EZH2 mutations are frequent and represent an early event in follicular lymphoma.
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ABSTRACT:
SUBMITTER: Bodor C
PROVIDER: S-EPMC3814734 | biostudies-literature | 2013 Oct
REPOSITORIES: biostudies-literature
Publications
EZH2 mutations are frequent and represent an early event in follicular lymphoma.
Bödör Csaba C Grossmann Vera V Popov Nikolay N Okosun Jessica J O'Riain Ciarán C Tan King K Marzec Jacek J Araf Shamzah S Wang Jun J Lee Abigail M AM Clear Andrew A Montoto Silvia S Matthews Janet J Iqbal Sameena S Rajnai Hajnalka H Rosenwald Andreas A Ott German G Campo Elias E Rimsza Lisa M LM Smeland Erlend B EB Chan Wing C WC Braziel Rita M RM Staudt Louis M LM Wright George G Lister T Andrew TA Elemento Olivier O Hills Robert R Gribben John G JG Chelala Claude C Matolcsy András A Kohlmann Alexander A Haferlach Torsten T Gascoyne Randy D RD Fitzgibbon Jude J
Blood 20130919 18
Gain of function mutations in the H3K27 methyltransferase EZH2 represent a promising therapeutic target in germinal center lymphomas. In this study, we assessed the frequency and distribution of EZH2 mutations in a large cohort of patients with follicular lymphoma (FL) (n = 366) and performed a longitudinal analysis of mutation during the disease progression from FL to transformed FL (tFL) (n = 33). Mutations were detected at 3 recurrent mutation hot spots (Y646, A682, and A692) in 27% of FL cas ...[more]
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Project description:Recent advances in molecular technologies enable sensitive and quantitative assessment of circulating tumor DNA, offering a noninvasive disease monitoring tool for patients with malignant disorders. Here, we demonstrated on four follicular lymphoma cases that circulating tumor DNA based EZH2 mutation analysis performed by a highly sensitive droplet digital PCR method may be a valuable treatment monitoring approach in EZH2 mutant follicular lymphoma. EZH2 variant allele frequencies changed in parallel with the volume of metabolically active tumor sites observed on 18F-fluorodeoxyglucose positron emission tomography combined with computer tomography (PET-CT) scans. Variant allele frequencies of EZH2 mutations decreased or were eliminated rapidly upon successful treatment, with treatment failure being associated with elevated EZH2 variant allele frequencies. We also demonstrated spatial heterogeneity in a patient with two different EZH2 mutations in distinct anatomical sites, with both mutations simultaneously detected in the liquid biopsy specimen. In summary, circulating tumor DNA based EZH2 mutation analysis offers a rapid, real-time, radiation-free monitoring tool for sensitive detection of EZH2 mutations deriving from different anatomical sites in follicular lymphoma patients receiving immunochemotherapy.
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Project description:Recent advances in follicular lymphoma (FL) have resulted in prolongation of overall survival (OS). Here we assessed if early events as defined by event-free survival (EFS) at 12 and 24 months from diagnosis (EFS12/EFS24) can inform subsequent OS in FL. 920 newly diagnosed grade 1-3A FL patients enrolled on the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER) from 2002-2012 were initially evaluated. EFS was defined as time from diagnosis to progression, relapse, re-treatment, or death due to any cause. OS was compared to age-and-sex-matched survival in the general US population using standardized mortality ratios (SMR) and 95% confidence intervals (CI). We used a cohort of 412 FL patients from two Lyon, France hospital registries for independent replication. Patients who failed to achieve EFS12 had poor subsequent OS (MER SMR?=?3.72, 95%CI: 2.78-4.88; Lyon SMR?=?8.74, 95%CI: 5.41-13.36). Conversely, patients achieving EFS12 had no added mortality beyond the background population (MER SMR?=?0.73, 95%CI: 0.56-0.94, Lyon SMR?=?1.02, 95%CI: 0.58-1.65). Patients with early events after immunochemotherapy had especially poor outcomes (EFS12 failure: MER SMR?=?17.63, 95%CI:11.97-25.02, Lyon SMR?=?19.10, 95%CI:9.86-33.36; EFS24 failure: MER SMR?=?13.02, 95%CI:9.31-17.74, Lyon SMR?=?7.22, 95%CI:4.13-11.74). In a combined dataset of all patients from both cohorts, baseline FLIPI was no longer informative in EFS12 achievers. Reassessment of patient status at 12 months from diagnosis in follicular lymphoma patients, or at 24 months in patients treated with immunochemotherapy, is a strong predictor of subsequent overall survival in FL. Early event status provides a simple, clinically relevant endpoint for studies assessing outcome in FL. Am. J. Hematol. 91:1096-1101, 2016. © 2016 Wiley Periodicals, Inc.
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Project description:Key Points • In a phase 3 clinical trial of FL, AICDA-mediated intraclonal heterogeneity was not prognostic.• TP53 mutated populations are common, subclonal, and their absence confers sensitivity to a radiation-containing regimen. Visual Abstract Abstract Although TP53 is commonly mutated in transformed follicular lymphoma, mutations are reported in <5% of pretreatment follicular lymphoma (FL) specimens. We assayed archival follicular B-cell non-Hodgkin lymphoma specimens from a completed clinical trial, Southwest Oncology Group S0016, a phase 3 randomized intergroup trial of CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone) chemotherapy plus R-CHOP (rituximab-CHOP) compared with CHOP chemotherapy plus 131-iodine tositumomab (radioimmunotherapy [RIT]-CHOP). Subclonal TP53 mutations (median allele frequency 0.02) were found in 25% of diagnostic FL specimens and in 27% of a separate validation cohort. In the R-CHOP arm, pathogenic TP53 mutations were not associated with progression-free survival (PFS) (10-year PFS 43% vs 44%). In contrast, among patients with no detectable pathogenic TP53 mutation, RIT-CHOP was associated with a longer PFS than with R-CHOP (10-year PFS 67% vs 44%; hazard ratio = 0.49; P = .008). No relationship was detected between PFS and the extent of activation-induced cytidine deaminase (AICDA)–mediated heterogeneity. In summary, subclonal TP53 mutations are common in FL and are a distinct phenomenon from AICDA-mediated genetic heterogeneity. The absence of a detectable subclonal mutation in TP53 defined a population that particularly benefited from RIT.
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Project description:EZH2 is mutated in nearly 25% of follicular lymphoma (FL) cases. Little is known about how EZH2 affects patients' response to therapy. In this context, the aim of this study was to retrospectively analyze the frequency of mutations in EZH2 at diagnosis in tissue and ctDNA in patients with FL and to assess the patients' outcomes after receiving immunochemotherapy, depending on the EZH2 mutation status. Among the 154 patients included in the study, 27% had mutated EZH2 (46% with high-grade and 26% with low-grade FL). Of the mutated tissue samples, the mutation in ctDNA was identified in 44% of cases. EZH2 mutation in ctDNA was not identified in any patient unmutated in the tissue.Unmutated patients who received R-CHOP had significantly more relapses than patients who received R-Bendamustine (16/49 vs. 2/23, p = 0.040). Furthermore, our results show that patients with mutated EZH2 treated with R-CHOP vs. those treated with R-Bendamustine present a lower incidence of relapse (10% vs. 42% p = 0.09 at 4 years), a higher PFS (92% vs. 40% p = 0.039 at 4 years), and higher OS (100% vs. 78% p = 0.039 at 4 years). Based on these data, RCHOP could be a more suitable regimen for mutated patients, and R-bendamustine for unmutated patients. These findings could mean the first-time identification of a useful biomarker to guide upfront therapy in FL.
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