Low T-cell proportion in the tumor microenvironment is associated with immune escape and poor survival in diffuse large B-cell lymphoma.

The tumor microenvironment (TME) is important in the pathogenesis and prognosis of lymphoma. Previous studies have demonstrated that features of the diffuse large B-cell lymphoma (DLBCL) TME can be associated with prognosis, but questions remain about the mechanisms underlying these TME features, and the interplay between tumor cells and the local TME. Therefore, we performed multispectral immunofluorescence (mIF) using two 6-color panels to interrogate the cellular proportions of T-cell subsets, macrophages, and natural killer cells in 57 cases of de novo DLBCL treated with R-CHOP chemotherapy. We found that very low CD3+ T-cell proportion and low CD4+PD1+ and CD8+PD1+ T cells have poor survival compared to those with a high T-cell proportion. Also, cases with concurrently low TIM3 and PD1 have a poor prognosis. This poor prognosis with low T-cell proportion was validated using immune deconvolution of gene expression profiling data from 351 cases of DLBCL and an additional cohort of 53 cases of DLBCL using routine immunohistochemistry. In addition, cases with loss of B2M, HLA I and/or HLA II protein expression on the tumor cells also had a low T-cell proportion, providing evidence that lack of these proteins allows for immune evasion. Overall, our results show that patients with DLBCL with a low T-cell proportion in the TME have a poor survival when treated with R-CHOP and exhibit mechanisms of immune escape.

Long-Term Outcomes of Patients with Acute Myelogenous Leukemia Treated with Myeloablative Fractionated Total Body Irradiation TBI-Based Conditioning with a Tacrolimus- and Sirolimus-Based Graft-versus-Host Disease Prophylaxis Regimen: 6-Year Follow-Up from a Single Center.

Cyclophosphamide (Cy)/etoposide combined with fractionated total body irradiation (FTBI) or i.v. busulfan (Bu) has been the main conditioning regimens for allogeneic hematopoietic cell transplantation (alloHCT) for young patients with acute myelogenous leukemia (AML) eligible for a myeloablative conditioning (MAC) regimen. Recent data has suggested that i.v. Bu could be the preferred myeloablative regimen in patients with myeloid malignancies. However, Bu-based regimens are associated with higher rates of sinusoidal obstruction syndrome. Here we report long-term survival outcomes of patients with AML receiving FTBI combined with Cy or etoposide before undergoing alloHCT at City of Hope (COH). We obtained a retrospective review of a prospectively maintained institutional registry of clinical outcomes in 167 patients (median age, 41 years; range, 18 to 57 years) with AML in first or second complete remission who underwent alloHCT at COH between 2005 and 2015. Eligible patients received a MAC regimen with FTBI (1320 cGy) and Cy (120 mg/kg) for unrelated donor transplantation or etoposide (60 mg/kg) for related donor transplantation. Graft-versus-host disease (GVHD) prophylaxis was provided with tacrolimus and sirolimus. In this retrospective study, 6-year overall survival was 60% and nonrelapse mortality was 15%. The GRFS rate was 45% at 1 year and 39% at 2 years. We also describe late metabolic effects and report the cumulative incidence of secondary malignancies (9.5%). Overall, in this young adult patient population, our results compare favorably to chemotherapy-based (i.v. Bu) conditioning regimens without significant long-term toxicity arising from TBI-based regimens.

Outcomes after Allogeneic Stem Cell Transplantation in Patients with Double-Hit and Double-Expressor Lymphoma.

Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are associated with resistance to frontline and salvage immunochemotherapy, as well as autologous stem cell transplantation (SCT). We hypothesized that allogeneic SCT (alloSCT) could overcome the chemoresistance associated with DEL/DHL. We retrospectively studied the impact of DEL/DHL status in a multicenter cohort of patients who underwent alloSCT for relapsed/refractory (rel/ref) aggressive B cell non-Hodgkin lymphoma (B-NHL). Seventy-eight patients transplanted at 3 centers in whom tumor tissue was available for immunohistochemistry and fluorescence in situ hybridization were enrolled; 47% had DEL and 13% had DHL. There were no significant differences in 4-year progression-free (PFS) or overall survival (OS) between patients with DEL compared with patients without DEL (PFS 30% versus 39%, P = .24; OS 31% versus 49%, P = .17) or between patients with DHL compared with patients without DHL (PFS 40% versus 34%, P = .62; OS 50% versus 38%, P = .46). The lack of association between DEL or DHL and outcome was confirmed in multivariable models, although inadequate sample size may have limited our ability to detect significant differences. In our cohort alloSCT produced durable remissions in patients with rel/ref aggressive B-NHL irrespective of DEL and DHL status, justifying its consideration in the treatment of patients with rel/ref DEL/DHL.

Favorable impact of allogeneic stem cell transplantation in patients with therapy-related myelodysplasia regardless of TP53 mutational status.

Therapy-related myelodysplastic syndrome is a long-term complication of cancer treatment in patients receiving cytotoxic therapy, characterized by high-risk genetics and poor outcomes. Allogeneic hematopoietic cell transplantation is the only potential cure for this disease, but the prognostic impact of pre-transplant genetics and clinical features has not yet been fully characterized. We report here the genetic and clinical characteristics and outcomes of a relatively large cohort of patients with therapy-related myelodysplastic syndrome (n=67) who underwent allogeneic transplantation, comparing these patients to similarly treated patients with de novo disease (n=199). The 5-year overall survival was not different between patients with therapy-related and de novo disease (49.9% versus 53.9%; P=0.61) despite a higher proportion of individuals with an Intermediate-2/High International Prognostic Scoring System classification (59.7% versus 43.7%; P=0.003) and high-risk karyotypes (61.2% versus 30.7%; P<0.01) among the patients with therapy-related disease. In mutational analysis, TP53 alteration was the most common abnormality in patients with therapy-related disease (n=18: 30%). Interestingly, the presence of mutations in TP53 or in any other of the high-risk genes (EZH2, ETV6, RUNX1, ASXL1: n=29: 48%) did not significantly affect either overall survival or relapse-free survival. Allogeneic stem-cell transplantation is, therefore, a curative treatment for patients with therapy-related myelodysplastic syndrome, conferring a similar long-term survival to that of patients with de novo disease despite higher-risk features. While TP53 alteration was the most common mutation in therapy-related myelodysplastic syndrome, the finding was not detrimental in our case-series.

Cyclin D1 expression in peripheral T-cell lymphomas.

Cyclin D1 is an important regulator of the cell cycle and overexpression of this protein by immunohistochemistry is characteristically seen in mantle cell lymphoma and other B-cell neoplasms. However, little is known about the expression of this protein in T-cell lymphomas. Cyclin-dependent kinase pathway inhibitors are in development, therefore identifying cyclin D1-positive T-cell lymphomas may provide a therapeutic target in a disease where novel treatments are urgently needed. We collected 200 peripheral T-cell lymphomas from three institutions including the following types of cases: 34 anaplastic large cell lymphoma, ALK+, 44 anaplastic large cell lymphoma, ALK negative, 68 peripheral T-cell lymphomas, not otherwise specified, 24 angioimmunoblastic T-cell lymphomas, 7 extranodal NK/T-cell lymphomas, 4 enteropathy associated T-cell lymphomas, 3 hepatosplenic T-cell lymphomas, 12 cutaneous T-cell lymphomas, and 4 large granular lymphocytic leukemias. Immunohistochemical stains for cyclin D1 protein (SP4 clone) were performed on paraffin-embedded tissue. In a subset of cases, IGH/CCND1 fluorescence in situ hybridization analysis was also performed. Cyclin D1 staining was predominantly seen in anaplastic large cell lymphoma, including 8 of 34 cases with ALK+ anaplastic large cell lymphoma (24%), and 3 of 44 cases of ALK-negative (7%) anaplastic large cell lymphoma. Three cases of peripheral T-cell lymphoma, not otherwise specified, were also positive (3/68, 4%). All other T-cell lymphomas were negative for cyclin D1. In four of the cyclin D1-positive T-cell lymphomas by immunohistochemistry, fluorescence in situ hybridization analysis was negative for IGH/CCND1 translocation or extra copies of the CCND1 gene. Cyclin D1 overexpression by immunohistochemistry is not limited to B-cell lymphomas and is also observed in some peripheral T-cell lymphomas, particularly in anaplastic large cell lymphoma, ALK+. Cyclin D1 expression was not associated with extra copies or translocation of the CCND1 gene. Cyclin D1 overexpression may be the result of a post-translational phenomenon and may represent a potential therapeutic target using agents that target the cyclin-dependent kinase pathway.

Late relapses following reduced intensity allogeneic transplantation in patients with multiple myeloma: a long-term follow-up study.

We analysed the long-term outcomes of 60 multiple myeloma patients who underwent reduced intensity allogeneic stem cell transplantation between August 2000 and March 2008. Regimens included fludarabine and melphalan conditioning (flu-mel regimen) for allogeneic haematopoietic cell transplant (HCT) or a planned tandem regimen consisting of high-dose melphalan conditioning for autograft followed by low-dose total body irradiation conditioning for allogeneic HCT (auto-allo regimen). Donors included human-leucocyte-antigen-matched siblings (n = 55) or matched unrelated donors (n = 5). With a median follow-up of 9·8 years, 7-year overall survival (OS) and progression-free survival (PFS) were 60% and 31%, respectively. By multivariate Cox regression analysis, disease status of complete response (CR) or partial response (PR) at transplant and the presence of chronic graft-versus-host disease were significantly associated with improved OS. Only disease status was significantly associated with improved PFS. We noted a surprising number of very late relapses, with six patients (10%) relapsing between 6 and 12 years post-transplant. Among the six late relapse patients, all were transplanted within 14 months of diagnosis, five had normal karyotypes, and five were in CR/PR. Our data provide additional evidence that, while survival may be extended by reduced intensity allogeneic transplant, ultimately, it may not offer a cure.

High-grade B-cell lymphoma with concurrent MYC rearrangement and 11q aberrations: clinicopathologic, cytogenetic, and molecular characterization of 4 cases.

High-grade B-cell lymphoma with 11q aberrations (LBL-11q) resembles Burkitt lymphoma (BL), is negative for MYC rearrangement, and harbors chromosome 11q aberrations. Rare cases of high-grade B-cell lymphoma with concurrent MYC rearrangement and 11q aberrations (HGBCL-MYC-11q) have been described. In this study, we report the clinicopathologic, cytogenetic, and molecular findings in 4 such cases. Diagnoses were made on tissue or bone marrow biopsies. Karyotype, fluorescence in situ hybridization, genomic microarray analyses, and next-generation sequencing were performed. All patients were male (median age, 39 years). Three cases were diagnosed as BL, while one was diagnosed as diffuse large B-cell lymphoma. Karyotypes (available in 2 patients) were complex. In 1 patient, copy number analysis showed gains at 1q21.1-q44 and 13q31.3 and loss of 13q34, abnormalities typically seen in BL. All of our cases showed 2 or more mutations that are recurrent in BL, including ID3, TP53, DDX3X, CCND3, FBXO1, and MYC. Two cases showed a GNA13 mutation, commonly seen in LBL-11q. Cases of HGBCL-MYC-11q display overlapping morphologic and immunophenotypic, as well as cytogenetic and molecular features between BL and LBL-11q, with a mutational landscape enriched for mutations recurrent in BL. Concurrent MYC rearrangement with 11q abnormalities is important to recognize, especially as it has implications for their classification.

Sequential bortezomib, dexamethasone, and thalidomide maintenance therapy after single autologous peripheral stem cell transplantation in patients with multiple myeloma.

We report feasibility and response results of a phase II study investigating prolonged weekly bortezomib and dexamethasone followed by thalidomide and dexamethasone as maintenance therapy after single autologous stem cell transplantation (ASCT) in patients with multiple myeloma. Within 4 to 8 weeks of ASCT, patients received weekly bortezomib and dexamethasone for six cycles, followed by thalidomide and dexamethasone for six more cycles. Thalidomide alone was continued until disease progression. Forty-five patients underwent ASCT. Forty patients started maintenance therapy; of these, 36 patients received four cycles, and 32 completed six cycles of maintenance bortezomib. Of these 40 patients, nine (22%) were in complete response (CR) before ASCT, 13 (32%) achieved CR after ASCT but before bortezomib maintenance therapy, and 21 (53%) achieved CR after bortezomib maintenance therapy. Nine patients not previously in CR (33%) upgraded their response to CR with bortezomib maintenance. At 1 year post-ASCT, 20 patients achieved CR, and two achieved very good partial response. Twenty-seven patients experienced peripheral neuropathy during bortezomib therapy, all grade 1 or 2. Our findings indicate that prolonged sequential weekly bortezomib, dexamethasone, and thalidomide maintenance therapy after single ASCT is feasible and well tolerated. Bortezomib maintenance treatment upgraded post-ASCT CR responses with no severe grade 3/4 peripheral neuropathy.

Quantitative Impact of the 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) Practice Guideline Update on Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: A Systematic Analysis.

CONTEXT.­: The global impact of the new 2018 American Society of Clinical Oncology/College of American Pathologists human epidermal growth factor receptor 2 (HER2) practice guideline update on the overall HER2 status designation, compared with the prior 2013 iteration, is unknown. OBJECTIVES.­: To report the quantitative impact of the new guideline on HER2 status distribution. DESIGN.­: The analysis comprised a retrospective cohort of patients from the authors' institution, combined with other peer-reviewed publications that assessed the impact of the 2018 guideline in relation to the 2013 guideline. RESULTS.­: Our study revealed that the new guideline led to an average 9% reclassification rate for the overall HER2 status, with a net gain in overall HER2 negative designation. This is largely due to reclassification of the equivocal (Group 4) groups. Unexpectedly, infrequent but consistent discordance between Group 1/5 and fluorescence in situ hybridization results are observed across studies (1.8%; 73 of 3965 cases where fluorescence in situ hybridization and immunohistochemistry are both reported). CONCLUSIONS.­: Early clinical recognition of these resultant changes, including emerging issues of tumor heterogeneity, and potential discordance between immunohistochemistry to fluorescence in situ hybridization, is important for accurate clinical assessment of individual HER2 test results.

Validation of the Double-Hit Gene Expression Signature (DLBCL90) in an Independent Cohort of Patients with Diffuse Large B-Cell Lymphoma of Germinal Center Origin.

The prognosis of diffuse large B-cell lymphoma (DLBCL) has been associated with clinical parameters, cell of origin, and various genetic aberrations. Recently, a NanoString gene expression assay (DLBCL90) was developed, which identifies DLBCL cases with an outcome similar to those with double- or triple-hit DLBCL with both MYC and BCL2 rearrangements. This study validates the predictive ability of the DLBCL90 assay in an independent cohort of patients with the germinal center B-cell subtype DLBCL. A customized targeted sequencing panel was used to analyze the mutational profile in these patients. Cases with a double or triple hit by conventional fluorescence in situ hybridization cytogenetic analysis are known to have a poor prognosis, and the DLBCL90 gene expression signature identified these cases, as well as additional cases that would have otherwise been missed by fluorescence in situ hybridization analysis. Our findings validate use of the DLBCL90 assay for identifying high-risk patients for new and innovative therapies.

Relative frequency and clinicopathologic characteristics of MYC-rearranged follicular lymphoma.

MYC rearrangement is a relatively rare genetic abnormality in follicular lymphoma (FL). In this study, we evaluated the relative frequency of MYC rearrangement in 522 cases of FL and studied their clinicopathologic, cytogenetic, and molecular characteristics. Fluorescence in situ hybridization studies for MYC (break-apart probe), MYC/IGH, IGH/BCL2, and BCL6 rearrangements were performed on tissue microarrays. Immunohistochemical stains for CD10, BCL2, BCL6, and MYC were performed and scored on MYC-rearranged cases. On 4 FL cases, a custom targeted panel of 356 genes was used for mutation analysis. Ten cases (1.9%) were positive for MYC rearrangement. Histologically, 6 of 10 cases were grade 1-2, and 4 cases were grade 3A. By immunohistochemistry, 9 of 9 tested cases were CD10+, all cases were BCL6+, and 9/10 cases were BCL2+. MYC protein staining was low in all cases tested. IGH/BCL2 rearrangement was detected in 5 of 9 cases, whereas BCL6 rearrangement was detected in 3 of 7 tested cases and 4 of 10 cases showed MYC/IGH rearrangement. The most commonly detected mutations in the MYC-positive cases included HLA-B, TNFRSF14, and KMT2D. MYC and/or B2M abnormalities were detected in 2 cases. In conclusion, MYC rearrangement is uncommon in FL and these cases do not appear to have specific histologic characteristics. Molecular analysis showed abnormalities in genes associated with transformation, namely MYC and B2M. Larger studies are needed to evaluate if MYC-rearrangement in FL has prognostic significance.

Double-hit Signature with TP53 Abnormalities Predicts Poor Survival in Patients with Germinal Center Type Diffuse Large B-cell Lymphoma Treated with R-CHOP.

PURPOSE: We performed detailed genomic analysis on 87 cases of de novo diffuse large B-cell lymphoma of germinal center type (GCB DLBCL) to identify characteristics that are associated with survival in those treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). EXPERIMENTAL DESIGN: The cases were extensively characterized by combining the results of IHC, cell-of-origin gene expression profiling (GEP; NanoString), double-hit GEP (DLBCL90), FISH cytogenetic analysis for double/triple-hit lymphoma, copy-number analysis, and targeted deep sequencing using a custom mutation panel of 334 genes. RESULTS: We identified four distinct biologic subgroups with different survivals, and with similarities to the genomic classifications from two large retrospective studies of DLBCL. Patients with the double-hit signature, but no abnormalities of TP53, and those lacking EZH2 mutation and/or BCL2 translocation, had an excellent prognosis. However, patients with an EZB-like profile had an intermediate prognosis, whereas those with TP53 inactivation combined with the double-hit signature had an extremely poor prognosis. This latter finding was validated using two independent cohorts. CONCLUSIONS: We propose a practical schema to use genomic variables to risk-stratify patients with GCB DLBCL. This schema provides a promising new approach to identify high-risk patients for new and innovative therapies.

Duplex DNA from Sites of Helicase-Polymerase Uncoupling Links Non-B DNA Structure Formation to Replicative Stress.

BACKGROUND: Replication impediments can produce helicase-polymerase uncoupling allowing lagging strand synthesis to continue for as much as 6 kb from the site of the impediment. MATERIALS AND METHODS: We developed a cloning procedure designed to recover fragments from lagging strand near the helicase halt site. RESULTS: A total of 62% of clones from a p53-deficient tumor cell line (PC3) and 33% of the clones from a primary cell line (HPS-19I) were within 5 kb of a G-quadruplex forming sequence. Analyses of a RACK7 gene sequence, that was cloned multiple times from the PC3 line, revealed multiple deletions in region about 1 kb from the cloned region that was present in a non-B conformation. Sequences from the region formed G-quadruplex and i-motif structures under physiological conditions. CONCLUSION: Defects in components of non-B structure suppression systems (e.g. p53 helicase targeting) promote replication-linked damage selectively targeted to sequences prone to G-quadruplex and i-motif formation.

Allogeneic Hematopoietic Cell Transplantation Outcomes in Patients Carrying Isocitrate Dehydrogenase Mutations.

BACKGROUND: Mutations in isocitrate dehydrogenase (IDH)1/2 genes result in nicotinamide adenine dinucleotide phosphate-dependent reduction of α-ketoglutarate and formation of 2-hydroxyglutarate, which blocks normal cellular differentiation and promotes leukemogenesis. Nearly 20% of acute myeloid leukemia (AML) patients carry IDH1/2 mutations. Although multiple investigators have described the prognostic implications of IDH mutations in AML patients receiving chemotherapy, the effect of these mutations on outcomes after allogeneic (allo) hematopoietic cell transplantation (HCT) is unknown. PATIENTS AND METHODS: We report on the clinical outcome of a cohort of AML patients, who were tested for IDH mutations and underwent alloHCT at City of Hope (2015-2017). Of a total of 317 screened patients, 99 (31%) underwent alloHCT, of whom 23 carried and 76 did not carry IDH mutations (control). RESULTS: No statistical significance was detected in patient's overall survival (P = .84). With a median follow-up of 7.8 months, 1-year relapse rate of 29% and 13% was seen in the IDH-mutated and control group, respectively (P = .033). IDH1/2 mutation status remained significantly associated with relapse (hazard ratio, 2.8; P = .046) after inclusion of pre-HCT disease status in a multivariable model. CONCLUSION: Our results, despite low patient numbers, indicate that IDH mutations are associated with higher relapse rate after alloHCT. Further prospective studies on post transplantation IDH inhibition is required to improve outcomes in AML patients who carry IDH mutations.

Assessing genome-wide copy number aberrations and copy-neutral loss-of-heterozygosity as best practice: An evidence-based review from the Cancer Genomics Consortium working group for plasma cell disorders.

BACKGROUND: Plasma cell neoplasms (PCNs) encompass a spectrum of disorders including monoclonal gammopathy of undetermined significance, smoldering myeloma, plasma cell myeloma, and plasma cell leukemia. Molecular subtypes have been defined by recurrent cytogenetic abnormalities and somatic mutations that are prognostic and predictive. Karyotype and fluorescence in situ hybridization (FISH) have historically been used to guide management; however, new technologies and markers raise the need to reassess current testing algorithms. METHODS: We convened a panel of representatives from international clinical laboratories to capture current state-of-the-art testing from published reports and to put forward recommendations for cytogenomic testing of plasma cell neoplasms. We reviewed 65 papers applying FISH, chromosomal microarray (CMA), next-generation sequencing, and gene expression profiling for plasma cell neoplasm diagnosis and prognosis. We also performed a survey of our peers to capture current laboratory practice employed outside our working group. RESULTS: Plasma cell enrichment is widely used prior to FISH testing, most commonly by magnetic bead selection. A variety of strategies for direct, short- and long-term cell culture are employed to ensure clonal representation for karyotyping. Testing of clinically-informative 1p/1q, del(13q) and del(17p) are common using karyotype, FISH and, increasingly, CMA testing. FISH for a variety of clinically-informative balanced IGH rearrangements is prevalent. Literature review found that CMA analysis can detect abnormalities in 85-100% of patients with PCNs; more specifically, in 5-53% (median 14%) of cases otherwise normal by FISH and cytogenetics. CMA results in plasma cell neoplasms are usually complex, with alteration counts ranging from 1 to 74 (median 10-20), primarily affecting loci not covered by FISH testing. Emerging biomarkers include structural alterations of MYC as well as somatic mutations of KRAS, NRAS, BRAF, and TP53. Together, these may be measured in a comprehensive manner by a combination of newer technologies including CMA and next-generation sequencing (NGS). Our survey suggests most laboratories have, or are soon to have, clinical CMA platforms, with a desire to move to NGS assays in the future. CONCLUSION: We present an overview of current practices in plasma cell neoplasm testing as well as an algorithm for integrated FISH and CMA testing to guide treatment of this disease.

Desmoplastic small round cell tumor of the kidney in childhood.

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a rare malignant tumor that generally manifests as abdominal paraserosal masses and affects mainly male adolescents and young adults. When presenting within visceral organs, the diagnosis of DSRCT poses significant difficulties. METHODOLOGY: Four primary renal DSRCT in children diagnosed during a 3-year period are the basis of this report. The medical records and pathologic material were reviewed, including immunohistochemical, ultrastructural, and cytogenetic/molecular studies. RESULTS: The age at presentation was 6 to 8 years, and all children presented with a left renal mass. The tumors measured 3.7 to 13.4 cm and consisted of nests, cords, or sheets of small undifferentiated cells with foci of necrosis and calcification. Desmoplasia was not seen. Tumor cells were immunopositive for vimentin, WT-1 (monoclonal and polyclonal), desmin, cytokeratin, and epithelial membrane antigen. A distinct paranuclear dotlike pattern was observed with vimentin and desmin. Tumor cells possessed rare or focal immunoreactivity for platelet derived growth factor-A and transforming growth factor-beta3, which have been implicated in the pathogenesis of desmoplasia in DSRCT. The EWS-WT1 t(11;22)(p13;q12) translocation was demonstrated in all 4 tumors by fluorescence in situ hybridization and/or reverse transcription-polymerase chain reaction. CONCLUSIONS: DSRCT should be considered in the differential diagnosis of renal tumors composed of small round cells. Undifferentiated morphology and lack of desmoplasia contribute to the difficulty in its recognition. Ancillary studies such as immunohistochemistry may suggest the diagnosis, but cytogenetic and molecular genetic studies are required for confirmation.

Cyclin D1 depletion induces DNA damage in mantle cell lymphoma lines.

Elevated cyclin D1 (CCND1) expression levels in mantle cell lymphoma (MCL) are associated with aggressive clinical manifestations related to chemoresistance, but little is known about how this important proto-oncogene contributes to the resistance of MCL. Here, we showed that RNA interference-mediated depletion of CCND1 increased caspase-3 activities and induced apoptosis in the human MCL lines UPN-1 and JEKO-1. In vitro and xenotransplant studies revealed that the toxic effect of CCND1 depletion in MCL cells was likely due to increase in histone H2AX phosphorylation, a DNA damage marker. DNA fiber analysis suggested deregulated replication initiation after CCND1 depletion as a potential cause of DNA damage. Finally, in contrast to depletion or inhibition of cyclin-dependent kinase 4, CCND1 depletion increased chemosensitivity of MCL cells to replication inhibitors hydroxyurea and cytarabine. Our findings have an important implication for CCND1 as a potential therapeutic target in MCL patients who are refractory to standard chemotherapy.

Relapsed or Refractory Double-Expressor and Double-Hit Lymphomas Have Inferior Progression-Free Survival After Autologous Stem-Cell Transplantation.

Purpose Double-hit lymphomas (DHLs) and double-expressor lymphomas (DELs) are subtypes of diffuse large B-cell lymphoma (DLBCL) associated with poor outcomes after standard chemoimmunotherapy. Data are limited regarding outcomes of patients with relapsed or refractory (rel/ref) DEL or DHL who undergo autologous stem-cell transplantation (ASCT). We retrospectively studied the prognostic impact of DEL and DHL status on ASCT outcomes in patients with rel/ref DLBCL. Methods Patients with chemotherapy-sensitive rel/ref DLBCL who underwent ASCT at two institutions and in whom archival tumor material was available were enrolled. Immunohistochemistry for MYC, BCL2, and BCL6 and fluorescence in situ hybridization (FISH) for MYC were performed. In cases with MYC rearrangement or copy gain, FISH for BCL2 and BCL6 was also performed. Results A total of 117 patients were included; 44% had DEL and 10% had DHL. DEL and DHL were associated with inferior progression-free survival (PFS), and DHL was associated with poorer overall survival (OS). The 4-year PFS in patients with DEL compared with those with non-DEL was 48% versus 59% ( P = .049), and the 4-year OS was 56% versus 67% ( P = .10); 4-year PFS in patients with DHL compared with those with non-DHL was 28% versus 57% ( P = .013), and 4-year OS was 25% versus 61% ( P = .002). The few patients with concurrent DEL and DHL had a poor outcome (4-year PFS, 0%). In multivariable models, DEL and DHL were independently associated with inferior PFS, whereas DHL and partial response ( v complete response) at transplant were associated with inferior OS. Conclusion DEL and DHL are both associated with inferior outcomes after ASCT in patients with rel/ref DLBCL. Although ASCT remains a potentially curative approach, these patients, particularly those with DHL, are a high-risk subset who should be targeted for investigational strategies other than standard ASCT.

Durable clinical, cytogenetic, and molecular remissions after allogeneic hematopoietic cell transplantation for refractory Sezary syndrome and mycosis fungoides.

PURPOSE: Sezary syndrome (SS) and tumor-stage mycosis fungoides (MF) are generally incurable with currently available treatments. We conducted a retrospective study to evaluate the outcome of allogeneic hematopoietic stem-cell transplantation (HSCT) in this patient population. PATIENT AND METHODS: From August 1996 through October 2002, eight patients with advanced MF/SS underwent allogeneic HSCT at our institution. All patients were heavily pretreated, having failed a median number of seven prior therapies (range, five to 12). Clonal T-cell populations in peripheral blood or bone marrow were detectable by polymerase chain reaction analyses of T-cell receptor gamma-chain gene rearrangements in six patients and cytogenetics in three patients. The conditioning regimen included total-body irradiation and cyclophosphamide (n = 3), busulfan and cyclophosphamide (n = 1), and the reduced-intensity regimen of fludarabine and melphalan (n = 4). Allogeneic hematopoietic stem cells were obtained from HLA-matched siblings (n = 4) and unrelated donors (n = 4). RESULTS: All patients achieved complete clinical remission and resolution of molecular and cytogenetic markers of disease within 30 to 60 days after HSCT. Two patients died from transplantation-related complications; graft-versus-host disease (GVHD; n = 1) and respiratory syncytial virus pneumonia (n = 1). With a median follow-up of 56 months, six patients remain alive and without evidence of lymphoma. CONCLUSION: Our results suggest that allogeneic HSCT from both HLA-matched sibling and unrelated donors can induce durable clinical, molecular, and cytogenetic remissions in patients with advanced cutaneous T-cell lymphoma that is refractory to standard therapies.