Sequencing-based analysis of clonal evolution of 25 mantle cell lymphoma patients at diagnosis and after failure of standard immunochemotherapy

Our knowledge of genetic aberrations, that is, variants and copy number variations (CNVs), associated with mantle cell lymphoma (MCL) relapse remains limited. A cohort of 25 patients with MCL at diagnosis and the first relapse after the failure of standard immunochemotherapy was analyzed using whole-exome sequencing. The most frequent variants at diagnosis and at relapse comprised six genes: TP53, ATM, KMT2D, CCND1, SP140, and LRP1B. The most frequent CNVs at diagnosis and at relapse included TP53 and CDKN2A/B deletions, and PIK3CA amplifications. The mean count of mutations per patient significantly increased at relapse (n = 34) compared to diagnosis (n = 27). The most frequent newly detected variants at relapse, LRP1B gene mutations, correlated with a higher mutational burden. Variant allele frequencies of TP53 variants increased from 0.35 to 0.76 at relapse. The frequency and length of predicted CNVs significantly increased at relapse with CDKN2A/B deletions being the most frequent. Our data suggest, that the resistant MCL clones detected at relapse were already present at diagnosis and were selected by therapy. We observed enrichment of genetic aberrations of DNA damage response pathway (TP53 and CDKN2A/B), and a significant increase in MCL heterogeneity. We identified LRP1B inactivation as a new potential driver of MCL relapse.

Anti-CD38 Therapy with Daratumumab for Relapsed/Refractory CD20-Negative Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common and one of the most aggressive subtypes of non-Hodgkin's lymphomas. Front-line therapy consists of chemotherapy in combination with anti-CD20 monoclonal antibody rituximab. Relapses after rituximab-based regimen have poor prognosis and call for new treatment options. Immunohistochemistry analysis of relapsed DLBCL often reveal CD20-negative lymphoma, which limits repeated use of rituximab in combination with salvage chemotherapy. CD38 is a surface antigen that binds to CD38, CD31/PECAM-1 and hyaluronic acid. CD38 is an important mediator of signal transmission from the microenvironment into the cell. Anti-CD38 monoclonal antibody daratumumab has been approved for the treatment of multiple myeloma. Expression of CD38 on the surface of DLBCL is highly variable (compared to strong expression on myeloma cells), but can be easily assessed by flow cytometry or immunohistochemistry. A patient-derived xenograft (PDX) model of CD20-negative, CD38-positive DLBCL derived from a patient with rituximab-refractory DLBCL was used for in vivo experiments. We demonstrated that daratumumab suppressed growth of subcutaneous PDX tumours significantly more effectively than rituximab. Analysis of tumours obtained from mice treated with daratumumab revealed down-regulation of surface CD38, suggesting endocytosis of CD38-daratumumab complexes. The results suggest a potential clinical use of daratumumab in combination with salvage chemotherapy in patients with relapses of CD20-negative DLBCL. In addition, daratumumab might potentially serve as a suitable antibody moiety for derivation of antibodydrug conjugates for the targeted delivery of toxic payloads to the lymphoma cells.

PD-1, PD-L1 and PD-L2 Expression in Mantle Cell Lymphoma and Healthy Population

Cell surface expression of PD-1, PD-L1 and PD-L2 immune checkpoints on B and T cells obtained from patients with mantle cell lymphoma shows ambiguous results across many studies and creates obstacles for the implementation of immune checkpoint inhibitors into the therapy of mantle cell lymphoma. Using multiparameter flow cytometry we analysed surface expression of PD-1, PD-L1 and PD-L2 molecules on B and T cells of 31 newly diagnosed mantle cell lymphomas and compared it with the results of 26 newly diagnosed chronic lymphocytic leukaemias and 20 healthy volunteers. To gain insight into the age-dependent changes of surface expression of these immune checkpoints, flow cytometric subanalysis of 30 healthy volunteers of 25-93 years of age was conducted. Overall, we demonstrated weak surface expression of PD-1, PD-L1 and PD-L2 on B and T cells of mantle cell lymphoma patients (< 10 % when compared to healthy individuals). A significant age-dependent increase in the expression of PD-1 and its ligand PD-L2 was observed in healthy volunteers. Our results suggest that neither PD-1 nor its ligands represent relevant druggable targets for the therapy of mantle cell lymphoma. The observed age-dependent changes in healthy population could impact efficiency of immune checkpoint inhibitors and could be at least partly connected with increased incidence of cancer with age.

Influence of Cytotoxic Drugs on Platelet Functions and Coagulation in vitro

Influence of melphalan on some platelet functions, plasmatic coagulation and fibrinolysis “in vitro” was investigated, using different concentrations of the drug (25, 50 and 250 μg/ml). The lowest concentration slightly inhibited adrenaline and/or collagen-induced platelet aggregation. Following the highest concentration of the drug, strong inhibition of aggregation was recorded, regardless of the inducer used. Melphalan was also shown to inhibit release of aggregating activity and release of platelet factor 4, as well as availibility of platelet factor 3 and platelet acid phosphatase. The intensity of inhibition depended on both, melphalan concentration and the time of preincubation. In contrast to this, adhesion of platelets to glass slide was not found to be influenced by melphalan. Similarly, melphalan did not induce (in any concentration) loss of LDH from platelet cytoplasma, while triton X-100 or freezing and thawing of platelets caused significant increase of LDH activity. From coagulation tests studied, only thrombin time and reptilase time was found to be moderately prolonged in the presence of melphalan.

Authors assumed that melphalan acts as a specific inhibitor of release reaction and can induce an acquired thrombocytopathy. The platelet membrane is not damaged by the drug, as was confirmed by the investigation of LDH activity. Influence on coagulation indicates some antithrombin effect of the drug. Although presented results were obtained in vitro, analogous changes in vivo could be suspected. Thus, impairement of platelet functions might play a part in haemorrhagic complications accompanying, in some cases, melphalan therapy.

The Plasminogen Activator of the Arterial Wall

The plasminogen activator in 645 specimens of various human arteries – thoracic, abdominal aorta, carotic, pulmonary, renal, basilar, coronary – was studied using Todd’s histochemi-cal method. 92 cadavers were used, 1–18 hours post mortem from subjects aged from 272 days to 83 years. 45 specimens of pulmonary, renal and splenic arteries were obtained during surgery.

The greatest fibrinolytic activity was within the adventitia. Intima occasionally showed very little fibrinolytic activity, or none at all.

No statistically significant differences in plasminogen activator activity were found between the various arteries examined.

A statistically significant increase in fibrinolysis in adventitia of atherosclerotic arteries was established. No correlation was found between the fibrinolytic activity of the arteries and their alkaline phosphatase content.

Some properties of the plasminogen activator of the arterial vessel wall were evaluated. Influence of storage, inactivation with epsilonaminocaproic acid and extracted with potassium thiocyanate was studied.

Cyclin D1 mRNA as a molecular marker for minimal residual disease monitoring in patients with mantle cell lymphoma

Chromosomal translocation t(11;14)(q13;q32) is a characteristic molecular marker of mantle cell lymphoma (MCL) and leads to the fusion of the immunoglobulin heavy chain enhancer-promoter with the cyclin D1 gene. Both aberrant cyclin D1 expression and underlying chromosomal aberration may be used as molecular targets for monitoring minimal residual disease (MRD). The present study aims to assess the usefulness of quantitative cyclin D1 gene expression compared to the standardised but more technologically demanding DNA-based method for immunoglobulin heavy chain (IGH) or t(11;14) clone-specific gene rearrangement quantification in a cohort of bone marrow (BM) and peripheral blood (PB) samples from patients with MCL. We simultaneously evaluated DNA-MRD and cyclin D1 expression levels in 234 samples from 57 patients. We observed that both in DNA-MRD positive and negative BM/PB pairs from the same time points the expression levels of cyclin D1 are lower in PB than in BM (median 19×, BM/PB range 0.41-352). The correlation of cyclin D1 transcript levels with DNA-MRD or with flow cytometry was good only in samples with a very high infiltration. In DNA-MRD-negative BM samples, we observed a significant heterogeneity of cyclin D1 expression (in the range of more than three orders of magnitude). This is in contrast to previous reports demonstrating the usefulness of cyclin D1 for MRD monitoring that did not use DNA-based method as a reference. In PB, the specificity of cyclin D1 expression was better due to a lower physiological background. In conclusion, we show that cyclin D1 is unsuitable for MRD monitoring in BM.

[Staging and Treatment Response Evaluation in Malignant Lymphomas - Czech Lymphoma Study Group Recommendations According to Criteria Revised in 2014 (Lugano Classification)]

BACKGROUND

Recent advances in the use of the imaging modalities, especially PET/CT, and their utilization for determining clinical stage (CS) and assessment treatment response (TR) in malignant lymphomas, along with development of prognostic tools and new treatment modalities, formed the basis for the revised criteria for evaluating CS and TR (published as the Lugano classification, 2014).

MATERIALS AND METHODS

The authors summarize the new Lugano recommendations (published in 2014) and the changes from the criteria published in 2007. Moreover, discussion of the changes places emphasis on practical use. The practicality of the Lugano classification, 2014 was the subject of consensus meeting at the annual meeting of the Cooperative Lymphoma Study Group (CLSG) in March 2015. This study reports the final consensus. The CLSG recommends use of the Lugano classification, 2014, but recommends some modifications.

CONCLUSIONS

Standardization of the criteria used to determine CS and TR in malignant lymphomas has led to improvements in initial staging and assessment of TR. The criteria are helpful for unifying response assessment in clinical trials and simplify the work of regulatory agencies (e.g., the EMA and the Czech State Institute for Drug Control) when registering new drugs. It also allows evaluation of treatment outcomes outside clinical trials, for example within the CLSG prospective registry of patients with newly diagnosed lymphoma.

KEY WORDS

malignant lymphoma - computed tomography - positron emission tomography - staging - treatment responseThis work was supported by the grant Prvouk P27/2012 of the Third Faculty of Medicine, Charles University in Prague and by the grant of the Czech Lymphoma Study Group No. NT12193-5/2011.The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 24. 1. 2016Accepted: 16. 2. 2016.

Comparison of Plasma Osteopontin Levels between Patients with Borderline Ovarian Tumours and Serous Ovarian Carcinoma

Osteopontin (OPN) is a novel biomarker of various cancers including ovarian carcinoma. OPN is a promising adjunct to a major biomarker of ovarian cancer, CA125, in diagnosis, differential diagnosis and prognosis. The aim of our study was to measure the plasma level of OPN and CA125 in patients with borderline ovarian tumours (BOTs), serous ovarian carcinoma, and controls to determine its potential role in the differential diagnosis between serous ovarian carcinoma and BOT. The plasma samples of 66 women were analysed using Luminex technology, designed to simultaneously measure multiple specific protein targets. The mean OPN plasma level for the control group was 23.3 ng/ml; for BOT 26.3 ng/ml; and for patients with serous ovarian carcinoma 59.5 ng/ml. Specifically, there was a significant difference between the OPN levels in patients with ovarian carcinoma and BOT (P < 0.001) as well as controls (P < 0.001). There was no difference between the mean levels of OPN in patients with BOT and the control group (P = 0.286). Using the receiver operating characteristic (ROC), we determined the utility of OPN and CA125 to differentiate between BOT and serous ovarian carcinoma. The area under the ROC curve (AUC) for OPN was 0.793 (95% confidence interval (CI) 0.669-0.917, P < 0.001) and for CA125 0.766 (95% CI 0.626-0.907, P = 0.002). Based on our data, we suggest that OPN can be used as a possible differential diagnostic biomarker to distinguish between malignant serous ovarian carcinoma and BOT.

[Malignant Lymphomas - Past, Present and Future]

This review summarizes the key steps on the way to understanding lymphoma biology and management. The history of lymphomas started in 1832 when Thomas Hodgkin first presented lymphomas. Classification of lymphoproliferative tumors has changed almost every 10 years as a reflection of deeper knowledge of this disease. Systemic therapy has developed in several steps starting by monotherapy with different chemotherapeutic agents, followed by the era of combination chemotherapy and by the rituximab era, which significantly changed the treatment paradigm. Several years ago, we entered into the fourth era characterized by many different targeted treatments. Radiotherapy remains an important part of lymphoma management. Lymphoproliferative tumors incidence is growing but mortality has started to decline starting in the year 2000 as the reflection of targeted therapy based on biology and pathogenesis.

[Mantle Cell Lymphoma - Cutting edge Dia-gnostics and Treatment Approaches]

BACKGROUND

Mantle cell lymphoma represents a specific subtype of B -cell non-Hodgkin lymphoma characterized on the molecular level by translocation t(11;14)(q13;q32) leading to aberrant overexpression of cyclin D1 and deregulation of the cell cycle. Despite sporadic indolent forms of mantle cell lymphoma, majority of patients present with advanced aggressive disease that requires immediate treatment. Despite chemosensitive nature of mantle cell lymphoma, approximately 10% patients present with a refractory disease, and the vast majority of patients who initially respond to therapy, relapse sooner or later. The course of mantle cell lymphoma thus represents a chronically relapsing malignancy requiring further and further lines of therapies. Prognosis of relapsed or refractory (R/ R) mantle cell lymphoma is dismal.

AIM

The goal of this article is to provide a cutting -edge review of currently used diagnostic and treatment approaches for mantle cell lymphoma.

RESULTS

Several key modifications of the therapeutic algorithm of mantle cell lymphoma treatment implemented in the past 10 years resulted in significantly improved prognosis of patients. The milestones in the therapy of mantle cell lymphoma include incorporation of anti-CD20 monoclonal antibody rituximab into induction therapy, intensification of polychemotherapeutic regimen including implementation of high-dose cytarabine, consolidation of response with high-dose therapy and autologous stem cell transplantation (HDT ASCT) in younger fit patients, and maintenance therapy with rituximab in the elderly patients. Besides such "optimization" of frontline therapy, introduction of novel antilymphoma agents into therapy of R/ R mantle cell lymphoma also contributed (and will contribute in the future) to improved prognosis of mantle cell lymphoma. Among these agents, there is a new cytostatic drug bendamustine, Bruton tyrosine- kinase inhibitor ibrutinib, immunomodulatory agent lenalidomide, mTOR inhibitor temsirolimus and proteasome inhibitor bortezomib.

CONCLUSION

The overall survival of mantle cell lymphoma virtually doubled in the recent 10 years as a result of two key factors: 1. optimization of frontline therapy with "conventional" antilymphoma agents, and 2. brand new possibilities of therapy for R/ R mantle cell lymphoma thanks to the introduction of novel antilymphoma agents. Combinatorial approaches using most efficacious combinations of novel and "conventional" anti-mantle cell lymphoma agents will definitely lead to further improvements of survival parameters in mantle cell lymphoma patients in near future.

Multi-level disruption of the extrinsic apoptotic pathway mediates resistance of leukemia cells to TNF-related apoptosis-inducing ligand (TRAIL)

Disruption of apoptotic pathways belongs to commonly reported molecular mechanisms that underlie cancer drug resistance. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL, Apo2L) is a cytokine of the TNF family with selective anti-tumor activity and minimal toxicity toward healthy tissues. Primary leukemia cells are, however, largely intrinsically resistant to TRAIL-induced apoptosis. In this study we analyzed molecular differences between TRAIL-resistant K562 cell line and TRAIL-sensitive K562 clones. We demonstrate that TRAIL-sensitive K562 cells differ from the TRAIL-resistant cell line by cell surface downregulation of TRAIL decoy receptor 1, upregulation of both TRAIL death receptors, enhanced assembly and improved functioning of the death-inducing signaling complex, and increased cytoplasmic protein expression of CASP8 and key proapoptotic BCL2 members BID, BIM, BAD and BAK. The molecular basis of the intrinsic leukemia cell TRAIL resistance thus appears a consequence of the multi-level disruption of the extrinsic apoptotic pathway. The results of this study also suggest that the leukemia TRAIL-resistance is functional, leaving a possibility of overcoming the resistance by preexposure of the leukemia cells to potent TRAIL sensitizers, e.g. BH3-mimetics.

[Epigenetic cancer drugs and their role in anticancer therapy]

Epigenetic modification have been causally linked to cancer development and progression, and are potentially reversible by treatments with epigenetic cancer drugs. The aim of this review is to give an overview of the basic current knowledge on molecular mechanisms of epigenetic cancer drugs and their possible clinical use. Many of them are in in clinical trials. However only two demethylating agents ie. inhibitors of DNA methyltransferase (5- azacytidin and decitabin) are approved in the treatment of myelodysplastic syndrome and a few inhibitors of histonacetylase (vorinostat, romidepsin and panobinostat) are approved in the treatment of hematological malignancies, particularly in refractory or relapsed cutaneous T cell lymhoma.

[Targeted therapeutics and their role in the treatment of internal diseases]

Targeted therapy is a conceptual notion that should be used for such a treatment approach that has been developed based upon the known pathophysiology and/or biomarkers of a particular disease, mainly malignancies. Monoclonal antibodies and tyrosine--kinase inhibitors were among the first molecularly targeted agents. Monoclonal antibodies approach is based on targeting a biomarker expressed either on the surface of cancer cells or targeting different cytokines. Tyrosin-kinase inhibitors are directed at the druggable molecule involved in the cancer pathophysiology inhibiting aberrant tyrosin-kinase activity. Classification of targeted drugs and their use in the clinical practice is shortly reviewed.

In vivo growth of mantle cell lymphoma xenografts in immunodeficient mice is positively regulated by VEGF and associated with significant up-regulation of CD31/PECAM1

Mantle cell lymphoma (MCL) is an aggressive lymphoma subtype with dismal prognosis. New treatments are needed to improve outcome of relapsed/ refractory disease. Recently, several drugs targeting at least partially the process of angiogenesis have been successfully tested in the therapy of MCL. Molecular mechanisms that regulate MCL-induced angiogenesis and that might represent potential new druggable targets remain, however, incompletely understood. We established two mouse models of human MCL by subcutaneous xenotransplantation of JEKO-1 and HBL-2 cell lines into immunodeficient mice. Histological analyses of xenografts confirmed their neovascularization. The growth of xenografts was significantly suppressed by single-agent therapy with bevacizumab, monoclonal antibody targeting vascular endothelial growth factor (VEGF). Subsequently, we analysed expression of 94 angiogenesis related genes in ex vivo isolated JEKO-1 and HBL-2 cells compared to in vitro growing cells using TaqMan low-density arrays. The most up-regulated genes in both JEKO-1 and HBL-2 xenografts were genes encoding platelet/endothelial cell-adhesion molecule (CD31/PECAM1), VEGF receptor 1 (FLT1), hepatocyte growth factor (HGF), angiogenin (ANG) and transcription factor PROX1. The most downregulated genes in both JEKO-1 and HBL-2 xenografts were midkine (MDK) and ephrine B2 (EPHB2). In summary, our results demonstrate an important role of angiogenesis in the biology of MCL and provide preclinical evidence of potent anti-MCL activity of bevacizumab. In addition, gene expression profiling of 94 angiogenesis-related targets revealed several in vivo up-regulated and down-regulated transcripts. The most differentially expressed target in both MCL tumours was CD31/PECAM1. Whether any of these molecules might represent a potential druggable target in MCL patients remains to be elucidated.

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.

[Angiogenesis as part of the tumor "ecosystem" and possibilities to influence it]

Angiogenesis is a complex process which is critical for the growth, invasion and metastasis of tumors. In the past ten years numerous new agents have been developed as angiogenesis inhibitors. In the review, angiogenesis inhibitors are classified by their targeted area of the angiogenic process. The role of VEGF and its receptors is described in detail, but other antiangiogenic strategies such as inhibition of endothelial proliferation, inhibition of matrix metalloproteinases and use of vascular disrupting agents are also reviewed.

[ABL1, SRC and other non-receptor protein tyrosine kinases as new targets for specific anticancer therapy]

Non-receptor protein tyrosine kinases are responsible for signal transduction during many physiologic cellular processes, including cell growth and proliferation, apoptosis, differentiation, regulation of actin cytoskeleton, cell shape, adhesion, motility and migration. Aberrant activity of protein tyrosine kinases (acquired as a result of chromosomal translocation or point mutation) has been implicated in the stimulation of cancer growth and progression, the induction of drug-resistance, tumour neovascularization, tissue invasion, extravasation and the formation of metastases. Small molecule tyrosine kinase inhibitors interfere with these pathophysiological circuits by blocking the signalling cascades triggered by the aberrantly activated protein tyrosine kinases (e.g. BCR-ABL1, FIP1L1-PDGFRA or ETV6-PDGFRB).Tyrosine kinase inhibitors (imatinib, nilotinib, dasatinib) now belong to established anti-cancer agents with clinical activity in patients with CML, Ph+ ALL, and myeloid neoplasms with overexpression of PDGFRA, PDGFRB and wild-type KIT. New generation tyrosine kinase inhibitors (e.g. dasatinib) with extended activity against SRC and EPH kinases belong to promising anti-cancer agents with documented preclinical activity in several solid tumours (e.g. prostate cancer).

[The outcome of whole-body FDG-PET examination predicts the future of patients with diffuse large-cell lymphoma in the use of both intermediary staging and at the end of standard chemotherapy]

AIM

Response to the therapy is one of the most valuable prognostic factors. The response evaluation is performed by computer tomography as a standard tool. The introduction of FDG-PET whole body imaging allows to discriminate viable tumor and fibrotic changes in structural abnormalities.

METHODS

We have performed retrospective analysis of 96 patients with diagnosis of diffuse large B-cell lymphoma (1999-2004) who were treated by anthracyclin based chemotherapy and FDG-PET was performed as a part of intermediate restaging (after 2nd-4th cycle, 69 patients) or/and at the end of standard chemotherapy (68 patients).

RESULTS

The progression free survival (PFS) and overall survival (OS) at 3 years were the endpoints. Median follow up was 30 months. The PFS and OS resp. for PET negative pts at intermediate restaging was 80.7% and 97.6% compared to the 50.5% and 71.5 % resp. for PET positive patients. The relapse risk and death risk for PET positive patients was 4.8 and 6.4 resp. The PFS and OS resp. for PET negative pts at the end of chemotherapy was 81.7% and 94.7% resp. compared to the 29.4% (p < 0.0001) and 57.5% (p < 0.0001) resp. for PET positive patients. The relapse risk and death risk for PET positive patients was 7.0 and 12.9 resp. Predictive value of PET at intermediate as well at the end restaging was observed in IPI low group as well IPI high risk subgroups for both PFS and OS, except OS in high risk subgroup at intermediate restaging.

CONCLUSION

The current analysis confirms predictive PET value for patients with DLBCL at intermediate as well at the end restaging. The question if and how to use the PET findings for tailoreing of therapy remains to be answered in prospective trials.

Dendritic cells and T lymphocyte interactions in patients with lymphoid malignancies

Dendritic cell (DC) vaccination is an attractive approach to the treatment of patients with lymphoid tumors. To evaluate its feasibility, we have tested the functional properties of DC and T-lymphocytes in patients with treated and untreated chronic lymphocytic leukemia (CLL) and follicular lymphoma (FL). Healthy volunteers were used both as controls and as a source of cells for allogeneic mixed leukocyte reaction (MLR). In these reactions, dendritic cells from both untreated and treated patients were comparable to dendritic cells from healthy volunteers. In all the untreated patients studied, autologous dendritic cells promoted the survival and proliferation of both CD4 and CD8 lymphocytes (though the proliferation response was much better in the CD4 subset), whereas only 3 out of 5 treated patients were able to mount this response with CD4 lymphocytes and 4 out of 5 with CD8 lymphocytes. In 3 out of 5 untreated patients, pulsing of DCs with tetanus toxoid promoted a better CD4 response than was achieved with unpulsed DCs, while none of 5 treated patients had an additional response after pulsing with tetanus toxoid. None of patients studied, either treated or untreated, had a better CD8 response to pulsed DCs than to unpulsed ones. During CD4 lymphocyte proliferation, more CD4(+)CD25(hi) lymphocytes were generated in both treated and untreated patients than in healthy controls. Poor proliferation of cytotoxic cells and preferential proliferation of CD4(+)CD25(hi) T-regulatory cells in response to self and/or foreign antigens might be one of the mechanisms responsible for immunosuppression and impaired tumor surveillance in patients with lymphoid malignancies.

[Ten years since the successful introduction of the first monoclonal antibody (rituximab) into the therapy of lymphomas]

Cancer treatment is based on combination of systemic chemotherapy and radiotherapy. The new methods of therapy based on biological priniciples have been introduced within last decade. The monoclonal antibody rituximab was launched ten years ago in 1997. This antibody against CD20 antigen, which is expressed on B cell lymphocytes and on the majority of B-cell lymphoid malignancies, has revolutionized the lymphoma therapeutic strategy. The immuno-chemotherapy has dramatically improved the outcome of diffuse large B-cell lymphomas patients. The combination of rituximab and chemotherapy as first line therapy has for the first time improved the survival of follicular lymphoma patients previously considered to be incurable. Rituximab has become the inevitable part of therapeutic regimens for other B-cell lymphomas, chronic lymphocytic leukaemia as well as for some non-malignant diseases. The important milestones, the therapeutic results of rituximab and other approved monoclonal antibodies (alemtuzumab, ibritumomab tiuxetan 90Y) is reviewed in this paper as well as short compendium of new antibodies is given. The cost effectiveness of the new therapy is discussed.

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.

[Cefepime as an empiric treatment of febrile neutropenia in patients after high dose therapy and autologous stem cell transplantation]

BACKGROUND

Febrile neutropenia is one of the most frequent complications in intensively treated hematooncological patients and almost inevitably occurs after high dose therapy and autologous stem cell transplantation. Empiric broad-spectrum antibiotic treatment is indicated in the initial management. Fourth-generation cephalosporins are the option. This retrospective study was initiated to assess efficacy and safety of cefepime as an empiric therapy of febrile neutropenia following high dose therapy and autologous stem cell transplantation.

METHODS AND RESULTS

319 high dose therapy procedures with autologous stem cell transplantation in 287 patients mostly with hematological malignancies were performed at our department between January 2002 and December 2005. We present analysis of 169 out of 229 febrile episodes in 163 patients (median age 53) being treated with cefepime in the initial empiric treatment of febrile neutropenia. 12 episodes (7.1 %) were clinically documented (pneumonia 9, sinusitis 2, acute cholecystitis 1), 60 (35.5 %) were confirmed microbiologically (presented as bacteremia) and 97 (57.4 %) were fever of unknown origin. 50 isolates (83.4 %) out of 60 microbiologically documented infections were G-positive bacteria, 8 isolates (13.3 %) were G-negative bacteria and 2 (3.3 %) were mixed G-positive and G-negative cultures. According to the MASCC score 14 episodes were assessed as high risk. Effect of cefepime as a single agent was observed in 85 episodes (50.3 %) and in 22 (13.0 %) episodes treated with combination therapy due to susceptibility of isolated pathogen in blood culture. Combination therapy of two antibiotics (cefepime + aminoglycoside or glycopeptide) given for persistent fever was effective in 13 patients (7.7 %). Treatment failure was observed in 48 (28.4 %) episodes, we registered 10 death.

CONCLUSIONS

Therapy with cefepime represents an appropriate choice for empiric antibiotic treatment of febrile neutropenia in hematooncological patients. Cefepime demonstrates clinical safety and efficacy and can be used in monotherapy or in combination with other drugs (overall response 72.2 %, as a single agent 50.3 %).

[Some new findings in the pathogenesis of myeloproliferative disorders and new insight into more effective treatment]

Advances in molecular biology and genomics enabled more detailed view on the pathogenesis of myeloproliferative disorders, which are considered to be a diseases of hematopoietic stem cell. The autor provides an brief overview of the genetic alterations, leading to the chronic myeloid leukemia, myelodysplastic syndrome and acute myeloid leukemia. In the second part, molecular targeted therapies that have been developed based on these insights are reviewed. These are particularly methods preventing increased proliferation such as inhibition of tyrosinkinases (imatinib, dasatinib), inhibitions of farnesyltransferase (tipifarnib), inhibition of angiogenesis (bevacizumab, vatalanib), induction of diferentiation (hypomethylating agenents) and induction of apoptosis (bortezomib). More detailed information is given on some novel drugs which are currently in clinical trials.

[High dose therapy with autologous stem cell transplantation in patients with Hodgkin's lymphoma: long-term follow-up in patients treated in one center]

BACKGROUND

Majority of patients with Hodgkin's Lymphoma (HL) can be cured by first line therapy. The high dose therapy (HDT) with autologous stem cell transplantation (ASCT) is the option which can be used in the situation when the conventional therapy failed. METHODS AND RESULTS. Beginning 1994 till 2005 84 pts with HL who did not respond the conventional chemotherapy underwent 105 HDT procedures with ASCT. The median age at the time of HDT was 30.5 years. The reason for salvage therapy followed by HDT with ASCT was the failure to achieve 1st complete remission-- CR (n 16) or the subsequent relapse or progression (n 68). The disease status at the time of HDT after conventional salvage chemotherapy was assessed as chemosensitive in 65 pts (77.4%) and chemoresistant in 19 pts (22.6%). The most frequent HDT regimen used was BEAM (82 HDT), 22 pts entered into the tandem HDT program. Bone marrow only was used as the source of progenitor cells in 4 ASCT, peripheral blood progenitor cells (PBPC) only were used in 85 ASCT and the combination of both in 16 ASCT. The disease status after the HDT with ASCT was assessed (77 pts were qualifiable) as CR in 39 pts (50.6%), PR in 31 (40.3%) and as stable disease or progression in 7 pts (9.1%). Treatment related mortality in HDT with PBPC was 3.9%. The median follow up is 5.3 years. The five year probability of event free survival (EFS) is 43.1% and overall survival 53.2%. The EFS and OS probability respectively for the chemosensitive patients was 48.6% and 62.9% respectively. The status at HDT and the results after it have prognostic significance. There were observed 39 deaths and 26 of them were caused by disease progression. Secondary tumor was observed in 5 pts and in all of them it caused the death.

CONCLUSIONS

The HDT with ASCT allows the long-term survival without disease progression in about a half of the patients with reasonable toxicity.

Cell death signalling pathways in the pathogenesis and therapy of haematologic malignancies: overview of apoptotic pathways

Apoptosis, a Greek descriptive term for falling leaves or petals, plays an important role in the progression of many diseases. Apoptosis is essential for the development and survival of multi-cellular organisms. Malignant diseases, including haematologic malignancies, are associated with defects in the cell death mechanism. These defects are not only important for the growth advantage of malignant clones, but when understood can be used for specific therapeutic targeting of malignant cells while sparing normal cells. The cellular and molecular mechanisms of apoptosis have been extensively demonstrated and are reviewed in this article. In this part of the review we focus on basic details of the apoptosis pathways, key players of the receptor-mediated apoptosis, and molecules involved in the cross-talk between individual apoptosis pathways and apoptosis regulation.

Cell death signalling pathways in the pathogenesis and therapy of haematologic malignancies: overview of therapeutic approaches

Malignant diseases, including haematologic malignancies, are associated with defects in the cell death mechanism. These defects are not only important for the growth advantage of the malignant clone, but when understood can be used for specific therapeutic targeting of malignant cells while sparing normal cells. The promising groups of agents that trigger, directly or indirectly, apoptosis of haematologic cancer cells are reviewed in this article. Some of the agents have recently been approved for therapy, some are under the clinical evaluation in various phases of clinical trials and some are tested under the experimental laboratory conditions.

[Current and perspective treatment of chronic lymphocytic leukemia]

Chronic lymphocytic leukemia represents the most frequent hematological malignancy in the western population. Important role in its pathogenesis has the inhibition of apoptosis, disturbances in differentiation of B-lymphocytes, slightly increased proliferation and induction of angiogenesis. Current treatment options (chemotherapy and immunotherapy) can improve the quality of life and prolong disease-free survival, but the overall survival is not significantly influenced. The only curative treatment alternative is the allogeneic hematopoietic stem cell transplantation. However, this treatment is accompanied by the risk of peritransplantation mortality and its use is limited for younger patients. Number of new compounds is clinically tested. New drugs can influence intracellular events such as induction of apoptosis or inhibition of the transduction cascade. Review summarises treatment alternatives and presents an algorithm for their clinical application.

[Bortezomib (Velcade) in relapsed/refractory multiple myeloma--the first experience in the Czech Republic]

BACKGROUND

Multiple myeloma is the second most prevalent and mostly fatal hematologic cancer. Further advances have been made in understanding the mechanisms involved in the myeloma pathogenesis and elucidation of critical signalling pathways as therapeutical targets. Proteasome inhibitors are the example of this new approach and bortezomib is the first agent in this class to enter clinical trials.

METHODS AND RESULTS

In 6 hematological centers in Czech Republic 29 patients with refractory/relapsed myeloma had been treated with bortezomib (Velcade, Millennium Pharmaceuticals) in 2004. The initial dose 1.3 mg/m2 of Velcade was given, in 1 case the dose was adjusted due to pre-existing renal failure to 1 mg/m2. The response was achieved in 17 patients (59%). Four patients had complete, 11 partial and two minor responses. In 5 cases stabilization of disease was observed and 6 patients progressed during the therapy.

CONCLUSIONS

Unfortunately, one patient died immediately after the start of therapy due to sepsis. The most common adverse events were thrombocytopenia, anaemia, neuropathy, gastrointestinal complication, renal failure and fatigue. Grade 4 adverse events occurred in 37.9% of patients (4x thrombocytopenia, 2x gastrointestinal, 2x renal failure, 1x sepsis, leucopenia, hepatopathy and anaemia, respectively). Peripheral neuropathic pain of grade 3 was reported in 4 cases, in one patient therapy had to be interrupted due to this complication. We confirmed promising results of phase II trials.

The use of comparative duplex PCR in monitoring of patients with non-Hodgkin's lymphoma and chronic lymphocytic leukaemia

Various quantitative PCR approaches have been utilized during the last years to provide information about the treatment efficacy and the risk of recurrent disease in haematological malignancies. Apart from the frequently used real-time PCR, cost-saving modified standard PCR methods may be applied as well. This report evaluates the utility of the end-point comparative duplex PCR. We have used this method for monitoring of 35 patients with either NHL or CLL and observed a good correlation between quantitative molecular results and clinical outcome. There was also an agreement between comparative duplex PCR and real-time PCR in patients who were monitored by both methods. We therefore believe that use of this technique should be strongly considered instead of simple qualitative detection in monitoring of therapeutic outcome in NHL or CLL patients.

[Proteasome inhibitors--new option in the treatment of tumor diseases]

Chemotherapy itself probably will not substantially improve the prognosis of cancer patients in the future. Therefore new methods are needed one of the promising option is the direct interference with intracellular metabolism--"the targeted therapy". Proteasome inhibitors are the example of this new approach and bortezomib is the first agent in this class, which enters clinical trials. We summarize theoretical background and the first clinical experiences with this drug.

[Imatinib--a new perspective in the treatment of tumors]

Among novel promising approaches to anticancer therapy belongs the targeting inhibition of signal transduction. This review outlines present-day experiences with imatinib (Glivec), a potent inhibitor of the tyrosine kinases bcr-abl, c-kit and platelet-derived growth factor receptor kinase. Due to inhibition of bcr-abl tyroxine kinase, imatinib has rapidly become the standard therapy for chronic myelocytic leukemia; inhibition of c-kit receptor explains its effectivity in the treatment of patients with gastrointestinal stromal tumors. Another known target of imatinib is tyrosine kinase of PDGFR, which is activated in numerous malignancies, particularly in dermatofibrosarcoma protuberans. Discovery of the novel fusion gene in hypereosinophilic syndrome (FIPILI-PFGFRA, whose product is an imatinib sensitive protein kinase) permitted to treat successfully this event. Possible combination of imatinib with conventional chemotherapeutic drugs and other key signal transduction inhibitors are mentioned.

[Long-term culture of plasma cells from patients with myeloma and establishment of a permanent cell line]

Multiple myeloma plasma cells are actively dividing cells with the long surviving ability in the ex-vivo culture. In the effort for better understanding of the proliferative potential of malignant myeloma cells and establishment of permanent myeloma cell lines we performed long term cultures of human myeloma cells ex-vivo. During the last two years we cultured 41 bone marrow samples from 39 patients with multiple myeloma. Cells were cultured in the RPMI 1640 culture medium with 15% fetal calf serum at 37 degrees C in 5% CO2 and approximately one third of the culture medium was changed regularly twice a week. Most of the marrows cultures died by apoptosis within 30 days. Four bone marrow samples were cultured for more than 11 months, however, no culture can be qualified as an established cell line. In three cases permanent B-lymphoblastoid cell lines were established (UHKT-55, UHKT-56 a UHKT-57) but secondary immortalization by Epstein-Barr virus was suggested.

CONCLUSIONS

Presented results suggest that myeloma plasma cells can survive and are able to proliferate in the ex-vivo culture for several months up to one year independently on the addition of any external growth factor without spontaneous apoptosis or necrosis. The probability of the establishment of a permanent cell line of plasma cell origin is, however, low. Presence of accessory bone marrow cells was the most important factor for the long-term survival of myeloma cells.

[Renal infiltration in lymphoma--diagnosis in renal biopsy (case report)]

A case story of a patient with renal biopsy (RB) proven infiltration with lymphoma is given. RB in patient with known malignancy and onset of renal failure was indicated with regard to an atypical picture of kidney involvement (non-enlarged kidneys, without any structural changes typical for tumour mass presence). Though spread of the primary tumour to the kidney is not uncommon, involvement severe enough to impair renal function is unusual and occurs primarily with rapidly growing haematologic malignancies; diagnosis is being established by renal biopsy only rarely.

[Intensive therapy with paclitaxel (Taxol) and cyclophosphamide followed by administration of G-CSF as a mobilization regimen in patients with breast carcinoma and indications for autologous hematopoietic cell transplantation]

Cyclophosphamide (4 g/m2) and paclitaxel (Taxol) (175, 200 or 250 mg/m2) therapy with subsequent administration of G-CSF (10 micrograms/kg) has been used as intensification and as mobilization therapy for patients with breast cancer. This regimen was used in 19 patients, as part of adjuvant therapy in 14 and as part of therapy of metastatic disease in five. Median number of collected CD34+ cells was 17.5 x 10(6)/kg (2.9-48.1). All patients except one (94.7%) reached minimal required number of CD34+ cells (> or = 3 x 10(6)/kg). Median number of leukapheresis was two. The required number of cells (> or = 3 x 10(6)/kg) was collected in one leukapheresis in 17 out of 19 patients (89.5%) and more than five and 10 x 10(6)/kg CD34+ cells respectively were collected in 14 (73.7%) and 11 (57.9%) patients respectively. No factor significantly influencing the amount of collected cells (except the trend in favour of later year of therapy and large-volume leukapheresis) was identified. Leukopenia gr. 4 was observed in 88.9% of treated patients and febrile neutropenia developed in 46.2% patients. Although the antitumour activity of this chemotherapy was not possible to assess it seems that this intensification could be successfully used as a therapy and as very potent mobilization regimen.