Sequence analyses of relapsed or refractory diffuse large B-cell lymphomas unravel three genetic subgroups of patients and the GNA13 mutant as poor prognostic biomarker, results of LNH-EP1 study.

Advances in molecular profiling of newly diagnosed diffuse large B-cell lymphoma (DLBCL) have recently refine genetic subgroups. Genetic subgroups remain undetermined at the time of relapse or refractory (RR) disease. This study aims to decipher genetic subgroups and search for prognostic molecular biomarkers in patients with RR-DLBCL. From 2015 to 2021, targeted next-generation sequencing analyses of germline-matched tumor samples and fresh tissue from RR-DLBCL patients were performed. Unsupervised clustering of somatic mutations was performed and correlations with patient outcome were sought. A number of 120 patients with RR-DLBCL were included in LNH-EP1 study and a molecular tumor landscape was successfully analyzed in 87% of patients (104/120 tumor samples). The median age was 67.5 years (range 27.4-87.4), median number of previous treatments was 2 (range 1-9). The most frequently mutated genes were TP53 (n = 53 mutations; 42% of samples), CREBBP (n = 39; 32%), BCL2 (n = 86; 31%), KMT2D (n = 39; 28%) and PIM1 (n = 54; 22%). Unsupervised clustering separated three genetic subgroups entitled BST (enriched in BCL2, SOCS1, and TNFRSF14 mutations); TKS (enriched in TP53, KMT2D, and STAT6 mutations); and PCM (enriched in PIM1, CD79B, and MYD88 mutations). Median overall survival (OS) was 11.0 (95% confidence interval [CI]: 8.1-12.6) months. OS was not significantly different between the three genetic subgroups. GNA13 mutant was significantly associated with an increased risk of death (hazard ratio: 6.6 [95% CI: 2.1-20.6]; p = .0011) and shorter OS (p = .0340). At the time of relapse or refractory disease, three genetic subgroups of DLBCL patients were delineated, which could help advance precision molecular medicine programs.

Rituximab and dose-dense chemotherapy for adults with Burkitt's lymphoma: a randomised, controlled, open-label, phase 3 trial.

BACKGROUND: Short intensive chemotherapy is the standard of care for adult patients with Burkitt's leukaemia or lymphoma. Findings from single-arm studies suggest that addition of rituximab to these regimens could improve patient outcomes. Our objective was to test this possibility in a randomised trial. METHODS: In this randomised, controlled, open-label, phase 3 trial, we recruited patients older than 18 years with untreated HIV-negative Burkitt's lymphoma (including Burkitt's leukaemia) from 45 haematological centres in France. Exclusion criteria were contraindications to any drug included in the chemotherapy regimens, any serious comorbidity, poor renal (creatinine concentration >150 µmol/L) or hepatic (cirrhosis or previous hepatitis B or C) function, pregnancy, and any history of cancer except for non-melanoma skin tumours or stage 0 (in situ) cervical carcinoma. Patients were stratified into two groups based on disease extension (absence [group B] or presence [group C] of bone marrow or central nervous system involvement). Patients were further stratified in group C according to age (<40 years, 40-60 years, and >60 years) and central nervous system involvement. Participants were randomly assigned in each group to either intravenous rituximab injections and chemotherapy (lymphome malin B [LMB]) or chemotherapy alone by the Groupe d'Etude des Lymphomes de l'Adulte datacentre. Randomisation was stratified by treatment group and centre using computer-assisted permuted-block randomisation (block size of four; allocation ratio 1:1). We gave rituximab (375 mg/m(2)) on day 1 and day 6 during the first two courses of chemotherapy (total of four infusions). The primary endpoint is 3 year event-free survival (EFS). We analysed all patients who had data available according to their originally assigned group. This trial is registered with ClinicalTrials.gov, number NCT00180882. RESULTS: Between Oct 14, 2004, and Sept 7, 2010, we randomly allocated 260 patients to rituximab or no rituximab (group B 124 patients [64 no rituximab; 60 rituximab]; group C 136 patients [66 no rituximab; 70 rituximab]). With a median follow-up of 38 months (IQR 24-59), patients in the rituximab group achieved better 3 year EFS (75% [95% CI 66-82]) than did those in the no rituximab group (62% [53-70]; log-rank p stratified by treatment group=0·024). The hazard ratio estimated with a Cox model stratified by treatment group, assuming proportionality, was 0·59 for EFS (95% CI 0·38-0·94; p=0·025). Adverse events did not differ between the two treatment groups. The most common adverse events were infectious (grade 3-4 in 137 [17%] treatment cycles in the rituximab group vs 115 [15%] in the no rituximab group) and haematological (mean duration of grade 4 neutropenia of 3·31 days per cycle [95% CI 3·01-3·61] vs 3·38 days per cycle [3·05-3·70]) events. INTERPRETATION: Addition of rituximab to a short intensive chemotherapy programme improves EFS in adults with Burkitt's leukaemia or lymphoma. FUNDING: Gustave Roussy Cancer Campus, Roche, Chugai, Sanofi.

Myelodysplastic syndrome following chimeric antigen receptor T-cell therapy treated with allogenic stem cell transplantation.

Chimeric antigen receptor (CAR) T-cell therapy is currently approved for the treatment of B-cell non-Hodgkin lymphomas and B-cell acute lymphoblastic leukemia. Prolonged hematological toxicity is an emergent concern following CAR T cells and occurred in 30% of patients with unknown mechanism. Few cases of myelodysplastic syndrome (MDS) following CAR T-cell therapy were reported and attributed to previous chemotherapies in heavily pretreated patients. The authors report the case of a patient with diffuse large B-cell lymphoma treated with axicabtagene ciloleucel who developed prolonged hematological toxicity by day 28. During the follow-up, the diagnosis of MDS was made. The patient underwent allogenic hematological stem cell transplantation. The patient remains in complete remission of his lymphoma and MDS 19 months after hematological stem cell transplantation.

Chimeric antigen receptor (CAR) T cell is a new type of immunotherapy that was recently validated for the treatment of some types of B-cell lymphoma and leukemia. One of the most recently reported side effects of CAR T cells is the appearance of anemia, thrombocytopenia and/or neutropenia lasting for a long duration. The authors report the case of a patient treated with CAR T cells for non-Hodgkin lymphoma who developed prolonged hematological toxicity. During follow-up, the diagnosis of myelodysplastic syndrome was made and the patient underwent allogenic bone marrow transplantation and remains in complete remission at last follow-up.

Liquid Biopsies for Circulating Tumor DNA Detection May Reveal Occult Hematologic Malignancies in Patients With Solid Tumors.

PURPOSE: High-risk clonal hematopoiesis (CH) is frequently incidentally found in patients with solid tumors undergoing plasma cell-free DNA sequencing. Here, we aimed to determine if the incidental detection of high-risk CH by liquid biopsy may reveal occult hematologic malignancies in patients with solid tumors. MATERIALS AND METHODS: Adult patients with advanced solid cancers enrolled in the Gustave Roussy Cancer Profiling study (ClinicalTrials.gov identifier: NCT04932525) underwent at least one liquid biopsy (FoundationOne Liquid CDx). Molecular reports were discussed within the Gustave Roussy Molecular Tumor Board (MTB). Potential CH alterations were observed, and patients referred to hematology consultation in the case of pathogenic mutations in JAK2, MPL, or MYD88, irrespective of the variant allele frequency (VAF), or in DNMT3A, TET2, ASXL1, IDH1, IDH2, SF3B1, or U2AF1 with VAF ≥ 10%, while also considering patient cancer-related prognosis. TP53 mutations were discussed case-by-case. RESULTS: Between March and October 2021, 1,416 patients were included. One hundred ten patients (7.7%) carried at least one high-risk CH mutation: DNMT3A (n = 32), JAK2 (n = 28), TET2 (n = 19), ASXL1 (n = 18), SF3B1 (n = 5), IDH1 (n = 4), IDH2 (n = 3), MPL (n = 3), and U2AF1 (n = 2). The MTB advised for hematologic consultation in 45 patients. Overall, 9 patients of 18 actually addressed had confirmed hematologic malignancies that were occult in six patients: two patients had myelodysplastic syndrome, two essential thrombocythemia, one a marginal lymphoma, and one a Waldenström macroglobulinemia. The other three patients were already followed up in hematology. CONCLUSION: The incidental findings of high-risk CH through liquid biopsy may trigger diagnostic hematologic tests and reveal an occult hematologic malignancy. Patients should have a multidisciplinary case-by-case evaluation.

Therapy-related Myeloid Neoplasms Following PARP Inhibitors: Real-life Experience.

PURPOSE: To provide insights into the diagnosis and management of therapy-related myeloid neoplasms (t-MN) following PARP inhibitors (PARPi). EXPERIMENTAL DESIGN: In a French cancer center, we identified and described the profiles of 13 t-MN diagnosed among 37 patients with ovarian cancer referred to hematology consultation for cytopenia under PARPi. Next, we described these 13 t-MN post-PARPi among 37 t-MN post ovarian cancer according to PARPi exposure. Finally, we described 69 t-MN post-PARPi in a national cohort. RESULTS: From 2016 to 2021, cumulative incidence of t-MN was 3.5% (13/373) among patients with ovarian cancer treated with PARPi. At time of hematologic consultation, patients with t-MN had a longer PARPi exposure (9 vs. 3 months, P = 0.01), lower platelet count (74 vs. 173 G/L, P = 0.0005), and more cytopenias (2 vs. 1, P = 0.0005). Compared with t-MN not exposed to PARPi, patients with t-MN-PARPi had more BRCA1/2 germline mutation (61.5% vs. 0%, P = 0.03) but similar overall survival (OS). In the national cohort, most t-MN post-PARPi had a complex karyotype (61%) associated with a high rate of TP53 mutation (71%). Median OS was 9.6 months (interquartile range, 4-14.6). In multivariate analysis, a longer time between end of PARPi and t-MN (HR, 1.046; P = 0.02), olaparib compared with other PARPi (HR, 5.82; P = 0.003) and acute myeloid leukemia (HR, 2.485; P = 0.01) were associated with shorter OS. CONCLUSIONS: In a large series, we described a high incidence of t-MN post-PARPi associated with unfavorable cytogenetic and molecular abnormalities leading to poor OS. Early detection is crucial, particularly in cases of delayed cytopenia.

Outcomes of Transplant-Eligible Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma After Second-Line Salvage Chemotherapy: The Gustave Roussy Experience.

INTRODUCTION: After failure of frontline therapy, patients with relapsed/refractory diffuse large B-cell lymphoma (RR-DLBCL) that does not respond to first-line salvage chemotherapy can be recommended second-line salvage chemotherapy. The available literature in this regard is weak, although many centers routinely offer this type of second-line salvage chemotherapy to their patients. PATIENTS AND METHODS: This retrospective study included transplant-eligible patients with RR-DLBCL treated at Gustave Roussy between January 2008 and April 2020. Eligible patients were those who received second-line salvage chemotherapy using R-DHAP or R-ICE in patients who experienced an insufficient partial response, stable disease, or progressive disease in response to first-line salvage chemoimmunotherapy using an alternative regimen. RESULTS: Forty-six RR-DLBCL patients received second-line salvage regimen, which yielded an objective response rate of 33%, median progression-free survival of 2.1 months, and overall survival of 11.4 months. Twelve patients proceeded to autologous stem-cell transplantation (ASCT), of whom 70% remained alive 1 year after ASCT. To explore the impact of transplantation, a multivariate analysis (excluding response to the first-line salvage regimen because this covariate was totally embedded within the transplantation covariate), ASCT was associated with progression-free survival (hazard ratio = 0.16; 95% confidence interval, 0.06-0.42) and overall survival (hazard ratio = 0.27; 95% confidence interval, 0.08-0.88). CONCLUSION: Second-line salvage chemotherapy with R-DHAP or R-ICE followed by ASCT leads to a favorable outcome in almost one third of patients with RR-DLBCL and offers a median overall survival of approximately 1 year. These data support the administration of second-line salvage chemotherapy followed by ASCT.

Large deletions in immunoglobulin genes are associated with a sustained absence of DNA Polymerase η.

Somatic hypermutation of immunoglobulin genes is a highly mutagenic process that is B cell-specific and occurs during antigen-driven responses leading to antigen specificity and antibody affinity maturation. Mutations at the Ig locus are initiated by Activation-Induced cytidine Deaminase and are equally distributed at G/C and A/T bases. This requires the establishment of error-prone repair pathways involving the activity of several low fidelity DNA polymerases. In the physiological context, the G/C base pair mutations involve multiple error-prone DNA polymerases, while the generation of mutations at A/T base pairs depends exclusively on the activity of DNA polymerase η. Using two large cohorts of individuals with xeroderma pigmentosum variant (XP-V), we report that the pattern of mutations at Ig genes becomes highly enriched with large deletions. This observation is more striking for patients older than 50 years. We propose that the absence of Pol η allows the recruitment of other DNA polymerases that profoundly affect the Ig genomic landscape.

[Burkitt lymphoma, a diagnostic emergency] / Lymphome de Burkitt, une urgence diagnostique

Burkitt lymphoma, a diagnostic emergency. Burkitt lymphoma is a highly aggressive B-cell non-Hodgkin lymphoma. This is the first human tumor where a chromosomal translocation that activates an oncogene (c-myc) has been described. The diagnosis and initiation of therapy is an emergency. The main lymphoma localizations are the digestive tract, the central nervous system and the bone marrow in the sporadic form observed in Western countries. Tumor lysis syndrome can be present even before therapy and can necessitate rapid chemotherapy in intensive care unit. Dose-dense chemotherapy regimens, implemented during the last 25 years can cure the majority of patients, especially children, but remains associated with a high toxicity. The adjunction of rituximab to chemotherapy is still investigated in high-risk groups in children and is now part of the treatment in adults.

Lymphome de burkitt, une urgence diagnostique. Le lymphome de Burkitt est une des entités les plus agressives de lymphome et la tumeur maligne de l'homme où a été identifié le premier oncogène (c-myc) grâce à l'existence d'une translocation chromosomique responsable de son activation. Son traitement est une urgence vu son taux très élevé de prolifération. Les localisations préférentielles de la maladie, dans la forme sporadique des pays occidentaux, sont le tube digestif, la moelle hématopoïétique et le système nerveux central. Un syndrome de lyse peut être présent avant tout traitement imposant une prise en charge en soins intensifs et l'initiation rapide d'une chimiothérapie. Les chimiothérapies délivrées à doses élevées et à un rythme dense élaborées durant les 25 dernières années permettent d'obtenir une guérison dans la plupart des cas au prix d'une toxicité hématologique importante. L'utilisation du rituximab en association à la chimiothérapie est évaluée en pédiatrie dans les formes graves de la maladie et fait maintenant partie du traitement chez l'adulte.

Immunophenotypic clustering of myelodysplastic syndromes.

Myelodysplastic syndromes (MDSs) are heterogeneous diseases of bone marrow (BM) cell precursors for which immunophenotypic characterization is still considered irrelevant despite the accuracy and sensitivity of flow cytometry techniques. The aim of this study was to determine whether immunophenotypic abnormalities could be defined in MDSs and could correlate with the French-American-British classification and cytogenetics. Analysis was performed on 275 BM samples (207 MDS patients, 68 controls) and 25 control blood samples. Immunophenotyping was based on a primary gating of blast cells, monocytes, and granulocytes according to CD45 antigen expression and side scatter light diffraction. Immunophenotypic hierarchical clustering was performed to analyze the results. The data obtained show that (1) immunophenotypic clustering partly discriminates patients with refractory anemia with excess blasts/refractory anemia with excess blasts in transformation (RAEB/RAEB-T), chronic myelomonocytic leukemia (CMML), and refractory anemia/refractory anemia with ring sideroblasts (RA/RARS) for CD45(lo) blast cells and patients with RA/CMML, RARS, and RAEB/RAEB-T for CD45(hi)/side scatter(hi) (SS(hi)) granulocytes; (2) the most discriminating markers were CD16, CD34, CD36, CD38, CD71, and HLA-DR for blast cells and CD11b, CD13, CD33, CD36, CD38, CD71, and HLA-DR for CD45(hi)/SS(hi) granulocytes; (3) clusters related to CD34 expression were associated with high levels of blast cells on BM smear; (4) clusters related to high levels of CD36 expression on CD45(lo) blast cells and CD45(hi)/SS(hi) granulocytes were associated with a poor International Prognosis Scoring System score; and (5) high levels of CD71 expression on CD45(hi)/SS(hi) granulocytes were associated with the RARS category. These results show a close relationship between immunophenotypic abnormalities and BM dysplasia and suggest that flow cytometry could be a future tool for the characterization of MDSs.