Low-burden TP53 mutations represent frequent genetic events in CLL with an increased risk for treatment initiation

TP53 aberrations predict chemoresistance and represent a contraindication for the use of standard chemoimmunotherapy in chronic lymphocytic leukaemia (CLL). Recent next-generation sequencing (NGS)-based studies have identified frequent low-burden TP53 mutations with variant allele frequencies below 10%, but the clinical impact of these low-burden TP53 mutations is still a matter of debate. In this study, we aimed to scrutinise the subclonal architecture and clinical impact of TP53 mutations using a sensitive, NGS-based mutation analysis in a 'real-world' cohort of 901 patients with CLL. In total, 225 TP53 mutations were identified in 17.5% (158/901) of the patients; 48% of these alterations represented high-burden mutations, while 52% were low-burden TP53 mutations. Low-burden mutations as sole alterations were identified in 39% (62/158) of all mutated cases with 82% (51/62) of these being represented by a single low-burden TP53 mutation. Patients harbouring low-burden TP53 mutations had significantly lower time to first treatment compared to patients with wild-type TP53. Our study has expanded the knowledge on the frequency, clonal architecture, and clinical impact of low-burden TP53 mutations. By demonstrating that patients with sole low-burden TP53 variants represent more than one-third of patients with TP53 mutations and have an increased risk for treatment initiation, our findings strengthen the need to redefine the threshold of TP53 variant reporting to below 10% in the routine diagnostic setting.

Parallel testing of liquid biopsy (ctDNA) and tissue biopsy samples reveals a higher frequency of EZH2 mutations in follicular lymphoma

BACKGROUND

Recent genomic studies revealed enhancer of zeste homolog 2 (EZH2) gain-of-function mutations, representing novel therapeutic targets in follicular lymphoma (FL) in around one quarter of patients. However, these analyses relied on single-site tissue biopsies and did not investigate the spatial heterogeneity and temporal dynamics of these alterations.

OBJECTIVES

We aimed to perform a systematic analysis of EZH2 mutations using paired tissue (tumor biopsies [TB]) and liquid biopsies (LB) collected prior to treatment within the framework of a nationwide multicentric study.

METHODS

Pretreatment LB and TB samples were collected from 123 patients. Among these, 114 had paired TB and LB, with 39 patients characterized with paired diagnostic and relapse samples available. The EZH2 mutation status and allele burden were assessed using an in-house-designed, highly sensitive multiplex droplet digital PCR assay.

RESULTS

EZH2 mutation frequency was found to be 41.5% in the entire cohort. In patients with paired TB and LB samples, EZH2 mutations were identified in 37.8% of the patients with mutations exclusively found in 5.3% and 7.9% of TB and LB samples, respectively. EZH2 mutation status switch was documented in 35.9% of the patients with paired diagnostic and relapse samples. We also found that EZH2 wild-type clones may infiltrate the bone marrow more frequently compared to the EZH2 mutant ones.

CONCLUSION

The in-depth spatio-temporal analysis identified EZH2 mutations in a considerably higher proportion of patients than previously reported. This expands the subset of FL patients who most likely would benefit from EZH2 inhibitor therapy.

Landscape of BCL2 Resistance Mutations in a Real-World Cohort of Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia Treated with Venetoclax

The oral, highly selective Bcl2 inhibitor venetoclax has substantially improved the therapeutic landscape of chronic lymphocytic leukemia (CLL). Despite the remarkable response rates in patients with relapsed/refractory (R/R) disease, acquired resistance is the leading cause of treatment failure, with somatic BCL2 mutations being the predominant genetic drivers underpinning venetoclax resistance. To assess the correlation between disease progression and the most common BCL2 mutations G101V and D103Y, sensitive (10−4) screening for the most common BCL2 mutations G101V and D103Y was performed in 67 R/R CLL patients during venetoclax single-agent or venetoclax–rituximab combination therapy. With a median follow-up time of 23 months, BCL2 G101V and D103Y were detected in 10.4% (7/67) and 11.9% (8/67) of the cases, respectively, with four patients harboring both resistance mutations. Ten out of eleven patients carrying BCL2 G101V and/or D103Y experienced relapse during the follow-up period, representing 43.5% of the cases (10/23) showing clinical signs of disease progression. All BCL2 G101V or D103Y variants were detected in patients receiving venetoclax as a continuous single-agent treatment while these mutations were not observed during or after fixed-duration venetoclax therapy. Targeted ultra-deep sequencing of BCL2 uncovered three additional variants in four patient samples obtained at relapse, suggesting convergent evolution and implying a cooperating role of BCL2 mutations in driving venetoclax resistance. This cohort is the largest R/R CLL patient population reported to date in which BCL2 resistance mutations were investigated. Our study demonstrates the feasibility and clinical value of sensitive screening for BCL2 resistance mutations in R/R CLL.

Pomalidomide Treatment in Relapsed/Refractory Multiple Myeloma Patients—Real-World Data From Hungary

Pomalidomide is a third generation immunomodulatory drug in the treatment of refractory and relapsed multiple myeloma patients. Our aim was to investigate the efficacy and safety of pomalidomide therapy in a real world setting. Eighty-six Hungarian patients were included, 45 of whom received pomalidomide ± an alkylating agent, while in 38 of them pomalidomide was combined with a proteasome inhibitor. 56 patients (65%) showed any response to the treatment with 18 complete or very good partial remissions and 38 partial remissions. At a median duration of follow-up of 18.6 months, the median progression-free survival (PFS) was 9.03 months, while the median overall survival (OS) was 16.53 months in the whole cohort. Patients with early stage disease (R-ISS 1 and 2) had better survival results than those with stage 3 myeloma (p = 0.002). Neither the number of prior treatment lines, nor lenalidomide refractoriness had a significant impact on PFS. PFS was found similar between the cohort of patients with impaired renal function and the cohort without kidney involvement. During the study, eight mortal infections and two fatal bleeding complications occurred, however, mild hematologic and gastrointestinal toxicities were identified as the most frequent adverse events. The results of our investigations confirm that pomalidomide is an effective treatment option for relapsed/refractory MM, besides, the safety profile is satisfactory in subjects with both normal and impaired renal function.

Revealing a Phenotypical Appearance of Ibrutinib Resistance in Patients With Chronic Lymphocytic Leukaemia by Flow Cytometry

Background: Ibrutinib is widely known as an effective and well-tolerated therapeutical choice of the chronic lymphocytic leukaemia (CLL). However, acquired resistance may occur during the treatment, causing relapse. Early detection of ibrutinib resistance is an important issue, therefore we aimed to find phenotypic markers on CLL cells the expression of which may correlate with the appearance of ibrutinib resistance.

Methods: We examined 28 patients’ peripheral blood (PB) samples (treatment naïve, ibrutinib sensitive, clinically ibrutinib resistant). The surface markers’ expression (CD27, CD69, CD86, CD184, CD185) were measured by flow cytometry. Furthermore, the BTK^C481S resistance mutation was assessed by digital droplet PCR. Moreover, the CLL cells’ phenotype of a patient with acquired ibrutinib resistance was observed during the ibrutinib treatment.

Results: The expression of CD27 (p = 0.030) and CD86 (p = 0.031) became higher in the clinically resistant cohort than in the ibrutinib sensitive cohort. Besides, we found that high CD86 and CD27 expressions were accompanied by BTK^C481S mutation. Our prospective study showed that the increase of the expression of CD27, CD69 and CD86 was noticed ahead of the clinical resistance with 3 months.

Conclusion: Our study suggests that the changes of the expression of these markers could indicate ibrutinib resistance and the examination of these phenotypic changes may become a part of the patients’ follow-up in the future.

Long-time progression-free survival in relapsed, refractory multiple myeloma with the oral ixazomib-lenalidomide-dexamethasone regime

Összefoglaló. Bevezetés: A myeloma multiplex mindmáig alapvetően gyógyíthatatlan betegség, ezért nagy klinikai jelentőségük van az eredményes mentő kezeléseknek. A szájon át adható első proteaszómagátlóval, az ixazomibbal kiegészített lenalidomid-dexametazon terápia jól tolerálható, csak orális szerekből álló kombináció, mely hazánkban 2015 áprilisától kezdődően a "Named Patient Program" keretén belül vált elérhetővé relabált, refrakter myeloma multiplexes betegek kezelésére. Célkitűzés: Kutatásunk célja az ixazomib-lenalidomid-dexametazon kezelés mellett a hosszú távon progressziómentes túlélők célzott vizsgálata. Módszer: A program keretében összesen 7 centrumban 80 visszaeső beteg részesült e triplet kezelésben, adataikat retrospektíven elemeztük. Leíró statisztikai és Kaplan-Meier-analízist végeztünk. Eredmények: A betegek nagyobb hányada reagált: 63,75%-os válaszarány mellett 14 (17,5%) betegnél nem volt terápiás válasz/stabil betegség alakult ki, és 15-nél (18,75%) a betegség a kezelés mellett is progrediált. A progressziómentes túlélés a teljes betegcsoportban 10,6 hónapnak adódott, ugyanakkor 16 beteg (18,75%) két éven túl progressziómentesnek bizonyult, sőt közülük 11-nél a betegség még 3 év után sem progrediált. Tanulmányunkban a fenti, hosszú távú túlélő betegcsoport tulajdonságait tárjuk fel. Megbeszélés: A folyamatos terápia a myeloma multiplex kezelésében meghatározóvá vált. Ezért fontos ismernünk, hogy kik lehetnek azok a betegek, akik különösen sokat profitálnak egy bizonyos terápiából. A hosszú távon progressziómentes túlélők között az immunglobulin-nehézláncot érintő transzlokációk vagy triszómiák közül (trend szintjén) az utóbbiak kedvezőbb progressziómentes túléléssel bírtak, de progressziómentes platót mindkét betegcsoportban észleltünk. A betegség tumortömegét mérő nemzetközi stádiumbeosztás (ISS) nem jelezte előre a hosszú túlélést. Gyógyszerelhagyáshoz vezető mellékhatást a hosszú távú túlélő csoportban egyet sem regisztráltunk; az észlelt mellékhatások nagy része enyhe volt. Következtetések: Munkánk során az ixazomib-lenalidomid-dexametazon kombinációt effektívnek és biztonságosnak találtuk relabált, refrakter myeloma multiplex kezelésére, mely a betegek mintegy hatodánál több éven át eredményesen alkalmazható. Cikkünkkel a hazai beteganyagon szerzett tapasztalatainkat szeretnénk megosztani a COVID-19-világjárvány alatt különösen aktuálissá vált, tisztán orális terápiás lehetőségről. Orv Hetil. 2021; 162(36): 1451-1458.

SUMMARY

INTRODUCTION

Despite great advances in therapy, multiple myeloma is still a largely incurable disease, therefore the importance of salvage therapies is paramount. The first oral proteasome inhibitor ixazomib in combination with lenalidomide-dexamethasone is a tolerable, orally administered regime, which has become available for Hungarian relapsed, refractory multiple myeloma patients from April 2015 in the Named Patient Program.

OBJECTIVE

Our goal was to investigate the long-time progression-free surviving patient population treated with the ixazomib-lenalidomide-dexamethasone triplet.

METHOD

We retrospectively studied a total of 80 patients from 7 centers who received the triplet combination. Survival analyses were performed.

RESULTS

Two-third of the patients responded: the overall response rate was 63.75%. 14 patients (17.5%) did not respond/had stable disease and 15 patients (18.75%) outright progressed upon therapy. Although progression-free survival was only 10.6 months for the entire patient cohort, the disease in a subgroup of 16 patients did not progress within two years. In fact, 11 of them were still in sustained remission after 3 years of therapy. Our goal was to analyze the characteristics of this subgroup.

DISCUSSION

The idea of long-term therapy of multiple myeloma is gaining widespread acceptance. Therefore it is important to know which patients may benefit the most from certain therapies. Among these 16 long-term responder patients, reciprocal translocation of the immunoglobulin heavy chain seemed to lack an adverse impact on progression-free survival; comparable to trisomies, both curves had a progression-free plateau. The International Staging System (ISS) score at the start of therapy did not predict long-term survivorship. Most of the side effects in this subgroup were mild, manageable, none led to therapy discontinuation.

CONCLUSION

Ixazomib-lenalidomide-dexamethasone was confirmed to be an effective and safe combination for relapsed, refractory multiple myeloma, and one-sixth of the treated patients were able to receive it for several years, effectively. This fully oral therapeutic option is at its best during the present COVID-19 pandemic. Orv Hetil. 2021; 162(36): 1451-1458.

Screening and monitoring of the BTKC481S mutation in a real-world cohort of patients with relapsed/refractory chronic lymphocytic leukaemia during ibrutinib therapy

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has revolutionised the therapeutic landscape of chronic lymphocytic leukaemia (CLL). Acquired mutations emerging at position C481 in the BTK tyrosine kinase domain are the predominant genetic alterations associated with secondary ibrutinib resistance. To assess the correlation between disease progression, and the emergence and temporal dynamics of the most common resistance mutation BTK^C481S , sensitive (10^-4 ) time-resolved screening was performed in 83 relapsed/refractory CLL patients during single-agent ibrutinib treatment. With a median follow-up time of 40 months, BTK^C481S was detected in 48·2% (40/83) of the patients, with 80·0% (32/40) of them showing disease progression during the examined period. In these 32 cases, representing 72·7% (32/44) of all patients experiencing relapse, emergence of the BTK^C481S mutation preceded the symptoms of clinical relapse with a median of nine months. Subsequent Bcl-2 inhibition therapy applied in 28/32 patients harbouring BTK^C481S and progressing on ibrutinib conferred clinical and molecular remission across the patients. Our study demonstrates the clinical value of sensitive BTK^C481S monitoring with the largest longitudinally analysed real-world patient cohort reported to date and validates the feasibility of an early prediction of relapse in the majority of ibrutinib-treated relapsed/refractory CLL patients experiencing disease progression.

Lenalidomide abrogates the survival effect of bone marrow stromal cells in chronic lymphocytic leukemia

In the pathogenesis of chronic lymphocytic leukemia (CLL) the microenvironment plays an important role, as it produces survival signals and mediates drug resistance. Lenalidomide, which has immunomodulatory effect, can enhance the activation of T-, NK-cells and endothelial cells, however there are no data available whether it can modulate bone marrow stromal cells (BMSCs). In our study, we investigated the effects of lenalidomide on BMSCs and CLL cells. CLL cells were cultured alone or with BMSCs and were treated with lenalidomide. Apoptosis, immunophenotype, and cytokine secretion of BMSCs and CLL cells were determined by flow cytometry. Lenalidomide slightly increased the apoptosis of CLL cells and abrogated the anti-apoptotic effect of BMSCs on CLL cells. Lenalidomide treatment decreased the expression of antigens on CLL cells, which mediate the interactions with the microenvironment. Interestingly, lenalidomide enhanced the expression of IRF4 and the co-stimulatory molecule CD86. The secretion of several cytokines was not changed significantly by lenalidomide. CD49d-negative CLL cases were more sensitive to lenalidomide treatment. Our results suggest that lenalidomide has a limited effect on BMSCs, but it renders CLL cells more immunogenic and unresponsive to survival signals provided by BMSCs.

Beneficial Effect of Lenalidomide-Dexamethason Treatment in Relapsed/Refractory Multiple Myeloma Patients: Results of Real-Life Data From 11 Hungarian Centers

In Hungary, the cost of lenalidomide-based therapy is covered only for relapsed multiple myeloma (MM) patients, therefore lenalidomide is typically used in the second-line either as part of a triplet with proteasome inhibitors or as a doublet. Lenalidomide-dexamethasone is a standard treatment approach for relapsed/refractory MM, and according to recent large randomized clinical trials (RCT, the standard arm of POLLUX, ASPIRE, TOURMALINE), the progression-free survival (PFS) is expected to be approximately 18 months. We surveyed ten Hungarian centers treating MM and collected data of 278 patients treated predominantly after 2016. The median age was 65 years, and patients were distributed roughly equally over the 3 international staging system groups, but patients with high risk cytogenetics were underrepresented. 15.8% of the patients reached complete response, 21.6% very good partial response, 40.6% partial response, 10.8% stable disease, and 2.5% progressed on treatment. The median PFS was unexpectedly long, 24 months, however only 9 months in those with high risk cytogenetics. We found interesting differences between centers regarding corticosteroid type (prednisolone, methylprednisolone or dexamethasone) and dosing, and also regarding the choice of anticoagulation, but the outcome of the various centers were not different. Although the higher equivalent steroid dose resulted in more complete responses, the median PFS of those having lower corticosteroid dose and methylprednisolone were not inferior compared to the ones with higher dose dexamethasone. On multivariate analysis high risk cytogenetics and the number of prior lines remained significant independent prognostic factors regarding PFS (p < 0.001 and p = 0.005). Our results show that in well-selected patients Lenalidomide-dexamethasone can be a very effective treatment with real-world results that may even outperform those reported in the recent RCTs. This real world information may be more valuable than outdated RCT data when treatment options are discussed with patients.

Real-world data on the efficacy and safety of daratumumab treatment in Hungarian relapsed/refractory multiple myeloma patients

Daratumumab is a human anti-CD38 monoclonal antibody used in the treatment of refractory and relapsed multiple myeloma. We investigated the efficacy and safety of daratumumab therapy in a real-world setting. Ninety-nine Hungarian patients were included; 48 received monotherapy, while lenalidomide and bortezomib combinations were administered in 29 and 19 cases, respectively. Overall response rate was assessable in 88 patients, with 12 complete, 10 very good partial, 34 partial, and seven minor responses. At a median duration of follow-up of 18.6 months, median progression-free survival (PFS) among all patients was 17.0 months. These values were inferior in the bortezomib combination and monotherapy groups. Patients with early-stage disease (ISS1) had better survival results than those with stage 2 or 3 myeloma (p = 0.009). Heavily pretreated patients had inferior PFS compared to those with 1-3 therapies (p = 0.035). Patients with impaired renal function had PFS results comparable with those having no kidney involvement. There were 10 fatal infections, and the most frequent adverse events were mild infusion-associated reactions and hematologic toxicities. Our results confirm that daratumumab is an effective treatment option for relapsed/refractory MM with an acceptable safety profile in patients with normal and impaired renal function.

[Impact of minimal residual disease detection after treatment of multiple myeloma]

INTRODUCTION

Prognostic impact of the detection of minimal residual disease (MRD) in multiple myeloma (MM) has been confirmed in numerous studies.

AIM

Retrospective examination of our patient database (107 newly diagnosed multiple myelomas between 2007 and 2017). Flow cytometry (FCM) was performed as MRD assessment.

METHOD

MRD assessment was performed in 56 patients (median age: 68 years), after induction treatment of multiple myeloma. The treatment contained bortezomib in 91%, autologous haematopoetic stem cell transplantation (ASCT) was perfomed in 50%. MRD detection was performed on bone marrow samples, predominantly in our hospital (BD FACScan, 3 colour, panel: CD38, CD138, CD19, CD45, CD56, CD28, CD117, cyKappa, cyLambda, 100 000 events).

STATISTICAL ANALYSIS

SPSS 13.0.

RESULTS

The progression-free survival (PFS) and the overall survival (OS) were significantly longer in MRD negative (n = 22) patients (PFS: 54 months, OS: 79% after 5 years) than MRD positive patients (n = 34, PFS: 22 months, OS 21% after 5 years, p = 0.001). Patients achieving complete response (CR) (n = 29) have different PFS (MRD negative CR: 60 months, MRD positive CR: 21 months, p<0.001). Patents achiving MRD negative very good partial response (n = 5) have similar PFS (54 months) as patients with MRD negative CR. The longest PFS (68 months) was observed in MRD negative patients, after ASCT (n = 11), while the PFS was significantly (p<0.001) shorter in patients who were MRD positive after ASCT (n = 18, PFS: 25 months), similarly in MRD positive patients without ASCT (n = 15, PFS 21 months). Cox regression analysis (stage, cytogenetic risk, ASCT) confirmed that MRD is an independent prognostic factor of PFS and OS. We did not find significant relationship between MRD and stage, cytogenetic risk, number of treatment cycles, ASCT.

CONCLUSIONS

The depth of response after induction treatment of MM is an independent predictor of survival. MRD assessment with FCM is recommended to define response. Consideration of maintenance treatment in MRD positive patients and eradication of MRD are also recommended. Orv Hetil. 2019; 160(13): 502-508.

[TP53 mutation analysis in chronic lymphocytic leukaemia]

INTRODUCTION

In recent years much progress has been made in the therapy of chronic lymphocytic leukaemia, as the new innovative medicine proved to be effective in managing patients carrying TP53 abnormalities. To identify all these patients, it is essential to screen for both forms of TP53 defects, including both 17p deletions and TP53 mutations.

AIM

The aim of this study was to determine the frequency of TP53 mutations and their association with 17p deletions in a large Hungarian cohort of 196 patients suffering from chronic lymphocytic leukaemia.

METHOD

We performed mutation analysis of TP53 (exons 3-10) using Sanger sequencing.

RESULTS

TP53 mutations were present in 15.8% of patients, half of which were associated with 17p deletion. By analysing both forms, TP53 defect was identified in 25.4% of the patients.

CONCLUSIONS

Our study demonstrates that by performing a TP53 mutation analysis, an additional 10% of high-risk patients can be detected. Orv. Hetil., 2017, 158(6), 220-228.

Essentialis thrombocythaemiás betegek kezelési eredményei osztályunkon

Introduction: Essential thrombocythemia is a Philadelphia chromosome-negative chronic myeloproliferative neoplasia with a risk of bleeding and thromboembolic complications during the course of illness. Cytoreductive drugs, such as non-selective hydroxyurea or interferon as first-line and specific, megakaryocyte-thrombocyte reductive anagrelide chosen as second-line treatment in cases of adverse, intolerable effects of hydroxyurea can lower the incidence of bleeding/thrombotic episodes in patients with essential thrombocythemia. Aim: In this observational survey the effect of anagrelide was investigated in patients with essential thrombocythemia, who were first treated with hydroxyurea but failed to have clinicopathologic reponse (resistant) or were intolerant (adverse effects). Method: Between 2000 and 2014, 104 patients were diagnosed with essential thrombocythemia and treated first-line with hydroxyurea (weekly median dose of 7500 mg) in the haematologic outpatient department of the authors. Because of intolerance and/or resistance, hydroxyurea was changed to anagrelide (7.5 mg weekly median dose), the doses of hydroxyurea and anagrelide were adjusted to achieve clinicopathological response according to the updated criteria of the European LeukemiaNET. Effect of anagrelide as monotherapy (first- or second-line after hydroxyurea) or in combination with hydroxyurea was followed. Statistical analysis was performed using the Windows Statistical Package Program. Results: Of the 104 patients with essential thrombocythemia (according to the updated WHO-ET classifications 58 patients JAK2V617F mutation positive, 46 patients negative, 15 patients calreticulin mutation negative, 6 patients MPL-1 mutation negative) 87 patients received hydroxyurea in first line, 4 patients interferon, and 13 patients acetylsalycilic acid only. Seven patients who proved to be intolerant and 22 patients who were resistant to hydroxyurea received anagrelide in second line (in 18 patients monotherapy and in 11 patients in combination with hydroxyurea), while other 5 rather young patients in first line therapy (34/104, 32.6%). In the anagrelide first line group 5 patients (100%), in the second line anagrelide monotherapy group 16 patients (88,8%), and in the combined hydroxyurea plus anagrelide group 9 patients (82.1%) achieved complete remission. The 10-year overall survival was 82.1%. In 2 patients treated with anagrelide major bleeding and in one patient myocardial infarction occurred, other serious adverse events due to anagrelide treatment were not detected. Three elder patients died from non-hematologic diseases, but leukaemic transformation was not observed. Conclusions: First or second line anagrelide therapy, combined with hydroxyurea if necessary, was able to reduce the platelet-count and the rate of complications, and to control the course of essential thrombocythemia with tolerable adverse effects. Orv. Hetil., 2016, 157(9), 336–341.

[Treatment outcome in primary testicular non-Hodgkin lymphoma]

INTRODUCTION

Primary testicular lymphoma constitutes a rare subgroup among extranodal non-Hodgkin's lymphomas. Because of its aggressive clinical behaviour due to high grade histological features developing mainly in older population, patients with this disease usually have a poor prognosis. Orchidectomy followed by combination immunochemotherapy is a traditional treatment method with a rather inferior outcome.

AIM

In this retrospective survey the authors analysed the clinical presentation, pathological features and treatment results of patients with primary testicular lymphoma diagnosed and treated in their haematology centre between 2000-2012 METHOD: During this period 334 patients with aggressive non-Hodgkin's lymphomas were treated, of whom 8 patients (2.39%; age between 23 and 86 years; median, 60 years) underwent semicastration for primary testicular lymphoma (7 patients had diffuse, large B-cell lymphoma and one patient had Burkitt-like lymphoma). According to the Ann Arbor staging system a limited stage I-IIE was diagnosed in 7 patients and advanced stage was found in one patient. All but one patients were treated with rituximab added to CHOP regimen (6 or 8 cycles in every 21 or 28 days), whereas one patient received radiotherapy only. Central nervous system intrathecal prophylaxis was used in one case and no preventive irradiation of the contralateral testis was used.

RESULTS

With a median follow-up of 50 months complete remission was observed in 7 patients. However, two patients died (one due to progression and one in remission from pulmonary solid tumour). Complete remission rate proved to be 87.5%, disease-free survival was between 13 and 152 months (median 38 months) and overall survival rates were between 17 and 156 months (median 43 months). The 5-year disease-free and overall survival rates were 37.5 %.

CONCLUSIONS

The relatively favourable treatment outcome could be mainly explained by the high number of patients with early-stage of the disease, early surgical removal of testicular lymphomas and the use if immunochemotherapy. This therapeutic regimen was effective to prevent localized and distant relapses. Despite omission of regular prophylaxis of the central nervous system, no relapse was detected.

[Detection and impact of minimal residual disease on outcome of chronic lymphocytic leukemia]

INTRODUCTION

Minimal residual disease is associated with longer overall survival in patients with chronic lymphocytic leukemia.

AIM

The aim of the authors was to determine the clinical significance of remission and minimal residual disease on the survival of patients with chronic lymphocytic leukemia.

METHODS

Data from 42 first-line treated patients with chronic lymphocytic leukemia were analyzed. Minimal residual disease was determined by flow cytometry.

RESULTS

Overall response and complete remission was achieved in 91%, 86%, 100% and 87%, 0%, 60% of patients with fludarabine-based combinations, single-agent fludarabine and cyclophosphamide + vincristin + prednisolone regimen, respectively. Minimal residual disease eradication was feasible only with fludarabine-based combinations in 60% of these cases. The ratio of minimal residual disease was 0.5% on average. During a median follow-up period lasting 30 months, the overall survival of patients with fludarabine-resistant disease proved to be significantly shorter (p = 0.04), while complete remission without minimal residual disease was associated with significantly longer progression free survival (p = 0.02).

CONCLUSION

Only fludarabine-based combinations were able to eradicate minimal residual disease in patients with chronic lymphocytic leukemia. Complete remission without minimal residual disease may predict longer progression free survival in these patients.

[Treatment outcome of immune thrombocytopenia]

INTRODUCTION

Treatment of immune thrombocytopenia is sometimes difficult and needs personal setting. According to evidence-based guidelines, corticosteroids are suggested for first-line treatment. In case of corticosteroid ineffectiveness, second-line therapeutic options (splenectomy, immunosuppressive drugs and, recently, thrombopoietin-mimetics) may result in beneficial therapeutic effect.

AIMS

The aim of the authors was to examine the clinicopathological data, disease course, treatment results, and the effectiveness of novel drugs in patients with immune thrombocytopenia.

PATIENTS AND METHODS

The authors retrospectively analysed the files of 79 immune thrombocytopenic patients (26 males and 53 females) diagnosed and treated at the hematologic in- and outpatient units of the Markusovszky Hospital, County Vas, Hungary between January 1, 2000 and December 31, 2011. Remission rates, disease-free and overall survivals in response to corticosteroids (first-line treatment), after splenectomy (in cases when corticosteroids proved to be ineffective) and following second-line treatment were analysed. Survival curves were constructed using statistical software programs.

RESULTS

Of the 79 patients during a median follow-up of 66 months (min. 3, max. 144 months), 28 patients receiving first-line corticosteroids achieved complete remission and remained in a prolonged disease-free condition (35.4%; median disease-free survival 75.5 months; min. 2, max. 140 months). Thirty-eight patients underwent splenectomy after ineffective treatment with corticosteroids or other immunosuppressive (48.0%; median disease-free survival 94.2 months; min. 6, max. 136 months). Surgical complications occurred in 2 cases, while postoperative and late infections were absent. Five patients died but death was not related to immune thrombocytemia. Second-line treatment was applied in 13 patients (16.4%) and among these patients relapse of immune thrombocytopenia after splenectomy was observed in 6 patients. Favourable effects of both conventional (immunosuppressive) and novel treatments (rituximab, thrombopoietin-mimetics) were also detected.

CONCLUSIONS

More than two-thirds of patients with immune thrombocytopenia responded to corticosteroids or to splenectomy and achieved prolonged disease-free remission. Novel drugs (rituximab, thrombopoietin-mimetics) applied only in few cases produced also favourable results in patients not responding to corticosteroids and splenectomy.

Significance of the JAK2V617F mutation in patients with chronic myeloproliferative neoplasia

In Philadelphia chromosome-negative chronic myeloproliferative neoplasia, i.e. polycythemia vera, essential thrombocythemia and primary idiopathic myelofibrosis enhanced risk of thrombosis could be connected with Janus kinase 2 gene mutation occurring in various frequency in these diseases (JAK2V617F). Since 2002 the presence of JAK2 mutation in chronic myeloproliferative neoplasia has been regularly detected. Aims: In a retrospective survey the possible connection between JAK2 mutation and thrombosis was analyzed in patients with chronic myeloproliferative neoplasia subgroups cared and treated in their hospital and outpatient departments. Patients and methods: Between 2007-2010 peripheral blood samples of 171 patients with chronic myeloproliferative neoplasia (68 patients of polycythemia vera, 84 of essential thrombocythemia and 19 ones with primary idiopathic myelofibrosis) were sent to several molecular biological laboratories, where V617F mutation from DNA specimens was detected by allele-specific polymerase chain reaction, as well. Thromboembolic complications (arterial, i.e. cerebro-and cardiovascular and venous thrombosis) occurred during course of illness of patients were registered. Statistical analysis was made by statistical software program for Windows. Results: JAK2 mutation in 53 patients with polycythemia vera (77.9%) was detected, whilst in essential thrombocythemia 55 patients (65.4%) and in primary idiopathic myelofibrosis 7 patients (36.8%) proved to be JAK2 positive. In 18 JAK2 positive patients of polycythemia vera thromboembolic episodes were observed (18/53, 33.9%), whilst in essential thrombocythemia JAK2 mutational status was accompanied with thromboembolic events in 17/55 patients (30.9%). In the 7 JAK2 positive ones with primary idiopathic myelofibrosis thrombotic complication did not occurred. However, in JAK2 negative cases thrombotic events could also be detected (from 10 JAK2 negative patients with polycythemia vera in four ones, and in six with JAK2 negative 23 essential thrombocythemic patients. Conclusions: Incidence of the JAK2 mutation in their patients with chronic myeloproliferative neoplasia subgroups mainly corresponds to the literary data. Thrombosis ensued both in JAK positive polycythemia vera and essential thrombocythemia cases occurred nearly in the same number, but the incidence of thrombosis ensued in JAK2 negative cases did not differ significantly from the JAK2 positive patients. From these results it could be suggested that the presence or absence of JAK2 mutation in the development of thrombosis has no predictive value in patients with chronic myeloproliferative neoplasia. Orv. Hetil., 2011, 152, 1795–1803.

[Therapeutic management of central nervous system lymphomas in a single hematological institute]

Primary central nervous system lymphoma is defined as an extranodal lymphoma arising in the central nervous system in the absence of systemic disease. Because of their rare occurrence among lymphomas, optimal treatment could hardly be established.

AIMS

In this retrospective survey we analyzed the result of combined treatment (systemic and intrathecal chemotherapy followed by consolidation radiotherapy) in patients with primary or relapsed central nervous system lymphomas diagnosed and treated in our hematological department between 1998-2009.

PATIENTS AND METHODS

During this period (mean follow-up of 13.2 months) from 427 patients with newly diagnosed non-Hodgkin's lymphomas, 22 primary central nervous system lymphoma was diagnosed (5.15%, 16 cerebral and 6 spinal cord lymphoma cases). Significant male predominance (14:8) was registered with an age distribution of 34-77 years (mean = 60.7, median = 64 years). No patients were immunocompromised. All central nervous system lymphoma specimens taken with neurosurgical resection or stereotaxic biopsies were confirmed histopathologically. All cerebral lymphoma cases proved to be diffuse large B-cell of origin, while in epidural lymphomas low grade subtypes also occurred. Epidural lymphomas were treated with local radiotherapy (30-40 Gy), except for patients with follicular lymphomas getting rituximab-containing polychemotherapy (R + CHOP regimen) before irradiation. In cerebral lymphoma (every patients had supratentorial localization) the following combined therapy protocol was used: up to three courses of high dose methotrexate (HD MTX 3g/m 2 in a single dose for 4 hours lasting drop-infusion) were given at 4-week intervals, followed by leucovorin-rescue 24 hours after MTX infusion. Intrathecal combination of methotrexate, cytosin-arabinosid and dexamethasone was given three times after HD MTX infusion. In complete response after chemotherapy (evaluated by cranial MRI or CT, PET/CT), whole-brain irradiation was used in a total dose of 30 Gy. In case of partial response, boost irradiation for the tumor bed was also given. In relapse or resistant cases, salvage regimen was applied: HD MTX course combined with high dose cytosin-arabinosid (HD Ara-C) 3g/m 2 /dose b.i.d. over 4 h c.i., repeated in three cycles every four weeks.

RESULTS

Complete remission has been achieved in 9 patients with cerebral and in 4 patients with spinal cord lymphoma (13/22; 59.0%), however, one relapsed patient became resistant and later expired, despite salvage therapy. Primarily 9 patients were not evaluable for response: 5 received only one or two HD MTX because of side effects, 4 patients died due to progression of the disease. Mean of the overall survival (OS) in cerebral lymphoma was 19.5 (3-46, median of 10) months, in epidural group 14.1 (2-76, median of 5) months, whilst mean time to progression (TTP) was 4.5 (2-6.5, median of 4 months). The 2-year survival for all patients was 50%. Acute toxicity of chemotherapy was usually hematological, moreover, in 8 patients impaired renal function and sepsis developed. No serious adverse effect of radiotherapy could be detected.

CONCLUSION

In primary central nervous system lymphoma, basic treatment HD methotrexate together with intrathecal combination of methotrexate + cytosin-arabinosid + dexamethasone followed by whole-brain irradiation of at least 30 Gy could produce a medium response rate in our study. In case of relapse or progression, other salvage regimens containing HD Ara-C alternating with HD MTX could reduce the treatment failure, as well. After therapy PET/CT was negative in five patients with prolonged disease-free survival.

Differential impact of Cetuximab, Pertuzumab and Trastuzumab on BT474 and SK-BR-3 breast cancer cell proliferation

OBJECTIVES

The potential of epidermal growth factor receptor (EGFR)- and Her2-targeted antibodies Cetuximab, Pertuzumab and Trastuzumab, used in combination to inhibit cell proliferation of breast cancer cells in vitro, has not been extensively investigated. It is anticipated that there would be differences between specific erbB receptor co-expression profiles that would affect tumour cell growth.

MATERIALS AND METHODS

We have examined the effects of Cetuximab, Pertuzumab and Trastuzumab, applied separately or in combination, on cell proliferation of BT474 and SK-BR-3 breast cancer cell lines. Cell cycle progression of BT474 and SK-BR-3 cells was statically and dynamically assessed using flow cytometry. In order to discover a potential influence of differential EGFR co-expression on sensitivity to antibody treatment, EGFR was down-regulated by siRNA in SK-BR-3. An annexinV/propidium iodide assay was used to identify potential induction of apoptosis.

RESULTS

Treatment with Pertuzumab and Trastuzumab, both targeted to Her2, resulted in a reduced fraction of proliferating cells, prolongation of G(1) phase and a great increase in quiescent BT474 cells. Cetuximab had no additional contribution to the effect of either Pertuzumab or Trastuzumab when administered simultaneously. Treatment with the antibodies did not induce an appreciable amount of apoptosis in either BT474 or SK-BR-3 cells. In contrast to SK-BR-3, the BT474 cell line appears to be more sensitive to antibody treatment due to low EGFR content besides Her2 overexpression.

CONCLUSION

The extent of decelerated or blocked cell proliferation after antibody treatment that is targeted to EGFR and to Her2 depends both on EGFR and Her2 co-expression and on antibody combination used in the treatment setting. Cetuximab did not enhance any inhibitory effect of Trastuzumab or Pertuzumab, most probably due to the dominant overexpression of Her2. Cell susceptibility to Trastuzumab/Pertuzumab, both targeted to Her2, was defined by the ratio of EGFR/Her2 co-expression.

Optimization of three- and four-color multiparameter DNA analysis in lymphoma specimens

BACKGROUND

Simultaneous analysis of DNA and immunophenotype of lymphoma cells by flow cytometry allows the calculation of the proliferative activity and aneuploidy in even a small lymphoma population. Unfavorable DNA binding characteristics or spectral features of DNA dyes impair the accuracy of multiparameter DNA analysis and limit their clinical application. We describe here a reliable and reproducible application of both three- and four-color multiparameter DNA analysis.

METHODS

After immunostaining of fresh samples of peripheral blood, bone marrow and single cell suspensions of lymph nodes from healthy and lymphoma patients, a methanol fixation for TO-PRO-3 and DRAQ5 staining was tested.

RESULTS

The red-excitable TO-PRO-3 on a FACSCalibur is limited to two-color antigen staining including fluorescein-isothiocyanate and phycoerythrin-labeled monoclonal antibodies due to its broad excitation spectrum. Although DRAQ5 is only applicable to flow cytometers equipped with a single argon laser emitting 488-nm light, its emission spectrum can be easily separated from the FITC, PE, and PE/Texas-Red emissions. DRAQ5 showed almost identical stoichiometric DNA binding characteristics as propidium iodide. Coefficient of variation produced by DRAQ5 staining is in the range of 3.5 and is adequate for detecting aneuploid amd near-diploid cells.

CONCLUSIONS

These advantageous features of DRAQ5 make it a reliable candidate for multiparameter clinical studies.