ALBERT

Beschreibung: Introduction: Diffuse large B-cell lymphoma (DLBCL) is an aggressive and heterogeneous disease that is characterized by recurrent translocations and somatic mutations. The prognosis of DLBCL has been associated with clinical features, cell-of-origin (COO) and genetic aberrations. The aim of this study was to determine whether somatic mutations are associated with overall survival (OS) in patients with DLBCL who have been treated with R-CHOP, and whether these mutations can be incorporated into a model to better predict survival. Methods: We identified 340 patients between 2000-2016 from two institutions with a diagnosis of de novo DLBCL treated with R-CHOP. A custom targeted panel with 334 genes which included frequently mutated genes in B-cell lymphoma was used and the captured DNA was sequenced on an Illumina HiSeq 2500. Cases were evaluated by immunohistochemistry (IHC: Hans algorithm; MYC and BCL2 expression), nCounter Nanostring (Lymph2Cx), and FISH analysis for BCL2, BCL6, and MYC rearrangement. OS was estimated using the Kaplan-Meier method. Multivariant modeling of OS was performed incorporating clinical features, IHC, COO by Nanostring, FISH, and mutation status of the most frequently mutated genes (≥5%). LASSO regression was performed to select for significant variables and determine coefficients for these variables and risk scores were calculated based on various fitted models. Concordance C-index was used to assess the discriminatory ability of different models, and three risk groups were determined by stratifying the risk scores in the final model. Results: 199 patients (median age 60 years, M:F ratio 1.4:1) had complete clinical and sequencing data. The germinal center B-cell phenotype (GCB) was more common (69%) than the activated B-cell phenotype (ABC; 26%), and 5% were unclassified by COO. The most frequently mutated genes were KMT2D (31%), CREBBP (21%), and TP53 (20%). Double/triple-hit (DH) lymphomas comprised of 11% of the cases, and 13% were double-protein expressors (MYC and BCL2) only. Significant variables selected by LASSO included factors in the IPI, FISH analysis, and 3 mutated genes (KMT2D, PIM1, and MEF2B). A formula was developed using the individual factors (elevated LDH, age ≥60 years, presence of extranodal sites, stage ≥ 3, male, DH status, and mutations in KMT2D, PIM1, and/or MEF2B. A three risk group model (m3D-IPI) was constructed based on these significant variables and its coefficients were superior in discriminating OS compared to the IPI alone (C-index: 0.830 vs. 0.775; Figures A and B). Within IPI group 3 (Figure C), Lasso 3 (high risk) identified patients that had a poor prognosis (p=0.022). In IPI group 4 (Figure D), Lasso 2 (intermediate risk) identified patients that had a better prognosis (p=0.0074). A simplified risk model using the same variables was also developed by assigning one point for each variable present, and these findings were validated in an independent cohort of DLBCL (Reddy et al, Genetic and Functional Drivers of Diffuse Large B Cell Lymphoma. Cell 2017;171(2):481-94). Conclusion: In this study, we incorporated mutation analysis of select genes with clinical risk factors and developed an improved risk model for patients with DLBCL treated with first-line therapy. Disclosures Herrera: Pharmacyclics: Consultancy, Research Funding; Gilead Sciences: Research Funding; Merck, Inc.: Consultancy, Research Funding; AstraZeneca: Research Funding; KiTE Pharma: Consultancy, Research Funding; Seattle Genetics: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Immune Design: Research Funding.

Beschreibung: Background: In diffuse large B-cell lymphoma (DLBCL), the presence of MYC and BCL2 and/or BCL6 translocations, so-called double-hit lymphoma (DH), has been associated with an aggressive clinical course. Recently, it was reported that gene expression profiling (GEP) could also identify cases with the biological and clinical characteristics of DH lymphoma, including some without the requisite translocations (DHITsig-positive cases)1. The purpose of this study was to develop a molecular subtyping schema for germinal center B-cell type (GCB) DLBCL using genomic studies such as fluorescence in situ hybridization (FISH) cytogenetic analysis, GEP, and mutation analysis to risk-stratify patients with GCB DLBCL. Method and Results: We performed a detailed genomic analysis of 87 cases of de novo GCB DLBCL to identify characteristics that are associated with survival in those treated with R-CHOP. The cases were extensively characterized by combining the results of immunohistochemistry, cell-of-origin GEP (Nanostring), DH GEP (DLBCL90)1, FISH cytogenetic analysis for DH lymphoma, copy number analysis (CNA), and targeted deep sequencing using a custom mutation panel of 334 genes. These studies were used to divide the cases into four groups. GCB1: DHITsig-positive with TP53 inactivation (DHIT+TP53): DLBCL with TP53 mutations and/or deletions has a poor prognosis in patients treated with R-CHOP. We found 7 cases (8% of all cases) of GCB DLBCL that were DHITsig-pos with TP53 abnormalities. By FISH analysis, two cases had a triple-hit (TH), one was DH with MYC/BCL2, and 2 cases had a MYC translocation only. Cases in GCB1 had the worst overall survival (OS; Hazard Ratio (HR)=9.2, P=0.0018) and shortest progression-free survival (PFS; HR=6.1, P=0.002) compared to other groups (Figures 1 A/B). However, cases with TP53 abnormalities that were DHITsig-neg did not have the same poor survival. GCB2: DHITsig-positive (DHITsig-pos): The other 8 cases (9%) who were DHITsig-pos from the DBLCL90 GEP but lacked TP53 abnormalities showed a predilection (88%) for having an EZH2 mutation and/or BCL2 translocation (EZB of Schmitz et al2). These cases also had a high frequency of MYC mutations (63%) but lacked mutations in SGK1 and had a low frequency of mutations in linker histone genes (e.g. HIST1H1E). By FISH analysis, 3 cases were DH lymphoma with MYC/BCL2, 2 cases were TH lymphoma, and 1 case had a MYC translocation only. Typically DHITsig-pos cases have a poor OS when compared to DHITsig-neg cases1, however this group demonstrated good survival in our study, after removing the cases with TP53 abnormalities. GCB3: DHITsig-negative and EZH2 mutation and/or BCL2 translocation (EZB-like): We had 28 cases (32%) that were DHITsig-neg and had an EZH2 mutation and/or BCL2 translocation. These were categorized as EZB-like with some overlapping features with the DLBCL in Cluster 3 of Chapuy et al3. The survival of this group was intermediate compared to the other groups (Figures 1A/B). GCB4: DHITsig-negative and not EZB-like (GCB Other): The largest group of cases (51%) were DHITsig-neg and lacked EZH2 mutations and BCL2 translocations. These cases had frequent mutations in SGK1 (16%) and histone modifying genes (50%), as well as TET2 mutations (25%). These cases have similarities to Cluster 4 of Chapuy et al3 and the ST2 group from Wright et al4. The survival of this group was excellent (Figures 1 A/B). These groups were validated in an independent cohort of 188 cases of GCB DLBCL4 (Figures 1 C/D). Conclusions: We have identified four distinct biologic subgroups of GCB DLBCL with different survival rates, and with similarities to the genomic classifications from recent large retrospective studies of DLBCL. Patients with the DH signature but no abnormalities of TP53 (GCB2), and those lacking EZH2 mutation and BCL2 translocation (GCB4), had an excellent prognosis. However, patients with an EZB-like profile (GCB3) had an intermediate prognosis, whereas those with TP53 inactivation combined with the DH signature (GCB1) had an extremely poor prognosis. We propose this as a practical schema to risk-stratify patients with GCB DLBCL. This schema provides a promising new approach to identify high-risk patients for new and innovative therapies. Figure 1 Disclosures Herrera: AstraZeneca: Research Funding; Karyopharm: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Other: Travel, Accomodations, Expenses, Research Funding; Gilead Sciences: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Immune Design: Research Funding; Pharmacyclics: Research Funding. Zain:Kyowa Kirlin: Research Funding; Mundai Pharma: Research Funding; Seattle Genetics: Research Funding. Popplewell:Pfizer: Research Funding; Novartis: Research Funding; Roche: Research Funding. Kwak:Celltrion Healthcare: Membership on an entity's Board of Directors or advisory committees; CJ Healthcare: Consultancy; Sellas Life Sciences Grp: Consultancy; Enzychem Life Sciences: Membership on an entity's Board of Directors or advisory committees; Antigenics: Other: equity; InnoLifes, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pepromene Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Xeme Biopharma/Theratest: Other: equity; Celltrion, Inc.: Consultancy. Scott:NIH: Consultancy, Other: Co-inventor on a patent related to the MCL35 assay filed at the National Institutes of Health, United States of America.; Roche/Genentech: Research Funding; Celgene: Consultancy; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoString, Research Funding; Abbvie: Consultancy; AstraZeneca: Consultancy; Janssen: Consultancy, Research Funding.