Key Points• ASXL2 was mutated in 22 ASXL2 mutations were similarly frequent in adults and children t(8;21) and were mutually exclusive with ASXL1 mutations. Although overall survival was similar between ASXL1 and ASXL2 mutant t(8;21) AML patients and their wild-type counterparts, patients with ASXL1 or ASXL2 mutations had a cumulative incidence of relapse of 54.6% and 36.0%, respectively, compared with 25% in ASXL1/2 wild-type counterparts (P 5 .226). These results identify a high-frequency mutation in t(8;21) AML and identify the need for future studies to investigate the clinical and biological relevance of ASXL2 mutations in this unique subset

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.

ASXL1 mutations. We hypothesize that the nature of the secondary genetic events observed in GATA2-mutated individuals may explain the clinical heterogeneity observed within and between pedigrees.

Diffuse large B cell lymphoma (DLBCL) is an aggressive and heterogeneous malignancy that can be divided in two major subgroups, germinal center B-cell-like (GCB) and activated B-cell-like (ABC). Activating mutations of genes involved in the BCR and NF-κB pathways (CD79A, CD79B, MYD88, and CARD11) or in epigenetic regulation (EZH2) have been recently reported, preferentially in one of the two DLBCL subtypes. We analyzed the mutational status of these five recurrently mutated genes in a cohort of 161 untreated de novo DLBCL. Overall, 93 mutations were detected, in 61 (38%) of the patients. The L265P MYD88 mutation was the most frequent MYD88 variant (n = 18), observed exclusively in the ABC subtype. CD79A/CD79B ITAM domains were targeted in ABC DLBCL (12/77; 16%), whereas CARD11 mutations were equally distributed in the two subtypes. The EZH2 Y641 substitution was found almost exclusively in the GCB subgroup (15/62; 24%). Twenty cases (12%) displayed two activating mutations, including the most frequent CD79/MYD88 variants combination (n = 8) which is observed exclusively in the ABC subtype. When considering only ABC DLBCL patients treated by rituximab plus chemotherapy, the presence of an activating NF-κB mutation was associated with an unfavorable outcome (3-years OS 26% for mutated cases versus 67% for the cases without mutations, P = 0.0337). Our study demonstrates that activating and targetable mutations are observed at a very high frequency in DLBCL at the time of diagnosis, indicating that sequencing of a limited number of genes could help tailor an optimal treatment strategy in DLBCL.

FIP1L1-PDGFRA-positive myeloid neoplasm with eosinophilia (F/P+ MN-eo) is a rare disease: robust epidemiological data are lacking and reported issues are scarce, of low sample-size and limited follow-up. Imatinib mesylate (IM) is highly efficient but no predictive factor of relapse after discontinuation has yet been identified. One hundred and fifty-one patients with F/P+ MN-eo (143 males; mean age at diagnosis 49 years; mean annual incidence: 0.18 case per million population) were included in this retrospective nationwide study involving all French laboratories who perform the search of F/P fusion gene (study period: 2003-2019). The main organs involved included the spleen (44%), skin (32%), lungs (30%), heart (19%) and central nervous system (9%). Serum vitamin

Gene expression profiling has identified two major molecular subtypes of diffuse large B-cell lymphoma (DLBCL) that are histologically indistinguishable but differ in cure rates. Here, we investigated whether the isotype of the B-cell receptor (BCR) expressed by the tumoral cells correlated with the molecular subtype and survival. Gene expression analysis clustered the 53 patients included in this study into three subgroups, 17 germinal center B-cell-like (GCB) cases, 26 activated B-celllike (ABC) cases and 10 intermediate cases. The molecular subtype was correlated with the isotype, as 15/17 GCB cases expressed a secondary isotype (immunoglobulin (Ig)G or IgA), whereas 24/26 ABC cases expressed a primary isotype (IgM or IgD) (Po0.0001). There was a trend toward a worse outcome for patients with an ABC DLBCL and a shorter overall survival for patients with IgM þ tumor (P ¼ 0.21 and 0.014, respectively). Finally, fluorescence in situ hybridization (FISH) analysis revealed a striking asymmetric pattern, as the IGHM gene is conserved only on the productive IGH allele in most IgM þ tumors. Taken together, these data indicate that the isotype of the BCR is a reliable indicator for the GCB and ABC subtypes in DLBCL, and suggest that the conservation of an IgM is required for ABC DLBCL lymphomagenesis to occur.

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 2 cycles of chemotherapy (C2). 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 non-interventional study. Median age of the patients was 33.5 years (range 20-86). Variants were identified in 42 (70%) patients. Mutations of NFKBIE, TNFAIP3, STAT6,

Introduction: Previous studies have highlighted the potential of circulating tumor DNA (ctDNA) to determine the mutational profile of DLBCL, and assess the molecular changes over time and the genetic mechanisms of resistance. In addition, the quantity of ctDNA could also predict the response and outcome of the patients. The aim of this study was to analyze the mutational profile at diagnosis and its dynamics after frontline treatment and in the refractory/relapse settings. Methods:We included 65 patients (M/F 32/33, median age 64 years) diagnosed with DLBCL in a single institution between 2016 and 2018 according to the WHO criteria. All patients were treated with chemoimmunotherapy. After initial treatment, 47 patients achieved CR, 4 PR, 7 were refractory and in 7 cases the response was not evaluable. Samples were obtained both at diagnosis and at relapse/progression in refractory/relapsed patients. Tumor genomic DNA (gDNA) was isolated from formalin-fixed paraffin-embedded (FFPE) diagnostic tissue biopsies and at relapse when available. A panel of 115 genes was amplified using a hybridization capture based protocol from 10-30 ng of ctDNA and 150 ng of gDNA (SureSelectXT-Agilent Technologies) and sequenced in a MiSeq instrument (Illumina). Results: ctDNA was obtained from all patients at diagnosis (median of 34 ng; range: 10-1507 ng) and from 12 refractory/relapsed cases. At least one mutation could be detected in 88% of the cases.Median number of mutations per sample was 6 (0-21 mutations).The genes most frequently mutated at diagnosis in plasma samples were KMT2D, TP53, MYD88, TNFRSF14, PIM1, CREBBP, BCL2 and EP300. In 38 cases, paired FFPE samples were available as detailed in the figure. Sensitivity of ctDNA to detect tumor mutations at baseline FFPE samples was 75% (95%IC: 69.5-80.5). Of note, most of the cases in which mutations were not detected in the ctDNA had a primary extranodal origin. In the 12 cases with a ctDNA sample at diagnosis and at progression, 5 cases showed the same mutational profile, whereas in 6 cases a change in the number of mutated genes was observed (3 cases had fewer mutations; 3 cases had new mutations) and in one case no mutations were detected at relapse. In addition, selection of minor subclonal mutations was observed in 2 cases. Patients with high pretreatment ctDNA levels (>3 log hGE/mL) had a worse PFS and OS than those with low levels (18-month PFS 24 vs 77%; 18-month OS 58 vs 94%; p<0.004).Conclusions: ctDNA shows a good correlation with the information obtained in the tumor. Therefore it could be a valuable tool to assess the mutational profile both at diagnosis and at relapse. Pretreatment ctDNA levels have an impact on outcome.Introduction: 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 (Am...