Efficacy and safety of ruxolitinib in patients with myelofibrosis: a retrospective and multicenter experience in Turkey

Background/aim: The aim of this study is to assess the efficacy and safety of ruxolitinib in patients with myelofibrosis. Materials and methods: From 15 centers, 176 patients (53.4% male, 46.6% female) were retrospectively evaluated. Results: The median age at ruxolitinib initiation was 62 (28­87) and 100 (56.8%) of all were diagnosed as PMF. Constitutional symptoms were observed in 84.7%. The median initiation dose of ruxolitinib was 30 mg (10­40). Dose change was made in 69 (39.2%) patients. Forty seven (35.6%) and 20 (15.2%) of 132 patients had hematological and nonhematological adverse events, respectively. The mean spleen sizes before and after ruxolitinib treatment were 219.67 ± 46.79 mm versus 199.49 ± 40.95 mm, respectively (p < 0.001). There was no correlation between baseline features and subsequent spleen response. Overall survival at 1-year was 89.5% and the median follow up was 10 (1­55) months. We could not show any relationship between survival and reduction in spleen size (p = 0.73). Conclusion: We found ruxolitinib to be safe, well tolerated, and effective in real-life clinical practice in Turkey. Ruxolitinib dose titration can provide better responses in terms of not only clinical benefit but also for long term of ruxolitinib treatment.

Incidence and risk factors for hepatic sinusoidal obstruction syndrome after allogeneic hematopoietic stem cell transplantation: A retrospective multicenter study of Turkish hematology research and education group (ThREG).

Hepatic sinusoidal obstruction syndrome (HSOS) is a potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively evaluated the incidence, risk factors, treatment and survival for HSOS after allo-HSCT in Turkey. We also reported our experience of defibrotide (DF) for HSOS prophylaxis in high-risk (HR) patients. Across Turkey, 1153 patients from 10 centers were enrolled in the study. We evaluated the medical records of patients who were treated with allo-SCT between January 2012 and December 2015. The study included 1153 patients (687 males/466 females) with median age of 38 (15-71) years. The incidence of HSOS was 7.5 % (n = 86). The incidences of HSOS in the HR/DF+, HR/DF- and standard risk (SR) group were 8%, 66.7 % and 6.2 %, respectively. The rate of HSOS development was not statistically different between HR/DF + and SR group (p = 0.237). HSOS prophylaxis (defibrotide) was significantly decreased HSOS-related mortality (p = 0.004). The incidence of HSOS was found similar to literature in this large Turkish cohort. Defibrotide prophylaxis appears to be associated with low incidence of HSOS development and reduced HSOS-related mortality. Although these results are promising, future studies are needed to support the efficacy of defibrotide prophylaxis in patients with risk of HSOS.

Efficacy and safety of lenalidomide and dexamethasone in patients with relapsed/ refractory multiple myeloma: a real-life experience

Background/aim: In Turkey, lenalidomide plus dexamethasone (RD) has been used to treat relapsed/refractory multiple myeloma (RRMM) since 2010. This retrospective, single-center study evaluated the efficacy and tolerability of RD in patients with RRMM between October 2010 and June 2016. Materials and methods: Patients' records were reviewed, and overall (OS) and progression-free survival (PFS) were assessed. Results: One hundred and twenty patients (71 males; 59.2%) were included in the study. The median number of prior lines of treatment was one (1­4); 72 patients (60.0%) received RD as second-line therapy and 51 patients (42.5%) had previously undergone autologous stem cell transplantation (ASCT). The overall response rate was 72.5%, with 19% of these patients achieving a complete response. The median length of follow-up and duration of response to RD was 14 months and 19 months, respectively. Median OS and PFS were 32 and 21 months, respectively. Prior ASCT, an overall response, and treatment with RD for >12 cycles were identified as independent prognostic factors for OS and PFS. Adverse events (AEs) occurred in 69 (57.5%) and 14 patients (11.7%) discontinued treatment due to AEs. Conclusion: We found RD to be safe, well tolerated, and effective in RRMM in everyday clinical practice in Turkey.

Risk factors for poor mobilization in solid tumors: How effectively can we mobilize patients with solid tumors?

BACKGROUND: In the literature, risk factors for poor mobilization were tried to identify. However, most of the studies consisted heterogeneous group of patients including both hematologic and oncologic malignancies. In this study, we aimed to identify the risk factors for poor mobilization in adults with solid tumors. METHODS: We enrolled 49(47 men, 2 women) adult patients with solid tumor who were mobilized between September 2007 and February 2017. All the mobilization procedures were performed with G-CSF(10µg/kg/day) with chemotherapy. Mobilization insufficiency was defined as peripheral blood CD34+stem cell number less than 10/µl and/or total collected CD34+cells less than 2.5×10 6/kg. RESULTS: The patients were divided into two groups, patients with successful mobilization at the first attempt(group 1, 36 patients,73.5%) and poor mobilizers (group 2, 13 patients 26.5%). Second and third mobilization attempt was needed in 11 and 2 patients, respectively. The median number of CD34+cells collected was 7,08×106/kg(0,6-19) with a median 4(1-6) apheresis. There was no statistical difference between two groups in terms of patient's and mobilization characteristics. Only number of CD 34+stem cells collected was statistically different (median 9,07×106/kg CD34+cells in group 1 versus 2,14×106/kg in group 2, p<0.05). The only possible risk factor that we could define was presence of organ metastasis. CONCLUSIONS: Since several methods and new drugs are available for peripheral stem cell collecting, risk factors should be identified clearly in adult population with solid tumors. So multicenter studies should be constructed for resolving this problem.

Epidemiology and analysis of invasive fungal infections in patients withhematological malignancies: a single-center real-life experience

Background/aim: Invasive fungal infection (IFI) causes morbidity and mortality among patients with hematological malignancies. We evaluated the incidence and treatment characteristics of IFIs between October 2012 and December 2013. Materials and methods: Patients who received chemotherapy or stem cell transplantation were retrospectively evaluated. Fungal infections were classified according to EORTC criteria.Results: Prophylaxis and antifungal therapy were given in 30.5% and 23.6% of 522 chemotherapy courses, respectively. The incidence of proven/probable IFI was 6.7%. The incidence of IFI among patients who received prophylaxis was significantly higher than among those who did not receive it (11.3% vs. 4.6%, P = 0.005). There was no significant difference between patients who received mold-active and no mold-active prophylaxis (P = 0.098). The most common single agent therapy and causative pathogen was liposomal amphotericin B (57.1%) and Aspergillus (n = 5), respectively. IFI-attributable mortality rate was 14.2% in 6 weeks.Conclusion: The IFI incidence and mortality rate were similar to that reported in the literature. The IFI rate was higher in the group using prophylaxis, as this is a high-risk group. Although the IFI rate was not significantly different between groups using prophylaxis, patients should be followed closely for the effective use of posaconazole prophylaxis.

The loss of CD34+ cells in peripheral hematopoietic stem cell products cryopreserved by non-controlled rate freezing and stored at -80 °C after overnight storage.

Although peripheral blood stem cell (PBSC) products cryopreserved by non-controlled rate freezing and stored at -80 °C after overnight storage are used frequently, data regarding the rate of loss of CD34+ cells in these products are limited. In this prospective study, CD34+ cells were counted at three (fresh, post-overnight and post-thaw) points in 83 PBSC products from 41 patients by flow cytometry. Compared to fresh products, the mean losses of post-overnight and post-thaw total CD34+ cells are 16.3% and 38.4% (p = 0.02), and the mean losses of post-overnight and post-thaw viable CD34+ cells are 16.5% and 48.5%, respectively (p < 0.001). The numbers of fresh viable, post-thaw total and post-thaw viable CD34+ cells were inversely correlated with the durations of neutrophil and platelet engraftment. Our results indicate that the mean loss of post-thaw total and viable CD34+ cells is approximately 20% higher than that observed in standard cryopreservation methods. In addition, fresh viable, post-thaw total and especially post-thaw viable CD34+ cell levels are valuable predictors of both neutrophil and platelet engraftments.

A Case of Myosin Heavy Chain 9-Related Disorder Following Splenectomy Due to Misdiagnosis of Idiopathic Thrombocytopenic Purpura.

This case study reports a patient with Myosin Heavy Chain 9 (MYH9)-related disorder (MYH9-RD) which is characterized by congenital macrothrombocytopenia, Döhle-like bodies, sensorineural hearing loss, cataracts, and glomerulopathy. Often misdiagnosed as idiopathic thrombocytopenic purpura (ITP), MYH9-RD requires accurate identification to avoid inappropriate treatments like steroids, rituximab, or splenectomy. Platelet transfusions were traditionally the only therapeutic option, but thrombopoietin receptor agonists (TPO-RA), specifically eltrombopag, have shown success in MYH9-RD treatment. The case report involves a 27-year-old male with chronic ITP post-splenectomy, revealing thrombocytopenia, mild anemia, giant platelets, kidney failure, and hearing loss. Genetic testing identified a c.287C>T; p.(Ser96Leu) variant associated with MYH9-RD. Eltrombopag treatment, initiated before the definitive diagnosis, exhibited clinical and laboratory success. The study discusses the evolving landscape of treatments for inherited thrombocytopenias, emphasizing eltrombopag's efficacy, especially post-splenectomy, and its potential application in short-term preparations for elective surgeries. The study underscores the importance of timely MYH9-RD diagnosis, preventing misdiagnoses and inappropriate treatments. Eltrombopag stands out as a potential therapeutic option, offering effective platelet count management, especially post-splenectomy, with ongoing research exploring alternative TPO-RAs. As MYH9-RDs are rare, increased awareness among healthcare professionals is crucial to ensure accurate diagnoses and optimal patient care.

Lactate level is an independent predictor of mortality in patients with hematologic malignancy receiving urgent chemotherapy in intensive care unit.

BACKGROUND: Intensive care unit (ICU) survival of cancer patients has improved. Urgent chemotherapy has become feasible in critically ill patients with specific organ dysfunction due to hematological malignancies. OBJECTIVE: The aim of the study was to assess ICU mortality rates and the factors associated with mortality in patients with hematologic malignancies receiving urgent chemotherapy in the ICU. METHODS: We retrospectively included all patients admitted to the ICU who received chemotherapy due to hematologic malignancy in 2012-2022. RESULTS: Of the 129 patients undergoing chemotherapy in the ICU, 50 (38.7 %) died during the ICU follow-up. The following conditions were significantly more common among nonsurvivors: presence of infection at the time of ICU admission (p < 0.001), the requirement for mechanical ventilation during ICU stay (p < 0.001), the need for noninvasive mechanical ventilation during ICU stay (p = 0.014), vasopressor support (p < 0.001), and sepsis (p < 0.001). Logistic regression analysis revealed that among laboratory parameters on ICU admission, lactate (p = 0.008), albumin (p = 0.022), C-reactive protein (p = 0.046), baseline sequential organ failure assessment (SOFA) score (p < 0.001), newly developed heart failure (p = 0.006), and the requirement for vasopressor agents during ICU stay (p < 0.001) significantly influenced the risk of mortality in the univariate analysis. The multivariate analysis revealed lactate levels (p = 0.047) on ICU admission as an independent predictor of mortality. CONCLUSION: The development of heart failure and lactate levels on admission were the main predictors of mortality. Additionally, higher SOFA scores revealed that illness severity was closely associated with mortality. Future studies should focus on strategies to further reduce these risks and achieve the best outcomes for these patients.

Massive bone marrow involvement in an end stage renal failure case with erythropoietin-resistant anemia and primary hyperoxaluria.

Primary hyperoxaluria is a rare autosomal recessive disorder. Type 1 PH is the most common form and develops due to a defect in a liver specific enzyme the alanine aminotransferase enzyme. As a result of the enzyme deficiency, there is an overproduction of oxalate and excessive urinary excretion. Recurrent urolithiasis and nephrocalcinosis are the most important findings of the disorder and often at the beginning end-stage renal disease develops. This report presents a case backed up by literature of a patient with end stage renal failure and erythropoietin-resistant anaemia whose bone marrow biopsy showed crystal deposition which received delayed diagnosis of oxalosis.

Eltrombopag for the Treatment of Allogeneic Hematopoietic Stem Cell Transplantation-Related Poor Graft Function.

INTRODUCTION: Allogeneic stem cell transplantation (ASCT) is a crucial therapeutic strategy for hematological and non-hematological disorders. Poor graft function (PGF) after ASCT presents a critical challenge that does not have a standardized treatment approach. A thrombopoietin-mimetic oral drug eltrombopag shows promise in some bone failure syndromes. This study aimed to analyze the efficacy of eltrombopag in treating PGF after ASCT. METHODS: Patients receiving eltrombopag for PGF after ASCT between 2017 and 2020 were retrospectively evaluated. Patients' characteristics, details for ASCT, timing, treatment, and possible contributors for PGF, response to eltrombopag treatment, and overall response rate (ORR) were analyzed.  Results: Eighteen patients were assessed. Eltrombopag treatment yielded a favorable response in 11 patients, resulting in an ORR of 61%. The ORR in secondary PGF was better than that in primary PGF (83% and 17% respectively). There was a marked enhancement in platelet and hemoglobin levels following eltrombopag treatment (p=0.001 and p=0.030, respectively), while neutrophil values exhibited no significant change (p=0.8). Among the responding patients, four individuals (22%) underwent a tapering and discontinuation of eltrombopag. No toxicity was observed above grade one, and no patient discontinued eltrombopag because of intolerability or adverse events. CONCLUSION: Our findings affirm that eltrombopag can treat poor graft function after allogeneic stem cell transplantation without significant toxicities. These results contribute to the growing body of evidence supporting the use of eltrombopag in poor graft function after allogeneic stem cell transplantation, providing insights into its potential benefits and limitations.

Biomarker diversity in increased inflammation: Secondary hemophagocytic syndrome vs. systemic inflammatory response syndrome.

INTRODUCTION: Secondary hemophagocytic syndrome (HPS) and systemic inflammatory response syndrome (SIRS) share similar clinical findings as a result of hyperinflammation. Due to high mortality rates in HPS; it is critical to diagnose promptly. Thus, this study aimed to evaluate the diagnostic and prognostic significance of inflammatory markers in these two increased inflammatory states. METHODS: We conducted a prospective observational study including patients hospitalized in the intensive care unit of the Internal Medicine Department of Ege University Hospital. RESULTS: Thirty-three patients with HPS and 46 patients with SIRS were evaluated. Serum ferritin and sIL-2r levels were significantly higher in the HPS group than in the SIRS group, as expected. Receiver operating curve (ROC) analysis showed that the optimal cutoff for ferritin to distinguish HPS from SIRS was 1703 µg/L (sensitivity: 75%, specificity: 94.1%, area under the curve (AUC): 0.871, p < 0.001), and that for sIL-2r was 5888 U/ml (sensitivity: 45.5%, specificity: 89.1%, AUC: 0.698, and p = 0.001). Temporal changes (Δ) in ferritin were determined as a mortality predictor. When evaluated in terms of prognostic significance in ROC analysis, a decrease in ferritin of less than 38% was the cutoff value (sensitivity: 92.3%, specificity: 76.9%, AUC: 0.888, and p < 0.001), in mortality. Contrarily, neither baseline nor temporal change in sIL-2r did not achieve prognostic significance as a mortality predictor. CONCLUSION: In this single-center study, serum ferritin level was found to be a particularly more valuable diagnostic and prognostic marker than sIL-2r in patients with HPS.

Adult Onset Langerhans Cell Histiocytosis: Clinical Characteristics and Treatment Outcomes.

PURPOSE: Langerhans cell histiocytosis (LCH) is a rare disease that can affect all tissues and organs. Our study evaluated the clinical characteristics and treatment outcomes of adult-onset LCH patients in a tertiary center. MATERIALS AND METHODS: Adult patients diagnosed with LCH were retrospectively evaluated. Their initial symptoms, stratification according to disease involvement, treatment details, treatment responses, and overall and progression-free survival (PFS) were analyzed. RESULTS: Thirty-three patients were included. There were 21 single system LCH, 10 multisystem LCH, and 2 pulmonary LCH patients. Patients with single system unifocal involvement were successfully treated with local therapies such as surgery and radiotherapy. Most of the multisystem LCH patients and patients with single system multifocal involvement were treated with systemic chemotherapy. Cladribine was the first choice in 10 out of 11 patients who received chemotherapy. Among all patients, the overall response rate (ORR) was 97%. Among those who had cladribine in the first-line the ORR was 81%. All these patients achieved a complete remission and were alive at the last visit. The median follow-up was 38 (range, 2-183) months. The median PFS has not yet been reached. Ten-year PFS was 90.9%. CONCLUSION: Besides successful local treatments with surgery and radiotherapy, our study provides information for front-line cladribine treatment.

Metastatic pulmonary calcinosis and leukocytoclastic vasculitis in a patient with multiple myeloma.

UNLABELLED: Both leukocytoclastic vasculitis and metastatic pulmonary calcification are conditions that rarely occur during the course of multiple myeloma. We present a multiple myeloma patient that had severe dyspnea due to metastatic pulmonary calcinosis, and ulceronecrotic skin lesions caused by leukocytoclastic vasculitis. After 3 courses of standarddose chemotherapy all skin and pulmonary lesions disappeared. Autologous peripheral stem cell transplantation was performed and during 1 year of follow-up the patient was in complete remission; after 1 year, laboratory test results indicated disease relapse. Although the patient was treated with bortezomib and dexamethasone, the disease progressed. Non-myeloablative allogeneic stem cell transplantation was performed, but despite of all treatment the patient died due to disease progression. CONFLICT OF INTEREST: None declared.

Turkey real-life data: demographic features, treatment results and effects of comorbidities in chronic myeloid leukemia.

Aim: This study aimed to identify patient characteristics, treatment patterns and outcomes and to evaluate the effects of presence of comorbidities at diagnosis in chronic phase (CP)-chronic myeloid leukemia (CML) patients in Turkey. Materials & methods: Hospital records between 2005 and 2018 were retrospectively reviewed. Results: Of 861 CP-CML patients included, 31% had at least one comorbidity at diagnosis. Sex, cardiovascular disease status at diagnosis and molecular (at least major) and cytogenetic (partial and complete) responses were the independent predictors of survival. Conclusion: The response rates of CP-CML patients to the tyrosine kinase inhibitors were satisfactory. In addition to tolerability and side effect profiles of drugs, comorbidity status of patients should also be considered in treatment choice in CML patients.

This study aimed to identify patient characteristics, treatment patterns and outcomes and to evaluate the effects of presence of comorbidities at diagnosis in chronic phase (CP)-chronic myeloid leukemia (CML) patients in Turkey. Hospital records of patients between 2005 and 2018 were retrospectively reviewed. Of the included 861 CP-CML patients, 31% had at least one comorbidity at diagnosis. The survival of the patients was affected by sex, cardiovascular disease status at diagnosis, and molecular (at least major) and cytogenetic (partial and complete) responses. The response rates of CP-CML patients to the tyrosine kinase inhibitors were satisfactory. In addition to tolerability and side effect profiles of drugs, comorbidity status of patients should also be considered in treatment choice in CML patients.

Factor V G1691A (Leiden) and prothrombiG20210A gene mutation status, and thrombosis in patients with chronic myeloproliferative disorders.

OBJECTIVE: The aim of this study was to examine Factor V G1691A (Leiden) (FVL) and prothrombin G20210A (PT) gene mutation status, and their relationship with thrombosis in patients with chronic myeloproliferative disorders (CMPDs). METHODS: The study included 160 patients with a CMPD that were regularly followed-up between 1993 and 2009. FVL and PT mutation status was established based on blood samples analyzed via PCR using specific primers. RESULTS: The frequency of FVL and PT mutation was 12.5% and 4.4%, respectively. In total, 27 episodes of thrombosis occurred in 24 (15%) of the patients, and there wasn't an association between the observed thrombotic events, and FVL or PT mutations. Hepatic vein thrombosis was noted in 3 patients that had FVL mutation, of which 1 also had PT mutation. CONCLUSION: We did not observe a relationship between thrombosis, and FVL or PT mutations in CMPD patients; however, 3 of the patients that had hepatic vein thrombosis also had FVL mutation. Larger studies are needed to more clearly determine if all CMPD patients with hepatic vein thrombosis need be investigated for FVL and PT mutation.

The Effect of Cryotherapy on the Prevention of Oral Mucositis and on the Oral pH Value in Multiple Myeloma Patients Undergoing Autologous Stem Cell Transplantation.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of cryotherapy on the prevention of oral mucositis (OM) and on the oral pH value in patients with multiple myeloma undergoing autologous stem cell transplantation. DATA SOURCES: This nonrandomized controlled clinical trial was carried out in Bone Marrow Transplant Centers of three hospitals with total 32 patients. In addition to standard oral care, a total of 80 minutes of cryotherapy was applied to the experimental group. OM was assessed according to the World Health Organization's Oral Toxicity Scale before chemotherapy and for 21 days after chemotherapy (every day in the first 14 days, then every other day until the 21st day [if not discharged]). CONCLUSION: According to the findings, cryotherapy did not change the incidence of oral OM, and neither affected the severity of nor decreased the duration of it. Oral pH value was found to be significantly different between the patient groups only before and 1 day after chemotherapy. IMPLICATIONS FOR NURSING PRACTICE: Cryotherapy is an inexpensive, easy-to-use method with no side effects; it would be beneficial to continue cryotherapy to prevent the development of OM in patients with cancer receiving drugs with a short half-life such as melphalan. It is also recommended to conduct further studies with different chemotherapy drugs with short half-lives to determine its effect on the prevention of OM development.

Hematopoietic Stem Cell Transplantation for Patients with Paroxysmal Nocturnal Hemoglobinuria with or without Aplastic Anemia: A Multicenter Turkish Experience

Objective: Although inhibition of the complement system at different steps is a promising therapy modality in patients with paroxysmal nocturnal hemoglobinuria (PNH), allogeneic hematopoietic stem cell transplantation (HCT) is still the only curative therapy, especially for patients with intractable hemolysis or bone marrow failure. The aim of this study is to evaluate the outcomes of allogeneic HCT in PNH patients with aplastic anemia (PNH-AA) or without. Materials and Methods: Thirty-five PNH/PNH-AA patients who were treated with allogeneic HCT in 10 transplantation centers in Turkey were retrospectively analyzed. Results: Sixteen (45.7%) and 19 (54.3%) patients were diagnosed with classical PNH and PNH-AA, respectively. The median age of the patients was 32 (18-51) years. The 2-year overall survival (OS) rate and rate of graft-versus-host disease-free, failure-free survival (GFFS) was 81.2% and 78.1%, respectively. The 2-year OS in cases of classical PNH and PNH-AA was 81.3% and 79.9%, respectively (p=0.87), and 2-year GFFS in cases of PNH and PNH-AA was 79% and 76% (p=0.977), without statistical significance. The OS and GFFS rates also did not differ between transplantations with matched sibling donors (MSDs) and matched unrelated donors (MUDs). Conclusion: Allogeneic HCT with MSDs or MUDs is a good option for selected patients with classical PNH and PNH-AA. In particular, patients with debilitating and refractory hemolysis and patients with bone marrow failure might form an excellent group of candidates for allogeneic HCT.

Non-Hodgkin's lymphoma with bone involvement: a single center experience with 18 patients.

OBJECTIVE: Non-Hodgkin's lymphoma (NHL) of bone is a rare entity. The most common histological subtype is diffuse large B cell lymphoma (DLBCL). The major presenting symptoms are soft tissue swelling, bone pain and pathological fracture. Treatment options are chemotherapy, radiotherapy, surgery, or a combination of these modalities. METHODS: We retrospectively analyzed the 18 patients (11 females, 7 males) with NHL of bone who were diagnosed and treated between 1995-2005. The median age was 56.5 years. The median duration of symptoms was 4.5 months. The bone pain was the first symptom in all patients. Tru-cut biopsy was performed for diagnosis in most of the cases. Diagnosis in five patients (27.8%) required open biopsy. RESULTS: DLBCL (77.8%) was the most common histological type among all patients. Other histological subtypes were anaplastic large cell lymphoma (11.1%), Burkitt-like lymphoma (5.6%) and marginal zone lymphoma (5.6%). According to Ann Arbor staging system, 44.4% of patients were Stage I, 11.1% were Stage II and 44.4% were Stage IV. Bone marrow involvement was determined in four patients (22.2%). All patients except one were treated with anthracycline-containing regimens and eight patients (44.4%) received rituximab combination with chemotherapy. Radiation therapy was performed as the first-line therapy in 9 (50%) patients. The median follow-up was 37 months (range, 2-124 months). Among the 17 patients who achieved complete remission, five (27.8%) relapsed. All patients were still alive. The five-year relapse-free survival was 73.5%. CONCLUSION: The treatment of bone lymphoma can be planned according to the stage and location of the disease. Although we had a relatively low number of patients, it could be concluded that whether or not radiation therapy is performed, rituximab in combination with systemic chemotherapy has been proven beneficial on survival.

Investigating the cytotoxic and apoptotic effects of sunitinib upon K-562 chronic myelogenous leukemia cell line and assessment of gene profiling.

OBJECTIVE: Tyrosine kinase inhibitors (TKIs) which efficiently inhibit BCR-ABL are highly effective for clinical treatment of chronic myeloid leukemia (CML), but development of resistance to TKIs is a big challenge to treatment. Sunitinib is a multitargeted TKI targeting vascular endothelial growth factor receptor and is defined a safe and effective candidate target, but its effect on other signaling pathways is unknown. To investigate the cytotoxic and apoptotic effect of sunitinib in CML cell model K-562 on JAK-STAT signaling pathway components, suppressor genes and oncogenes, hematopoiesis-related genes, cell cycle and VEGF pathway components, and mRNA level expression changes was aimed. MATERIALS AND METHODS: Sunitinib's effective dose cytotoxic IC50 was determined by trypan blue and WST-1 cell proliferation assay tests. Expression levels of target genes were determined by quantitative reverse transcriptase polymerase chain reaction simultaneously after sunitinib application. Protein expression analysis was determined by "WesternBreeze Chromogenic Kit-Anti-Rabbit" based on the principles of the application kit by Western blot analysis. RESULTS: Assessing the cytotoxicity of K-562 cells following sunitinib treatment revealed that sunitinib decreased cell proliferation in a time- and dose-dependent manner. According to the sunitinib inhibition curve, IC50 dose was calculated as 3.5 µM at 48th h for K-562 cells and apoptosis assays pointed that sunitinib induces apoptotic cell death of leukemic cells at moderate levels. CONCLUSION: Our study supports that sunitinib might be used as a novel therapeutic target to trigger apoptosis in CML cells which in turn might accelerate therapeutic response in regard to inhibiting oncogenes and enhancing tumor suppressors in cooperation with cell cycle regulatory genes.