Unmet clinical needs and challenges in the management of acute leukemia in Turkey: a modified Delphi study.

Aim: To determine the unmet needs and challenges in management, diagnosis, treatment, follow-up and patient-physician communication in acute leukemia (AL). Materials & methods: The study was based on a modified Delphi approach. A questionnaire including the major potential obstacles was circulated twice among 13 hematologists. Results: The obstacles in AL management were limited access to the novel treatments and genetic tests, limited bed capacity, insufficient level of knowledge among allied health personnel, limited availability of psycho-oncological support and low levels of awareness in the population about the importance of stem cell donation. Conclusion: The challenges in the management of AL are critical to guide the efforts to improve the quality of healthcare delivery and the evidence-based decision making at treatment of AL patients.

Pomalidomide, bortezomib, and dexamethasone at first relapse in lenalidomide-pretreated myeloma: A subanalysis of OPTIMISMM by clinical characteristics.

OBJECTIVE: We evaluated the efficacy and safety of pomalidomide, bortezomib, and dexamethasone (PVd) vs bortezomib and dexamethasone (Vd) by age, renal function, and high-risk cytogenetic abnormalities in lenalidomide-pretreated patients with multiple myeloma at first relapse. METHODS: OPTIMISMM was a phase 3, multicenter, open-label, randomized study (NCT01734928; N = 559). The primary endpoint was progression-free survival (PFS). RESULTS: Overall, 226 patients had received one prior line of therapy. PVd significantly prolonged PFS vs Vd in patients aged ≤65 years (median, 22.0 vs 13.1 months; P = .0258) and >65 years (median, 17.6 vs 9.9 months; P = .0369). Median PFS in patients with renal impairment (RI; creatinine clearance <60 mL/min) was 15.1 months with PVd vs 9.5 months with Vd (hazard ratio [HR], 0.67 [95% CI, 0.34-1.34]). In patients without RI, median PFS was 22.0 vs 13.1 months (HR, 0.45 [95% CI, 0.27-0.76]). In patients with high-risk cytogenetics, median PFS was 14.7 vs 9.9 months (HR, 0.39 [95% CI, 0.13-1.17]). PVd significantly improved overall response rate vs Vd in all subgroups. The safety profile of PVd was consistent with previous reports. CONCLUSIONS: These findings confirmed the benefits of PVd at first relapse, including in patients with poor prognostic factors.

Prospective registry of adult patients receiving therapeutic plasma exchange with a presumptive diagnosis of thrombotic microangiopathy (TMA): The Turkish hematology research and education group (ThREG)-TMA02 study.

Thrombotic microanjiopathy (TMA) is a pathological diagnosis characterized by abnormalities of small vessels leading to microvascular thrombosis of arterioles and capillaries. The current prospective, non-interventional, multicenter study aimed to define the distribution of different TMA forms in adult Turkish patients who were referred for therapeutic plasma exchange (TPE) for presumptive diagnosis of TMA. Patients with serum ADAMTS13 activity <5% were diagnosed as having acquired thrombotic thrombocytopenic purpura (aTTP). Patients presenting with ADAMTS13 activity 6-10 % / normal renal function and patients with ADAMTS13 activity >10 %, normal renal function and no secondary TMA were treated as unclassified TMA. The study included a total of 80 patients (women: 50; man: 30) with a median age of 48 (20-74). Detailed evaluation at 1 month after hospital admission revealed aTTP, secondary TMA, infection/complement-associated hemolytic uremic syndrome and unclassified TMA in 29 (36.2 %), 22 (27.5 %), 23 (28.8 %) and 6 (7.5 %) patients respectively. As subclassification of various TMAs will dictate specific therapy, proper diagnosis in a timely manner is of utmost clinical significance.

Prospective registry of adult patients receiving therapeutic plasma exchange with a presumptive diagnosis of thrombotic microangiopathy (TMA): The Turkish hematology research and education group (ThREG)-TMA02 study.

Thrombotic microangiopathy(TMA) is a pathological diagnosis characterized by abnormalities of small vessels leading to microvascular thrombosis of arterioles and capillaries. The current prospective, non-interventional, multicenter (n:18) study aimed to define distribution of different TMA forms in adult Turkish patients who were referred for therapeutic plasma exchange (TPE) for a presumptive diagnosis of TMA. Patients with serum ADAMTS13 activity <5% were diagnosed as acquired thrombotic thrombocytopenic purpura (aTTP). Patients presenting with ADAMTS13 activity 6-10 % / normal renal function and patients with ADAMTS13 activity >10 %, normal renal function and no secondary TMA were treated as unclassified TMA. The study included a total of 97 patients (female: 60; male: 30) with a median age of 48 (18-74). Detailed evaluation at 1 month after hospital admission revealed aTTP, secondary TMA, infection/complement-associated hemolytic uremic syndrome and unclassified TMA in 32 (33 %), 33 (34 %), 26 (27 %) and 6 (6%) patients respectively. As subclassification of various TMAs will dictate specific therapy, proper diagnosis in a timely manner is of utmost clinical significance.

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.

The Turkish experience with therapeutic plasma exchange: A national survey.

Therapeutic plasma exchange (TPE) is used to treat more than 60 diseases worldwide and has drawn growing interest. Little is known about the current situation of TPE activity in Turkey, so we developed a survey to obtain information about this timely topic. We collected data on TPE from 28 apheresis units throughout Turkey. We performed a total of 24,912 TPE procedures with 3203 patients over the past decade. Twenty years ago, the majority of procedures were performed for neurological and hematological disorders, and today, most TPE procedures are done for the same reasons. The only historical change has been an increase in TPE procedures in renal conditions. Currently, renal conditions were more frequently an indication for TPE than rheumatic conditions. Fresh frozen plasma was the most frequently used replacement fluid, followed by 5% albumin, used in 57.9% and 34.6% of procedures, respectively. The most frequently used anticoagulants in TPE were ACD-A and heparin/ACD-A, used with 1671 (52.2%) and 1164 (36.4%) patients, respectively. The frequency of adverse events (AEs) was 12.6%. The most common AEs were hypocalcemia-related symptoms, hypotension, and urticaria. We encountered no severe AEs that led to severe morbidity and mortality. Overall, more than two thirds of the patients showed improvement in the underlying disease. Here, we report on a nationwide survey on TPE activity in Turkey. We conclude that there has been a great increase in apheresis science, and the number of TPE procedures conducted in Turkey has increased steadily over time. Finally, we would like to point out that our past experiences and published international guidelines were the most important tools in gaining expertise regarding TPE.

Effect of Recombinant Zoster Vaccine on Incidence of Herpes Zoster After Autologous Stem Cell Transplantation: A Randomized Clinical Trial.

Importance: Herpes zoster, a frequent complication following autologous hematopoietic stem cell transplantation (HSCT), is associated with significant morbidity. A nonlive adjuvanted recombinant zoster vaccine has been developed to prevent posttransplantation zoster. Objective: To assess the efficacy and adverse event profile of the recombinant zoster vaccine in immunocompromised autologous HSCT recipients. Design, Setting, and Participants: Phase 3, randomized, observer-blinded study conducted in 167 centers in 28 countries between July 13, 2012, and February 1, 2017, among 1846 patients aged 18 years or older who had undergone recent autologous HSCT. Interventions: Participants were randomized to receive 2 doses of either recombinant zoster vaccine (n = 922) or placebo (n = 924) administered into the deltoid muscle; the first dose was given 50 to 70 days after transplantation and the second dose 1 to 2 months thereafter. Main Outcomes and Measures: The primary end point was occurrence of confirmed herpes zoster cases. Results: Among 1846 autologous HSCT recipients (mean age, 55 years; 688 [37%] women) who received 1 vaccine or placebo dose, 1735 (94%) received a second dose and 1366 (74%) completed the study. During the 21-month median follow-up, at least 1 herpes zoster episode was confirmed in 49 vaccine and 135 placebo recipients (incidence, 30 and 94 per 1000 person-years, respectively), an incidence rate ratio (IRR) of 0.32 (95% CI, 0.22-0.44; P < .001), equivalent to 68.2% vaccine efficacy. Of 8 secondary end points, 3 showed significant reductions in incidence of postherpetic neuralgia (vaccine, n=1; placebo, n=9; IRR, 0.1; 95% CI, 0.00-0.78; P = .02) and of other prespecified herpes zoster-related complications (vaccine, n=3; placebo, n=13; IRR, 0.22; 95% CI, 0.04-0.81; P = .02) and in duration of severe worst herpes zoster-associated pain (vaccine, 892.0 days; placebo, 6275.0 days; hazard ratio, 0.62; 95% CI, 0.42-0.89; P = .01). Five secondary objectives were descriptive. Injection site reactions were recorded in 86% of vaccine and 10% of placebo recipients, of which pain was the most common, occurring in 84% of vaccine recipients (grade 3: 11%). Unsolicited and serious adverse events, potentially immune-mediated diseases, and underlying disease relapses were similar between groups at all time points. Conclusions and Relevance: Among adults who had undergone autologous HSCT, a 2-dose course of recombinant zoster vaccine compared with placebo significantly reduced the incidence of herpes zoster over a median follow-up of 21 months. Trial Registration: ClinicalTrials.gov Identifier: NCT01610414.

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.

Autologous hematopoietic progenitor cell mobilization and collection in adult patients presenting with multiple myeloma and lymphoma: A position-statement from the Turkish Society of Apheresis (TSA).

Autologous hematopoietic cell transplantation (AHCT) is a routinely used procedure in the treatment of adult patients presenting with multiple myeloma (MM), Hodgkin lymphoma (HL) and various subtypes of non-Hodgkin lymphoma (NHL) in upfront and relapsed/refractory settings. Successful hematopoietic progenitor cell mobilization (HPCM) and collection are the rate limiting first steps for application of AHCT. In 2015, almost 1700 AHCT procedures have been performed for MM, HL and NHL in Turkey. Although there are recently published consensus guidelines addressing critical issues regarding autologous HPCM, there is a tremendous heterogeneity in terms of mobilization strategies of transplant centers across the world. In order to pave the way to a more standardized HPCM approach in Turkey, Turkish Society of Apheresis (TSA) assembled a working group consisting of experts in the field. Here we report the position statement of TSA regarding autologous HPCM mobilization strategies in adult patients presenting with MM and lymphoma.

Current practice of autologous hematopoietic progenitor cell mobilization in adult patients with multiple myeloma and lymphoma: The results of a survey from Turkish hematology research and education group (ThREG).

Autologous hematopoietic cell transplantation (AHCT) is an established treatment option for adult patients presenting with multiple myeloma (MM), Hodgkin lymphoma (HL) and various subtypes of non-Hodgkin lymphoma (NHL) in upfront and/or relapsed/refractory disease settings. Although there are recently published consensus guidelines addressing critical issues regarding autologous hematopoietic progenitor cell mobilization (HPCM), mobilization strategies of transplant centers show high variability in terms of routine practice. In order to understand the current institutional policies regarding HPCM in Turkey and to obtain the required basic data for preparation of a national positional statement on this issue, Turkish Hematology Research and Education Group (ThREG) conducted a web-based HPCM survey. The survey was designed to include multiple-choice questions regarding institutional practice of HPCM in adults presenting MM, HL, and NHL. The representatives of 27 adult HCT centers participated to the study. Here we report the results of this survey shedding light on the real-world experience in Turkey in terms of autologous HPCM mobilization strategies in patients presenting with MM and lymphoma.

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 clearance time of infused hematopoietic stem cell from the blood circulation.

There is no detailed information about the clearance time of infused hematopoietic stem cell (HSC) from the blood circulation in humans. In this prospective study, peripheral blood CD34+ cell counts were detected during the 4days period following autologous HSC transplantation in 20 patients by means of flow cytometry. The median CD34+ cells were at the highest level in the first hour and decreased below pre-infusion values on the first day after HSC infusion. By nonparametric analysis, positive correlation was found between CD34+ cell levels at the first hour and the post-thaw CD34+ cell dose (r=0.57, p=0.01). An inverse correlation was determined between CD34+ cell levels at the first hour and neutrophil engraftment (r=-0.54, p=0.01). Compared with the patients having CD34+ cell count of ⩾2µL(-1) in the first hour following HSC infusion, the patients having CD34+ cell count of <2µL(-1) had delayed both neutrophil (20 vs. 12, p=0.008) and platelet (47 vs. 11, p=0.01) engraftments. Our results indicated that infused HSCs were removed from the blood circulation within 1day. In addition, CD34+ cell levels at the first hour may be used as an important indicator to predict the delay of neutrophil and platelet engraftments.

CD31 expression on peripheral blood stem cells predicts both early neutrophil and platelet engraftments.

No detailed information currently exists about the immune phenotypic profiles of peripheral blood stem cells (PBSCs) obtained by different mobilization regimens. The effects of these profiles on the outcome of transplantation are largely unknown. In this prospective study, the surface immune phenotypic features (CD11a, CD18, CD31, CD38, CD44, CD62e, CD62L, CD90, CD117, CD135 and CD184 expression) of sorted PBSCs that had been mobilized by growth factor with (group I and group II) or without (group III) disease-specific chemotherapies were investigated. The immune phenotypic features on mobilized PBSCs in groups I, II and III were not significantly different. The CD31 (platelet endothelial cell adhesion molecule-1) positivity ratio on PBSCs inversely correlated with both the duration of neutrophil (r=-0.32, p=0.03) and platelet (r=-0.36, p=0.02) engraftment. No relationship was found between the engraftment (neutrophil and platelet) durations and CD184 (chemokine receptor CXC motif receptor 4 [CXCR4]) expression on PBSCs. We demonstrated that the surface immune phenotypic profiles on PBSCs obtained by several mobilization regimens were not different. To our knowledge, this is the first study to demonstrate that CD31 expression on human PBSCs may positively affect both neutrophil and platelet engraftment. Contrary to our expectations, CD184 (CXCR4) expression on PBSCs has no effect on neutrophil or platelet engraftment. Considered together, our results suggest that additional surface antigens (such as CD31) may be more effective in the homing process.

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.

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.

Prophylactic Central Nervous System Irradiation Is Not Indispensable in Adult Patients with Acute Lymphoblastic Leukemia: A Multicenter Retrospective Cohort Study

Objective: Studies comparing the efficacy and safety of prophylactic regimens for central nervous system (CNS) involvement in acute lymphoblastic leukemia (ALL) are scarce in adults. This multicenter retrospective study aimed to compare the efficacy of prophylactic regimens with and without CNS irradiation on the development of CNS relapse during follow-up. Materials and Methods: This was a multicenter comparative cohort study. A total of 203 patients were included from four tertiary care centers in Turkey. Patients were divided into two groups according to whether they received CNS irradiation or not. The groups were analyzed retrospectively regarding patient and disease characteristics, with the main focus being CNS relapse. Results: While 105 patients received chemotherapy-based prophylaxis, 98 patients received additional CNS irradiation. These groups were statistically comparable in terms of demographic characteristics and risk factors for CNS involvement. In the irradiation group, patients were younger and had more stem cell transplants. In a median of 23.8 (11.1-62.4) months, there was no difference between the two groups regarding CNS relapse-free survival (log-rank p=0.787). Conclusion: Craniospinal irradiation may not be indispensable for every adult patient with ALL, similarly to pediatric patients. It is crucial to avoid the long-term toxicities of radiation, especially in patients with long life expectancy. Craniospinal irradiation may be reserved for therapeutic use in cases of CNS relapse and prophylaxis for some high-risk patients.