Drivers of deep molecular response and long-term outcomes in patients with core binding factor acute myeloid leukemia.

A swimmer plot on clinical course of patients undergoing allogeneic stem cell transplant for core binding factor acute myeloid leukemia.

Acquisition of IDH2 mutations in relapsed/refractory AML is associated with worse patient outcomes.

OBJECTIVES: The presence of targeted therapy, Enasidenib, for IDH2-mutated AML underscores the importance of understanding the clonal dynamics of IDH2 mutations, which has not been elucidated. In the largest study of IDH2 clonal dynamics, we detail the IDH2-evolutionary patterns and their clinical significance. METHODS: We analyzed ~6000 patients with NGS results to identify 120 AML patients with IDH2 mutations and longitudinal NGS testing. IDH2 mutation status was recorded at diagnosis, remission, relapse, and persistent disease. RESULTS: One hundred and five patients were IDH2-positive at the initial diagnosis, and 15 acquired the mutation later. Of those 15 patients, 7 patients gained the mutation during persistent disease, 6 during relapse, and 2 at remission. Twenty-one patients (18%) who were IDH2-positive in a prior test remained IDH2-positive in remission. Twenty-four patients with IDH2-positive AML were IDH2-positive at relapse. IDH2-positive at diagnosis had better survival than IDH2 mutation acquired later in disease (P = .024). Patients who were IDH2-negative in remission had significantly improved survival (P = .002). Also, loss-of-IDH2 mutation with persistent disease had better OS (P = .035). CONCLUSIONS: There are 70% that clear IDH2 in disease remission. 12% gain IDH2 mutation later, usually in the setting of refractory/relapsed AML. These patients fared worse. Longitudinal IDH2 testing may be helpful in prognostic stratification.

Genomic characteristics and prognostic significance of co-mutated ASXL1/SRSF2 acute myeloid leukemia.

The ASXL1 and SRSF2 mutations in AML are frequently found in patients with preexisting myeloid malignancies and are individually associated with poor outcomes. In this multi-institutional retrospective analysis, we assessed the genetic features and clinical outcomes of 43 patients with ASXL1mut SRSF2mut AML and compared outcomes to patients with either ASXL1 (n = 57) or SRSF2 (n = 70) mutations. Twenty-six (60%) had secondary-AML (s-AML). Variant allele fractions suggested that SRSF2 mutations preceded ASXL1 mutational events. Median overall survival (OS) was 7.0 months (95% CI:3.8,15.3) and was significantly longer in patients with de novo vs s-AML (15.3 vs 6.4 months, respectively; P = .04 on adjusted analysis). Compared to ASXL1mut SRSF2wt and ASXL1wt SRSF2mut , co-mutated patients had a 1.4 and 1.6 times increase in the probability of death, respectively (P = .049), with a trend towards inferior OS (median OS = 7.0 vs 11.5 vs 10.9 months, respectively; P = .10). Multivariable analysis suggests this difference in OS is attributable to the high proportion of s-AML patients in the co-mutated cohort (60% vs 32% and 23%, respectively). Although this study is limited by the retrospective data collection and the relatively small sample size, these data suggest that ASXL1mut SRSF2mut AML is a distinct subgroup of AML frequently associated with s-AML and differs from ASXL1mut SRSF2wt /ASXL1wt SRSF2mut with respect to etiology and leukemogenesis.

Assessment of Clonotypic Rearrangements and Minimal Residual Disease in Lymphoid Malignancies.

CONTEXT.­: Measurable (minimal) residual disease (MRD) is an independent prognostic factor for survival outcomes in patients with lymphoid and plasma cell malignancies and has been incorporated into consensus criteria regarding treatment response, strategy, and clinical trial endpoints. clonoSEQ (a next-generation sequencing [NGS]-MRD assay) uses multiplex polymerase chain reaction and NGS to identify clonotypic rearrangements at the immunoglobulin (Ig) H, IgK, IgL, T-cell receptor (TCR)-ß, and TCR-γ loci, as well as translocated B-cell lymphoma 1/IgH and 2/IgH sequences for MRD assessment. Additionally, it can be used to confirm diagnoses of cutaneous T-cell lymphoma (CTCL). OBJECTIVE.­: To review the technical aspects of our experience using the clonoSEQ Assay in routine clinical practice. DESIGN.­: In this single-center experience, 390 patients with lymphoid and plasma cell malignancies were assessed with the NGS-MRD Assay at a central laboratory. RESULTS.­: Median time from arrival of the shipment to initiation of the assay (defined as captured in Adaptive's secure tracking system) was 2.1 hours. Overall, 317 patients had 1 or more samples submitted for sequence identification. Of these, 290 (91.5%) had trackable sequences identified. The median calibration rate of samples by malignancy (where n ≥ 10 samples, excluding CTCL samples) was 88.1%, across a variety of fresh and archived sample sources (177 of 201 samples). TCR-ß and/or TCR-γ clonotypes were identified in 40 of 95 samples (42.1%) from 66 patients with suspected CTCL. CONCLUSIONS.­: This NGS-MRD Assay is a valuable and sensitive tool for monitoring MRD in patients with plasma cell and lymphoid malignancies and assisting in the diagnosis of CTCL.

Post-transplant relapse of therapy-related MDS as gastric myeloid sarcoma: Case report and review of literature.

INTRODUCTION: Myelodysplastic syndrome (MDS) are hematologic neoplasms characterized by morphologic dysplasia and ineffective hematopoiesis in the bone marrow. The only potentially curative therapy is stem cell transplant. However, relapse remains a major challenge and is seen in about 25-40% of cases. Myeloid sarcoma presenting as relapse post allogeneic transplant for myeloid neoplasms is rare. We report the sentinel case of a patient with MDS who relapsed as gastric myeloid sarcoma 1 ½ years after allogeneic stem cell transplant. CASE PRESENTATION: Sixty-nine-year-old male who was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in 2006 and transitional cell bladder carcinoma in 2008. In 2011, he developed therapy-related myeloid neoplasm t(7;22) and no excess blasts. He was treated with Vidaza followed by a MUD hematopoietic stem cell transplant on 8/24/2012. In 2013 the patient developed anorexia and gastric biopsies showed severe gastritis. Repeat gastric biopsy on 02/05/2014 showed an extensive mononuclear infiltrate which could easily be confused with lymphocytes but staining showed myeloid sarcoma. Marrow was negative. The patient remained refractory to therapy and expired 08/10/2016. CONCLUSION: In summary, we report the first case of GI relapse of MDS as a myeloid sarcoma post-transplant. We seek to alert our audience of this potentially serious diagnostic pitfall, particularly one that can be relatively easily resolved on the basis of immunohistochemical profiling.

Concurrent mutations in other epigenetic modulators portend better prognosis in BCOR-mutated myelodysplastic syndrome.

INTRODUCTION: The role of single mutations has been extensively studied myelodysplastic syndromes (MDS), but the impact of genetic aberrations in the context of other mutations is less well understood. BCOR is an epigenetic transcriptional corepressor. In MDS, BCOR mutations are rare and certain mutations are associated with poor prognosis. Our aim was to investigate the role of concurrent mutations in epigenetic MDS-driver genes in BCOR-mutated MDS. We hypothesised that these would be redundant and would not contribute to worse prognosis. METHODS: Internal Next Generation Sequencing (NGS) database with targeted genetic profiling of >4000 tumor cases was queried to locate cases of MDS with BCL6 Corepressor protein (BCOR) mutations only (pBCOR) and cBCOR (comutated epigenetic modulators: TET2, ASXL1, DNMT3A, EZH2, IDH2, IDH1, BCORL1, ATRX). Overall survival was determined by chart review. Fischer's exact test and unpaired t-test was performed for statistical analysis. RESULTS: 25 patients with cBCOR were detected. Only five MDS patients with pBCOR were found. The number of patients with comutations (cBCOR) in epigenetic modulators comprised TET2 (n=5), ASXL1 (n=9), DNMT3A (n=11), EZH2 (n=2), IDH2 (n=4), IDH1 (n=1), BCORL1 (n=3), ATRX (n=1). cBCOR overall survival was 23.8 months versus 11.8 months for pBCOR group. CONCLUSIONS: In this study, we confirm the rarity of BCOR mutations. Our results show that there is a trend towards poorer prognosis in patient with pBCOR versus cBCOR although statistical significance was not reached. This may be due to enrichment of poor cytogenetics in pBCOR or increased responsiveness to hypomethylating agents in cBCOR. Larger studies are needed to validate our data.

Detection of Novel t(12;17)(p12;p13) in Relapsed Refractory Acute Myeloid Leukemia by Anchored Multiplex PCR(AMP)-based Next-Generation Sequencing.

Although several technologies can be used to detect gene fusions, anchored multiplex PCR next-generation sequencing (AMP-NGS) offers the advantage of novel fusion detection and the ability to multiplex multitudinous genes. We applied AMP-NGS technology in the evaluation of a 56-year-old gentleman with myelodysplastic syndrome transformed acute myeloid leukemia (AML). Patient was initially diagnosed with low-risk myelodysplastic syndrome-refractory cytopenias and multilineage dysplasia (MDS-RCMD), progressed to AML after failing hypomethylating agent therapy. At progression patients had normal cytogenetics but NGS profiling showed ETV6 c.416_417del CT frame shift and U2AF1 S34F mutations. Patient attains brief remission of 2 months after induction chemotherapy and then he was refractory to 2 salvage chemotherapy regimens. Reassessment after failing second salvage, identified t(12;17)(p13;p13)[20] by karyotype. It was postulated that the 12p13 locus might represent a new rearrangement of ETV6. AMP-NGS confirmed involvement of the ETV6 with discovery of a novel fusion partner, HIC1. The detection of the novel fusion partners was supported by the breakpoints originally observed by karyotype. This discovery of ETV6-HIC1 gene fusion by AMP-NGS technology provided new insight into a leukemogenic pathway in AML. Future use of this technology can serve as an adjunct tool in workup of patients with AML and can also help in formulating therapeutic strategies.

Transformation of T-Cell Acute Lymphoblastic Lymphoma to Peripheral T-Cell Lymphoma: A Report of Two Cases.

Nonhepatosplenic/noncutaneous γδ peripheral T-cell lymphoma (NHNCγδ PTCL) represents a miscellaneous group of unrelated T-cell lymphomas of which only isolated cases have been reported. We describe two cases of transformation from T-lymphoblastic leukemia/lymphoma to NHNCγδ PTCL. Transformation into more aggressive disease is a rare event in T-cell lineage-derived hematologic malignancies compared to B-cell neoplasms. Nevertheless, both of our cases involved relapse as PTCL manifested with skin involvement and an overt shift from blastic morphology to large granular leukemia-like mature T cells. Among other notable molecular characteristics, expression of immature markers such as TdT was lost in both cases. Based on cytogenetics, phenotype, and morphology, both patients represent a novel phenomenon of clonal transformation from T-ALL to PTCL which has rarely been reported in the literature. Such transformation may carry important diagnostic and biological implications.

Sentinel case of Richter transformation from chronic lymphocytic leukaemia/small lymphocytic lymphoma to CD3+ diffuse large B-cell lymphoma.

AIM: To report the first case of a Richter syndrome where small lymphocytic lymphoma (SLL) progressed to a CD3+ diffuse large B-cell lymphoma (DLBCL). METHODS: Macrodissection of small and large cell lymphomatous components was performed. This was followed by flow cytometric analysis along with molecular B-cell immunoglobulin (heavy and light chains) and T-cell receptor (γ and ß chains) gene rearrangement studies to investigate a clonal relationship between the components. RESULTS: The immunophenotypic profile was similar between small and large cell components of the lymphoma by flow cytometry. Furthermore, shared clonal peaks were observed between both components based on molecular B-cell and T-cell receptor gene rearrangement studies, confirming a clonal relationship. CONCLUSIONS: Chronic lymphocytic leukaemia/SLL may rarely undergo Richter transformation to a DLBCL demonstrating lineage infidelity. This is a potentially important diagnostic pitfall and such cases should not be confused with a de novo T-cell lymphoma.

CD4-positive diffuse large B-cell lymphoma: A variant with aggressive clinical potential.

CD4 expression is rare in diffuse large B-cell lymphoma (DLBCL), with 4 previously reported cases. Its significance is uncertain. We report five patients with CD4(+) DLBCL and one CD4(+) primary mediastinal large B-cell lymphoma. Cases were identified by searching the electronic database of the department; each was reviewed. Average age was 56 years. Neoplastic cells expressed CD20 (5/6 tested cases). BCL2/BCL6 expression were seen in 3/3 tested cases, suggesting a germinal center origin. Additionally, expression of T-cell antigens CD2 and CD5 was noted in 2/2 and CD7 in 1/1 tested case. CD3 was negative in all. Lymph nodes were commonly involved (67%). Patients received chemotherapy +/- radiation (6/6) and bone marrow transplant (2/6). Average survival was 44.2 mo. CD4 expression in DLBCL raises questions of lineage commitment. CD4(+) DLBCL is rare; care should be exercised not to diagnose these as T-cell lymphomas. A subset behaves aggressively.