Kooperativer Bibliotheksverbund

In: Virchows Archiv, Springer Science and Business Media LLC, Vol. 467, No. 3 ( 2015-9), p. 255-263

Type of Medium: Online Resource

ISSN: 0945-6317 , 1432-2307

URL: Article

DOI: 10.1007/s00428-015-1803-y

Language: English

Publisher: Springer Science and Business Media LLC

Publication Date: 2015

detail.hit.zdb_id: 1463276-7

In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 2667-2667

Abstract: Background: Peripheral T cell lymphoma not otherwise specified (PTCL NOS) and angioimmunoblastic T cell lymphoma (AITL) together comprise approximately half of all peripheral T cell lymphomas. Malignant T cells in AITL and in a subset of PTCL-NOS exhibit a phenotype mimicking that of normal T-follicular helper (TFH) cells. Immunohistochemical (IHC) studies performed on paraffin-embedded tissues are a mainstay of diagnostic histopathology, but can be difficult to interpret when the malignant T cells show limited cytological atypia and when there are abundant infiltrating reactive T cells. Flow cytometry represents an alternate means to define the cellular immunophenotype, but requires access to single cell suspensions of viable tumor cells. Flow cytometry has certain additional benefits over IHC including highly quantitative measurement of multiple antigens simultaneously and statistical power afforded by analyzing tens of thousands of individual cells. We report here immunophenotypic characterization of a large cohort of cases of PTCL NOS and AITL using a 12-color flow cytometry assay and correlation of immunophenotypic features with clinical outcomes. Methods: Cases of PTCL-NOS and AITL spanning a 24 year period (1990-2014) for which viably frozen cell suspensions from diagnostic lymph node biopsies were available were identified within the British Columbia Cancer Agency (BCCA) lymphoma database. Cryopreserved cell suspensions were thawed and stained with a 12-color panel including 11fluorochrome-conjugated antibodies against lineage (CD45, CD19, CD3, CD4, CD8), pan-T cell (CD2, CD5, CD7), and TFH cell (CD10, CD279, CXCR5) markers, plus DAPI for gating of live cells. Flow cytometric data was acquired on a Becton Dickinson FACSAria3 instrument as part of a sorting experiment to isolate tumor cell subpopulations. Data was analyzed by conventional gating and bivariate plot display using FlowJo software and correlated with clinical outcome data. Results: 74 cases of PTCL-NOS and 55 cases of AITL were analyzed. The median age at diagnosis was 57 years (y) for PTCL NOS (male:female 1.6) and 75 y for AITL (male:female 1.0). The median follow up for living patients was 5.15 y. The median specimen viability was 36.5% (range 0.8-89.3%) and median specimen tumour content was 64.3% of viable events (range 0.98-91.8%). Aberrant T cell immunophenotypes were identified in 50 of 74 cases (68%) of PTCL NOS and 36 of 55 cases (65%) of AITL. Five specimens had more than one identifiable immunophenotypically aberrant T cell population. For the 50 PTCL NOS cases with an aberrant immunophenotype, 31 (62%) demonstrated loss of CD3 and 42 (84%) demonstrated loss of CD7. About half of cases were CD4+CD8- (27, or 54%) including 11 (22%) that exhibited a TFH-like phenotype (positive for at least 2 of the 3 assayed TFH markers), while the remaining were CD4-CD8- (23, or 46%). TFH-like cells were also identified in 11 of 24 (46%) cases lacking an aberrant T cell immunophenotype. For the 36 AITL cases with an aberrant immunophenotype, 21 (58%) demonstrated loss of CD3 and 29 (80%) demonstrated loss of CD7. The majority of cases were CD4+ (30, or 83%) including 21 (58%) that exhibited a TFH-like phenotype, while the remaining were either CD8+ (4, or 11%) or CD4-CD8- (2, or 6%). TFH-like cells were also identified in 7 of 19 (37%) cases lacking an aberrant T cell immunophenotype. Similar to other patient cohorts, the 5 y PFS and 5 y OS was 21% and 40%, respectively, for PTCL NOS and 17% and 28%, respectively, for AITL. The presence of an aberrant phenotype, CD3 status, and CD4/CD8 status were not associated with prognosis in either PTCL subtype. A preliminary analysis suggests loss of CD7 expression in PTCL NOS is associated with an inferior outcome. Analysis of archival material and exploration in a validation cohort is ongoing. Discussion: An aberrant population of varying abundance was detected in 〉 65% of specimens for PTCL NOS and AITL. The aberrant immunophenotype in PTCL NOS was evenly split between CD4+CD8- and CD4-CD8- cases. Interestingly, nearly half of CD4+ cases showed evidence of TFH-like differentiation, possibly corresponding to the TFH-like variant of PTCL NOS. The aberrant immunophenotype in AITL was typically CD4+ and often with co-expression of TFH-associated markers. Loss of CD7 and CD3 were the most common abnormalities. Loss of CD7 may demonstrate a poor-risk group of patients with inferior outcomes in PTCL NOS. Disclosures Savage: Seattle Genetics: Honoraria, Speakers Bureau; BMS: Honoraria; Infinity: Honoraria; Roche: Other: Institutional research funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V126.23.2667.2667

Language: English

Publisher: American Society of Hematology

Publication Date: 2015

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 122, No. 21 ( 2013-11-15), p. 73-73

Abstract: The diffuse large B-cell lymphoma (DLBCL) cell-of-origin (COO) distinction into germinal center B cell (GCB) and activated B cell (ABC) subtypes, as molecularly described by our group, has profound biological, prognostic, and potential therapeutic implications. New therapeutic agents with selective activity in ABC and GCB DLBCL are under development. An accurate diagnostic assay is urgently needed to qualify patients for clinical trials using targeted agents and as a predictive biomarker. Although the subtypes were originally defined using gene expression profiling on snap-frozen tissues (frozen-GEP), it has become common practice to use less precise but relatively inexpensive and broadly applicable immunohistochemical (IHC) methods in formalin-fixed paraffin-embedded tissue (FFPET). We sought to create a robust, highly accurate molecular assay for COO distinction using new GEP techniques applicable to FFPET. Studies were performed on centrally reviewed DLBCL FFPET biopsies using cases that had “gold standard” COO assigned by frozen-GEP using Affymetrix U133 plus 2.0 microarrays. The training cohort consisted of 51 cases comprising 20 GCB, 19 ABC and 12 Unclassifiable (U) cases. An independent validation cohort, consisting of 68 cases (28 GCB, 30 ABC, 10 U) drawn from the validation cohort of Lenz et al (NEJM 2008) had the typical proportions of COO subtypes seen in DLBCL populations. Nucleic acids were extracted from 10um FFPET scrolls. Digital gene expression was performed on 200ng of RNA using NanoString technology (Seattle, WA). All FFPET GEP studies were performed in parallel at two independent sites (BC Cancer Agency, Vancouver, and NCI, Frederick, MD) using different FFPET scrolls to determine inter-site concordance and assess the robustness and portability of the assay. To assign COO by IHC, tissue microarrays were made using 0.6mm duplicate cores from 60/68 validation cohort cases, and stained for CD10, BCL6, MUM1, FOXP1, GCET1 and LMO2. Two hematopathologists independently assessed the proportion of tumor cells stained, with consensus on discordant cases reached with a third hematopathologist. For the validation studies, those producing and analyzing the GEP and IHC data were blinded to the “gold standard” COO. All 119 FFPET biopsies yielded sufficient RNA. A pilot study using the training cohort identified 20 genes (15 genes of interest and 5 house keeping genes) whose expression, measured using NanoString, would allow accurate replication of the COO assignment model of Lenz et al (NEJM 2008). NanoString was then used to quantitate these 20 genes in the training cohort, allowing the COO model to be optimized. Despite the age of the FFPET blocks (6-32 years old), 95% (49/51) of the training samples gave gene expression data of sufficient quality. The model, including coefficients, thresholds and QC parameters was then “locked” and applied to the independent validation cohort. Ninety-nine percent (67/68) of the samples from the validation cohort (5-12 years old) provided gene expression of adequate quality. Three cases did not give interpretable IHC results. When considering the “gold standard” ABC and GCB cases, the COO assignments by the NanoString assay at the NCI site were 93% concordant, with 5% labeled U and 1 ABC misclassified as GCB (see table). This 2% rate of misclassification of ABC and GCB cases compares favorably with the 9%, 6% and 17% rates for the interpretable cases from the Hans, Tally and Choi algorithms, respectively. Furthermore, the 98% concordance of COO assignment (95% if “gold standard” U cases are also included) between the NCI and BC Cancer Agency sites indicates that, in contrast to the IHC algorithms, the assay is reproducible.TableNanoString GEP assay - NCIHans algorithmTally algorithmChoi algorithmGCBUABCGCBNon-GCBGCBABCGCBABCFrozen GEPGCB2800210183192U721552864ABC1325422026620 In summary, 119 well-characterized DLBCL cases from the LLMPP, previously subtyped by our published disease-defining algorithm using frozen-GEP, were used to develop a highly accurate and robust NanoString 20 gene assay, applicable to RNA from FFPET that is routinely obtained for diagnosis. This new assay shows excellent performance in archival FFPET, and the rapid turn-around time ( 〈 36 hours from FFPET block to result) will allow prospective implementation in future therapeutic trials and, ultimately, clinical practice. Disclosures: No relevant conflicts of interest to declare.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V122.21.73.73

Language: English

Publisher: American Society of Hematology

Publication Date: 2013

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 124, No. 21 ( 2014-12-06), p. 495-495

Abstract: Introduction: Recent studies have established that concurrent MYC and BCL2 protein expression by immunohistochemistry (IHC) identifies a subgroup of patients with diffuse large B-cell lymphoma (DLBCL) with a poor outcome. Classic dual translocation MYC/ BCL2, so called double hit' disease, is associated with a high risk of central nervous system (CNS) relapse; however the impact of concurrent MYC and BCL2 protein expression on the risk of CNS relapse remains unknown. Further, robust biological markers that accurately predict the risk of CNS relapse in DLBCL would also be of value in clinical practice. Methods: Cases of pre-treatment formalin fixed paraffin embedded DLBCL in two tissue microarrays were independently scored by two expert hematopathologist (GWS and KLT or PF and AM) for expression of MYC (Epitomics Y69), BCL2 (Dako 124), CD10, BCL6 and MUM1 by IHC. MYC and BCL2 positivity were defined as ≥ 40% and ≥ 50% cells with staining, respectively, in accordance with previously established cutoffs (Johnson, JCO 2012; 30). Cases with discordant scores were reviewed by a third hematopathologist (RDG) to reach a consensus. Cell of origin (COO) was assigned according to the Hans IHC algorithm (Hans, Blood 103: 2004) as well as by the recently described gene expression profiling Lymph2Cx 20 gene assay based on NanoString technology (Scott, Blood 2014; 123) in the subset of patients with ≥ 40% tumor content. Patients treated with at least one cycle of R-CHOP chemotherapy with curative intent were included and those with established CNS disease at diagnosis were excluded. Results: 447 patients were identified with the following baseline clinical characteristics: Median age 65 y (16-92y); males n=280, 63%; performance status ≥ 2, n= 147, 33%; stage 3 or 4 disease n=242, 54%; elevated LDH n=219, 47%; EN 〉 1 n= 80, 17%. With a median follow-up of 6.75 years for living patients, the 3 year time to progression, progression-free and overall survival for all patients were 68%, 66%, and 73%, respectively. In total, 131 (29%) were MYC+BCL2+ and 316 (71%) were non-MYC+BCL2+. By COO assignment using the Hans algorithm (n=444), 192 were non-GCB (43%) and 252 were GCB (57%) and by the Lymph2Cx (n=308); 103 were ABC (33%), 172 were GCB (56%) and 33 (11%) were unclassifiable. The 2 year cumulative risk of CNS relapse for the whole cohort was 4.3%. The cumulative risk of CNS relapse was higher in cases that were MYC+BCL2+ (2 year risk 9.4% vs 2.4%, P=0.001) with similar results obtained if classic MYC+BCL2+ double hit cases are excluded. There were no cases of CNS relapse in cases MYC+ alone by IHC. By COO, patients with a non-GCB phenotype by the Hans algorithm had an increased risk of CNS relapse (2 year risk 6.9% vs 2.6%, P=0.03) and similarly, cases assigned as ABC DLBCL by the Lymph2Cx assay also identified a group with a higher risk of CNS relapse compared to GCB cases (9.5% vs 2.5%, P=0.03) (Figure 1). In Cox regression multivariate analysis including the COO (Hans), IPI group (0/1 vs 2/3 vs 4/5) and MYC/BCL2 IHC, only the IPI (HR 2.18, P=0.02) and MYC+BCL2+ IHC (HR=3.76, P=0.007) were associated with an increased risk of CNS relapse. Similar results were obtained using the Lymph2Cx COO designation. Within the IPI risk groups, MYC+BCL2+ status further stratified patients in the intermediate risk group (IPI 2 or 3, n=206) into a higher risk group (2 year CNS relapse 12.6%) and a low risk group (2 year CNS relapse 2.9%) (P=0.01). A similar trend was observed in the high IPI risk group (IPI 4 or 5, n=86, 2 year CNS relapse MYC+BCL2+ 17.2% vs 4.7%, P=.0.18) but it was not useful in the low IPI risk group (IP1 0 or 1 (n=155), 2 year CNS relapse 4% vs 1%, P=0.39) where the overall risk was low. Within the COO subgroups, MYC+BCL2+ status also defined a group at high cumulative risk of CNS relapse within the non-GCB subtype (12.9% vs 3%, P=0.001) and by the Lymph2Cx defined ABC subtype (16.9% vs 2.2%, P= 0.03) and a trend was observed for GCB defined by Lymph2Cx (6.6% vs 1.5%. P=.08) but not by Hans criteria (P=0.40). Conclusion: Concurrent expression of MYC and BCL2 protein in DLBCL defines a group of patients at high risk of CNS relapse, independent of the IPI and COO. MYC+BCL2+ status may help to further risk stratify patients in the intermediate and high IPI risk groups and within the ABC subtype to identify patients who should undergo additional diagnostic testing and in whom to explore the effectiveness of prophylactic CNS strategies. Figure 1 Figure 1. Disclosures Savage: F Hoffmann-La Roche: Other. Sehn:Roche: Research Funding. Connors:Seattle Genetics, Inc.: Research Funding; Roche: Research Funding. Gascoyne:Hoffman La-Roche: Research Funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V124.21.495.495

Language: English

Publisher: American Society of Hematology

Publication Date: 2014

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 126, No. 23 ( 2015-12-03), p. 111-111

Abstract: Background: Diffuse large B cell lymphoma (DLBCL) is divided into two distinct molecular subtypes, germinal center B cell (GCB) subtype and activated B cell (ABC) subtype. Genetic landscape studies of DLBCL have revealed several GCB-DLBCL specific mutations, including CREBBP, GNA13, EZH2, TNFRSF14, BCL2 and MEF2B. Functional studies have recently shown that the inactivation of Gα13 signaling pathway genes, including GNA13, together with BCL2 over-expression, allows GC B-cells to escape the germinal center niche and widely disseminate. Although these findings revealed a critical role of genetic alterations of Gα13 signaling pathway in GC-driven mouse models of lymphomagenesis, clinical correlation is lacking. Here we analyzed the clinical impact of genetic alterations of Gα13 signaling pathway in a large population-based DLBCL cohort. Methods: We analyzed 347 newly diagnosed de novo DLBCL cases that were uniformly treated with R-CHOP at the BC Cancer Agency. Comprehensive clinical annotation was available through the BCCA Lymphoid Cancer Database. Deep targeted re-sequencing of the coding exons of GNA13, P2RY8, ARHGEF1, S1PR2 and RHOA was performed using a Truseq Custom Amplicon assay (Illumina) and/or Fluidigm Access Array chips. High-resolution copy number analyses were performed using Affymetrix SNP 6.0 arrays. Immunohistochemical staining and break-apart FISH assays for MYC and BCL2 were performed on tissue microarrays (n=332). Cell-of-origin classification was available in 331 cases, according to gene expression profiling by the Lymph2Cx assay using the NanoString platform (Scott, Blood 2014; 123) in 299 patients and the Hans algorithm (Hans, Blood 2004; 103) in 32 cases with low tumor content ( 〈 40%). Results: Using next generation sequencing, 225 SNVs and 5 Indels were detected in GNA13 (16%), P2RY8 (18%), ARHGEF1 (6%), S1PR2 (3%) and RHOA (6%). SNP 6.0 microarrays revealed heterozygous deletions in GNA13 (2%), ARHGEF1 (1%), S1PR2 (4%) and RHOA (8%), but homozygous deletion was not found in any of these five loci. GNA13, P2RY8 and ARHGEF1 mutations were significantly more frequent in the GCB subtype than ABC subtype (26% vs. 6%; p 〈 .0001, 25% vs 7%; p=.0002, and 8% vs. 5%; p=.008, respectively). 185 GCB-DLBCL cases were further analyzed for clinical correlations. In the cases with mutations of any of the five Gα13 signaling pathway genes, BCL2 over-expression (cut off; 50%) and translocation was associated with increasing stage (p=.018 and p=.005, respectively), but not in wt cases (p=.53 and p=.63, respectively). Specifically, in the cases with GNA13 and P2RY8 mutations individually, BCL2 over-expression was associated with advanced stage (stage III/IV, p=.018 and p=.037, respectively), but not in wild type (wt) cases. Importantly, BCL2 over-expression in the cases harboring Gα13 pathway mutations was not significantly associated with other poor risk features, including any other IPI factors or bone marrow involvement, indicating that genetic alterations in Gα13 signaling pathway accompanied by BCL2 over-expression might promote lymphoma dissemination into lymph nodes but not extranodal sites. With a median follow up of 6.5 years for living patients, there was no prognostic impact of harboring any isolated Gα13 pathway mutation in GCB-DLBCL patients. However, in cases with any Gα13 pathway mutations, BCL2 over-expression was significantly associated with an inferior 5y-time to progression (TTP; 90% vs 62%, p=.003) and disease-specific survival (DSS; 90% vs 71%, p=.042), but not in wt cases (Fig 1). In a Cox model of TTP including the IPI, BCL2 over-expression remained prognostic in the cases harboring any Gα13 pathway mutations (HR=4.13 [1.42-12.01], p=.009), but not in wt cases (HR=1.70 [0.62-4.68] , p=.31). In cases with any Gα13 pathway alterations including copy number loss, BCL2 over-expression was also significantly associated with an inferior TTP (HR=3.64 [1.39-9.57], p=.009) independent of IPI, but not in the cases without genetic alterations (HR=1.75 [0.57-5.34] , p=.33). Conclusions: Genetic alterations in Gα13 signaling pathway genes cooperate with BCL2 over-expression to promotes lymphoma dissemination to nodal sites and is associated with the poor outcome in GCB-DLBCL Figure 1. TTP and DSS according to BCL2 over-expression with/without Gα13 signaling pathway mutations in GCB-DLBCL patients (n=185) treated with R-CHOP Figure 1. TTP and DSS according to BCL2 over-expression with/without Gα13 signaling pathway mutations in GCB-DLBCL patients (n=185) treated with R-CHOP Disclosures Savage: Seattle Genetics: Honoraria, Speakers Bureau; BMS: Honoraria; Infinity: Honoraria; Roche: Other: Institutional research funding. Connors:Roche: Research Funding; Seattle Genetics: Research Funding. Scott:Celgene: Consultancy, Honoraria; NanoString: Patents & Royalties: Inventor on a patent that NanoString has licensed.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V126.23.111.111

Language: English

Publisher: American Society of Hematology

Publication Date: 2015

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 127, No. 18 ( 2016-05-05), p. 2182-2188

Abstract: Dual expression of MYC and BCL2 is associated with an increased risk of CNS relapse in DLBCL treated with R-CHOP.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2015-10-676700

Language: English

Publisher: American Society of Hematology

Publication Date: 2016

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 110, No. 9 ( 2007-11-01), p. 3387-3390

Abstract: Aberrant activities of JAK/STAT signaling pathways have been observed in several hematologic malignancies. Here, we show high expression of JAK2 in the tumor cells of lymphocyte-predominant Hodgkin lymphoma in 85% of cases and activation of JAK2 in 39% of cases. STAT6, which is a target of JAK2, was activated in 50% of the cases. SOCS1 controls JAK2 activity and degradation. Mutations in SOCS1 of either somatic or germ-line origin were observed in micromanipulated tumor cells of 50% of cases. Most mutations truncated SOCS1 or caused replacement of amino acids in functional important regions. Activating mutations in exon 12 of JAK2, which are frequent in myeloproliferative diseases, were not observed. In lymphocyte-predominant Hodgkin lymphoma SOCS1 function may thus be frequently impaired by mutations, and this may contribute to high JAK2 expression and activation of the JAK2/STAT6 pathway.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2007-03-082511

Language: English

Publisher: American Society of Hematology

Publication Date: 2007

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 128, No. 22 ( 2016-12-02), p. 1091-1091

Abstract: Introduction: Follicular lymphoma (FL) remains a significant clinical burden as it is an incurable disease and most patients will eventually suffer from disease progression. Two clinical events are associated with poor outcomes for patients with FL: (1) histological transformation (TFL) of their original FL into a high-grade, aggressive lymphoma subtype (2-3% of patients per year) and (2) early disease progression (PFL) where patients experience treatment failure within 2 years of receiving therapy (20% of patients). Despite recent high-throughput sequencing studies, the nature of tumor clonal dynamics leading to TFL or PFL is poorly understood and it is unknown if similar, or contrasting, modes of selection underpin these FL clinical events. Materials & Methods:We assembled a study cohort consisting of 21 patients: 15 experiencing TFL and 6 PFL. For each TFL and PFL patient, we obtained primary biopsies (T1; taken at the time of the initial FL diagnosis), biopsies at transformation/progression (T2) and matched normal samples. We performed whole genome sequencing on each specimen and identified single point mutations and copy number alterations using MutationSeq and TITAN, respectively. We compared T1 to T2 somatic mutation profiles and identified mutations associated with extinction of T1 clones and expansion of T2 clones. To validate these patterns, we selected 192 positions from each patient for deep-targeted sequencing validation (~10733X) in their T1, T2, and normal samples. We applied a statistical model (PyClone) to estimate cancer cell fraction (CCF) of each validated mutation. These CCF estimates were used to construct clonal phylogenies (Citup) and infer clonal dynamic patterns during their evolutionary histories. The Wright-Fisher model of genetic drift was used to model tumor evolution. Results: Temporal analysis of mutational burden revealed that mutational burden was significantly higher in T2 (8162 mutations ± 2146) than in T1 (6373 ± 2630) tumors for both TFL and PFL patients (Wilcox P 〈 0.001). This was independent of time interval between sampling (Spearman R2 = 0.029, P = 0.456). Mutation variant allelic fraction (VAF) distributions revealed that all distributions showed evidence of shared clonal ancestry between T1 and T2 tumors accompanied by substantial numbers of T1 and T2-specific mutations. We selected ≥ 192 mutations per patient from these distributions and performed deep-targeted amplicon sequencing, validating 96.3% of mutations and acquiring precise VAFs to infer clonal dynamics. In 13 of 15 TFL patients (87%), we observed dramatic clonal dynamics, characteristic of T2 tumors dominated by clones (or phylogenetic lineages) that were absent or extremely rare in T1 tumors ( 〈 1% CCF). Digital droplet PCR was used to confirm the existence of both scenarios (confirming a clone as rare as 2 out of approximately 105 cells). Tumor evolution modeling demonstrated that this mode of evolution was driven through positive selection for mutations that confer fitness advantages and not by genetic drift. In contrast, PFL patients exhibited markedly different patterns of clonal dynamics compared to TFL patients. 4 of 6 PFL patients (67%) harbored readily detectable clones at T1, which expanded to full clonal prevalence during treatment with immuno-chemotherapy. Tumor evolution modeling demonstrated that this mode of evolution could be explained under neutral evolutionary dynamics (drift). Conclusions: We have shown that histological transformation and early progression manifest through divergent modes of tumor evolution. As the transformation phenotype may arise after diagnosis, more frequent monitoring of these patients will be required to determine the exact timing of the evolutionary inflection point that elicits transformation. In comparison, prediction of early treatment resistance should be achievable through comprehensive characterization of the genetic and clonal composition at diagnosis; this would ultimately identify patients who may benefit from upfront alternative therapies without the need to first endure predictable early treatment failure. Disclosures Sehn: roche/genentech: Consultancy, Honoraria; amgen: Consultancy, Honoraria; seattle genetics: Consultancy, Honoraria; abbvie: Consultancy, Honoraria; TG therapeutics: Consultancy, Honoraria; celgene: Consultancy, Honoraria; lundbeck: Consultancy, Honoraria; janssen: Consultancy, Honoraria. Connors:Millennium Takeda: Research Funding; Seattle Genetics: Research Funding; F Hoffmann-La Roche: Research Funding; Bristol Myers Squib: Research Funding; NanoString Technologies: Research Funding. Scott:Janssen: Consultancy; Celgene: Consultancy; Roche: Honoraria; BC Cancer Agency: Patents & Royalties: Inventor on a patent licensed to NanoString Technologies.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood.V128.22.1091.1091

Language: English

Publisher: American Society of Hematology

Publication Date: 2016

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 921-921

Abstract: Recognizing biological heterogeneity in diffuse large B-cell lymphoma (DLBCL), significant effort has been made to define distinct molecular subgroups of prognostic importance which harbor potentially targetable biology. Reflecting this, in the recent revision of the WHO classification, DLBCL was divided into cell-of-origin molecular subtypes and a new entity was defined - high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBL-DH/TH). ~8% of tumors with DLBCL morphology are HGBL-DH/TH and all HGBL-DH/TH with BCL2 translocations (HGBL-DH/TH-BCL2) are of the GCB molecular subtype. To explore specific biology operating in HGBL-DH/TH-BCL2, we analyzed RNAseq data from 157 de novo GCB DLBCL tumors (25 being HGBL-DH/TH-BCL2) with the aim of defining gene expression signatures that distinguish such cases from other GCB-DLBCLs. We identified 104 genes that were most significantly differentially expressed between HGBL-DH/TH-BCL2 and other GCB-DLBCLs, defined as having a 95% confidence interval of the Importance Score that did not cross 0. A model constructed from the expression of these genes clustered 42 tumors into one group ("double-hit signature" positive - DHITsig pos), and 115 tumors into the DHITsig neg group. 22 tumors were HGBL-DH/TH-BCL2 within the DHITsig pos group compared with only 3 tumors in the DHITsig neg group. We next assessed the clinical impact of the DHITsig within a uniformly R-CHOP treated cohort of de novo GCB-DLBCL drawn from a population-based registry, which included the discovery cases. The DHITsig pos group had significantly inferior outcomes for time to progression (TTP) and overall survival (OS) (P & lt; 0.001 and P = 0.01, respectively) similar to ABC-DLBCL (Figs A, B). Notably, the non-HGBL-DH/TH-BCL2 cases sharing the DHITsig showed the same poor prognosis as the HGBL-DH/TH-BCL2 cases. A multivariate Cox model of TTP revealed that DHITsig remained prognostic, independent of IPI and MYC/BCL2 dual protein expression (HR = 3.1 [1.5 - 6.4], P = 0.002). We then applied this gene expression model to GCB-DLBCL in an independent dataset (n = 262 GCB-DLBCLs; Reddy et al,Cell 2017). Validating the prognostic significance, the DHITsig pos group had significantly inferior OS compared with other GCB-DLBCLs (P & lt; 0.001) similar to ABC-DLBCL (Fig C). We then sought to determine whether differentially expressed genes, according to DHITsig, could inform on the biology of the DHITsig pos group. Gene set enrichment analysis (GSEA) strongly suggested a germinal centre dark-zone (DZ) cell-of-origin for the DHITsig pos tumors with significant enrichment of DZ and light-zone (LZ) gene signatures (Victora et al, Blood 2012) in DHITsig pos and neg tumors, respectively (FDR = 0.002 and & lt; 0.001). Furthermore, the DHITsig pos group had up-regulation of pathways related to mitochondrial metabolism and RNA synthesis (both FDR & lt; 0.001). We separately identified mutations associated with DHITsig pos cases within GCB-DLBCL. In addition to the expected enrichment of MYC and BCL2 mutations, chromatin modifiers EZH2 and CREBBP, as well as RFX7 and DDX3X (mutated in Burkitt lymphoma), were more frequently mutated in DHITsig pos tumors. In contrast, mutations of TNFAIP3, MYD88 and IRF4, more typical of ABC-DLBCLs, were more prevalent in DHITsig neg tumors. To enable application to FFPE biopsies, the DLBCL90 NanoString assay was developed by translating the DHIT gene expression signature into a 30-gene module that was then added to the Lymph2Cx assay. The DLBCL90 assay was applied to 171 DLBCL tumors (including 156 from the discovery cohort), yielding 26% DHITsig pos, 64% DHITsig neg, and 10% unclassified, with a frank misclassification rate of 3% against the RNAseq comparator. The prognostic significance of the groups was maintained (Fig D). Importantly, the DHITsig neg group had a disease specific survival of 91% at 5 years. To validate the association between the DHITsig and HGBL-DH/TH-BCL2 tumors, the DLBCL90 assay was applied to 113 transformed follicular lymphoma tumors. Within the DHITsig pos group, 19/34 tumors were HGBL-DH/TH-BCL2 compared with 0/58 in the DHITsig neg group. In conclusion, we have identified a clinically and biologically distinct subgroup of GCB-DLBCL tumors that are defined by the HGBL-DH/TH-BCL2 gene signature. The translation to an assay applicable to FFPE allows exploration of its utility to guide patient management within the context of clinical trials. Figure. Figure. Disclosures Sehn: Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Roche/Genentech: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Steidl:Nanostring: Patents & Royalties: patent holding; Roche: Consultancy; Tioma: Research Funding; Seattle Genetics: Consultancy; Bristol-Myers Squibb: Research Funding; Juno Therapeutics: Consultancy. Connors:Cephalon: Research Funding; Amgen: Research Funding; F Hoffmann-La Roche: Research Funding; Roche Canada: Research Funding; Bristol Myers-Squibb: Research Funding; Janssen: Research Funding; Bayer Healthcare: Research Funding; Takeda: Research Funding; NanoString Technologies: Patents & Royalties: Named Inventor on a patent licensed to NanoString Technologies, Research Funding; Seattle Genetics: Honoraria, Research Funding; Merck: Research Funding; Genentech: Research Funding; Lilly: Research Funding. Gascoyne:NanoString: Patents & Royalties: Named Inventor on a patent licensed to NanoString Technologies. Scott:Roche: Research Funding; Celgene: Consultancy, Honoraria; NanoString: Patents & Royalties: Named Inventor on a patent licensed to NanoString Technologies, Research Funding; Janssen: Research Funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2018-99-116827

Language: English

Publisher: American Society of Hematology

Publication Date: 2018

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7

In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 3964-3964

Abstract: Background: Diffuse large B-cell lymphoma (DLBCL) is a highly heterogeneous neoplasm with 40% of patients experiencing treatment failure following immuno-chemotherapy (R-CHOP). Both cell-of-origin (COO) and presence of concurrent MYC/BCL2 rearrangements (DHIT) are significantly associated with distinct inferior outcome. Recently, next-generation sequencing (NGS) studies have uncovered distinct genetic subtypes, including a sizable ABC/GCB-independent group characterized by more frequent TP53 abnormalities. The patterns of TP53 mutations and the prognostic significance in DLBCL have been previously reported. However, such information is rarely available at the time of diagnosis as diagnosis of DLBCL for most patients is based on morphology and phenotype, assessed by immunohistochemistry (IHC). To bridge the gap between genotype and phenotype, we examined the TP53 mutational status and TP53 protein over-expression (IHC) in a large population-based DLBCL cohort uniformly treated with R-CHOP (Ennishi et al. Blood 2017 129:2760-2770). Methods: We analyzed 347 newly diagnosed de novo DLBCL cases uniformly treated with R-CHOP in British Columbia. Comprehensive clinical annotation was available through the BC Cancer Lymphoid Cancer Database. Deep targeted re-sequencing of the coding exons of TP53 was performed using a Truseq Custom Amplicon assay (Illumina) on the Miseq platform. IHC staining for TP53 (DO7), TP21, COO (Hans) and break-apart FISH assays for MYC and BCL2 were performed on tissue microarrays (n=332). COO classification was also performed using the Lymph2Cx assay (NanoString) (n=324). Strong TP53 expression (TP53+) was defined as high intensity (3/3) expression in 〉 50% of the malignant cells. Results: TP53 mutations (p53mut) were present in 72 cases (22.2%) with 84% being missense and 64% localized to the DNA binding-motifs. There were 54 TP53+ tumors by IHC (17%), of which 51 (94%) had p53mut, with a sensitivity of 70% for detection of p53mut. All but one TP53+ with p53mut (50/51 cases) had missense mutations. All TP53+ with missense p53mut (85% of all missense p53mut) showed strong nuclear expression, one recurrent nonsense p53mut showed combined cytoplasm/nuclear TP53+, while all splice site and frameshift variants were TP53+-negative. All TP53+ cases were negative for TP21; 30 (56%) cases were GCB (Hans) while 24 (44%) cases were non-GCB (Hans) and only 4 (16%) cases were DHIT. Both p53mut and TP53+ were associated with poor overall survival (OS) (p=0.004 and p=0.007, respectively) and disease-specific survival (DSS) (p=0.003 and p=0.001, respectively). In multivariate analysis with IPI, COO (Hans) and DHIT status, both p53mut and TP53+ were independent predictors of OS (HR=0.6, 95%CI=0.4-0.9, p=0.008 and HR=0.6, 95%CI=0.4-0.9, p=0.011, respectively) and DSS (HR=0.6, 95%CI=0.4-0.9, p=0.01 and HR=0.5, 95%CI=0.3-0.8, p=0.004, respectively). These results were consistent when the Lymph2Cx was used to assign COO (n = 324). Importantly, patients with TP53+ tumors showed significantly poorer outcome (OS and DSS) when compared with patients with tumors negative for TP53 stratified by both Hans COO subtypes (p=0.001 and p 〈 0.001, respectively) and DHIT tumors (p=0.02 and p=0.003, respectively). Conclusion: TP53+ shows good correlation with the presence and type of TP53 mutations and can be readily performed in routine clinical practice. TP53+ is a strong predictor of clinical outcome in DLBCL patients treated with R-CHOP and independent of IPI, COO and DHIT. TP53+ can be easily performed in current diagnostic laboratories and complements known biomarkers to better stratify DLBCL patients and potentially improve their clinical management. Figure Disclosures Villa: Roche, Abbvie, Celgene, Seattle Genetics, Lundbeck, AstraZeneca, Nanostring, Janssen, Gilead: Consultancy, Honoraria. Savage:BMS, Merck, Novartis, Verastem, Abbvie, Servier, and Seattle Genetics: Consultancy, Honoraria; Seattle Genetics, Inc.: Consultancy, Honoraria, Research Funding. Sehn:Abbvie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Verastem: Consultancy, Honoraria; Apobiologix: Consultancy, Honoraria; Janssen-Ortho: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Janssen-Ortho: Honoraria; Merck: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria. Steidl:Nanostring: Patents & Royalties: Filed patent on behalf of BC Cancer; Bristol-Myers Squibb: Research Funding; Roche: Consultancy; Bayer: Consultancy; Seattle Genetics: Consultancy; Juno Therapeutics: Consultancy; Tioma: Research Funding. Scott:Roche/Genentech: Research Funding; Celgene: Consultancy; Janssen: Consultancy, Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding.

Type of Medium: Online Resource

ISSN: 0006-4971 , 1528-0020

URL: Article

DOI: 10.1182/blood-2019-121943

Language: English

Publisher: American Society of Hematology

Publication Date: 2019

detail.hit.zdb_id: 1468538-3

detail.hit.zdb_id: 80069-7