Dong Won Baek

BACKGROUND Histiocytic sarcoma is a rare and aggressive hematopoietic malignancy, characterized by tumor cells exhibiting features of histiocytes or dendritic cells. Extranodal involvement, particularly in the gastrointestinal tract, skin, and soft tissues, is common and often associated with aggressive clinical behavior and poor outcomes. Due to its rarity, no standardized treatment has been established. Current therapeutic approaches are generally adapted from aggressive non-Hodgkin lymphoma protocols, typically involving multi-agent chemotherapy. However, therapeutic responses are often suboptimal, with frequent relapses. In selected cases, hematopoietic stem cell transplantation has been employed following intensive chemotherapy for disease control. CASE REPORT A 44-year-old woman presented with pancytopenia and was initially diagnosed with immune thrombocytopenia. After splenectomy for refractory disease, histopathlogic examination of spleen confirmed histiocytic sarcoma. She received 6 cycles of chemotherapy with cyclophosphamide, doxorubicin (hydroxydaunorubicin), vincristine (Oncovin), etoposide, and prednisone. Despite an initial response, the disease progressed. She underwent high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation, but ultimately died due to disease relapse. CONCLUSIONS This case demonstrates the highly aggressive course and poor prognosis of histiocytic sarcoma, even after intensive chemotherapy and autologous stem cell transplanatation. Given the highly aggressive nature of histiocytic sarcoma and its generally poor prognosis, allogeneic stem cell transplantation may offer a more effective strategy for achieving long-term remission, particularly in patients with relapsed or refractory disease. Large-scale studies are needed to establish treatment guidelines for histiocytic sarcoma.

Background/Aims: To determine the effectiveness of tyrosine kinase inhibitor (TKI) plus reduced-intensity therapy in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL), this retrospective study compared treatment outcomes and induction mortality according to backbone regimen intensity.Methods: The data of 132 patients diagnosed with Ph-positive ALL were retrospectively collected from five centers. Patients received imatinib plus intensive chemotherapy (modified VPD, KALLA1407, or hyper-CVAD) or reduced-intensity chemotherapy (EWALL) for curative purposes. This study analyzed 117 patients, of which 35,22,46, and 14 received modified VPD, KALLA1407, hyper-CVAD, and EWALL, respectively. All patients used imatinib as a TKI.Results: The median age of the patients who received reduced-intensity chemotherapy was 64.4 years, while that of the patients with intensive regimens was 47.5 years. There was no induction death in the reduced-intensity group, while nine patients died in the intensive therapy group. Major molecular response achievement tended to be higher in the intensive chemotherapy group than in the reduced-intensity group. More patients in the intensive chemotherapy group received allogeneic stem cell transplantation (allo-SCT). There was no statistically significant difference in long-term survival between the two groups in terms of relapse-free survival and overall survival rates.Conclusions: When imatinib plus reduced-intensity therapy was used as a frontline treatment, there was no inferiority in obtaining complete remission compared to imatinib plus intensive chemotherapy or significant difference in long-term survival. Since imatinib plus reduced-intensity therapy has limitations in obtaining a deep molecular response, proceeding to allo-SCT should be considered.

Successful Treatment of a Patient Presenting with Simultaneous Diffuse Large B-Cell Lymphoma and Hodgkin Lymphoma: A Case Report - Article abstract #945435

Background Using granulocyte colony-stimulating factor (G-CSF) after completing chemotherapy reduces the duration of neutropenia and infections. However, the efficacy and safety of prophylactic pegfilgrastim in acute lymphoblastic leukemia (ALL) patients have not yet been evaluated after intensive cytotoxic chemotherapy compared to the daily G-CSF. This study aimed to evaluate the efficacy of pegfilgrastim for ALL patients who received intensive chemotherapy compared with a short-acting G-CSF. Patients and methods Clinical data of 145 patients treated with hyper-CVAD, modified VPDL/VPD, or KALLA 1406/1407 regimen were retrospectively evaluated. Pegfilgrastim or the short-acting G-CSF was selected according to the clinician’s discretion. Patients not receiving pegfilgrastim were treated with the short-acting G-CSF. Results The median age of enrolled patients was 45 years. Sixty newly diagnosed ALL patients were treated with hyper-CVAD regimen, while KALLA and VPDL regimens were administered to 39 and 46 patients, respectively. Among the 60 patients treated with hyper-CVAD, 20 patients received pegfilgrastim. Patients who received pegfilgrastim had a significantly shorter duration of neutropenia and hospitalization and reduced incidence of severe infections compared to patients receiving the short-acting G-CSF. Consistent results were also confirmed in an analysis targeting only patients who achieved remission during hyper-CVAD induction therapy. There was no significant difference in neutrophil recovery ability and hospitalization duration when the daily short-acting G-CSF was used prophylactically after completing hyper-CVAD, KALLA, and VPDL regimens as induction therapy. Conclusion Using pegfilgrastim after hyper-CVAD therapy was more effective than the short-acting G-CSF in terms of infection, neutropenia recovery, and hospitalization in patients with newly diagnosed ALL.

Summary: The optimal treatment strategy for newly diagnosed primary central nervous system lymphoma (PCNSL) has yet to be established, especially in the elderly. In the current study, we conducted a phase II study to evaluate the efficacy and safety of rituximab plus high‐dose MTX followed by rituximab plus cytarabine in patients aged ≥60 years newly diagnosed with PCNSL. Patients received an induction treatment of high‐dose methotrexate plus rituximab followed by two cycles of a consolidation treatment of cytarabine plus rituximab. The primary end‐point was a 2‐year progression‐free survival (PFS) rate. A total of 35 patients were recruited, and their median age was 73 (range: 60–81). After induction treatment, the complete and partial responses (PRs) were 56% and 20% respectively. Twenty‐six patients proceeded to the consolidation treatment; the complete and PRs were 59% and 9% respectively. After a median follow‐up duration of 36.0 months, the 2‐year PFS rate was 58.7%. Treatment was generally well‐tolerated as only three patients were withdrawn from the study due to toxicity, and no treatment‐related mortality was reported. The 2‐year overall survival rate was 77.9%. The current study may suggest the feasibility of administering high‐dose MTX plus cytarabine in PCNSL patients aged ≥60 years and the potential role of additive rituximab.

Background/Aim: To date, therapeutic options for T-cell acute lymphoblastic leukemia (T-ALL) remain very limited. This study evaluated the efficacy of monotherapies and combination therapies including a selective BCL-2 inhibitor for T-ALL cell lines, namely Jurkat, CCRF-CEM, and Loucy. Materials and Methods: Loucy is an early T-precursor ALL (ETP-ALL) cell line characterized by an immature phenotype, whereas Jurkat and CCRF-CEM are late T-cell progenitor ALL (LTP-ALL) cell lines. Monotherapy was conducted with venetoclax, cytarabine, bendamustine, or azacytidine, whereas combination therapy was performed with venetoclax plus cytarabine, venetoclax plus bendamustine, or venetoclax plus azacytidine. Cell viability assay was conducted after 48 h using Trypan blue and the 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS). Statistical analysis for evaluating synergistic interactions between anticancer drugs was performed by using the SynergyFinder Plus and drc R package. Results: Adding venetoclax to cytarabine, bendamustine, or azacitidine achieved an additive effect, with Loewe synergic scores ranging from −10 to 10 in Jurkat and CCRF-CEM. Conversely, the combination of venetoclax and cytarabine displayed an additive effect (Loewe synergic score: 8.45 and 5.82 with MTS and Trypan blue assays, respectively), whereas venetoclax plus bendamustine or azacitidine exhibited a synergistic effect (Loewe synergic score >10 with MTS assay) in Loucy. Remarkably, the Bliss/Loewe score revealed that the combination of venetoclax and bendamustine was the most synergistic, yielding a score of 13.832±0.55. Conclusion: The combination of venetoclax and bendamustine demonstrated the greatest synergistic effect in suppressing ETP-ALL cell proliferation. Further studies are warranted to determine the mechanisms for the synergism between venetoclax and bendamustine in high-risk T-ALL.

IntroductionThe treatment outcomes for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) have improved with various tyrosine kinase inhibitors (TKIs) and bispecific T-cell engagers. Although allogeneic stem cell transplantation (allo-SCT) is the standard treatment for young patients with Ph+ALL, its role remains debatable in the era of TKIs and blinatumomab.Areas coveredThere are some issues regarding Ph+ALL. First, do young patients require intensive chemotherapy (IC) in the era of multitarget agents? Second, which TKI is preferred for frontline therapy? Third, should allo-SCT be performed in patients achieving complete remission with ponatinib and IC? Fourth, can chemo-free treatment lead to a cure without allo-SCT? We searched relevant literature from the last 30 years on PubMed; reviewed the role of chemo-free therapies and combinations of ponatinib and IC; and assessed the necessity of allo-SCT in young patients with Ph+ALL.Expert opinionAllo-SCT may not be needed, even in young patients with Ph+ALL treated with ponatinib-based IC or combined ponatinib and blinatumomab as frontline therapy. When adopting a ponatinib-based chemo-minimized regimen for induction, allo-SCT is needed with posttransplant ponatinib maintenance. Continuous exposure to ponatinib at pre- or post-transplant is regarded as one of the most important factor for the success of treatment.

Background/Aim: This study evaluated the possibility of clinical use of circulating-tumor DNA (ctDNA) as a biomarker to determine up-front autologous stem cell transplantation (auto-SCT) for patients with high-risk diffuse large B-cell lymphoma (DLBCL) in practice. Patients and Methods: To explore the dynamics of ctDNA in DLBCL, blood samples were collected sequentially before and after treatment from patients with newly diagnosed DLBCL who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. To conduct ctDNA genotyping and ctDNA monitoring simultaneously, targeted sequencing by cancer personalized profiling using deep sequencing was used. Results: Ten patients between the ages of 50 and 60 years were enrolled. Based on the international prognostic index (IPI), seven patients were classified as high-IPI-risk group, and three patients were classified as low-IPI-risk group. The IPI risk group correlated with total metabolic tumor volume. All patients completed six cycles of R-CHOP chemotherapy, and seven patients achieved complete response. Changes in ctDNA mutation numbers did not correlate with changes in PET scan images and treatment response. In most high-risk patients, new mutations appeared in ctDNA after completion of chemotherapy that conceivably marked resistant clones. Notably, disease relapse did not occur in high-risk patients with poor prognostic mutations who underwent autologous SCT. Conclusion: ctDNA monitoring was meaningful in high-risk patients. Moreover, ctDNA and well-known prognostic factors should be considered in the decision making for auto-SCT. If a new genetic mutation in ctDNA with a negative prognosis would emerge during treatment, high-risk patients should consider auto-SCT.

This study aimed to identify the benefits of autologous-stem cell transplantation (auto-SCT) and allogeneic-SCT (allo-SCT) in patients with aggressive T-cell lymphomas to aid in the selection of transplantation type in clinical practice. This study retrospectively analyzed data from 598 patients who underwent transplantation for T-cell lymphomas from 2010 to 2020. In total, 317 patients underwent up-front SCT as consolidation therapy. The 3-year progression-free survival (PFS) and overall survival (OS) were 68.7% and 76.1%, respectively. Patients who underwent auto-SCT had significantly better OS (p = 0.026) than those who underwent allo-SCT; however, no statistical difference in PFS was found. Transplantation was used as a salvage therapy in 188 patients who had relapsed/refractory disease. Overall, 96 (51.1%) patients underwent auto-SCT and 92 (48.9%) patients underwent allo-SCT. Auto-SCT improved long-term survival in patients with complete remission (CR). Allo-SCT demonstrated better 3-year PFS in patients with partial remission and relapsed/refractory disease status. However, >50% of patients died within 1 year of allo-SCT. As a consolidative therapy, up-front auto-SCT demonstrated a survival benefit. Auto-SCT was also effective in patients who achieved CR after salvage therapy. If the disease persists or cannot be controlled, allo-SCT may be considered with reduced intensity conditioning.