between glyphosate use and NHL incidence overall and by histological sub-type were evaluated in a pooled analysis of case-control studies. Methods The analysis included 1690 NHL cases [647 diffuse large B-cell lymphoma (DLBCL), 468 follicular lymphoma (FL), 171 small lymphocytic lymphoma (SLL), and 404 other sub-types] and 5131 controls. Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for NHL overall and sub-types with self-reported ever/never, duration, frequency, and lifetime-days of glyphosate use. Results Subjects who ever used glyphosate had an excess of NHL overall (OR 1.43, 95% CI 1.11-1.83). After adjustment for other pesticides, the OR for NHL overall with "ever use" was 1.13 (95% CI 0.84-1.51), with a statistically significant association for handling glyphosate >2 days/year (OR 1.73, 95% CI 1.02-2.94, P-trend=0.2). In pesticide-adjusted sub-type analyses, the ordinal measure of lifetime-days was statistically significant (P=0.03) for SLL, and associations were elevated, but not statistically significant, for ever years or days/year of use. Handling glyphosate >2 days/year had an excess of DLBCL (OR 2.14, 95% CI 1.07-4.28; P-trend=0.2). However, as with the other sub-types, consistent patterns of association across different metrics were not observed. Conclusions There was some limited evidence of an association between glyphosate use and NHL in this pooled analysis. Suggestive associations, especially for SLL, deserve additional attention.

Non-Hodgkin lymphoma risk and organophosphate and carbamate insecticide use in the north American pooled project

Organophosphates and carbamates have been among the most commonly used insecticides, with both agricultural and residential uses. Previous studies have suggested associations of non-Hodgkin lymphoma (NHL) with some of these chemicals; however, many studies have been limited in their ability to evaluate associations with lymphoma subtypes. We evaluated the use of eleven organophosphate and two carbamate insecticides in association with NHL in the North American Pooled Project, which includes data from case-control studies in the United States and Canada (1690 cases/5131 controls). We used unconditional logistic regression adjusting for potential confounders, including use of other pesticides, to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between these chemicals and NHL overall, and NHL subtypes, i.e., follicular (FL), diffuse large B-cell (DLBCL), small lymphocytic lymphoma (SLL) and others. Ever use of malathion was associated with increased risk of NHL overall (OR = 1.43; 95% CI: 1.14-1.81) compared with never users. Categories using tertiles of duration (<4 yrs., 4-12 yrs., and >12 yrs) also showed a significant exposure-response for increasing years of use of malathion and risk of NHL (OR_<4vsUnex = 1.33 (0.88, 2.03), OR_4-12vsUnex = 1.42 (1.02, 1.96), OR_>12vsUnex = 1.55 (1.05, 2.28, p-trend < 0.01)). In addition, malathion use was statistically significantly associated with FL (OR = 1.58; 95% CI: 1.11-2.27) and DLBCL (OR = 1.61; 95% CI: 1.16-2.22) while there were no apparent associations with SLL or other subtypes, the p-value for heterogeneity across subtypes, however, was not significant. These results support previous studies suggesting an association between insecticide use and NHL overall, and provide new information on associations with NHL subtypes.

Epidemiology and Pathology of T- and NK-Cell Lymphomas

PURPOSE

This review will describe and update readers on the recent changes in the 2017 WHO classification regarding peripheral T-cell lymphomas.

RECENT FINDINGS

Signficant advances in molecular studies have resulted in revisions to the classification as well as introduction to provisional entities such as breast implant-associated ALCL and nodal PTCL with T-follicular helper phenotype.

SUMMARY

Major advances in molecular and gene expression profiling has expanded our knowledge of these rare and aggressive diseases.

Molecular classification of primary mediastinal large B-cell lymphoma using routinely available tissue specimens

Primary mediastinal large B-cell lymphoma (PMBCL) is recognized as a distinct entity in the World Health Organization classification. Currently, the diagnosis relies on consensus of histopathology, clinical variables, and presentation, giving rise to diagnostic inaccuracy in routine practice. Previous studies have demonstrated that PMBCL can be distinguished from subtypes of diffuse large B-cell lymphoma (DLBCL) based on gene expression signatures. However, requirement of fresh-frozen biopsy material has precluded the transfer of gene expression-based assays to the clinic. Here, we developed a robust and accurate molecular classification assay (Lymph3Cx) for the distinction of PMBCL from DLBCL subtypes based on gene expression measurements in formalin-fixed, paraffin-embedded tissue. A probabilistic model accounting for classification error, comprising 58 gene features, was trained on 68 cases of PMBCL and DLBCL. Performance of the model was subsequently evaluated in an independent validation cohort of 158 cases and showed high agreement of the Lymph3Cx molecular classification with the clinicopathological diagnosis of an expert panel (frank misclassification rate, 3.8%). Furthermore, we demonstrate reproducibility of the assay with 100% concordance of subtype assignments at 2 independent laboratories. Future studies will determine Lymph3Cx's utility for routine diagnostic purposes and therapeutic decision making.

Outcomes after Allogeneic Stem Cell Transplantation in Patients with Double-Hit and Double-Expressor Lymphoma

Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are associated with resistance to frontline and salvage immunochemotherapy, as well as autologous stem cell transplantation (SCT). We hypothesized that allogeneic SCT (alloSCT) could overcome the chemoresistance associated with DEL/DHL. We retrospectively studied the impact of DEL/DHL status in a multicenter cohort of patients who underwent alloSCT for relapsed/refractory (rel/ref) aggressive B cell non-Hodgkin lymphoma (B-NHL). Seventy-eight patients transplanted at 3 centers in whom tumor tissue was available for immunohistochemistry and fluorescence in situ hybridization were enrolled; 47% had DEL and 13% had DHL. There were no significant differences in 4-year progression-free (PFS) or overall survival (OS) between patients with DEL compared with patients without DEL (PFS 30% versus 39%, P = .24; OS 31% versus 49%, P = .17) or between patients with DHL compared with patients without DHL (PFS 40% versus 34%, P = .62; OS 50% versus 38%, P = .46). The lack of association between DEL or DHL and outcome was confirmed in multivariable models, although inadequate sample size may have limited our ability to detect significant differences. In our cohort alloSCT produced durable remissions in patients with rel/ref aggressive B-NHL irrespective of DEL and DHL status, justifying its consideration in the treatment of patients with rel/ref DEL/DHL.

Value, Access, and Cost of Cancer Care Delivery at Academic Cancer Centers

Key challenges facing the oncology community today include access to appropriate, high quality, patient-centered cancer care; defining and delivering high-value care; and rising costs. The National Comprehensive Cancer Network convened a Work Group composed of NCCN Member Institution cancer center directors and their delegates to examine the challenges of access, high costs, and defining and demonstrating value at the academic cancer centers. The group identified key challenges and possible solutions to addressing these issues. The findings and recommendations of the Work Group were then presented at the Value, Access, and Cost of Cancer Care Policy Summit in September 2015 and multi-stakeholder roundtable panel discussions explored these findings and recommendations along with additional items.

Abstract 2157: P73 isoforms regulate cellular survival and response to treatment in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma (NHL) and is curable in more than 60% of the cases. Despite long-term remission achieved with current therapies, relapse occurs in almost one-third of the cases. Rearrangements of chromosome locus 1p36 with ensuing deletion or disruption of TP73, one of the most distally located putative tumor suppressor genes, is frequent in many NHL subtypes, including DLBCL, and confers inferior prognosis. Recent reports in normal B-cells and lymphoma animal models suggest an important role of p73 in B-cell lymphomas; however, the biological significance of p73 isoforms in DLBCL is not clear. TP73 is a member of the TP53 family that shares structural homology and hence is capable of transactivating p53 target genes. We investigated the relationship between rearrangements of chromosome locus 1p36 and p73 expression and examined whether differential expression of p73 isoforms (TAp73 and ΔNp73) correlate with proliferation and apoptosis in DLBCL. We utilized molecular techniques in conjunction with fluorescence in situ hybridization (FISH) in untreated histologically confirmed DLBCL patient specimens. In our data set, the 1p36 chromosomal locus was disrupted (mainly heterozygous deletion) in 35% of the cases and was significantly associated with ΔNp73 expression. Subsequent immunohistochemical analysis showed a significant positive correlation between TAp73 and cleaved caspase-3 expression and between ΔNp73 and Ki-67 expression. Additionally, we observed a negative correlation between TAp73 and the anti-apoptotic molecules Bcl-2 and Bcl-6. We then performed in vitro studies in DLBCL cells and modulated the expression of TAp73 and ΔNp73 using expression vectors and siRNA. TAp73-transfected cells were more susceptible to serum deprivation and doxorubicin treatment, conversely the ΔNp73-transfected cells were more resistant to serum deprivation and doxorubicin treatment compared to control cells. Thus, rearrangements of 1p36 consequently deregulates p73 isoform expression in DLBCL. Our data emphasizes the importance of delineating the functional aspect of genetic alterations and underscores the significant role of p73 isoforms in DLBCL pathogenesis and treatment.

Citation Format: Hesham M. Hassan, Michelle L. Varney, Pamela A. Althof, Gabriel C. Caponetti, Kai Fu, Dennis D. Weisenburger, Rakesh K. Singh, Bhavana J. Dave. P73 isoforms regulate cellular survival and response to treatment in diffuse large B-cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2157. doi:10.1158/1538-7445.AM2017-2157

New Molecular Assay for the Proliferation Signature in Mantle Cell Lymphoma Applicable to Formalin-Fixed Paraffin-Embedded Biopsies

Purpose Mantle cell lymphoma is an aggressive B-cell neoplasm that displays heterogeneous outcomes after treatment. In 2003, the Lymphoma/Leukemia Molecular Profiling Project described a powerful biomarker-the proliferation signature-using gene expression in fresh frozen material. Herein, we describe the training and validation of a new assay that measures the proliferation signature in RNA derived from routinely available formalin-fixed paraffin-embedded (FFPE) biopsies. Methods Forty-seven FFPE biopsies were used to train an assay on the NanoString platform, using microarray gene expression data of matched fresh frozen biopsies as a gold standard. The locked assay was applied to pretreatment FFPE lymph node biopsies from an independent cohort of 110 patients uniformly treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone. Seventeen biopsies were tested across three laboratories to assess assay reproducibility. Results The MCL35 assay, which contained a 17-gene proliferation signature, yielded gene expression of sufficient quality to assign an assay score and risk group in 108 (98%) of 110 archival FFPE biopsies. The MCL35 assay assigned patients to high-risk (26%), standard-risk (29%), and low-risk (45%) groups, with different lengths of overall survival (OS): a median of 1.1, 2.6, and 8.6 years, respectively (log-rank for trend, P < .001). In multivariable analysis, these risk groups and the Mantle Cell Lymphoma International Prognostic Index were independently associated with OS ( P < .001 for both variables). Concordance of risk assignment across the three independent laboratories was 100%. Conclusion The newly developed and validated MCL35 assay for FFPE biopsies uses the proliferation signature to define groups of patients with significantly different OS independent of the Mantle Cell Lymphoma International Prognostic Index. Importantly, the analytic and clinical validity of this assay defines it as a reliable biomarker to support risk-adapted clinical trials.

Combined copy number and mutation analysis identifies oncogenic pathways associated with transformation of follicular lymphoma

Follicular lymphoma (FL) is typically an indolent disease, but 30-40% of FL cases transform into an aggressive lymphoma (tFL) with a poor prognosis. To identify the genetic changes that drive this transformation, we sequenced the exomes of 12 cases with paired FL and tFL biopsies and identified 45 recurrently mutated genes in the FL-tFL data set and 39 in the tFL cases. We selected 496 genes of potential importance in transformation and sequenced them in 23 additional tFL cases. Integration of the mutation data with copy-number abnormality (CNA) data provided complementary information. We found recurrent mutations of miR-142, which has not been previously been reported to be mutated in FL/tFL. The genes most frequently mutated in tFL included KMT2D (MLL2), CREBBP, EZH2, BCL2 and MEF2B. Many recurrently mutated genes are involved in epigenetic regulation, the Janus-activated kinase-signal transducer and activator of transcription (STAT) or the nuclear factor-κB pathways, immune surveillance and cell cycle regulation or are TFs involved in B-cell development. Of particular interest are mutations and CNAs affecting S1P-activated pathways through S1PR1 or S1PR2, which likely regulate lymphoma cell migration and survival outside of follicles. Our custom gene enrichment panel provides high depth of coverage for the study of clonal evolution or divergence.

Modulation of p73 isoforms expression induces anti-proliferative and pro-apoptotic activity in mantle cell lymphoma independent of p53 status

Mantle cell lymphoma (MCL) is characterized by a clinically aggressive course with frequent relapse and poor survival. The p53 pathway is frequently dysregulated and p53 status predicts clinical outcome. In this report, we investigated whether modulation of p73 isoforms by diclofenac inhibits cell growth, induces apoptosis and/or cell cycle arrest in MCL relative to p53 status. Wild-type p53 [Granta-519 and JVM-2], mutant p53 [Jeko-1 and Mino-1] expressing cells, therapy resistant cell lines, and primary human cells isolated from MCL patients were used. Overexpression of pro-apoptotic TAp73 enhanced MCL cell apoptosis. Diclofenac induced a concentration- and duration-dependent increase in TAp73, cell cycle arrest, cell death, and inhibited MCL cell growth independent of p53 status. Diclofenac treatment was associated with increased activity of caspases 3, 7, and 8 and induction of p53 transcriptional target genes. These studies demonstrate the potential for diclofenac as novel therapeutic agent in MCL independent of p53 status.

Cyclin D1 expression in peripheral T-cell lymphomas

Cyclin D1 is an important regulator of the cell cycle and overexpression of this protein by immunohistochemistry is characteristically seen in mantle cell lymphoma and other B-cell neoplasms. However, little is known about the expression of this protein in T-cell lymphomas. Cyclin-dependent kinase pathway inhibitors are in development, therefore identifying cyclin D1-positive T-cell lymphomas may provide a therapeutic target in a disease where novel treatments are urgently needed. We collected 200 peripheral T-cell lymphomas from three institutions including the following types of cases: 34 anaplastic large cell lymphoma, ALK+, 44 anaplastic large cell lymphoma, ALK negative, 68 peripheral T-cell lymphomas, not otherwise specified, 24 angioimmunoblastic T-cell lymphomas, 7 extranodal NK/T-cell lymphomas, 4 enteropathy associated T-cell lymphomas, 3 hepatosplenic T-cell lymphomas, 12 cutaneous T-cell lymphomas, and 4 large granular lymphocytic leukemias. Immunohistochemical stains for cyclin D1 protein (SP4 clone) were performed on paraffin-embedded tissue. In a subset of cases, IGH/CCND1 fluorescence in situ hybridization analysis was also performed. Cyclin D1 staining was predominantly seen in anaplastic large cell lymphoma, including 8 of 34 cases with ALK+ anaplastic large cell lymphoma (24%), and 3 of 44 cases of ALK-negative (7%) anaplastic large cell lymphoma. Three cases of peripheral T-cell lymphoma, not otherwise specified, were also positive (3/68, 4%). All other T-cell lymphomas were negative for cyclin D1. In four of the cyclin D1-positive T-cell lymphomas by immunohistochemistry, fluorescence in situ hybridization analysis was negative for IGH/CCND1 translocation or extra copies of the CCND1 gene. Cyclin D1 overexpression by immunohistochemistry is not limited to B-cell lymphomas and is also observed in some peripheral T-cell lymphomas, particularly in anaplastic large cell lymphoma, ALK+. Cyclin D1 expression was not associated with extra copies or translocation of the CCND1 gene. Cyclin D1 overexpression may be the result of a post-translational phenomenon and may represent a potential therapeutic target using agents that target the cyclin-dependent kinase pathway.

Relapsed or Refractory Double-Expressor and Double-Hit Lymphomas Have Inferior Progression-Free Survival After Autologous Stem-Cell Transplantation

Purpose Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are subtypes of diffuse large B-cell lymphoma (DLBCL) associated with poor outcomes after standard chemoimmunotherapy. Data are limited regarding outcomes of patients with relapsed or refractory (rel/ref) DEL or DHL who undergo autologous stem-cell transplantation (ASCT). We retrospectively studied the prognostic impact of DEL and DHL status on ASCT outcomes in patients with rel/ref DLBCL. Methods Patients with chemotherapy-sensitive rel/ref DLBCL who underwent ASCT at two institutions and in whom archival tumor material was available were enrolled. Immunohistochemistry for MYC, BCL2, and BCL6 and fluorescence in situ hybridization (FISH) for MYC were performed. In cases with MYC rearrangement or copy gain, FISH for BCL2 and BCL6 was also performed. Results A total of 117 patients were included; 44% had DEL and 10% had DHL. DEL and DHL were associated with inferior progression-free survival (PFS), and DHL was associated with poorer overall survival (OS). The 4-year PFS in patients with DEL compared with those with non-DEL was 48% versus 59% ( P = .049), and the 4-year OS was 56% versus 67% ( P = .10); 4-year PFS in patients with DHL compared with those with non-DHL was 28% versus 57% ( P = .013), and 4-year OS was 25% versus 61% ( P = .002). The few patients with concurrent DEL and DHL had a poor outcome (4-year PFS, 0%). In multivariable models, DEL and DHL were independently associated with inferior PFS, whereas DHL and partial response ( v complete response) at transplant were associated with inferior OS. Conclusion DEL and DHL are both associated with inferior outcomes after ASCT in patients with rel/ref DLBCL. Although ASCT remains a potentially curative approach, these patients, particularly those with DHL, are a high-risk subset who should be targeted for investigational strategies other than standard ASCT.

Four Lymphomas in 1 Patient: A Unique Case of Triple Composite Non-Hodgkin Lymphoma Followed by Classical Hodgkin Lymphoma

Composite lymphomas consist of 2 or more distinct lymphomas occurring in a single anatomical site or simultaneously in different sites and can be composed of any combination of B-cell non-Hodgkin lymphoma (NHL), T-cell NHL, or Hodgkin lymphoma (HL). Cases of composite lymphomas with more than 2 lymphomas are extremely rare, with only 4 reports in the literature. We report the case of a 49-year-old man with a triple composite lymphoma in a single lymph node, consisting of small lymphocytic lymphoma, follicular lymphoma, and mantle cell lymphoma in situ. The patient received multiple courses of chemotherapy and an autologous stem cell transplant, which resulted in complete remission. Then, 6 years after the stem cell transplant, he developed classical HL. This unique case is, to our knowledge, the first report of a patient with triple composite lymphoma consisting of 3 small mature B-cell NHLs, who subsequently developed a fourth lymphoma.

Non-Hodgkin lymphoma in the developing world: review of 4539 cases from the International Non-Hodgkin Lymphoma Classification Project

The distribution of non-Hodgkin lymphoma subtypes varies around the world, but a large systematic comparative study has never been done. In this study, we evaluated the clinical features and relative frequencies of non-Hodgkin lymphoma subtypes in five developing regions of the world and compared the findings to the developed world. Five expert hematopathologists classified 4848 consecutive cases of lymphoma from 26 centers in 24 countries using the World Health Organization classification, and 4539 (93.6%) were confirmed to be non-Hodgkin lymphoma, with a significantly greater number of males than females in the developing regions compared to the developed world (P<0.05). The median age at diagnosis was significantly lower for both low- and high-grade B-cell lymphoma in the developing regions. The developing regions had a significantly lower frequency of B-cell lymphoma (86.6%) and a higher frequency of T- and natural killer-cell lymphoma (13.4%) compared to the developed world (90.7% and 9.3%, respectively). Also, the developing regions had significantly more cases of high-grade B-cell lymphoma (59.6%) and fewer cases of low-grade B-cell lymphoma (22.7%) compared to the developed world (39.2% and 32.7%, respectively). Among the B-cell lymphomas, diffuse large B-cell lymphoma was the most common subtype (42.5%) in the developing regions. Burkitt lymphoma (2.2%), precursor B- and T-lymphoblastic leukemia/lymphoma (1.1% and 2.9%, respectively) and extranodal natural killer/T-cell lymphoma (2.2%) were also significantly increased in the developing regions. These findings suggest that differences in etiologic and host risk factors are likely responsible, and more detailed epidemiological studies are needed to better understand these differences.

Cyclin D1 depletion induces DNA damage in mantle cell lymphoma lines

Elevated cyclin D1 (CCND1) expression levels in mantle cell lymphoma (MCL) are associated with aggressive clinical manifestations related to chemoresistance, but little is known about how this important proto-oncogene contributes to the resistance of MCL. Here, we showed that RNA interference-mediated depletion of CCND1 increased caspase-3 activities and induced apoptosis in the human MCL lines UPN-1 and JEKO-1. In vitro and xenotransplant studies revealed that the toxic effect of CCND1 depletion in MCL cells was likely due to increase in histone H2AX phosphorylation, a DNA damage marker. DNA fiber analysis suggested deregulated replication initiation after CCND1 depletion as a potential cause of DNA damage. Finally, in contrast to depletion or inhibition of cyclin-dependent kinase 4, CCND1 depletion increased chemosensitivity of MCL cells to replication inhibitors hydroxyurea and cytarabine. Our findings have an important implication for CCND1 as a potential therapeutic target in MCL patients who are refractory to standard chemotherapy.

Genetically predicted longer telomere length is associated with increased risk of B-cell lymphoma subtypes

Evidence from a small number of studies suggests that longer telomere length measured in peripheral leukocytes is associated with an increased risk of non-Hodgkin lymphoma (NHL). However, these studies may be biased by reverse causation, confounded by unmeasured environmental exposures and might miss time points for which prospective telomere measurement would best reveal a relationship between telomere length and NHL risk. We performed an analysis of genetically inferred telomere length and NHL risk in a study of 10 102 NHL cases of the four most common B-cell histologic types and 9562 controls using a genetic risk score (GRS) comprising nine telomere length-associated single-nucleotide polymorphisms. This approach uses existing genotype data and estimates telomere length by weighing the number of telomere length-associated variant alleles an individual carries with the published change in kb of telomere length. The analysis of the telomere length GRS resulted in an association between longer telomere length and increased NHL risk [four B-cell histologic types combined; odds ratio (OR) = 1.49, 95% CI 1.22-1.82,P-value = 8.5 × 10(-5)]. Subtype-specific analyses indicated that chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) was the principal NHL subtype contributing to this association (OR = 2.60, 95% CI 1.93-3.51,P-value = 4.0 × 10(-10)). Significant interactions were observed across strata of sex for CLL/SLL and marginal zone lymphoma subtypes as well as age for the follicular lymphoma subtype. Our results indicate that a genetic background that favors longer telomere length may increase NHL risk, particularly risk of CLL/SLL, and are consistent with earlier studies relating longer telomere length with increased NHL risk.

Recurrent activating mutations of CD28 in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) comprise a heterogeneous group of mature T-cell neoplasms with a poor prognosis. Recently, mutations in TET2 and other epigenetic modifiers as well as RHOA have been identified in these diseases, particularly in angioimmunoblastic T-cell lymphoma (AITL). CD28 is the major co-stimulatory receptor in T cells which, upon binding ligand, induces sustained T-cell proliferation and cytokine production when combined with T-cell receptor stimulation. We have identified recurrent mutations in CD28 in PTCLs. Two residues-D124 and T195-were recurrently mutated in 11.3% of cases of AITL and in one case of PTCL, not otherwise specified (PTCL-NOS). Surface plasmon resonance analysis of mutations at these residues with predicted differential partner interactions showed increased affinity for ligand CD86 (residue D124) and increased affinity for intracellular adaptor proteins GRB2 and GADS/GRAP2 (residue T195). Molecular modeling studies on each of these mutations suggested how these mutants result in increased affinities. We found increased transcription of the CD28-responsive genes CD226 and TNFA in cells expressing the T195P mutant in response to CD3 and CD86 co-stimulation and increased downstream activation of NF-κB by both D124V and T195P mutants, suggesting a potential therapeutic target in CD28-mutated PTCLs.

Non-Hodgkin lymphoma in Southern Africa: review of 487 cases from The International Non-Hodgkin Lymphoma Classification Project

Comparative data on the distribution of non-Hodgkin lymphoma (NHL) subtypes in Southern Africa (SAF) is scarce. In this study, five expert haematopathologists classified 487 consecutive cases of NHL from SAF using the World Health Organization classification, and compared the results to North America (NA) and Western Europe (WEU). Southern Africa had a significantly lower proportion of low-grade (LG) B-NHL (34·3%) and a higher proportion of high-grade (HG) B-NHL (51·5%) compared to WEU (54·5% and 36·4%) and NA (56·1% and 34·3%). High-grade Burkitt-like lymphoma was significantly more common in SAF (8·2%) than in WEU (2·4%) and NA (2·5%), most likely due to human immunodeficiency virus infection. When SAF patients were divided by race, whites had a significantly higher frequency of LG B-NHL (60·4%) and a lower frequency of HG B-NHL (32·7%) compared to blacks (22·5% and 62·6%), whereas the other races were intermediate. Whites and other races had a significantly higher frequency of follicular lymphoma and a lower frequency of Burkitt-like lymphoma compared to blacks. The median ages of whites with LG B-NHL, HG B-NHL and T-NHL (64, 56 and 67 years) were significantly higher than those of blacks (55, 41 and 34 years). Epidemiological studies are needed to better understand these differences.

Relative frequency of non-Hodgkin lymphoma subtypes in selected centres in North Africa, the middle east and India: a review of 971 cases

Comparative data regarding the distribution of non-Hodgkin lymphoma (NHL) subtypes in North Africa, the Middle East and India (NAF/ME/IN) is scarce in the literature. In this study, we evaluated the relative frequencies of NHL subtypes in this region. Five expert haematopathologists classified 971 consecutive cases of newly-diagnosed NHL from five countries in NAF/ME/IN. After review, 890 cases (91·7%) were confirmed to be NHL and compared to 399 cases from North America (NA). The male-to-female ratio was significantly higher in NAF/ME/IN (1·8) compared to NA (1·1; P< 0·05). The median ages of patients with low-grade (LG) and high-grade (HG) B-NHL in NAF/ME/IN (56 and 52 years, respectively) were significantly lower than in NA (64 and 68 years, respectively). In NAF/ME/IN, a significantly lower proportion of LG B-NHL (28·4%) and a higher proportion of HG B-NHL (58·4%) were found compared to NA (56·1% and 34·3%, respectively). Diffuse large B-cell lymphoma was more common in NAF/ME/IN (49·4%) compared to NA (29·3%), whereas follicular lymphoma was less common in NAF/ME/IN (12·4%) than in NA (33·6%). In conclusion, we found significant differences in NHL subtypes and clinical features between NAF/ME/IN and NA. Epidemiological studies are needed to better understand the pathobiology of these differences.

Complete Surgical Excision Is Essential for the Management of Patients With Breast Implant-Associated Anaplastic Large-Cell Lymphoma

PURPOSE

Breast implant-associated anaplastic large-cell lymphoma (BI-ALCL) is a rare type of T-cell lymphoma that arises around breast implants. The optimal management of this disease has not been established. The goal of this study is to evaluate the efficacy of different therapies used in patients with BI-ALCL to determine an optimal treatment approach.

PATIENTS AND METHODS

In this study, we applied strict criteria to pathologic findings, assessed therapies used, and conducted a clinical follow-up of 87 patients with BI-ALCL, including 50 previously reported in the literature and 37 unreported. A Prentice, Williams, and Peterson model was used to assess the rate of events for each therapeutic intervention.

RESULTS

The median and mean follow-up times were 45 and 30 months, respectively (range, 3 to 217 months). The median overall survival (OS) time after diagnosis of BI-ALCL was 13 years, and the OS rate was 93% and 89% at 3 and 5 years, respectively. Patients with lymphoma confined by the fibrous capsule surrounding the implant had better event-free survival (EFS) and OS than did patients with lymphoma that had spread beyond the capsule (P = .03). Patients who underwent a complete surgical excision that consisted of total capsulectomy with breast implant removal had better OS (P = .022) and EFS (P = .014) than did patients who received partial capsulectomy, systemic chemotherapy, or radiation therapy.

CONCLUSION

Surgical management with complete surgical excision is essential to achieve optimal EFS in patients with BI-ALCL.