Circulating microRNAs in Cerebrospinal Fluid and Plasma: Sensitive Tool for Detection of Secondary CNS Involvement, Monitoring of Therapy and Prediction of CNS Relapse in Aggressive B-NHL Lymphomas

Simple Summary

Lymphoma involving the central nervous system and CNS relapse present diagnostic and predictive challenges. Its diagnosis is based on conventional methods with low sensitivity and/or specificity. More powerful tools for its early detection, response evaluation, and CNS relapse prediction are needed. MicroRNAs are short post-transcriptional gene regulators that are remarkably stable and detectable extracellularly in body fluids. We evaluated the diagnostic and predictive potential of circulating oncogenic microRNAs (oncomiRs) in CSF and plasma for the detection of secondary CNS involvement in aggressive B-NHL lymphomas, as well as for detection and prediction of their CNS relapse. Our findings indicate that the evaluation of oncogenic microRNAs in CSF and plasma potentially provides a sensitive tool for the early detection of secondary CNS lymphoma, the monitoring and estimating of treatment efficacy, and the prediction and early detection of CNS relapse.

Abstract

Lymphoma with secondary central nervous system (CNS) involvement represents one of the most aggressive malignancies, with poor prognosis and high mortality. New diagnostic tools for its early detection, response evaluation, and CNS relapse prediction are needed. We analyzed circulating microRNAs in the cerebrospinal fluid (CSF) and plasma of 162 patients with aggressive B-cell non-Hodgkin’s lymphomas (B-NHL) and compared their levels in CNS-involving lymphomas versus in systemic lymphomas, at diagnosis and during treatment and CNS relapse. We identified a set of five oncogenic microRNAs (miR-19a, miR-20a, miR-21, miR-92a, and miR-155) in CSF that detect, with high sensitivity, secondary CNS lymphoma involvement in aggressive B-NHL, including DLBCL, MCL, and Burkitt lymphoma. Their combination into an oncomiR index enables the separation of CNS lymphomas from systemic lymphomas or nonmalignant controls with high sensitivity and specificity, and high Receiver Operating Characteristics (DLBCL AUC = 0.96, MCL = 0.93, BL = 1.0). Longitudinal analysis showed that oncomiR levels reflect treatment efficacy and clinical outcomes, allowing their monitoring and prediction. In contrast to conventional methods, CSF oncomiRs enable detection of early and residual CNS involvement, as well as parenchymal involvement. These circulating oncomiRs increase 1–4 months before CNS relapse, allowing its early detection and improving the prediction of CNS relapse risk in DLBCL. Similar effects were detectable, to a lesser extent, in plasma.

β-Catenin-TCF/LEF signaling promotes steady-state and emergency granulopoiesis via G-CSF receptor upregulation

The canonical Wnt signaling pathway is mediated by interaction of β-catenin with the T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription factors and subsequent transcription activation of Wnt-target genes. In the hematopoietic system, the function of the pathway has been mainly investigated by rather unspecific genetic manipulations of β-catenin that yielded contradictory results. Here, we used a mouse expressing a truncated dominant negative form of the human TCF4 transcription factor (dnTCF4) that specifically abrogates β-catenin-TCF/LEF interaction. Disruption of the β-catenin-TCF/LEF interaction resulted in the accumulation of immature cells and reduced granulocytic differentiation. Mechanistically, dnTCF4 progenitors exhibited downregulation of the Csf3r gene, reduced granulocyte colony-stimulating factor (G-CSF) receptor levels, attenuation of downstream Stat3 phosphorylation after G-CSF treatment, and impaired G-CSF-mediated differentiation. Chromatin immunoprecipitation assays confirmed direct binding of TCF/LEF factors to the promoter and putative enhancer regions of CSF3R. Inhibition of β-catenin signaling compromised activation of the emergency granulopoiesis program, which requires maintenance and expansion of myeloid progenitors. Consequently, dnTCF4 mice were more susceptible to Candida albicans infection and more sensitive to 5-fluorouracil-induced granulocytic regeneration. Importantly, genetic and chemical inhibition of β-catenin-TCF/LEF signaling in human CD34+ cells reduced granulocytic differentiation, whereas its activation enhanced myelopoiesis. Altogether, our data indicate that the β-catenin-TCF/LEF complex directly regulates G-CSF receptor levels, and consequently controls proper differentiation of myeloid progenitors into granulocytes in steady-state and emergency granulopoiesis. Our results uncover a role for the β-catenin signaling pathway in fine tuning the granulocytic production, opening venues for clinical intervention that require enhanced or reduced production of neutrophils.

The interval between progression and therapy initiation is the key prognostic parameter in relapsing diffuse large B cell lymphoma: analysis from the Czech Lymphoma Study Group database (NIHIL)

Relapsing diffuse large B cell lymphomas (rDLBCL) represent a heterogeneous disease. This heterogeneity should be recognized and reflected, because it can deform the interpretation of clinical trial results. DLBCL patients with the first relapse and without CNS involvement were identified in the Czech Lymphoma Study Group (CLSG) database. Interval-to-therapy (ITT) was defined as the time between the first manifestation of rDLBCL and the start of any treatment. The overall survival (OS) of different ITT cohorts (< 7 vs. 7-21 vs. > 21 days) was compared. In total, 587 rDLBCLs (51.8% males) progressed with a median of 12.8 months (range 1.6 to 152.3) since the initial diagnosis (2000-2017). At the time of relapse, the median age was 67 years (range 22-95). First-line therapy was administered in 99.3% of the patients; CHOP and anti-CD20 were given to 69.2% and 84.7% of the patients, respectively. The salvage immune/chemotherapy was administered in 88.1% of the patients (39.2% platinum-based regimen). The median ITT was 20 days (range 1-851), but 23.2% of patients initiated therapy within 7 days. The 5-year OS was 17.4% (range 10-24.5%) vs. 20.5% (range 13.5-27.4%) vs. 42.2% (range 35.5-48.8%) for ITT < 7 vs. 7-21 vs. > 21 days (p < 0.001). ITT was associated with B symptoms (p 0.004), ECOG (p < 0.001), stage (p 0.002), bulky disease (p 0.005), elevated LDH (p < 0.001), and IPI (p < 0.001). The ITT mirrors the real clinical behavior of rDLBCL. There are patients (ITT < 7 days) with aggressive disease and a poor outcome. Conversely, there are rDLBCLs with ITT ≥ 21 days who survive for a long time.

Combined treatment of primary vitreoretinal lymphomas significantly prolongs the time to first relapse

BACKGROUND

Vitreoretinal lymphomas belong to the family of central nervous system (CNS) lymphomas. The optimal approach for the treatment of isolated primary vitreoretinal lymphoma is unclear because of the lack of large comparative clinical series. Combination of intravitreal and systemic chemotherapy is recommended in many reports. The aim of our retrospective study was to compare the survival rate and prognosis of patients with vitreoretinal lymphoma with and without CNS involvement.

METHODS

Twenty patients with vitreoretinal lymphomas were observed between the years 2004and2016, 10 patients with primary vitreoretinal lymphoma and 10 with primary CNS lymphoma. To compare survival rates, we included 53 patients diagnosed with primary CNS lymphoma without vitreoretinal involvement between the years 2002and2011 from our haemato-oncology department.

RESULTS

The 5-year survival rate was estimated 71% in patients with vitreoretinal lymphoma in our observation. Significantly longer 5-year overall survival (P˂0.01) was observed in patients with vitreoretinal lymphoma compared with patients with primary CNS lymphoma without vitreoretinal involvement. Progression-free survival was almost equal in both groups of patients with primary vitreoretinal lymphoma and primary CNS lymphoma (P=0.363). The relapse of lymphoma was frequent (50%-60%) with the median time to first relapse of 31 months. Combined treatment (local and systemic) in patients without CNS involvement significantly prolonged progression-free survival in our study (P˂0.05).

CONCLUSION

Combined treatment of primary vitreoretinal lymphoma significantly delays the relapse of lymphoma compared with local therapy alone. Intraocular involvement brings significant positive prognostic value when overall survival is compared.

The incidence of biopsy-proven transformation in follicular lymphoma in the rituximab era. A retrospective analysis from the Czech Lymphoma Study Group (CLSG) database

The aim of this study is to assess the incidence, risk factors, and outcome of biopsy-proven transformation in follicular lymphoma (FL) patients in the rituximab era. Transformation was analyzed in 1233 patients with initially diagnosed FL grades 1-3A, identified between 2002 and 2012 in the prospectively maintained Czech Lymphoma Study Group database. Only patients with histologically proven transformation (HT) were included. HT occurred in 58 cases at a median of 3.0 years from the initial FL diagnosis; the HT rate was 4% at 5 years. Transformation occurred most frequently at the first relapse (84% patients). Median OS from the HT was 2.5 years (95% CI 0.4-4.6) and 6-year OS with HT was shorter compared to all FLs (60 vs. 83.9%; 95% CI). A bulky tumor (≥ 10 cm), increased lactate dehydrogenase, age ≥ 60 years, and International Prognostic Index (intermediate/high risk), but not Follicular Lymphoma International Prognostic Index, were associated with transformation (p < 0.05). In the first line, 70% of patients received rituximab (including 36% rituximab maintenance), 57% CHOP-like regimens, and 2.6% of patients were treated with fludarabine-based therapy, whereas 11% of patients were watched only. The patients treated with R-CHOP in the first line (n = 591) showed the transformation rate at 5 years of 4.23% (95% CI 2.52-5.93); subsequent rituximab maintenance (n = 276) vs. observation (n = 153) was associated with a lower transformation rate (p.033; HR 3.29; CI 1.10-9.82). The transformation rate seems to be lower than in previous series, which may be influenced by broad use of rituximab, but prognosis of HT developed during therapy continues to be poor.

Abstract 1479: Differential expression of microRNAs in transformation of follicular lymphoma to diffuse large B cell lymphoma

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression, and are frequently aberrantly expressed in cancer. We aimed to understand their role in the transformation of indolent follicular lymphoma (FL) into an aggressive diffuse large B cell lymphoma. This happens in ~3% of cases per year during the course of the disease, and is associated with median survival of only 2 years. The NGS revealed number of aberrations associated with transformed FL (tFL), including frequent high-level activity of MYC (amplifications, translocations, and mutations) or loss of DNA damage regulators (p53, CDKN2A/B). Firstly, we performed a miRNA profiling (TaqMan miRNA Arrays) in paired FL and tFL samples (N=8 pairs). This revealed a relatively small group of 5 miRNAs that are consistently differentially expressed in tFL (P&lt;0.05, fold-change &gt;1.5). Since the most frequently acquired aberration in tFL is the high-level activity of MYC we performed a correlation analysis of MYC levels and expression of these miRNAs in additional samples of FL, tFL, and CLL samples with/without MYC duplication (N=40 FL/tFL, N=39 CLL). This revealed that at least one of these miRNAs is significantly down-modulated (P&lt;0.05) in cases with high-levels of MYC. The MYC-mediated repression of miRNA levels was also observed (P&lt;0.05) in B cells from transgenic MYC over-expressing mice (MYC controlled by an Ig-alpha enhancer) in comparison to wild-type animals (samples obtained from young animals before occurrence of any malignancy). We have further shown that the levels of this miRNA affect B cell proliferation in vitro, and its low-levels associate with percentage of Ki67 positive cells in FL samples (P&lt;0.005). Moreover, low levels of tFL-associated miRNA were present in FL cases with a shorter overall survival (P&lt;0.01), and its expression directly affected BCR signalling (calcium flux assay after anti-IgM). We have shown that the expression of this miRNA is not only down-modulated by high-level MYC expression, but also by B cell adhesion to stromal cells in co-culture in vitro (HS-5 stromal cells). This suggests that its normal physiological function might be related to regulation of B cell functions in the context of immune niches, and this might play a role in FL progression and transformation. It remains to be elucidated what other molecular mechanisms ensure low-level expression of the studied miRNA in cases that do not harbor MYC over-expression, and what pool of target mRNAs is regulated by this miRNA in FL cells.This work was supported by: the Ministry of Health of the Czech Republic, grant nr. 16-29622A. All rights reserved. contact: marek.mraz@email.cz

Citation Format: Katerina Musilova, Gabriela Pavlasova, Vaclav Seda, Eva Vojackova, Katerina Cerna, Veronika Svobodova, Robert Pytlik, Vit Prochazka, Zuzana Prouzova, Sarka Pospisilova, Lenka Zlamalikova, Heidi Mocikova, Lenka Kruzova, Marie Jarosova, Andrew Evans, Clive Zent, Leos Kren, Marek Trneny, Jiri Mayer, Andrea Janikova, Marek Mraz. Differential expression of microRNAs in transformation of follicular lymphoma to diffuse large B cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1479. doi:10.1158/1538-7445.AM2017-1479

Role of rituximab in treatment of patients with primary central nervous system lymphoma: a retrospective analysis of the Czech lymphoma study group registry

We have investigated whether the addition of rituximab to methotrexate, procarbazine, vincristine, radiotherapy and cytarabine was associated with improved outcome of primary central nervous system lymphomas (PCNSL). Of 164 patients, 49 received rituximab. Median age was 63 years, median Karnofsky performance score (KPS) was 60 and median follow-up of living patients was 59.5 months. 1- and 2-year PFS were 49.7 and 37.9%, 1- and 2-year OS were 57.0 and 45.3%. Median progression-free survival (PFS), but not overall survival (OS) was significantly better for patients treated with rituximab (22.9 vs. 10.9 months, p = 0.037). In multivariate analysis, age ≤70 years and KPS ≥90 were predictive for PFS and OS, rituximab was an independent prognostic factor for PFS only. In landmark analyses, rituximab was not found beneficial for long-term survivors and no group particularly benefited from rituximab. In conclusion, addition of rituximab was associated with improved PFS, but not OS in this unselected cohort of PCNSL patients.

Targeting of BCL2 Family Proteins with ABT-199 and Homoharringtonine Reveals BCL2- and MCL1-Dependent Subgroups of Diffuse Large B-Cell Lymphoma

PURPOSE

To investigate the roles of BCL2, MCL1, and BCL-XL in the survival of diffuse large B-cell lymphoma (DLBCL).

EXPERIMENTAL DESIGNS

Immunohistochemical analysis of 105 primary DLBCL samples, and Western blot analysis of 18 DLBCL cell lines for the expression of BCL2, MCL1, and BCL-XL. Pharmacologic targeting of BCL2, MCL1, and BCL-XL with ABT-199, homoharringtonine (HHT), and ABT-737. Analysis of DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL. Immunoprecipitation of MCL1 complexes in selected DLBCL cell lines. Experimental therapy aimed at inhibition of BCL2 and MCL1 using ABT-199 and HHT, single agent, or in combination, in vitro and in vivo on primary cell-based murine xenograft models of DLBCL.

RESULTS

By the pharmacologic targeting of BCL2, MCL1, and BCL-XL, we demonstrated that DLBCL can be divided into BCL2-dependent and MCL1-dependent subgroups with a less pronounced role left for BCL-XL. Derived DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL, as well as the immunoprecipitation experiments, which analyzed MCL1 protein complexes, confirmed these findings at the molecular level. We demonstrated that concurrent inhibition of BCL2 and MCL1 with ABT-199 and HHT induced significant synthetic lethality in most BCL2-expressing DLBCL cell lines. The marked cytotoxic synergy between ABT-199 and HHT was also confirmed in vivo using primary cell-based murine xenograft models of DLBCL.

CONCLUSIONS

As homoharringtonine is a clinically approved antileukemia drug, and ABT-199 is in advanced phases of diverse clinical trials, our data might have direct implications for novel concepts of early clinical trials in patients with aggressive DLBCL.

Impact of rituximab maintenance and maintenance schedule on prognosis in first-line treatment of follicular lymphoma. Retrospective analysis from Czech Lymphoma Study Group (CLSG) database

Rituximab maintenance (RM) improves time to progression (PFS) in advanced follicular lymphoma (FL), but the impact of various RM schedules remains unknown. This study performed a retrospective evaluation of RM given for up to 2 years vs observation in 319 untreated FL patients (stage II-IV; grade 1-3A) responding to RCHOP induction and a comparison of two different RM schedules (RM8=eight doses given every 3 months and RM12=12 doses given every 2 months). A total of 183 patients received RM and 136 patients were observed; 5-year PFS was better in the RM arm, 74.1% vs 52.3% (p<0.001), which was projected in 5-year OS 93.8% vs 87.5% (p=0.005). However, 5-year PFS was similar in both the RM8 (n=54) and RM12 (n=56) arms. In the first line, RM significantly prolongs PFS and OS in FL, but different RM schedules bring a similar benefit.

Can Rituximab Improve the Outcome of Patients with Nodular Lymphocyte-Predominant Hodgkin's Lymphoma?

BACKGROUND

Nodular lymphocyte-predominant Hodgkin's lymphoma (NLPHL) is a rare subtype of Hodgkin's lymphoma showing strong CD20 expression. The role of rituximab in treating NLPHL still needs clarification.

METHODS

We retrospectively reviewed the outcome of 23 patients with NLPHL treated with rituximab alone or in combination with chemotherapy and/or radiotherapy as part of their first- or second-line treatment.

RESULTS

The median follow-up of the whole group was 67 months, and all patients remained alive. Twenty-two patients achieved complete remission after rituximab-based therapy, and one of them relapsed 32 months after treatment. One patient treated with rituximab alone achieved partial remission and progressed 22 months after treatment.

CONCLUSION

The prognosis of NLPHL is excellent. Rituximab combined with chemotherapy and/or radiotherapy appears to prevent disease progression/relapse.

Radiotherapy with rituximab may be better than radiotherapy alone in first-line treatment of early-stage follicular lymphoma: is it time to change the standard strategy?

Early-stage follicular lymphoma (FL) has traditionally been treated with involved-field radiotherapy (RT). Rituximab (R) is a low-toxic, efficient systemic therapy for FL, but there are no data about its clinical impact in early FL. We retrospectively analyzed 93 patients with stage I-II indolent FL treated with RT (n=65) or RT+R (n=14) or R alone (n=14). Median follow-up was 5.0 years for patients with RT, 2.8 years for the RT+R subgroup and 2.5 years for patients treated with R. The complete response rate was 92%, 100% and 86% (not significant) and the median PFS was 3.3 years, not reached and 4.9 years (p=0.035) for the RT, RT+R and R arms, with no impact on overall survival. R combined with RT seems to give better results in terms of global FL control, but longer follow-up and prospective comparison are needed to verify these results.

Evaluation of sericin as a fetal bovine serum-replacing cryoprotectant during freezing of human mesenchymal stromal cells and human osteoblast-like cells

A reliable, cryoprotective, xeno-free medium suitable for different cell types is highly desirable in regenerative medicine. There is danger of infection or allergic reaction with the use of fetal bovine serum (FBS), making it problematic for medical applications. The aim of the present study was to develop an FBS-free cryoprotective medium for human mesenchymal stromal cells (hMSCs; primary cells) and immortalized human osteoblasts (SAOS-2 cell line). Furthermore, we endeavored to eliminate or reduce the presence of dimethyl sulfoxide (DMSO) in the medium. Sericin, a sticky protein derived from the silkworm cocoon, was investigated as a substitute for FBS and DMSO in the freezing medium. Cell viability (24 hours after thawing, both hMSC and SAOS-2) and colony-forming ability (2 weeks after thawing, only for hMSCs) were both determined. The FBS-free medium with 1% sericin in 10% DMSO was found to be a suitable freezing medium for primary hMSCs, in contrast to immortalized human osteoblasts. Surprisingly, the storage of hMSCs in a cultivation medium with only 10% DMSO also provided satisfactory results. Any drop in DMSO concentration led to significantly worse survival of cells, with little improvement in hMSC survival in the presence of sericin. Thus, sericin may substitute for FBS in the freezing medium for primary hMSCs, but cannot substitute for DMSO.

Complications of MRI-guided stereotactic biopsy of brain lymphoma

OBJECTIVES

Stereotactic biopsy is a suitable method for sampling intrinsic brain lesions. Although this method is considered to be a safe procedure, some risk of complications still exists. The aim of the study was to retrospectively assess the morbidity and mortality of MRI-guided stereotactic biopsy of lesions which were histologically proven to be brain lymphoma.

METHODS

We retrospectively studied all accessible medical records for patients who had undergone MRI-guided stereotactic biopsy of brain lesions with histologically proven brain lymphoma from January 2007 to December 2012. Our cohort included 45 patients, 27 males and 18 females, aged 23-84 (63±14) years.

RESULTS

Forty-nine biopsies were carried out on 45 patients; the average number of tissue specimens was 3±1. The diagnostic yield of the stereotactic biopsy was 92%. Overall major morbidity directly related to stereotactic biopsy of brain lymphoma was 6.1% (3 cases) including 4.1% mortality (2 cases). Both deaths after the stereotactic procedure were due to intracranial hemorrhage and subsequent complications and both these patients had a history of treatment of systemic lymphomas. In one patient the stereotactic biopsy was complicated by a brain abscess which was successfully treated.

CONCLUSION

Stereotactic biopsy is still a mandatory diagnostic procedure for primary brain lymphomas, with an acceptable risk of complications. However, according to our results, the risk of complications can be higher in patients who have previously been treated for secondary lymphomas.

Retrospective analysis of 235 unselected patients with mantle cell lymphoma confirms prognostic relevance of Mantle Cell Lymphoma International Prognostic Index and Ki-67 in the era of rituximab: long-term data from the Czech Lymphoma Project Database

Although a prognostic model (MIPI, Mantle Cell Lymphoma International Prognostic Index) for patients with mantle cell lymphoma (MCL) has been established, its clinical significance for daily practice in the rituximab era remains controversial. Data of 235 unselected patients with MCL from the Czech Lymphoma Project Database were analyzed. MIPI, simplified MIPI (s-MIPI) and Ki-67 proliferation index were assessed for all patients and for a subgroup of 155 rituximab-treated (RT) patients. MIPI divided all patients into subgroups of low-risk (22%), intermediate-risk (29%) and high-risk (49%), with median overall survival 105.8 vs. 54.1 vs. 24.6 months, respectively (p < 0.001). s-MIPI revealed similar results. The validity of both indexes was confirmed in RT patients. We confirmed the Ki-67 index to be a powerful single prognostic factor for overall survival (64.4 vs. 20.1 months, p < 0.001) for all patients and for the RT subset. Our results confirm the clinical relevance of MIPI, s-MIPI and Ki-67 for risk stratification in MCL also in the rituximab era.

The Hans algorithm failed to predict outcome in patients with diffuse large B-cell lymphoma treated with rituximab

Diffuse large B-cell lymphoma (DLBCL) consists of at least two biologically and pathogenetically different subtypes, the germinal centre B-cell (GCB) and the activated B cell type (ABC). It has been suggested that immunohistochemistry can discriminate these subtypes as well. The aim of this study was to verify the validity of the most commonly used Hans algorithm in patients with DLBCL treated with anthracycline- based chemotherapy with rituximab. Immunohistochemical staining using standard protocols was performed on formalin fixed paraffin-embedded tissues. CD20, CD5, CD23, BCL2, CD10, BCL6, MUM1 and Ki67 antibodies were applied. Out of 120 examined cases 52 patients were evaluated as GCB type and 68 patients as having non-GCB, out of a set of 99 patients treated with immunochemotherapy 45 patients with GCB and 54 patients with non-GCB DLBCL were identified. In this set of patients, there was no statistically significant difference neither in overall survival (OS) (HR 1.47 95% CI 0.51-2.63; p=0.45) nor in progression free survival (PFS) (HR 1.57, 95 % CI 0.76-3.22; p=0.731) between both groups.

Distinguishing of primary mediastinal B-cell lymphoma and diffuse large B-cell lymphoma using real-time quantitative polymerase chain reaction

Primary mediastinal B-cell lymphoma (PMBL) seems to be reliably distinguished from diffuse large B-cell lymphoma (DLBCL) with microarray technology. We measured expression of Fcer2, Pdl2 and Blk genes using real-time quantitative polymerase chain reaction (RTqPCR) on formalin fixed, paraffin embedded material (FFPE) and suggested a formula to discriminate PMBL from DLBCL. For 39/82 included patients the diagnosis of PMBL was expected clinico-pathologically. Diagnosis of 10/39 and 2/43 of clinically considered PMBLs and DLBCLs, respectively, was not genetically confirmed. Compared to confirmed PMBLs, unconfirmed ones showed clinical features similar to DLBCLs, e.g. spleen infiltration (p=0,028) and decreased invasiveness in pericardium (p=0,045). They tended to have more common infradiaphragmatic involvement, less often tumor sclerosis or fluidothorax. There were no immunohistochemical differences between genetically confirmed and unconfirmed PMBLs. New approach of distinguishing PMBL and DLBCL is presented. It is based on expression of three genes in routinely available FFPE material using RTqPCR.

The role of apoptosis in cancer development and treatment: focusing on the development and treatment of hematologic malignancies

Apoptosis is a normal aspect of human physiology ensuring tissue homeostasis. Evasion of endogenous cell death processes, including apoptosis, represents one of the characteristics of cancer. Defects in the physiological mechanisms of apoptosis contribute to the pathological cell expansion and to the development and progression of cancer. Resistance of malignant cells to cancer therapeutic agents may be, in some cases, caused by dysregulation of apoptotic pathways, e.g. BCL2 or IAP overexpression. The understanding of the physiological mechanisms that control apoptosis and the elucidation of apoptotic defects in cancer cells may lead to the development of targeted cancer therapies. Apoptotic pathways, molecules involved in the cross-talk between individual apoptosis pathways and promising new anti-cancer agents, which trigger directly or indirectly apoptosis of hematologic cancer cells, are reviewed in this article.

Rituximab based therapy followed by autologous stem cell transplantation leads to superior outcome and high rates of PCR negativity in patients with indolent B-cell lymphoproliferative disorders

Autologous stem cell transplantation (ASCT) and rituximab based therapy represent effective treatments of indolent B-cell lymphoproliferative disorders (B-LPDs) that often induce molecular remission (MR). We assessed the impact of MR after treatment on prognosis of 57 patients with indolent B-LPDs. We also evaluated the impact of therapy on patients' outcome. Failure to achieve MR was identified as an independent risk factor regardless of treatment modality. PCR positive patients had shorter progression free survival (PFS) in contrast with patients in MR after rituximab (median 0.75 and 2.5 years respectively; p=0.006) or patients in MR after rituximab followed by ASCT (median 3.3 years; p=0.0032). PCR positive patients had a 5-year overall survival (OS) of only 40% compared to a 5-year OS of 76% for PCR negative patients after rituximab (p=0.0186) and 86% PCR negative patients after rituximab with ASCT (p=0.003). All nine patients transplanted with PCR positive graft relapsed (p=0.0023) with shorter PFS (p=0.0008). Rituximab based therapy induced MR in 25 (64%) compared to 18 (100%) patients after rituximab followed by ASCT (p=0.0025). We observed no difference in PFS between the transplant group (3.3 years) and rituximab based treatment (1.9 years), but the 5-year OS of patients with transplant was 85 and 59% respectively (p=0.0271). Patients with indolent B-LPDs who achieve MR have better prognosis. Rituximab based therapy induces MR in high number of patients, which can be further improved by ASCT and patients have an excellent outcome. PCR positive harvest represents a high risk of relapse after ASCT.

Vincristine sulfate liposomes injection (Marqibo) in heavily pretreated patients with refractory aggressive non-Hodgkin lymphoma: report of the pivotal phase 2 study

BACKGROUND

Marqibo, a sphingosomal/cholesterol encapsulation of vincristine sulfate has targeted, increased, and sustained delivery of vincristine to tumor tissues. A phase 2, open-label, single-arm, and multinational study evaluated the efficacy and tolerability of Marqibo as a single agent in patients with multiply relapsed or refractory aggressive non-Hodgkin lymphoma (NHL).

METHODS

Eligible patients had relapsed or refractory de novo or transformed aggressive NHL and prior treatment with at least 2 multiagent chemotherapy regimens. Marqibo was administered at 2 mg/m2, every 2 weeks, for a maximum of 12 cycles or until toxicity or disease progression.

RESULTS

One hundred and nineteen patients were enrolled and treated on trial. Ninety-six had histological confirmed de novo (N=89) or transformed (N=7) aggressive NHL. Median number of cycles was 4 (median dose/cycle 4 mg). Overall response (CR and complete response unconfirmed and PR) was 25% (95% confidence interval [CI], 17, 35), CR and complete response unconfirmed confirmed by external reviewers was 5%. Median overall survival was 6.6 months (Kaplan-Meier estimate, 95% CI, 4.7, 9.8). Grade 3 of 4 neurotoxicity occurred in 32% of patients. All patients had prior neurotoxic agents, and 85% had baseline residual neuropathy symptoms (grades 1-2) from prior treatment.

CONCLUSIONS

Marqibo is an active agent in patients with heavily pretreated aggressive NHL, and tolerated at approximately twice the dose intensity of standard vincristine. Its activity supports further investigation as a substitution for vincristine in combination treatment of lymphoid disorders.

Peripheral T-cell lymphoma, unspecified - the analysis of the data from the Czech Lymphoma Study Group (CLSG) registry

BACKGROUND

Peripheral T-cell lymphoma, unspecified (PTCL-US) is one of the entities from the infrequent family of nodal mature T-cell lymphomas. The clinical course is aggressive, and despite multiagent chemotherapy, the median survival is about 2 years. Published data are limited to retrospective, mostly single-center studies or reviews and usually include more lymphoma subtypes.

AIM

To evaluate the current treatment modalities, clinical outcome and prognostic factors in unselected, new diagnosed patients with PTCL-US in the population of the central european region (Czech Republic).

METHOD

Czech Lymphoma Study Group is a national scientific organization which provides an on-line database registry which collects a data about almost all new diagnosed lymphoma patients since year 2000. All diagnostic biopsies were reviewed by a reference pathologist.

RESULTS

We analyzed 63 patients with new diagnosis of PTCL-US. The median age was 59 years (25-81), chemotherapy (CHT) was administered in 56 of the 63 patients: anthracyclin-based CHT in 51%, intensive CHT in 21% and non-anthracyclin regimen was applied in 13% of the patients. The overall response rate was 74.4%, (CR in 57.4%). After a median follow-up of 19.6 months, 41% of the patients were in CR, 3.4% in PR or stable disease and 55% of the patients died. The estimated survival probability in 3 years was 36%. Clinical stage (IV) and CR achievement were found to be independent survival predictors in a multivariate analysis.

CONCLUSIONS

Although the current treatment modalities are mostly ineffective in PTCL-US, appropriate intensive treatment may lead to prolonged remission but not survival.

Prediction of outcome using positron emission tomography (PET) compared to standard response criteria and potential role in treatment decisions in diffuse large B-cell lymphoma (DLBCL) patients

7565

Background: PET has been demonstrated to give valid information about viable tumor residua. There are however only limited data regarding the combination of classical response criteria with PET and there is a lack of information on the impact of additional therapy (add-Th) on the outcome of PET neg. or PET pos. pts. Methods: One hundred thirty-nine pts (median age 50y) with newly diagnosed DLBCL who were examined by PET during (after 2–4 cycles CHT - ‘early PET’) or/and at the end of therapy (‘end PET’) were analyzed retrospectively. IPI risk distribution were as follows: L 28%, LI 24%, IH 33% and H 15% pts. All pts were treated with anthracyclin based CHT. “Early PET” was performed in 84 pts. and “end PET” in 103 pts before add-Th, PET at both time points was performed in 48 pts. Add-Th (HDT with ASCT or/and radiotherapy), was given as planned or as a result of response evaluation (conventional methods - CT, trephine biopsy). No treatment modification was made on PET result only, except for 2 cases when planned RT was skipped because of PET neg. RT was performed in 59 pts (42.4%) and HDT with ASCT as consolidation in 54 pts (38.8%). Median follow up was 30 m. Results: CR or CRu was achieved after CHT in 102 (74%) pts, PR in 24 (17%) pts, stable or progress dis. in 13 (9%). ‘Early PET’ was neg. in 60% pts and ‘end PET’ was neg in 67% pts. PET neg. was achieved at least once in 97 (70%) pts, and PET pos. at least once was found in 50 pts (36%). The PFS at 30 m according to the combination of conventional and PET response was as follows: for CR PET-neg. pts 89%, for PR PET-neg. pts 90%, for CR PET-pos. pts 45% and for PR PET-pos. pts 64% (p=0.0001). OS was 93%, 63%, 90% and 83%, respect.(p=0.004). The analysis of impact of add-Th showed PFS at 30 m: for PET-neg pts with Add-Th 96%, for PET-neg. pts without Add-Th 82%. PET-pos. pts without Add-Th had a PFS of only 10% and PET-pos. pts with add-Th had PFS 58% (p=0.0001). The OS was 92%, 98%, 38% and 74% respect. (p=0.0001). Conclusions: Our data demonstrate that PET give more powerful information than standard response criteria. The second analysis support the the idea that pts with DLBCL in CR who remain PET pos. should undergo the additional therapy. Partial support: Grant MSM 0021620808

No significant financial relationships to disclose.

Anagrelide for thrombocytosis in myeloproliferative disorders: a prospective study to assess efficacy and adverse event profile

BACKGROUND

Although the platelet count does not correlate with the rate of thrombosis, there is evidence that a strict control of the platelet count decreases the incidence of thromboembolic complications in essential thrombocythemia. In the current study, the authors evaluated the efficacy and tolerability of anagrelide in thrombocytosis associated with myeloproliferative disorders.

METHODS

The study cohort comprised 97 patients (n = 69 females, n = 28 males) with a median age of 59 years (range, 21-80 years). Patients with essential thrombocythemia (n = 79) or with thrombocytosis due to polycythemia vera (n = 16) or to chronic idiopathic myelofibrosis (n = 2) were enrolled in the multicenter, prospective study. Patients received anagrelide at a starting dose of 0.5 mg twice per day, which was then adjusted for each patient.

RESULTS

Treatment with anagrelide resulted in a rapid decrease in the platelet count, from a median baseline platelet count of 743 x 10(9)/L to a median platelet count of 441 x 10(9)/L after 6 months (P < 0.0001). The proportion of patients with a platelet count < 600 x 10(9)/L increased from 30% at baseline to 77% after the 6-month study period. The rate of major thrombotic complications significantly decreased from 5% to 2% (P = 0.2568). For patients with essential thrombocythemia, the reduction of major thromboembolic complications was significant (P = 0.0455). The rate of minor thromboembolic complications decreased from 25% before anagrelide treatment to 14% during anagrelide treatment (P = 0.0278). No severe side effects were observed during the study period. There was, however, evidence that concomitant administration of acetylsalicylic acid may increase bleeding tendency.

CONCLUSIONS

Anagrelide was an effective and well tolerated treatment modality for reducing platelet counts in both newly diagnosed and pretreated patients with thrombocytosis due to myeloproliferative disorders.