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Purpose:The histone-methyl transferase EZH2, catalytic subunit of the PRC2 complex involved in transcriptional regulation, is mutated in approximately 25% of germinal center B-cell lymphomas. Aberrant proliferative dependency on EZH2 activity can be targeted by the orally available EZH2 inhibitor tazemetostat (EPZ-6438). We report the results of the phase Ib tazemetostat plus R-CHOP combination (NCT02889523), in patients 60 to 80 years of age with newly diagnosed diffuse large B-cell lymphoma.Patients and Methods:The primary objective of this dose-escalation study was to evaluate the safety of the combination and to determine the recommended phase II dose (RP2D) of tazemetostat.Results:A total of 17 patients were enrolled. During C1 and C2, two dose-limiting toxicities were observed: one grade 3 constipation at 400 mg and one grade 5 pulmonary infection at 800 mg. Grade 3 or more toxicities observed in more than 10% of the patients were constipation (24%), nausea (12%), and hypokalemia (12%). Grade 3 to 4 hematologic adverse events were recorded in 8 patients (47%): neutropenia (47%), leukopenia (29%), anemia (18%), and thrombocytopenia (12%). The tazemetostat RP2D was 800 mg. No organ-oriented toxicity increased with tazemetostat dosage escalation (severity and incidence). At 800 mg, AUC and Cmax of tazemetostat were similar compared with the single-agent study (E7438-G000-101).Conclusions:The RP2D of tazemetostat combined with R-CHOP is 800 mg twice a day. The association presents safety and PK comparable with R-CHOP alone. Preliminary efficacy data are encouraging and further investigations in phase II trial are warranted.

Supplementary Figures 1-10 Figure S1. MYD88 mutation VAF according to L265P or non-L265P variants. Figure S2. Age according to MYD88 mutation status and variant among ABC patients. Figure S3. Genomic profiles of DLBCL according to the presence of MYD88 L265P or non-L265P variants. Figure S4. Relative L265P allele expression level according to L265P VAF. Figure S5. Gene expression according to MYD88 status. Figure S6. NFkB pathway gene expression according to MYD88 mutational status. Figure S7. LPS score according to subtype and downstream NFkB alterations. Figure S8. Clustering according to expression levels of 27 genes involved in LPS response and differentially expressed according to MYD88 L265P. Figure S9. TNFAIP3 and CARD11 expression according to their copy number status. Figure S10. Additional survival analyses.

Clinical characteristics of the 17 patients with CNS relapse are provided, included time to CNS relapse, first-line treatment and response after first-line treatment. CR, Complete Response; PR, Partial Response; PD, Progressive Disease.

All relevant clinical data is included. Immunohistochemical results for BCL2, CD10, BCL6, MUM1, FOXP1, IgM and MYC are transcribed: 0 indicates negativity and 1 indicates positivity. For BCL2 and MYC, positivity is according to a threshold of 50% or 40% respectively.

Purpose: MYD88 mutations, notably the recurrent gain-of-function L265P variant, are a distinguishing feature of activated B-cell like (ABC) diffuse large B-cell lymphoma (DLBCL), leading to constitutive NFκB pathway activation. The aim of this study was to examine the distinct genomic profiles of MYD88-mutant DLBCL, notably according to the presence of the L265P or other non-L265P MYD88 variants.Experimental Design: A cohort of 361 DLBCL cases (94 MYD88 mutant and 267 MYD88 wild-type) was submitted to next-generation sequencing (NGS) focusing on 34 genes to analyze associated mutations and copy number variations, as well as gene expression profiling, and clinical and prognostic analyses.Results: Importantly, we highlighted different genomic profiles for MYD88 L265P and MYD88 non-L265P–mutant DLBCL, shedding light on their divergent backgrounds. Clustering analysis also segregated subgroups according to associated genetic alterations among patients with the same MYD88 mutation. We showed that associated CD79B and MYD88 L265P mutations act synergistically to increase NFκB pathway activation, although the majority of MYD88 L265P–mutant cases harbors downstream NFκB alterations, which can predict BTK inhibitor resistance. Finally, although the MYD88 L265P variant was not an independent prognostic factor in ABC DLBCL, associated CD79B mutations significantly improved the survival of MYD88 L265P–mutant ABC DLBCL in our cohort.Conclusions: This study highlights the relative heterogeneity of MYD88-mutant DLBCL, adding to the field's knowledge of the theranostic importance of MYD88 mutations, but also of associated alterations, emphasizing the usefulness of genomic profiling to best stratify patients for targeted therapy. Clin Cancer Res; 23(9); 2232–44. ©2016 AACR.

Supplementary methods, supplementary figure & table legends, and supplementary tables 3, 4, 8 & 9. Table S3: Overview of the Lymphopanel used for NGS analysis. Table S4: Overview of pathway selection Table S8. Genes involved in the LPS score. Table S9. Expression levels of genes involved in response to LPS stimulation according to MYD88 L265P.

Statistically significant differences (p

Supplementary table 1: incidence of Grade 3-5 hematologic toxicities with Epi-R-CHOP compared to recent R-CHOP trial and other R-CHOP / novel agent combinations. - Supplementary table 2: metabolic CR rate for the recent R-CHOP and R-CHOP combination studies. - Supplementary figure 1: Pharmacokinetic analysis - Supplementary figure 2: mutation frequencies for the 15 evaluable cases

This table presents all variants identified among our cohort by Lymphopanel NGS. Variant type and variant allele frequency (VAF) are indicated.

This table presents all CNVs identified among our cohort using the ONCOCNV software. Duplication was considered when copy number was superior to 2 and deletion was considered when copy number was inferior to 2. False discovery rate (FDR) cutoff was set at 0.01.

COO information according to the three techniques used in this study is given according to the various MYD88 variants present in our cohort.

Purpose: The histone-methyl transferase EZH2, catalytic subunit of the PRC2 complex involved in transcriptional regulation, is mutated in approximately 25% of germinal center B-cell lymphomas. Aberrant proliferative dependency on EZH2 activity can be targeted by the orally available EZH2 inhibitor tazemetostat (EPZ-6438). We report the results of the phase Ib tazemetostat plus R-CHOP combination (NCT02889523), in patients 60 to 80 years of age with newly diagnosed diffuse large B-cell lymphoma. Patients and Methods: The primary objective of this dose-escalation study was to evaluate the safety of the combination and to determine the recommended phase II dose (RP2D) of tazemetostat. Results: A total of 17 patients were enrolled. During C1 and C2, two dose-limiting toxicities were observed: one grade 3 constipation at 400 mg and one grade 5 pulmonary infection at 800 mg. Grade 3 or more toxicities observed in more than 10% of the patients were constipation (24%), nausea (12%), and hypokalemia (12%). Grade 3 to 4 hematologic adverse events were recorded in 8 patients (47%): neutropenia (47%), leukopenia (29%), anemia (18%), and thrombocytopenia (12%). The tazemetostat RP2D was 800 mg. No organ-oriented toxicity increased with tazemetostat dosage escalation (severity and incidence). At 800 mg, AUC and Cmax of tazemetostat were similar compared with the single-agent study (E7438-G000-101). Conclusions: The RP2D of tazemetostat combined with R-CHOP is 800 mg twice a day. The association presents safety and PK comparable with R-CHOP alone. Preliminary efficacy data are encouraging and further investigations in phase II trial are warranted.

The relevance of circulating tumor DNA (ctDNA) analysis as a liquid biopsy and minimal residual disease tool in the management of classical Hodgkin lymphoma (cHL) patients was demonstrated in retrospective settings and remains to be confirmed in a prospective setting. We developed a targeted Next-Generation sequencing (NGS) panel for fast analysis (AmpliSeq® technology) of nine commonly mutated genes in biopies and ctDNA of cHL patients. We then conducted a prospective trial to assess ctDNA follow-up at diagnosis and after two cycles (C2) of chemotherapy. Sixty cHL patients treated by first line conventional chemotherapy (BEACOPPescalated [21.3%], ABVD/ABVD-like [73.5%] and other regimens [5.2%, for elderly patients]) were assessed in this noninterventional study. The median age of the patients was 33.5 years (range: 20-86). Variants were identified in 42 (70%) patients. Mutations of NFKBIE, TNFAIP3, STAT6, PTPN1, B2M, XPO1, ITPKB, GNA13 and SOCS1 were found in 13.3%, 31.7%, 23.3%, 5%, 33.3%, 10%, 23.3%, 13.3% and 50% of patients, respectively. ctDNA concentration and genotype were correlated with clinical characteristics and presentation. Regarding early therapeutic response, 45 patients (83%, not available [NA] =6) had a negative positron emission tomography (PET) after C2 (Deauville Score 1-3). The mean of DeltaSUVmax after C2 was -78.8%. ctDNA after C2 was analysed in 54 patients (90%). ctDNA became rapidly undetectable in all cases after C2. Variant detection in ctDNA is suitable to depict the genetic features of cHL at diagnosis and may help to assess early treatment response, in association with PET. Clinical Trial reference: NCT02815137.

Composite and sequential lymphomas involving both classical Hodgkin lymphoma (CHL) and primary mediastinal B-cell lymphoma (PMBCL) are rare phenomena. Beyond the relevant biological interest raised by these cases, treatments and outcome data are poorly covered in the recent literature. This retrospective analysis describes the pathological and clinical characteristics of 10 composite and 15 sequential cases included after a central pathological review. At diagnosis, 70% of the composite lymphomas presented a disseminated and extranodal disease. Among the 15 sequential lymphomas, 12 were CHL at first occurrence and three were PMBCL. Based on their clinical evolution, these sequential lymphomas could be divided into early (i.e., diagnosis of second lymphoma within a year) and late [(i.e., a second lymphoma occurrence occurring after a long period of complete remission]). All composite cases were alive in complete remission after a median follow-up of 34 months. If the early sequential lymphoma presented a particularly poor outcome with a median overall survival shorter than one year, the late cases were efficiently salvaged. Further molecular studies are needed to describe the underlying biology of these rare diseases, possibly representing the extreme of tumour cell plasticity found in grey-zone lymphoma.

Synchronous Hodgkin Lymphoma and Primary Mediastinal B‐cell Lymphoma is possible, with molecular analyses proving the absence of clonal filiation between both entities. This suggests a common etiology but the existence of two divergent clones.

Background: We explored, within the EORTC10994 study, the outcomes for patients with molecular apocrine (MA) breast cancer, and defined immunohistochemistry (IHC) as androgen-receptor (AR) positive, oestrogen (ER) and progesterone (PR) negative. We also assessed the concordance between IHC and gene expression arrays (GEA) in the identification of MA cancers. Methods: Centrally assessed biopsies for AR, ER, PR, HER2 and Ki67 by IHC were classified into six subtypes: MA, triple-negative (TN) basal-like, luminal A, luminal B HER2 negative, luminal B HER2 positive and “other”. The two main objectives were the pCR rates and survival outcomes in the overall MA subtype (and further divided by HER2 status) and the remaining five subtypes. Results: IHC subtyping was obtained in 846 eligible patients. Ninety-three (11%) tumours were classified as the MA subtype. Both IHC and GEA data were available for 64 patients. In this subset, IHC concordance was 88.3% in identifying MA tumours compared with GEA. Within the MA subtype, pCR was observed in 33.3% of the patients (95% CI: 29.4–43.9) and the 5-year recurrence-free interval was 59.2% (95% CI: 48.2–68.6). Patients with MA and TN basal-like tumours have lower survival outcomes. Conclusions: Irrespective of their HER2 status, the prognosis for MA tumours remains poor and adjuvant trials evaluating anti-androgens should be considered., SCOPUS: ar.j, info:eu-repo/semantics/published

To evaluate the benefit of cetuximab (Cx) addition to platinum-based and 5-fluorouracil chemotherapy (PFU) in unselected recurrent and/or metastatic head and neck cancer patients (R/MHNC) according to KRAS-LCS6 variant status. All patients who received at least two PFU ± Cx cycles from 2004 to 2014 were retrospectively included into to two distinct study periods according to Cx implementation: patients treated by PFU alone before 2009 and those treated by PFU + Cx from 2009. Primary objective was to evaluate the progression-free survival (PFS) between the two groups. Secondary objectives were to analyze the overall survival (OS) between the two groups and the prognostic impact of KRAS-LCS6 variant. Factors associated with survival were determined by a Cox multivariate analysis including age, WHO performance status (PS), type of treatment, KRAS-LCS6 variant, Charlson’s score and p16 status. Overall, 134 patients were included: 59 (44%) in PFU group and 75 (56%) in PFU + Cx group. Baseline characteristics were well balanced including 30% of patients with 2–3 PS. Median PFS was significantly improved in PFU + Cx group compared to PFU group (6.1 vs 4.4 months, respectively, HR 0.68, p = 0.02) and with a trend for better OS. A KRAS-LCS6 variant was found in 27 (25%) of samples without prognostic impact neither in whole population nor according to treatment. In multivariate analysis, addition of Cx to PFU was the only factor significantly associated with a better PFS (p = 0.01, HR 0.6). Our results suggest that PFU + Cx combination may be effective in unselected population of R/MHNC regardless the KRAS-LCS6 variant status.

The genetic basis of peripheral T-cell lymphoma (PTCL) is complex and encompasses several recurrent fusion transcripts discovered over the past years by means of massive parallel sequencing. However, there is currently no affordable and rapid technology for their simultaneous detection in clinical samples. Herein, we developed a multiplex ligation-dependent RT-PCR–based assay, followed by high-throughput sequencing, to detect 33 known PTCL-associated fusion transcripts. Anaplastic lymphoma kinase (ALK) fusion transcripts were detected in 15 of 16 ALK-positive anaplastic large-cell lymphomas. The latter case was further characterized by a novel SATB1_ALK fusion transcript. Among 239 other PTCLs, representative of nine entities, non-ALK fusion transcripts were detected in 24 samples, mostly of follicular helper T-cell (TFH) derivation. The most frequent non-ALK fusion transcript was ICOS_CD28 in nine TFH-PTCLs, one PTCL not otherwise specified, and one adult T-cell leukemia/lymphoma, followed by VAV1 rearrangements with multiple partners (STAP2, THAP4, MYO1F, and CD28) in five samples (three PTCL not otherwise specified and two TFH-PTCLs). The other rearrangements were CTLA4_CD28 (one TFH-PTCL), ITK_SYK (two TFH-PTCLs), ITK_FER (one TFH-PTCL), IKZF2_ERBB4 (one TFH-PTCL and one adult T-cell leukemia/lymphoma), and TP63_TBL1XR1 (one ALK-negative anaplastic large-cell lymphoma). All fusions detected by our assay were validated by conventional RT-PCR and Sanger sequencing in 30 samples with adequate material. The simplicity and robustness of this targeted multiplex assay make it an attractive tool for the characterization of these heterogeneous diseases.

Peripheral T-cell lymphoma comprises a heterogeneous group of mature non-Hodgkin lymphomas. Their diagnosis is challenging, with up to 30% of cases remaining unclassifiable and referred to as "not otherwise specified". We developed a reverse transcriptase-multiplex ligation-dependent probe amplification gene expression profiling assay to differentiate the main T-cell lymphoma entities and to study the heterogeneity of the "not specified" category. The test evaluates the expression of 20 genes, including 17 markers relevant to T-cell immunology and lymphoma biopathology, one Epstein-Barr virus-related transcript, and variants of RHOA (G17V) and IDH2 (R172K/T). By unsupervised hierarchical clustering, our assay accurately identified 21 of 21 ALK-positive anaplastic large cell lymphomas, 16 of 16 extranodal natural killer (NK)/T-cell lymphomas, 6 of 6 hepatosplenic T-cell lymphomas, and 13 of 13 adult T-cell leukemia/lymphomas. ALK-negative anaplastic lymphomas (n=34) segregated into one cytotoxic cluster (n=10) and one non-cytotoxic cluster expressing Th2 markers (n=24) and enriched in DUSP22-rearranged cases. The 63 T FH -derived lymphomas divided into two subgroups according to a predominant T FH (n=50) or an enrichment in Th2 (n=13) signatures. We next developed a support vector machine predictor which attributed a molecular class to 27 of 77 not specified T-cell lymphomas: 17 T FH , five cytotoxic ALK-negative anaplastic and five NK/T-cell lymphomas. Among the remaining cases, we identified two cell-of-origin subgroups corresponding to cytotoxic/Th1 (n=19) and Th2 (n=24) signatures. A reproducibility test on 40 cases yielded a 90% concordance between three independent laboratories. This study demonstrates the applicability of a simple gene expression assay for the classification of peripheral T-cell lymphomas. Its applicability to routinely-fixed samples makes it an attractive adjunct in diagnostic practice.

INTRODUCTION: Histologic subtypes of malignant pleural mesothelioma are a major prognostic indicator and decision denominator for all therapeutic strategies. In an ambiguous case, a rare transitional mesothelioma (TM) pattern may be diagnosed by pathologists either as epithelioid mesothelioma (EM), biphasic mesothelioma (BM), or sarcomatoid mesothelioma (SM). This study aimed to better characterize the TM subtype from a histological, immunohistochemical, and molecular standpoint. Deep learning of pathologic slides was applied to this cohort. METHODS: A random selection of 49 representative digitalized sections from surgical biopsies of TM was reviewed by 16 panelists. We evaluated BAP1 expression and CDKN2A (p16) homozygous deletion. We conducted a comprehensive, integrated, transcriptomic analysis. An unsupervised deep learning algorithm was trained to classify tumors. RESULTS: The 16 panelists recorded 784 diagnoses on the 49 cases. Even though a Kappa value of 0.42 is moderate, the presence of a TM component was diagnosed in 51%. In 49% of the histological evaluation, the reviewers classified the lesion as EM in 53%, SM in 33%, or BM in 14%. Median survival was 6.7 months. Loss of BAP1 observed in 44% was less frequent in TM than in EM and BM. p16 homozygous deletion was higher in TM (73%), followed by BM (63%) and SM (46%). RNA sequencing unsupervised clustering analysis revealed that TM grouped together and were closer to SM than to EM. Deep learning analysis achieved 94% accuracy for TM identification. CONCLUSION: These results revealed that the TM pattern should be classified as non-EM or at minimum as a subgroup of the SM type. ispartof: JOURNAL OF THORACIC ONCOLOGY vol:15 issue:6 pages:1037-1053 ispartof: location:United States status: published

Non-Hodgkin B-cell lymphomas (B-NHLs) are a highly heterogeneous group of mature B-cell malignancies. Their classification thus requires skillful evaluation by expert hematopathologists, but the risk of error remains higher in these tumors than in many other areas of pathology. To facilitate diagnosis, we have thus developed a gene expression assay able to discriminate the seven most frequent B-cell NHL categories. This assay relies on the combination of ligation-dependent RT-PCR and next-generation sequencing, and addresses the expression of more than 130 genetic markers. It was designed to retrieve the main gene expression signatures of B-NHL cells and their microenvironment. The classification is handled by a random forest algorithm which we trained and validated on a large cohort of more than 400 annotated cases of different histology. Its clinical relevance was verified through its capacity to prevent important misclassification in low grade lymphomas and to retrieve clinically important characteristics in high grade lymphomas including the cell-of-origin signatures and the MYC and BCL2 expression levels. This accurate pan-B-NHL predictor, which allows a systematic evaluation of numerous diagnostic and prognostic markers, could thus be proposed as a complement to conventional histology to guide the management of patients and facilitate their stratification into clinical trials.

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Introduction Non-Hodgkin B-cell lymphomas (B-NHLs) are a highly heterogeneous group of mature B-cell malignancies associated with very diverse clinical behaviors. They rely on the activation of different signaling pathways for proliferation and survival which might be amenable to targeted therapies, increasing the need for precision diagnosis. Unfortunately, their accurate classification can be challenging, even for expert hemato-pathologists, and secondary reviews recurrently differ from initial diagnosis. To address this issue we have developed a pan-B-NHL classifier based on a middle throughput gene expression assay coupled with a random forest algorithm. Material and Methods Five hundred ten B-NHL diagnosed according to the WHO criteria were studied, with 325 diffuse large B-cell lymphomas (DLBCL), 43 primary mediastinal B-cell lymphomas (PMBL), 55 follicular lymphomas (FL), 31 mantle cell lymphomas (MCL), 17 small lymphocytic lymphomas (SLL), 20 marginal zone lymphomas (MZL), 11 marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) and 8 lymphoplasmacytic lymphomas (LPL). To train and validate the predictor the samples were randomly split into a training (2/3) and an independent validation cohort (1/3). A panel of 137 genes was designed by purposely selecting the differentiation markers identified in the WHO classification for their capacity to provide diagnostic and prognostic information in NHLs. Gene expression profiles were generated by ligation dependent RT-PCR applied to RNA extracted from frozen or FFPE tissue and analyzed on a MiSeq sequencer. For analysis, the sequencing reads were de-multiplexed, aligned with the sequences of the LD-RTPCR probes and counted. Results were normalized using unique molecular indexes counts to correct PCR amplification biases. Results In DLBCL, unsupervised gene expression analysis retrieved the expected GCB, ABC and PMBL signatures (Fig A). These tumors also showed higher expressions of the KI67 (proliferation), CD68 and CD163 (tumor associated macrophages), and PD-L1/2 (immune response) markers. We also observed that the dual expression of MYC and BCL2 at the mRNA level significantly associates with inferior PFS and OS, independent from the International Prognostic Index and from the GCB/ABC cell-of-origin signature, validating the capacity of the assay to identify these highly aggressive lymphomas (Fig C). Overall, low-grade lymphomas were characterized by a significant T cell component. FLs associated with the GCB (BCL6, MYBL1, CD10 and LMO2) and Tfh (CD3, CD5, CD28, ICOS, CD40L, CXCL13) signatures. Other small B-cell lymphomas tended to overexpress activated B-cell markers (LIMD1, TACI, IRF4,FOXP1...), and the expected CD5, CD10, CD23 and CCND1 differential expressions in SLL, MCL and MZL were correctly retrieved (Fig B). Surprisingly, our analysis revealed that the Ie-Ce sterile transcript, expressed from the IGH locus during IgE isotype switching, is almost exclusively expressed by FLs, constituting one of the most discriminant markers for this pathology. We next trained a random forest classifier to discriminate the 7 principal subtypes of B-NHLs. The training cohort comprised 162 DLBCLs (ABC or GCB), 28 PMBL, 35 FLs (grade 1-3A), 21 MCLs, 12 SLLs, and 25 NHLs grouped into the MZL category (13 MZLs, 8 MALT and 4 LPLs). The independent validation series comprised 90 DLBCLs classified as GCB or ABC DLBCLs by the Lymph2Cx assay, 15 PMBLs, 12 FLs (grade 1-3A), 10 MCLs, 5 SLLs and 14 MZLs (7 MZL, 3 MALT and 4 LPL). The RF algorithm classified all cases of the training series into the expected subtype, as well as 94.5% samples of the independent validation cohort (Fig D). For ABC and GCB DLBCLs, the concordance with the Lymph2Cx assay in the validation cohort was 94.3%. Conclusion We have developed a comprehensive gene expression based solution which allows a systematic evaluation of multiple diagnostic and prognostic markers expressed by the tumor and by the microenvironment in B-NHLs. This assay, which does not require any specific platform, could be implemented in complement to histology in many diagnostic laboratories and, with the current development of targeted therapies, enable a more accurate and standardized B-NHL diagnosis. Together, our data illustrate how the integration of gene expression profiling and artificial intelligence can increase precision diagnosis in cancers. Figure Disclosures Oberic: Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees. Haioun:Miltenyi: Honoraria; Takeda: Honoraria; Servier: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Gilead: Honoraria; Janssen: Honoraria. Salles:Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events; BMS: Honoraria; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Epizyme: Consultancy, Honoraria. Tilly:roche: Membership on an entity's Board of Directors or advisory committees; servier: Honoraria; merck: Honoraria; Roche: Consultancy; Celgene: Consultancy, Research Funding; Astra-Zeneca: Consultancy; Karyopharm: Consultancy; BMS: Honoraria; Janssen: Honoraria; Gilead: Honoraria. Jardin:celgene: Honoraria; roche: Honoraria; amgen: Honoraria; Servier: Honoraria; janssen: Honoraria.

From a liquid biopsy, cell-free DNA (cfDNA) can provide information regarding basal tumoral genetic patterns and changes upon treatment. In a prospective cohort of 30 diffuse large B-cell lymphomas (DLBCL), we determined the clinical relevance of cfDNA using targeted next-generation sequencing and its correlation with PET scan imaging at the time of diagnosis and during treatment. Using a dedicated DLBCL panel, mutations were identified at baseline for 19 cfDNAs and profiles were consistent with expected DLBCL patterns. Tumor burden-related clinical and PET scan features (LDH, IPI, and metabolic tumor volume) were significantly correlated with the quantity of tumoral cfDNA. Among the four patients presenting additional mutations in their cfDNAs, three had high metabolic tumor volumes, suggesting that cfDNA more accurately reflects tumor heterogeneity than tissues biopsy itself. Mid-treatment, four patients still had basal mutations in their cfDNAs, including three in partial response according to their Deauville scores. Our study highlights the major interests in liquid biopsy, in particular in the context of bulky tumors where cfDNA allows capturing the entire tumoral mutation profile. Therefore, cfDNA analysis in DLBCL represents a complementary approach to PET scan imaging.

Mantle cell lymphoma (MCL) is a hematologic neoplasm characterised by the t(11;14)(q13;q32) translocation leading to aberrant cyclin D1 expression. The cell functions of cyclin D1 depend on its partners and/or subcellular distribution, resulting in different oncogenic properties. We observed the accumulation of cyclin D1 in the cytoplasm of a subset of MCL cell lines and primary cells. In primary cells, this cytoplasmic distribution was correlated with a more frequent blastoid phenotype. We performed immunoprecipitation assays and mass spectrometry on enriched cytosolic fractions from two cell lines. The cyclin D1 interactome was found to include several factors involved in adhesion, migration and invasion. We found that the accumulation of cyclin D1 in the cytoplasm was associated with higher levels of migration and invasiveness. We also showed that MCL cells with high cytoplasmic levels of cyclin D1 engrafted more rapidly into the bone marrow, spleen, and brain in immunodeficient mice. Both migration and invasion processes, both in vivo and in vitro, were counteracted by the exportin 1 inhibitor KPT-330, which retains cyclin D1 in the nucleus. Our data reveal a role of cytoplasmic cyclin D1 in the control of MCL cell migration and invasion, and as a true operator of MCL pathogenesis.

Little is known on the phylogenetic relationship between diagnostic and relapse clones of diffuse large B-cell lymphoma (DLBCL). We applied high throughput sequencing (HTS) of the VDJ locus of Immunoglobulin heavy chain (IGHV) on 14 DLBCL patients with serial samples, including tumor biopsies and/or peripheral blood mononuclear cells (PBMC). Phylogenetic data were consolidated with targeted sequencing and cytogenetics. Phylogeny clearly showed that DLBCL relapse could occur according either an early or a late divergent mode. These two modes of divergence were independent from the elapsed time between diagnosis and relapse. We found no significant features for antigen selection pressure in complementary determining region both at diagnosis and relapse for 9/12 pairs and a conserved negative selection pressure for the three remaining cases. Targeted HTS and conventional cytogenetics revealed a branched vs. linear evolution for 5/5 IGHV early divergent cases, but unexpected such "oncogenetic" branched evolution could be found in at least 2/7 IGHV late divergent cases. Thus, if BCR signaling is mandatory for DLBCL emergence, oncogenetic events under chemotherapy selection pressure may be the main driving forces at relapse. Finally, circulating subclones with divergent IGHV somatic hypermutations patterns from initial biopsy could be detected in PBMC at diagnosis for 4/6 patients and, for two of them, at least one was similar to the ones found at relapse. This study highlights that oncogenetic intraclonal diversity of DLBCL should be evaluated beyond the scope a single biopsy and represents a rationale for future investigations using peripheral blood for lymphoid malignancies genotyping. Am. J. Hematol. 92:68-76, 2017. © 2016 Wiley Periodicals, Inc.

International audience; The impact of the local inhibition of soluble epoxide hydrolase, which metabolizes vasodilator and anti-inflammatory epoxyeicosanoids, on diabetic skin microvascular dysfunction was assessed. In diabetic db/db mice, basal skin blood flow assessed using laser Doppler imaging was similar to that of control mice, but thermal hyperemia was markedly reduced. At 2 h after the topical administration of an aqueous gel containing the soluble epoxide hydrolase inhibitor trans-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (t-AUCB: 400 mg/L), the peak concentration of t-AUCB was detected in the skin of diabetic mice, which quickly decreased thereafter. In parallel, 2 h after application of t-AUCB treatment, thermal hyperemia was increased compared to the control gel. Quantification of t-AUCB in plasma of treated animals showed no or low systemic diffusion. Furthermore, haematoxylin and eosin histological staining of skin biopsies showed that skin integrity was preserved in t-AUCB-treated mice. Finally, for pig ear skin, a surrogate for human skin, using Franz diffusion cells, we observed a continuous diffusion of t-AUCB from 2 h after application to beyond 24 h. A single topical administration of a soluble epoxide hydrolase inhibitor improves microcirculatory function in the skin of db/db mice and might represent a new therapeutic approach for preventing the development of skin complications in diabetic patients.

International audience; About Related Information ePDFPDF Request permission Export citation Add to favorites Track citationShare a linkShare on Email Facebook Twitter LinkedIn RedditIntroduction: The relevance of circulating tumor DNA (ctDNA) analysis as a liquid biopsy and minimal residual disease tool in the management of classical Hodgkin Lymphoma (cHL) patients was demonstrated in retrospective settings and remains to be confirmed.Methods: We developed a targeted Next‐Generation sequencing (NGS) panel for fast analysis (AmpliSeq® technology) of nine commonly mutated genes in biopsy and ctDNA of cHL patients. We then conducted a prospective trial to assess ctDNA follow up at diagnosis and after 2 cycles of chemotherapy (C2). A dedicated bioinformatics pipeline to optimize detections of variants with low rates and minimize artefactual misinterpretations was built. Sixty cHL patients treated by first line conventional chemotherapy (BEACOPPescalated [21.3%], ABVD/ABVD‐like [73.5%] and other regimens [5.2%, for elderly patients] were included in this non‐interventional study (NCT02815137).Results: Median age of the patients was 33.5 years (range 20‐86) with a predominance of male patients, scleronodular subtype and ECOG 0‐1 (53.3%, 70% and 88.3%, respectively). Variants were identified in 33 (55%) patients, precisely in 16/30 (53.3%) and 30/60 (50%) of available biopsy and ctDNA samples respectively. Concordance between genetic profiles of biopsy and ctDNA was accurate for 22/30 patients (73.3%). Mutations of NFKBIE, TNFAIP3, STAT6, PTPN1, B2M, XPO1, ITPKB, GNA13 and SOCS1were found in 11.7% (mean number of variants by sample [range]: 1 [0‐1]), 25% (1.1 [0‐2]), 21.7% (1.4 [0‐2]), 1.7% (1 [0‐1]), 25% (1.3 [0‐3]), 6.7% (1 [0‐1]), 15% (1.4 [0‐3]), 5% (1.3 [0‐2]) and 31.7% (1.8 [0‐7]) of all patients, respectively. Unsupervised hierarchical clustering was performed among the 9 genes to represent the association of alterations (See Figure 1).Higher level of [ctDNA] at diagnosis was associated with adverse characteristics: age ≥45 years, presence of anemia (hemoglobin

International audience; Multi-organ AL amyloidosis is a therapeutic challenge because of light chain deposits severely damaging the function of concerned organs. Cardiac involvement, which leads to concentric hypertrophy of both ventricles, is particularly severe and leads to poor prognosis regardless of combination chemotherapy. This case pinpoints the relevance of combining clinical, histological, and echocardiographic information in the management of this complex and life-threatening disease.

Primary mediastinal B-cell lymphoma (PMBL) is an entity of B-cell lymphoma distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin-β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray-zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT-185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP-defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild-type cases. KPT-185 induced a dose-dependent decrease in cell proliferation and increased cell-death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT-330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild-type protein.

HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1, HACE1, located on chromosome 6q, encodes an E3 ubiquitin ligase and is downregulated in many human tumors. Here, we report HACE1 as a candidate tumor suppressor gene down-regulated by a combination of deletion and epigenetic mechanisms. HACE1 deletions were observed in 40% of B-cell lymphoma tumors. Hypermethylation of the HACE1 promoter CpG177 island was found in 60% (68/111) of cases and in all tested B-cell lymphoma lines. Using HDAC inhibitors, we observed predominantly inactive chromatin conformation (methylated H3 histones H3K9me2) in HACE1 gene promoter region. We demonstrated in Ramos and Raji cells that down-regulation of HACE1 expression was associated with a significant decrease in apoptosis and an accumulation of cells in the S and G2/M phases. Our experiments indicate that HACE1 can act as a haploinsufficient tumor suppressor gene in most B-cell lymphomas and can be downregulated by deacetylation of its promoter region chromatin, which makes HACE1 a potential target for HDAC inhibitors.

International audience; Recent studies have suggested that the lipid-lowering agent simvastatin holds great promise as a cancer therapeutic; it inhibits the growth of multiple tumors, including triple-negative breast cancer. Doxorubicin- and simvastatin-induced cytotoxicity has been associated with the modulation of Ca2+ signaling, but the underlying mechanisms remain incompletely understood. Here we identify how Ca2+ signaling regulates the breast tumor cell response to doxorubicin and simvastatin. These two drugs inhibit cell survival while increasing apoptosis in two human breast cancer cell lines and five primary breast tumor specimens through the modulation of Ca2+ signaling. Signal transduction and functional studies revealed that both simvastatin and doxorubicin trigger persistent cytosolic Ca2+ release, thereby stimulating the proapoptotic BIM pathway and mitochondrial Ca2+ overload, which are responsible for metabolic dysfunction and apoptosis induction. Simvastatin and doxorubicin suppress the prosurvival ERK1/2 pathway in a Ca2+-independent and Ca2+-dependent manner, respectively. In addition, reduction of the Ca2+ signal by chelation or pharmacological inhibition significantly prevents drug-mediated anticancer signaling. Unexpectedly, a scratch-wound assay indicated that these two drugs induce rapid cell migration, while inhibiting cell invasion and colony formation in a Ca2+-dependent manner. Further, the in vivo data for MDA-MB-231 xenografts demonstrate that upon chelation of Ca2+, the ability of both drugs to reduce the tumor burden was significantly reduced via caspase-3 deactivation. Our results establish a calcium-based mechanism as crucial for executing the cell death process triggered by simvastatin and doxorubicin, and suggest that combining simvastatin with doxorubicin may be an effective regimen for the treatment of breast cancer.

Classical Hodgkin lymphoma (cHL) accounts for 30% of all lymphomas [1]. Currently, 20–25% of cHL cases relapse or are refractory after first-line standard treatments, leading to the need to better ...

Acquired estrogen receptor gene (ESR1) mutations have been recently reported as a marker of resistance to aromatase inhibitors in hormone receptor positive metastatic breast cancer. We retrospectively considered seven patients treated for metastatic breast cancer with available samples from the primary tumor before any treatment, cryopreserved metastasis removed during progression and concomitant plasmas. All these seven patients were in disease progression after previous exposure to aromatase inhibitors for at least 6 months, and were assessed for ESR1 mutations detection in tumor and circulating DNA. For these patients, Sanger sequencing identified four metastases with clear ESR1 mutation and one possible, whereas digital PCR identified six mutated metastases. Then, under blind conditions and using digital PCR, corresponding circulating ESR1 mutations were successfully detected in four of these six metastatic breast cancer patients. Moreover, in two patients with serial blood samples following treatments exposure, the monitoring of circulating ESR1 mutations clearly predicted disease evolution. In the context of high interest for ESR1 mutations, our results highlight that these acquired recurrent mutations may be tracked in circulating tumor DNA and may be of clinical relevance for metastatic breast cancer patient monitoring.

Recent studies have suggested that the lipid-lowering agent simvastatin holds great promise as a cancer therapeutic; it inhibits the growth of multiple tumors, including triple-negative breast cancer. Doxorubicin- and simvastatin-induced cytotoxicity has been associated with the modulation of Ca

// Maxime Fontanilles 1, 2 , Florent Marguet 3, 4 , Elodie Bohers 2 , Pierre-Julien Viailly 2 , Sydney Dubois 2 , Philippe Bertrand 2 , Vincent Camus 1, 2 , Sylvain Mareschal 2 , Philippe Ruminy 2 , Catherine Maingonnat 2 , Stephane Lepretre 1 , Elena-Liana Veresezan 5 , Stephane Derrey 6 , Herve Tilly 1, 2 , Jean-Michel Picquenot 5 , Annie Laquerriere 3, 4 and Fabrice Jardin 1, 2 1 Department of Hematology, Cancer Center Henri Becquerel, 76000 Rouen, France 2 INSERM U1245, Cancer Center Henri Becquerel, Institute of Research and Innovation in Biomedicine (IRIB), University of Normandy, UNIVROUEN, 76000 Rouen, France 3 INSERM U1245 and Hopital Charles Nicolle, NeoVasc Team, University of Normandy, UNIVROUEN, CHU-Hopitaux de Rouen, 76031 Rouen, France 4 Department of Neuropathology, Hopital Charles Nicolle, Normandy Center for Genomic and Personalized Medicine, CHU-Hopitaux de Rouen, 76031 Rouen, France 5 Department of Pathology, Cancer Center Henri Becquerel, 76000 Rouen, France 6 Department of Neurosurgery, Hopital Charles Nicolle, CHU-Hopitaux de Rouen, 76031 Rouen, France Correspondence to: Fabrice Jardin, email: fabrice.jardin@chb.unicancer.fr Keywords: primary central nervous system lymphoma, circulating cell-free tumor DNA, somatic mutation, liquid biopsy, next-generation sequencing Received: March 08, 2017 Accepted: May 03, 2017 Published: June 01, 2017 ABSTRACT Purpose: Primary central nervous system lymphomas (PCNSL) have recurrent genomic alterations. The main objective of our study was to demonstrate that targeted sequencing of circulating cell-free DNA (cfDNA) released by PCNSL at the time of diagnosis could identify somatic mutations by next-generation sequencing (NGS). Patients and Methods: PlasmacfDNA and matched tumor DNA (tDNA) from 25 PCNSL patients were sequenced using an Ion Torrent Personal Genome Machine (Life Technologies ® ). First, patient-specific targeted sequencing of identified somatic mutations in tDNA was performed. Then, a second sequencing targeting MYD88 c.T778C was performed and compared to plasma samples from 25 age-matched control patients suffering from other types of cancer. Results: According to the patient-specific targeted sequencing, eight patients (32% [95% CI 15-54%]) had detectable somatic mutations in cfDNA. Considering MYD88 sequencing, six patients had the specific c.T778C alteration detected in plasma. Using a control group, the sensitivity was 24% [9-45%] and the specificity was 100%. Tumor volume or deep brain structure involvement did not influence the detection of somatic mutations in plasma. Conclusion: This pilot study provided evidence that somatic mutations can be detected by NGS in the cfDNA of a subset of patients suffering from PCNSL.

Purpose To prospectively assess the clinical impact of expert review of lymphoma diagnosis in France. Materials and Methods From January 2010 to December 2013, 42,145 samples from patients with newly diagnosed or suspected lymphomas were reviewed, according to the 2008 WHO classification, in real time by experts through the Lymphopath Network. Changes in diagnosis between referral and expert review were classified as major or minor according to their potential impact on patient care. Results The 42,145 reviewed samples comprised 36,920 newly diagnosed mature lymphomas, 321 precursor lymphoid neoplasms, 314 myeloid disorders, and 200 nonhematopoietic neoplasms, with 4,390 benign lesions. There were 4,352 cutaneous and 32,568 noncutaneous lymphomas. The most common mature noncutaneous lymphomas were diffuse large B-cell lymphomas (32.4%), follicular lymphomas (15.3%), classic Hodgkin lymphomas (13%), peripheral T-cell lymphomas (6.3%) of which angioimmunoblastic T-cell lymphomas (2.3%) were the most frequent, and mucosa-associated lymphoid tissue lymphomas (5.8%). A diagnostic change between referral and expert review occurred in 19.7% of patients, with an estimated impact on patient care for 17.4% of patients. This rate was significantly higher for patients sent with a provisional diagnosis seeking expert second opinion (37.8%) than for patients sent with a formal diagnosis (3.7%). The most frequent discrepancies were misclassifications in lymphoma subtype (41.3%), with 12.3% being misclassifications among small B-cell lymphoma entities. Fewer than 2% of changes were between benign and malignant lymphoid conditions. Minor changes (2.3%) mostly consisted of follicular lymphoma misgrading and diffuse large B-cell lymphoma subtype misclassification. Conclusion To our knowledge, this study provides the largest ever description of the distribution of lymphoma entities in a western country and highlights how expert review significantly contributes to a precise lymphoma diagnosis and optimal clinical management in a proportion of patients.

Introduction: MYD88 mutations, notably the recurrent gain-of-function L265P variant, are a distinguishing feature of Activated B-Cell like (ABC) Diffuse Large B Cell Lymphoma (DLBCL), leading to constitutive NFkB pathway activation. The frequency of MYD88 mutations in DLBCL and other hematologic malignancies is well described; however, there has not yet been a large-scale study of a MYD88 mutated patient cohort with additional Next Generation Sequencing (NGS), copy number variation (CNV), and gene expression data, in order to thoroughly characterize the associated genomic profiles of these patients. The aims of our study were to compare the L265P and non-L265P mutations in terms of pathological and genetic features, to better detail the genomic background associated with MYD88 mutations in order to delineate patients potentially sensitive to targeted therapies, and to define the prognostic value of MYD88 mutations according to different genomic contexts. Methods: A cohort of 361 DLBCL patients (94 MYD88 mutant and 267 MYD88 wild-type) was selected among the prospective, multicenter and randomized LNH-03B and LNH09-7B (NCT01195714) LYSA trials, as well as among patients sequenced at our institution as part of routine procedure. Cell of origin (COO) classification was obtained with HGU133+2.0 Affymetrix GeneChip arrays for 214 patients, with RT-MLPA for 77 patients1 and with Hans immunohistochemistry (IHC) method for 49 patients. All cases were submitted to next generation sequencing (NGS) focusing on 34 genes (Lymphopanel2) in order to analyze associated mutations and copy number variations (CNVs), as well as IHC, FISH, and clinical and prognostic analyses. Results: Importantly, we highlighted different genomic profiles for MYD88 L265P and MYD88 non-L265P mutant DLBCL, shedding light on their divergent backgrounds. Clustering analysis segregated subgroups according to associated genetic alterations among patients with either MYD88 L265P or non-L265P mutations. As such, clustering separated MYD88 L265P mutated DLBCL with associated PIM1 (52%), CD79B (52%), KMT2D (42%), and PRDM1 (32%) mutations, as well as MYD88 L265P mutated DLBCL with CDKN2A/B (67%/50%), PRDM1 (57%) and TNFAIP3 (52%) CNVs. We showed that associated CD79B and MYD88 L265P mutations act synergistically to increase NFkB pathway activation, although the majority of ABC MYD88 L265P mutant cases harbor downstream NFkB alterations, which can potentially predict BTK inhibitor resistance. Of note, although the MYD88 L265P variant was not an independent prognostic factor in ABC DLBCL, associated CD79B mutations significantly improved the survival of MYD88 L265P mutant ABC DLBCL in our cohort both in OS (p=0.02) and PFS (p=0.01), whereas the association of CARD11 or TNFAIP3 alterations did not impact survival. Interestingly, MYD88 mutant DLBCL cases were significantly more likely to experience central nervous system (CNS) relapse than MYD88 WT cases (p=0.02), as were MYD88 L265P mutant cases specifically (p=0.03). This result still tended toward statistical significance when considering only ABC patients (7 of 11 ABC CNS-relapsing cases were MYD88 mutant, p=0.1) but would have to be confirmed in a larger cohort. Conclusions: This study highlights the relative heterogeneity of MYD88 mutant DLBCBL, adding to the field's knowledge of the distinct genetic backgrounds of these subgroups. Our data highlights the theranostic and prognostic relevance of examining MYD88 and associated genomic alterations, emphasizing the usefulness of genomic profiling to best stratify patients for targeted therapy. 1. Mareschal S, Ruminy P, Bagacean C, et al. Accurate Classification of Germinal Center B-Cell-Like/Activated B-Cell-Like Diffuse Large B-Cell Lymphoma Using a Simple and Rapid Reverse Transcriptase-Multiplex Ligation-Dependent Probe Amplification Assay: A CALYM Study. The Journal of molecular diagnostics : JMD. 2015;17(3):273-283. 2. Dubois S, Viailly P-J, Mareschal S, et al. Next Generation Sequencing in Diffuse Large B Cell Lymphoma Highlights Molecular Divergence and Therapeutic Opportunities: a LYSA Study. Clinical cancer research : an official journal of the American Association for Cancer Research. 2016;22(12):2919-2928. Disclosures Salles: Novartis: Consultancy, Honoraria; Mundipharma: Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria, Research Funding.

International audience; Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma. It includes three major subtypes termed germinal center B-cell-like, activated B-cell-like, and primary mediastinal B-cell lymphoma. With the emergence of novel targeted therapies, accurate methods capable of interrogating this cell-of-origin classification should soon become essential in the clinics. To address this issue, we developed a novel gene expression profiling DLBCL classifier based on reverse transcriptase multiplex ligation-dependent probe amplification. This assay simultaneously evaluates the expression of 21 markers, to differentiate primary mediastinal B-cell lymphoma, activated B-cell-like, germinal center B-cell-like, and also Epstein-Barr virus-positive DLBCLs. It was trained using 70 paraffin-embedded biopsies and validated using >160 independent samples. Compared with a reference classification established from Affymetrix U133 + 2 data, reverse transcriptase multiplex ligation-dependent probe amplification classified 85.0% samples into the expected subtype, comparing favorably with current diagnostic methods. This assay also proved to be highly efficient in detecting the MYD88 L265P mutation, even in archival paraffin-embedded tissues. This reliable, rapid, and cost-effective method uses common instruments and reagents and could thus easily be implemented into routine diagnosis workflows, to improve the management of these aggressive tumors.

Introduction Various Peripheral T-cell lymphoma (PTCL) entities are recognized in the World Health Organization (WHO) classification based on clinical, histopathological, phenotypic and molecular criteria. Their diagnosis is however often challenging for pathologists, and up to 30% of cases, currently not classifiable, are recognized as not otherwise specified (NOS). Recent gene expression profiling (GEP) studies have significantly improved the molecular and ontogenic characterization of these tumors, but such high-throughput technologies are hardly feasible in the routine clinical setting. There is therefore an important need for alternative diagnostic strategies to allow for the development of specific therapies. Here, we sought to create a parsimonious and robust GEP assay to differentiate the different PTCL entities and to better characterize the heterogeneity of PTCL-NOS. Methods A Reverse Transcriptase-Multiplex Ligation dependant Probe Amplification (RT-MLPA) assay addressing 20 markers was applied to a cohort of 227 PTCLs biopsies enriched in PTCL-NOS (n=126). This assay determines the expression of seventeen genes routinely tested as immunohistochemical (IHC) markers or selected from high throughput GEP studies, together with the EBV infection status (EBER1 expression) and the presence of RHOAG17V and IDH2R172K/T mutations. Results Unsupervised hierarchical clustering analysis of 101 control cases representing the main PTCL entities other than PTCL-NOS by RT-MLPA accurately classified 28/29 Angioimmunoblastic T-cell lymphomas (AITL), 21/21 Anaplastic large T-cell lymphomas (ALCL) ALK+, 16/16 NK/T-cell lymphomas (NKTCL), 6/6 Hepatosplenic T-cell lymphomas (HSTL) and 12/12 Adult T-cell Leukemia/Lymphomas (ATLL)(Figure). AITL were classified according to the expression of Tfh markers (CXCL13, CXCR5, ICOS, BCL6) and RHOA mutations (n=18); NKTCLs according to EBER1, GZMB and Th1 markers (TBX21, IFNγ); HSTLs to CD56, GATA3, TBX21 and BCL6; ALCL ALK+ according to CD30, ALK and cytotoxic markers (PRF, GZMB); ATLLs to ICOS and Th2 markers (GATA3, CCR4). Interestingly, ALCL ALK- cases (n=17) were divided into 2 subgroups: one, associated with high expression of CD30 and cytotoxic markers (PRF, GZMB), clustered with ALCL ALK+ cases (n=11), the other showed absence of PRF and GZMB, but expression of CD30 and Th2 markers (n=6). Applied to 126 nodal PTCL-NOS, the RT-MLPA classifier identified 33 AITL-Like cases expressing Tfh markers and often presenting with RHOA mutations (15 cases). It also identified 5 NKTCL-like cases (EBV-cytoxic) and 1 ALCL-like case (cytotoxic-CD30).The CD30-Th2 signature was found in 15 cases, reinforcing the hypothesis that it may delineate a novel PTCL entity, at the frontier between ALCL ALK- and other PTCLs. In agreement with previous GEP studies, 23 cases expressed Th2 markers but no CD30 (often in association with a significant Tfh signature, probably reflecting a contribution from the microenvironment). Twenty-five other cases showed a hybrid cytotoxic-Th1 signature. The remaining 14 cases did not reveal any recognizable gene expression profile. Finally, we observed a strong correlation between RT-MLPA and IHC for most markers evaluated by both methods (p Conclusion This study demonstrates the applicability of a parsimonious RT-MLPA classifier for the classification of PTCLs. Its simplicity of use and its applicability on FFPE samples makes it an attractive alternative to high throughput GEP approaches and IHC. Its implementation in clinical trials, in combination with conventional pathological evaluation, may thus participate to improve the classification of PTCLs and therefore the management of PTCL patients. Figure Prediction of PTCL subgroups using RT-MLPA. The assay was used to differentiate AITL, ALCL, ATLL, HSTL and NKTCL within 101 biopsies. Differential gene expression is depicted according to a red (positive) to green (negative) color scale (lower panel). Concordances with histopathological diagnosis and immunohistochemisty are indicated in the upper panel. Figure. Prediction of PTCL subgroups using RT-MLPA. The assay was used to differentiate AITL, ALCL, ATLL, HSTL and NKTCL within 101 biopsies. Differential gene expression is depicted according to a red (positive) to green (negative) color scale (lower panel). Concordances with histopathological diagnosis and immunohistochemisty are indicated in the upper panel. Disclosures No relevant conflicts of interest to declare.