Extramedullary Leukemia Research Articles

Clinical and molecular characteristics of extramedullary acute myeloid leukemias

Clinical and molecular characteristics of extramedullary acute myeloid leukemias

Prognostic Factors of Pediatric Acute Myeloid Leukemia Patients with t(8;21) (q22;q22): A Single-Center Retrospective Study.

This retrospective study aimed to analyze the treatment effect and prognostic factors of pediatric acute myeloid leukemia (AML) patients with t(8;21). A total of 268 newly diagnosed pediatric AML (pAML) enrolled from 1 January 2005 to 31 December 2022 were retrospectively reviewed, and 50 (18.7%) patients harbored t(8;21) translocation. CR rate, OS, EFS, and RFS were assessed by multivariate Logistic and Cox regression models in these patients. Of the 50 patients, 2 patients abandoned treatment during the first induction course. Of the remaining 48 patients who received double-induction therapy and were included in the final analyses, CR1 and CR2 were 75.0% (36/48) and 95.8% (46/48), respectively. The overall three-year OS, EFS, and RFS were 68.4% (95% CI, 55.0-85.1), 64.2% (95% CI, 50.7-81.4), and 65.5% (95% CI, 51.9-82.8), respectively. The presence of loss of sex chromosome (LOS) at diagnosis (n = 21) was associated with a better 3-year OS [87.5% (95% CI, 72.7-100) vs. 52.7% (95% CI, 35.1-79.3), p = 0.0089], 3-year EFS [81.6% (95% CI, 64.7-100) vs. 49.7% (95% CI, 32.4-76.4), p = 0.023], and 3-year RFS [81.6% (95% CI, 64.7-100) vs. 51.7% (95% CI, 33.9-78.9), p = 0.036] than those without LOS (n = 27), and it was also an independent good prognostic factor of OS (HR, 0.08 [95% CI, 0.01-0.48], p = 0.005), EFS (HR, 0.22 [95% CI, 0.05-0.85], p = 0.029), and RFS (HR, 0.21 [95% CI, 0.05-0.90], p = 0.035). However, extramedullary leukemia (EML) featured the independent risk factors of inferior OS (HR, 10.99 [95% CI, 2.08-58.12], p = 0.005), EFS (HR, 4.75 [95% CI, 1.10-20.61], p = 0.037), and RFS (HR, 6.55 [95% CI, 1.40-30.63], p = 0.017) in pediatric individuals with t(8;21) AML. Further analysis of combining LOS with EML indicated that the EML+LOS- subgroup had significantly inferior OS (92.9%, [95% CI, 80.3-100]), EFS (86.2%, [95% CI, 70.0-100]), and RFS (86.2%, [95% CI, 80.3-100]) compared to the other three subgroups (all p < 0.001). LOS and EML are independent prognostic factors of OS, EFS, and RFS with t(8;21) pAML patients. LOS combined with EML may help improve risk stratification.

Organomegalies as a predictive indicator of leukemia cutis in patients with acute myeloid leukemia.

Leukemia cutis (LC) is an extramedullary acute myeloid leukemia (AML) infiltrate. No previous study has described the clinical characteristics and outcomes of Thai patients diagnosed with AML with LC. We conducted a 7-year retrospective case-control study on Thai AML patients at Siriraj Hospital from November 2013 to July 2020. Patients were divided into LC and non-LC groups. Initial clinical presentations and laboratory findings were examined to identify LC-associated factors. Overall survival (OS) and relapse-free survival (RFS) were assessed. Pathological tissues underwent re-evaluation to validate the LC diagnoses. The study included 159 patients in a 2:1 ratio (106 non-LC and 53 LC). The LC group had a mean ± SD age of 54.3 ± 15.5 years; females were predominant. Three-fifths of the LC patients had intermediate-risk cytogenetics; 20.4% had an adverse risk, and 10.2% had a favorable risk. Most were classified as AML-M4 and AML-M5. Leukemic nodules were the primary finding in 58.5% of the cases, mainly on the legs. In the multivariate analysis of predictive factors associated with LC, organomegalies, specifically hepatomegaly, and lymphadenopathy, remained significant factors associated with LC [OR 4.45 (95%CI 1.20, 16.50); p = 0.026 and OR 5.48 (95%CI 1.65, 18.20); p = 0.005], respectively. The LC group demonstrated a significantly reduced OS (log-rank test p = 0.002) (median OS of 8.6 months vs. 32.4 months). RFS was considerably lower in the LC group (log-rank test p = 0.001) (median duration of 10.3 months vs. 24.4 months in the non-LC). AML patients who developed LC tended to experience notably poorer prognoses. Therefore, it is imperative to consider aggressive treatment options for such individuals. The presence of organomegalies in AML patients serves as a strong predictor of the possible occurrence of LC when accompanied by skin lesions.

Abstract C156: Dasatinib targets an upregulated SRC family kinase gene in extramedullary leukemia, improving prognosis in these patients

Abstract Purpose: To review outcomes of pts with extramedullary leukemic tumors (EMLT) treated with the second-generation tryrosine kinase inhibitor (TKI) dasatinib. Procedures: Reported cases of extramedullary leukemic tumors in patients treated with TKIs were reviewed and survivals elicited from authors. RNA seq and RT-PCR for lymphocyte-specific kinase (LCK) mRNA were performed on cases of EMLT in breast. Summary: Leukemic cells growing as tumors in any organ lead to treatment failure and death, even if marrow is in remission. Median survival of patients with EMLT is 5 months, unchanged for the last 50 years. Like solid cancers, EMLT are invasive and metastatic, showing desmoplastic fibrosis and invasion of adipose tissue. Traditional anti-leukemia chemo has not reliably cured EMLT in any site, but excision of primary tumors followed by adjuvant chemo has achieved remissions of &amp;gt; 20 yrs. This suggests the benefit of removing tumor microenvironment (TME) containing cytokines and immune cells influencing tumor growth and resistance. TME is a logical target to ablate EMLT; TME is not affected by agents that kill replicating leukemia cells. RNAseq of very long-stored samples of EMLT in breast found upregulation of LCK compared to normal breast, confirmed by LCK RT-PCR analysis in 3 of 5 ALL tumors (2 Ph+ALL, 1 B-ALL) and 1 of 8 AML tumors. LCK is a target of DAS, a second-generation TKI that, like first-generation imatinab (IM), effectively controls BCR-ABL+ (Ph+) chronic myeloid leukemia (CML) marrow. However, IM cannot prevent or treat EM relapse, documented in 90 reported cases, mostly in CNS sites, with or without blastic marrow. CNS leukemia can lead to blindness, deafness, and paralysis. Responses to routine CNS therapy with RT and intrathecal or high-dose chemo +/- transplant, occur but lengthy DFS is rare. Since 2004, DAS +/- routine therapy has cleared CNS sites (meninges, brain, optic nerve) for up to 7+ yrs in Ph+ and T lymphoid leukemias. LCK is expressed diffusely in the CNS within neurons and ependymal cells. Tumors in non-CNS sites have also been cleared by DAS +/- routine therapy in pts with CML, Ph+ALL, T-ALL, and Ph+ B lymphoblastic lymphoma. Sites include skin, pancreas, stomach, testis, and epidural space, with DFS up to 9+ yrs. Among 137 of 153 DAS-treated pts with EMLT with followup after response, 23 have had progression in EM sites, while 47 were disease-free for 1 to 10 yrs (29 pts &amp;gt; 2 yrs). Conclusions: DAS appears to be an effective agent for treatment of EMLT. LCK is a potential DAS target in both Ph+ and non-Ph+ hematologic malignancies (HM), as EM tumors occur in leukemias, lymphomas, and myeloma. DAS combined with other therapies may benefit some HM patients and improve survival. Prospective clinical studies are needed to define which patients might benefit from DAS and the role of LCK. Routine scanning by PET/CT should be conducted in HM to find clinically unrecognized EMLT and to document response. Citation Format: Isabel Cunningham, Jianqi Yang, Herbert B Newton, Rory A Fisher. Dasatinib targets an upregulated SRC family kinase gene in extramedullary leukemia, improving prognosis in these patients [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C156.

Acute myeloid leukemia with monocytic differentiation (myeloid sarcoma) masquerading as bone-soft tissue malignancy

Abstract Introduction/Objective Myeloid sarcoma is an extramedullary solid neoplasm composed of myeloid precursors with or without maturation. This tumor usually occurs simultaneously or following the onset of acute leukemia. Rarely, it can be the first manifestation of acute myeloid leukemia. We report a case of this rare tumor presenting histologically as a bone sarcoma with features of extraskeletal myxoid chondrosarcoma and myoepithelial carcinoma Methods/Case Report A 76-year-old female was referred to our institution for evaluation of a right foot mass associated with pain and swelling. MRI showed a 2.4 x 1.5x 1.2 cm soft tissue mass along the lateral margin of proximal and mid diaphysis of first metatarsal. The clinical and radiologic differential diagnosis was primary bone-soft tissue malignancy, or infection. Histologically, the biopsies showed sheets and cords of cells in a myxoid background. Cytologically the cells were plasmacytoid, mononuclear, mitotically active with immature chromatin, prominent nucleoli, and moderate to abundant cytoplasm. This morphologic appearance elicited the differential diagnosis of extraskeletal myxoid chondrosarcoma, myoepithelial carcinoma, and plasmacytoma. An initial panel of immunohistochemical stains showed the lesional cells to be negative for S-100, SOX-10, pancytokeratin, desmin, p63, EMA, CAM5.2, and CD138 but positive for CD43. Additional immunohistochemistry showed diffuse reactivity for CD33, and lysozyme; CD163 was focally positive, and the cells were negative for CD20, CD3, CD30, CD99, MUM1, CD138, and CD34. A diagnosis of extramedullary acute myeloid leukemia with monocytic differentiation (myeloid sarcoma) was rendered. Subsequently, patient underwent bone marrow biopsy which showed involvement by acute myeloid leukemia with monocytic differentiation. Results (if a Case Study enter NA) NA Conclusion Myeloid sarcoma is a rare tumor and presentation as an isolated metatarsal mass is highly unusual and exceedingly rare. This can mislead clinicians, radiologists, and pathologists. Pathologists need to keep hematopoietic tumors in their differential diagnosis even when the anatomic sites as well as the morphology are not typical of hematopoietic malignancies.

Mini-Hyper-CVD Plus Venetoclax for Treatment of Older Adults with Newly Diagnosed Ph-Negative B-ALL or T-ALL

Introduction Treatment of Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) in older patients (pts) is challenging due to poor tolerance of conventional chemotherapy and chemo-resistant disease. Pre-clinical work demonstrates that lymphoblasts are BCL2-dependent and sensitive to the BCL2 inhibitor venetoclax (VEN). We hypothesized that VEN plus dose-reduced hyper-CVD (cyclophosphamide, vincristine, dexamethasone) chemotherapy would be well tolerated and effective in older pts. We previously reported the safety and tolerability of VEN plus hyper-CVD in newly diagnosed and relapsed/refractory (R/R) pts (Jain ASH 2019), with a maximum tolerated dose of VEN 600 mg daily on days 1-21 per 28-day cycle. Preliminarily efficacy was promising in newly diagnosed pts, which prompted study extension to phase (P) 2, enrolling newly diagnosed older pts with Ph-negative (neg) B-ALL and T-ALL. Methods Pts with Ph-neg B-ALL or T-ALL were enrolled in a multi-center Phase Ib/II study (NCT03319901). In P1, both R/R pts and newly diagnosed pts ≥ 60 years (yrs) were enrolled. In P2, only newly diagnosed pts ≥ 55 yrs old or ≥ 50 yrs old with BMI ≥ 35 kg/m2 were enrolled. Pts began with VEN ramp-up (P1 over 7d; P2 over 3d) to target dose (P1: dose level [DL]1 400 mg/d; DL2 600 mg/d; P2 400 mg/d), Figure 1. Hyper-CVD, including central nervous system (CNS) prophylaxis with intrathecal chemotherapy, was then given with VEN per DL for 21/28 days per cycle, for up to 8 cycles. Following completion of hyper-CVD courses, pts received VEN plus POMP maintenance for up to 2 yrs. Pts were recommended to receive fewer than 8 cycles of hyper-CVD in the setting of toxicity or to proceed to allogeneic hematopoietic stem cell transplant (HSCT) per physician discretion. This report updates follow-up of the newly diagnosed pts enrolled in P1 and the P2 cohort. Complete remission (CR) was defined as &amp;lt;5% marrow blasts, no evidence of extramedullary or CNS leukemia, ANC &amp;gt;1.0 K/uL and platelets &amp;gt;100 K/uL. Measurable residual disease (MRD) was evaluated by multicolor flow cytometry (MFC) and negative defined as &amp;lt;0.01%. Survival outcomes are presented via Kaplan Meier. Results In total, 30 newly diagnosed pts [P1 11 (DL1=3; DL2=8); P2 18] were treated with a median age of 68 yrs (range, 57-81 yrs, n=12 [40%] ≥70 yrs); n=15 (50%) women, n=4 (13%) Hispanic, and n=1 (3%) Black. Twenty-three (77%) pts had B-ALL and 7 (23%) pts had T-ALL (6/7 early T-cell precursor). Two (6%) pts had central nervous system (CNS) involvement at diagnosis (1-CNS3, 1-CNS2). High risk genetics were present in 56% (13/23) of B-ALL pts: TP53 (n=9 associated with complex [n=3] or hypodiploid [n=5] karyotype), KMT2A (n=1), IKZF1 abnormality (n=2), and Ph-like (n=1). Eight B-ALL pts had received prior chemotherapy for multiple myeloma (n=6; n=4 auto HSCT, n=5 lenalidomide), diffuse large B-cell lymphoma (n=1, RCHOP), and breast cancer (n=1, docetaxel, carboplatin, trastuzumab). The median number of hyper-CVD cycles received was 4 (range 1-8) among the 27 pts who have completed the hyper-CVD phase of treatment (3 pts are currently receiving consolidation). Mortality within 30 days was 3% (n=1). One patient died in CR due to sepsis during cycle 4. Venetoclax did not impair count recovery: median time from C1 to C2 was 34 days (range 27-47). Dose adjustments of VEN occurred in 4 pts (15%). An MRD-neg CR was achieved in 25/30 (83%) pts. The median cycles to achieve both CR and MRD negativity by MFC was one (range: CR 1-2 cycles; MRD negativity 1-4 cycles). Remaining pts had refractory disease (n=4, 13%), or were not assessed (n=1, 3%) due to early death. Of the 25 pts who achieved CR, 11/25 (44%) received allogeneic HSCT in CR1 after a median of 200 days (range 138 to 347). With a median follow-up of 16.4 months, the estimated 12- and 24-month OS are 82.1% (95% CI 66, 98) and 74.6% (95% CI 54, 95), Figure 2; and RFS are 82.9% (95% CI 65, 100.0) and 67.8% (95% CI 44, 92), respectively. At data cut-off, 22 pts (73%) are alive. Death events (n=8, 27%) were due to early mortality (n=1, related to both ALL and infection), post HSCT complications (n=3), refractory ALL (n=1), relapsed ALL (n=1), sepsis in CR (n=1), and complications of cardiac surgery in CR (n=1). Conclusion In this ongoing study, the addition of VEN to hyper-CVD in newly diagnosed ALL was well tolerated with encouraging responses. A future amendment will incorporate blinatumomab consolidation for pts with B-ALL.

3rd-Generation Tyrosine Kinase-Inhibitors and Azacitidine Are Safe and Effective in Myeloid Blast-Phase Chronic Myeloid Leukaemia and Result in a High Proportion of Subjects in 2 nd Chronic Phase Able to Receive a Transplant

Background Myeloidblast phase of chronic myeloid leukemia (CML-MBP) has a terrible prognosis with a haemopoietic cell transplant the only likely cure. Probability of transplant success is markedly increased if someone can be returned to chronic phase. Purposes Study safety and efficacy of olverembatinib or ponatinib and azacitidine (AZA) in this setting. MethodsCML-MBP was diagnosed according to the WHO 2016 criteria. Ponatinib, 45 mg/d or olverembatinib, 30 mg every other d were combined with azacitidine, 75 mg/mE+2/d for 7 d in 28 d cycles. Subjects achieving 2 nd chronic phase received an allotransplant whereas others continued the therapy specified. 2 nd chronic phase was defined as &amp;lt; 10% blood and bone marrow blasts and no extra-medullary leukaemia for ≥ 4 w. Event-free survival (EFS) was defined as interval from therapy start to no response, progression to accelerated or blast phase or CML-related death. CML-related survival was defined as interval from therapy start to death from blast phase and survival, this interval to death from any cause. Haematologic, cytogenetic and molecular responses were monitored. Targeted DNA sequencing and whole RNA sequencing were done before therapy start. “MOVICS” package in R software was used for multi-omics integrated analyses and molecular sub-type classification. Cox regression models were used to identify co-variates associated with outcomes. The study was registered in Chinese Clinical Trial Registry (ChiCTR2200055887). Results 39 consecutive subjects were registered from October, 2020 to July, 2023. 21 were male. Median age was 50 years (Interquartile range [IQR], 33-54 years). 23 received olverembatinib; 16, ponatinib. Median follow-up was 10 months (mo) (IQR, 3-19 mo). 30 (77%) subjects achieved a 2 nd chronic phase after 1 cycle, 11 of whom received a transplant, 8 progressed to blast phase again; and 9 (23%) others had no response. 25 subjects died of progression (N = 19), transplant-related mortality (N = 3), COVID-19 (N = 2) or heart failure (N = 1). Median EFS, CML-related survival and survival were 4 (95% Confidence Interval [CI], 1-6) months, 12 (8-17) months and 11 (6-15) months. Subjects receiving a transplant had better EFS ( p= 0.03), CML-related survival ( p= 0.009) and survival ( p= 0.04) compared with non-transplant subjects ( Figure 1). Most treatment-related severe adverse events were tolerable and manageable including 25 subjects (65%) developing ≥ 4 grade neutropenia with or without thrombocytopenia except only 1 subject developing early death due to heart failure. In addition, 2 subjects experienced COVID-19 and died subsequently. In adjusted Cox regression analyses of genomic (N = 37) and transcriptomic (N = 34) data KRASmutation was significantly-associated with worse EFS ( p= 0.05), CML-related survival ( p&amp;lt; 0.001) and survival ( p= 0.009). TP53mutation was associated with worse CML-related survival ( p= 0.02) and survival ( p= 0.003). PFKFB3::LINC02649 fusion was associated with better EFS ( p= 0.001), CML-related survival ( p= 0.007) and survival ( p= 0.005). Based on these data 34 subjects were divided into 2 clusters. Subjects in cluster 2 (N = 14) had worse EFS ( p= 0.001), CML-related survival ( p= 0.008) and survival ( p= 0.005) compared with those in cluster 1 (N = 20). In differential gene expression analyses 1,564 genes were up-regulated and 1,000 down-regulated in cluster 2 compared with cluster 1. In KEGG analyses up-regulated genes were enriched in signaling pathways including cytokine-cytokine receptor interaction, cell adhesion molecules, natural-killer (NK) cell mediated cytotoxicity, primary immune deficiency and Toll-like receptor. Down-regulated genes were enriched in cell-cycle and DNA replication pathways. Conclusion s Olverembatinib or ponatinib combined with azacitidine is a safe and effective therapy of CML-MBP allowing many subjects to receive a transplant in 2 nd chronic phase. KRAS and TP53 mutations and PFKFB3::LINC02649 fusions had predictive impact on outcomes. Determining whether adding azacitidine to a 3 rd-generation TKI requires a randomized controlled trial.

The Topoisomerase-I Inhibitor Gimatecan Exhibits Potent and Selective Activities Against B-Cell Precursor Acute Lymphoblastic Leukemia with a Favorable Cardiotoxicity Profile

Topoisomerase-II inhibitors such as daunorubicin have long been the standard chemotherapeutic agents for managing acute leukemias. Yet, severe complications could be resulted from their myelosuppressive and cardiotoxic nature. Here, we report preclinical evidence showing the exceptional activities of gimatecan, an orally available topoisomerase-I inhibitor currently being investigated in Phase II trials for solid cancers, on hematologic malignancies. Activity screening on leukemia cell lines revealed a substantially higher potency of gimatecan than frontline chemotherapeutics against B-cell precursor acute lymphoblastic leukemia (BCP-ALL) driven by on-target depletion of topoisomerase-I. Gimatecan had a median IC50 of 0.9 nM against BCP-ALL with profound selectivity over acute myeloid leukemia (AML, 3.6-fold, P&amp;lt; 0.01) or hematopoietic stem/progenitor cells (HSPCs, 75-fold, P&amp;lt; 0.001). In contrast, the four standard chemotherapeutics (cytarabine, daunorubicin, dexamethasone and vincristine) exhibited much higher median IC50s against BCP-ALL (18-2,201 nM). Following single-agent gimatecan treatment, complete dissolution of medullary and extramedullary leukemia (CNS and testis) by &amp;gt;95% inhibition concomitant with markedly extended survival (1.2 to 3.3-fold, P&amp;lt; 0.01) were demonstrated in animals grafted with cytogenetically distinct lymphoid leukemia cell lines (Reh, ETV6-RUNX1+; 697, TCF3-PBX1+; RS4;11, KMT2A-AFF1+; HAL-01, TCF3-HLF+) and in patient-derived xenografts from three cases of highly resistant BCP-ALL failing salvage chemotherapy or upfront immunotherapies. Splenocytes isolated from NSG mice relapsed from gimatecan treatment demonstrated recurrent drug sensitivity ex vivo comparing with vehicle controls and that gimatecan reinduction offered additional survival benefits in the xenograft model ( P&amp;lt; 0.05). The therapeutic efficacy was also observed at varied initial tumor load, together suggesting its potential for reinduction and flexibility on the administration schedule. In NSG mice reconstituted with cord blood HSPCs, gimatecan displayed a mild but transient suppression on normal hematopoiesis without bias on lineage output (63% reduction at 6 weeks, P=0.002; not statistically significant at 14 weeks). Importantly, gimatecan did not affect the viability of human iPSC-derived cardiomyocytes (hiPSC-CM) even at the highest tested dose (1,000 nM) as opposed to daunorubicin (IC50: 130 nM). Concordantly, no noticeable signs of DNA damage (by γ-H2AX staining) or apoptotic events (by enumeration of condensed nuclei) on hiPSC-CMs were observed after gimatecan exposure at doses at or above its Cmax (~130 nM). The gross structure of heart tissues harvested from gimatecan-treated mice was also intact without signs of cardiotoxicity at the dose effective to suppress leukemia (0.2 mg/kg). When compared with malignant B-lymphoblasts, there was a declined expression of topoisomerase-I in HSPCs (0.63-fold, P=0.025) and cardiomyocytes (0.24-fold, P&amp;lt;0.001), potentially explaining its selectivity against BCP-ALL. Mechanistically, gimatecan induced time- and dose-dependent cell death via intrinsic apoptosis coupled with G2/M cell cycle arrest. RNA-seq analysis of gimatecan-treated BCP-ALL cells showed activation of the tumor suppressive p53 pathway and suppression of the MYC pathway. Phosphorylation of p53 and appearance of DNA damage markers, including CHK1/2, PARP and H2AX, were robustly detected upon gimatecan treatment. In short, gimatecan possesses remarkable anti-leukemia activities and tolerable toxicity profiles compared to counterpart topoisomerase-II inhibitor. This study, therefore, puts forward a new agent for BCP-ALL and points towards randomized clinical trials to realize its potential on acute leukemias.

Leukemia cutis egy eset kapcsán

Leukemia cutis is a subtype of extramedullary leukemia, characterized by the infiltration of the skin with leukemic cells. It affects approximately 5% of the patients diagnosed with leukemia. The disease may appear in any type of leukemia, at any age, with the same distribution in both sexes. The authors report a case of a 14-year-old girl who presented at the Dermatology Department of Heim Pál National Children’s Institute with livid-erythematous nodules on her face, scalp, and trunk. Clinical and laboratory tests suggested lymphoproliferative disease, which was confirmed with histological and bone marrow examination, and acute myeloid leukemia with skin involvement was proven.

Expression profiling of extramedullary acute myeloid leukemia suggests involvement of epithelial-mesenchymal transition pathways.

Extramedullary (EM) colonization is a rare complication of acute myeloid leukemia (AML), occurring in about 10% of patients, but the processes underlying tissue invasion are not entirely characterized. Through the application of RNAseq technology, we examined the transcriptome profile of 13 AMLs, 9 of whom presented an EM localization. Our analysis revealed significant deregulation within the extracellular matrix (ECM)-receptor interaction and focal-adhesion pathways, specifically in the EM sites. The transcription factor TWIST1, which is known to impact on cancer invasion by dysregulating epithelial-mesenchymal-transition (EMT) processes, was significantly upregulated in EM-AML. To test the functional impact of TWIST1 overexpression, we treated OCI-AML3s with TWIST1-siRNA or metformin, a drug known to inhibit tumor progression in cancer models. After 48 h, we showed downregulation of TWIST1, and of the EMT-related genes FN1 and SNAI2. This was associated with significant impairment of migration and invasion processes by Boyden chamber assays. Our study shed light on the molecular mechanisms associated with EM tissue invasion in AML, and on the ability of metformin to interfere with key players of this process. TWIST1 may configure as candidate marker of EM-AML progression, and inhibition of EMT-pathways may represent an innovative therapeutic intervention to prevent or treat this complication.

Irradiated Extramedullary Acute Myeloid Leukemia Increases Survival in a Leukemic Mouse Model

The systemic nature of AML likely limits their immunogenicity because antigen presentation is primarily mediated by splenic dendritic cells, which induces immune tolerance. Since antigen presentation in tissue draining lymph nodes can induce anti-tumor immune responses, we hypothesized that local irradiation of cutaneous, extramedullary leukemias will increase immunogenic cell death, dendritic cell maturation and improved survival. A murine AML cell line C1498 was assessed for immunogenic markers calreticulin (CALR), HMGB1 and cGAS-STING pathway using fluorescence cytometry and qRT-PCR. Syngeneic mice were injected with C1498 subcutaneously to model extramedullary lesions and intravenously to model systemic leukemias. Cells and subcutaneous tumor were focally irradiated with 2 Gy or 8 Gy. Two-way ANOVA and Student's t-test were used for paired-wise comparisons. Survival was estimated by Kaplan-Meier plot and groups were compared using log-rank test. C1498 cells or tumors irradiated with 2 Gy or 8 Gy showed increased CALR and HMGB1 as well as (cGAS/Md21b1; 5-fold; p<0.001) and interferon alpha (Ifna; 3-fold; p<0.001) after 48h (18- and 4-fold, respectively; p<0.05) compared to not treated controls (NTC). Irradiated C1498 subcutaneous tumors displayed increased CD11b-positive cells (9-fold; p<0.001), CD11c (6-fold; p<0.001), and MHCII-positive CD11c cells (4-fold; p<0.01) in irradiated tumors compared to NTC. Irradiation of subcutaneous C1498 tumors increased median survival in mice also injected with C1498 cells intravenously compared to non-irradiated mice bearing systemic leukemias (46 vs. 25 days; p<0.01). Irradiation of C1498 tumors combined with anti-PDL1 treatment further increased median survival in our leukemia model compared to untreated controls (>50 vs. <30 days; p<0.001). Irradiated extramedullary AML increased immunogenic markers and activation of immune effector cells that correlated with increased survival in mice also bearing systemic leukemia. These results suggest focal irradiation of extramedullary AML may facilitate eradiation of systemic leukemias.

Salvage hematopoietic stem cell transplantation for patients with higher leukemia burden in relapsed or refractory acute myeloid leukemia: a ten-year study.

Patients with relapsed and refractory acute myeloid leukemia (R-R AML), especially those in non-remission (NR) have a poor prognosis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In order to optimize the entire allo-HSCT process for R-R AML patients and identify potential factors affecting clinical outcomes after HSCT, we retrospectively analyzed 44 adult patients with R-R AML who underwent salvage allo-HSCT while in NR or with concomitant extramedullary leukemia at the Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from 2013 to 2022. The 1-year and 2-year overall survival (OS) of the 44 patients were 55.3% (95% confidence interval [CI], 41.1%-74.3%) and 44.4% (95%CI, 30.2%-65.4%), respectively. The 1-year and 2-year cumulative incidence of relapse (CIR) were 39.4% (95%CI, 38.0%-40.7%) and 53.0% (95%CI, 51.0%-55.1%), respectively, and the 1-year and 2-year leukemia-free survival (LFS) were 37.8% (95%CI, 24.8%-57.7%) and 20.3% (95%CI, 9.1%-45.3%), respectively. The 100-day, 1-year and 2-year treatment-related mortality (TRM) was 13.8% (95%CI, 13.3%-14.4%), 22.8% (95%CI, 21.9%-23.7%) and 26.7% (95%CI, 25.5%-27.8%), respectively. Multivariate analysis revealed that patients who developed chronic graft-versus-host disease (cGVHD) after transplantation had lower relapse rate. Our analysis also indicated that patients with blast counts in bone marrow (BM) <20% and those with ≥20% had comparable clinical outcomes after allo-HSCT. In conclusion, our study demonstrated that R-R AML patients in NR or with concomitant extramedullary leukemia can benefit from allo-HSCT, regardless of leukemia burden at the time of transplantation. Patients who experience cGVHD after allo-HSCT may have lower relapse rate due to enhanced graft-versus-leukemia (GVL) effects, but cGVHD should be controlled at mild to moderate level to avoid life-threatening complications.

Early occurrence of acute myelomonocytic leukemia (M4/M5) after liver transplantation: a case report

IntroductionAcute myeloid leukemia is a rare event in post-liver-transplantation recipients. In the present report, we described a case of extramedullary acute myeloid leukemia, M4/M5 subtype, following orthotopic liver transplant.Case presentationThe patient was a 50-year-old Iranian woman who underwent orthotopic liver transplant due to hepatitis B-related cirrhosis (Child C, MELD (model for end-stage liver disease score) = 22). Orthotopic liver transplant was performed using the piggy back technique in January 2022. Induction immunosuppressive therapy was 1 gm methylprednisolone for 3 days followed by a triple maintenance immunosuppressive regimen including mycophenolate mofetil, prednisolone, and tacrolimus. About 5 months after orthotopic liver transplant in June 2022, the patient presented with leukocytosis, with white blood cell count of 99.4 × 103/µl, and physical examination revealed only cervical lymphadenopathy. Biopsy of cervical lymph nodes showed a myeloid tumor. She was immediately hospitalized. Eight hours after hospitalization, the patient gradually developed lethargy and decreased O2 saturation to approximately 89%. Flow cytometry demonstrated the markers of a myelomonocytic acute myeloid leukemia (M4/M5). Cytoreduction was immediately started by intensive leukopheresis followed by induction therapy. Because of a septic complication during the induction therapy, further chemotherapy was discontinued and broad-spectrum antibiotics and antifungal treatments started. Unfortunately, our patient died of severe septic shock 42 days after hospitalization.ConclusionAcute myeloid leukemia is a rare phenomenon after liver transplantation, and it can follow a rapidly fatal clinical course.

Isolated Extramedulary Relapse in T-Acute Lymphoblastic Leukemia

Isolated extramedullary acute lymphoblastic leukemia is a rare phenomenon. This event is more common in acute myeloid leukemia as myeloid sarcoma. This terminology is near the lymphoblastic lymphoma. Isolated extramedullary presentations hasn’t bone marrow involvement morphologically .Submicroscopic bone marrow involvement confirmed by a high-resolution flowcytometry detection method.

Post CAR T-cell therapy outcomes and management in HSCT-naive patients: a single-center experience

BackgroundTisagenlecleucel (tisa-cel) is increasingly being used in hematopoietic stem cell transplantation (HSCT)-naive patients. Outcomes for HSCT patients following chimeric antigen receptor (CAR) T-cell therapy demonstrate low relapse rates; however, a significant number of patients who receive tisa-cel can maintain remission without an HSCT. Multiple factors are considered when choosing whether or not to proceed with HSCT.MethodsWe retrospectively reviewed 31 patients who had received tisa-cel at our institution and who were transplant naive at the time of infusion. The aim was to determine the rate and timing of consolidative HSCT, factors that led to HSCT, and overall survival.ResultsThree of the 31 patients were non-responders to tisa-cel and ultimately died of disease. Twelve of the 28 responders remain alive with no evidence of disease (NED) without subsequent therapy. Of these patients, 5 of the 12 had isolated extramedullary acute lymphoblastic leukemia (ALL) (CNS, n = 4; testes, n = 1) and 2 of the 12 had Down syndrome, so no transplantation was planned. In the remaining 5 of 12 patients, close monitoring for signs of relapsed ALL, using serial next-generation sequencing (NGS) minimal residual disease (MRD) and lymphocyte subpopulation measurements, was performed. Owing to continued negative findings, no HSCT was chosen. Ultimately, 43% (12 of 28) of responders proceeded to HSCT, with three receiving tisa-cel as a planned bridge to HSCT as a result of CD22 negativity and/or provider preference (two patients survived with NED); three proceeded to HSCT as a result of early loss of B-cell aplasia (BCA) (all survived with NED); and six had salvage HSCT following relapse (three patients survived with NED and one patient was alive in relapse). Three of the 28 patients died following relapse post CAR T-cell therapy without HSCT. The final patient had an isolated extramedullary soft tissue CD19+ relapse 1 year post tisa-cel treatment, and is now NED without HSCT and persistent BCA.ConclusionClose monitoring of NGS results and BCA, as well as consideration of the site of the disease, can spare a subset of patients HSCT with the maintenance of leukemia-free remission, while still allowing for later HSCT in others. In our cohort, only a small subset of patients was unable to proceed to HSCT following relapse post-CAR T-cell therapy.

Optimized treatment of childhood B-lineage acute lymphoblastic leukemia

Childhood acute lymphoblastic leukemia (ALL) accounts for about 75% of childhood leukemia cases, and B-lineage acute lymphoblastic leukemia (B-ALL) accounts for more than 80% of childhood ALL cases. Over the past half century, new molecular biological targets discovered by new techniques have been used in precise stratification of disease prognosis, and there has been a gradual increase in the 5-year overall survival rate of childhood ALL. With the increasing attention to long-term quality of life, the treatment of childhood B-ALL has been constantly optimized from induction therapy to the intensity of maintenance therapy, including the treatment of extramedullary leukemia without radiotherapy, which has been tried with successful results. The realization of optimized treatment also benefits from the development of new techniques associated with immunology and molecular biology and the establishment of standardized clinical cohorts and corresponding biobanks. This article summarizes the relevant research on the implementation of precise stratification and the intensity reduction and optimization treatment of B-ALL in recent years, providing reference for clinicians.

A Pilot Study of Azacitidine As Epigenetic Priming for Chemotherapy in Infants Less Than 1 Year of Age with KMT2A-Rearranged Acute Lymphoblastic Leukemia (ALL); Results from the Children's Oncology Group (COG) Trial AALL15P1

Introduction Acute lymphoblastic leukemia (ALL) with KMT2A-rearrangement (KMT2A-r) in infants <1 year is a high-risk childhood ALL subtype, with consistently poor event-free survival (EFS) of approximately 35% when treated with intensive chemotherapy with or without hematopoietic stem cell transplant. Infant ALL blasts are characterized by DNA hypermethylation, which is hypothesized to contribute to chemoresistance by altering transcriptional regulation of gene expression. In preclinical studies of KMT2A-r blasts, epigenetic priming with DNA methyltransferase inhibitors improved the in vitro cytotoxicity of chemotherapy. Azacitidine, a pyrimidine nucleoside analog of cytidine and hypomethylating agent, has been used in combination with chemotherapy in children with leukemia. We previously reported that azacitidine was safe and well tolerated in AALL15P1 (ASPHO 2021) and herein we report survival outcomes. Methods The Children's Oncology Group (COG) trial AALL15P1 (NCT02828358) was a single arm, open label, groupwide pilot trial. The primary aim of the trial was to evaluate the tolerability of azacitidine in addition to Interfant-06 standard chemotherapy in infants with newly diagnosed KMT2A-r ALL. Estimation of 5-year EFS was an exploratory aim, given the small sample size. Eligibility criteria included B-ALL or acute leukemia of ambiguous lineage with ≥50% B-lymphoblasts, <366 days of age at diagnosis, and >36 weeks gestational age at enrollment. Exclusions included Down syndrome, secondary ALL, and prior cytotoxic therapy (except intrathecal chemotherapy or corticosteroids). Following an Interfant-based induction, infants with KMT2A-r received 4 courses of azacitidine, 2.5 mg/kg/dose intravenously over 10-40 minutes daily for 5 consecutive days in each course, immediately preceding the start of a chemotherapy course on day 6. Infants without KMT2A-r were removed from protocol following induction and did not receive azacitidine. Treatment failure was defined as failure to achieve M1 marrow status (<5% blasts by morphology) with resolution of extramedullary leukemia by the end of consolidation. EFS and overall survival (OS) were measured from the time of enrollment. Results The study accrued from March 2017 to December 2019 and all protocol-directed treatment concluded in December 2021. Of the 78 infants enrolled, 56 had KMT2A-r (72%), and 53 completed induction therapy and received at least 1 course of azacitidine. No patients were ineligible. Diagnostic clinical characteristics of infants with KMT2A-r included four infants age <7 days (7%), 13 age <90 days (23%), 18 with white blood cell count ≥300,000/µL (32%), 32 CNS2 (57%), and four CNS3 (7%). As of the data cutoff (06/30/2022), the median follow-up is 3.8 years, and the 3-year EFS (SE) and OS (SE) rates are 34.2% (+/- 0.08) and 63.8% (+/-0.08), respectively, for infants with KMT2A-r. Six infants experienced treatment failure. Minimal residual disease (MRD) levels of marrow blasts by flow cytometry in COG-approved laboratories were submitted for 49 KMT2A-r patients at the end of induction. Of those, 32 were MRD negative <0.01% (65%), eight MRD positive 0.01%-<1% (16%) and nine MRD positive ≥1% (18%). Event-free survival was significantly associated with MRD; the 3-year EFS of patients with any positive MRD was 20.6% (+/-0.13) vs. 40.1% (+/-0.09) (p=0.0185) for those without MRD. As previously reported, at no time did the trial meet or exceed the pre-determined dose limiting toxicity boundaries, and the rates and types of toxicities observed were within the expected range for infants receiving standard chemotherapy alone. Conclusions Epigenetic priming with azacitidine prior to standard chemotherapy was well tolerated in infants with KMT2A-r ALL, but the EFS was consistent with the poor survival of historical outcomes. Positive flow MRD at the end of induction predicted a higher risk of treatment failure, relapse, or death, in comparison to negative MRD, but EFS was still unacceptably low for MRD-negative patients. There remains an urgent need for improved therapies for infants with KMT2A-r ALL. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Acute Leukemias of Ambiguous Lineage presenting in Extramedullary Location – Unusual and Challenging Diagnoses: A Report of Two Cases

Abstract Introduction/Objective Acute leukemias of ambiguous lineage are uncommon, accounting for &amp;lt;1% of all leukemias, and extramedullary presentations of these leukemias are rare. Methods/Case Report We report two cases of acute leukemia of ambiguous lineage presenting in extramedullary sites. Case 1 is a 41-year-old female who presented with right cervical lymphadenopathy and fatigue. Laboratory and imaging studies showed leukopenia, anemia, and abnormal cervical, supraclavicular, axillary, mediastinal, and abdominal pelvic lymphadenopathy. Biopsy of the axillary lymph node revealed sheets of morphologic blasts. Flow cytometry showed the blasts were of mixed phenotype, with T-cell differentiation supported by CD3 and TdT, and myeloid subpopulation supported by myeloperoxidase and lysozyme. Both these populations were negative for CD10, CD20, CD4, CD8, CD34, CD138, CD1a, CD79a. The morphology and immunophenote establish the diagnosis of T/myeloid mixed-phenotype acute leukemia, not otherwise specified. Case 2 is a 65-year-old female who presented with bilateral lower extremity weakness. Multiple lytic lesions involving the thoracic and cervical spine were detected by imaging. Biopsy of a T12 vertebral lesion revealed sheets of large malignant cells. Extensive immunohistochemical workup revealed positivity for CD45 (weak), CD4, and CD43, supporting a diagnosis of hematopoietic neoplasm of likely hematopoietic origin. Subsequent evaluation eventually led to discovery of chronic myeloid leukemia in blast phase with undifferentiated blasts, BCR-ABL1 positive, originally presenting as extramedullary acute leukemia with undifferentiated blasts. Results (if a Case Study enter NA) NA. Conclusion These cases highlight the challenges of diagnosing peripheral solid tumors of unknown origin. Extramedullary presentation of acute leukemia of ambiguous lineage are particularly challenging and, although rare, include phenotypes ranging from mixed phenotype to undifferentiated types.

PLEURAL EFFUSION AS AN INITIAL PRESENTATION OF EXTRAMEDULLARY ACUTE MYELOID LEUKEMIA: A RARE PHENOMENON

PLEURAL EFFUSION AS AN INITIAL PRESENTATION OF EXTRAMEDULLARY ACUTE MYELOID LEUKEMIA: A RARE PHENOMENON

Secondary donor-derived CD19 CAR-T therapy is safe and efficacious in acute lymphoblastic leukemia with extramedullary relapse after first autologous CAR-T therapy.

Despite the advancement of treatments, adults with relapsed/refractory (R/R) B-lineage acute lymphoblastic leukemia (B-ALL) have poor prognosis, with an expected five-year overall survival (OS) rate of 10%‒20% (Nguyen et al., 2008; Oriol et al., 2010). Extramedullary relapse of B-ALL is regarded as a high-risk factor generally associated with poor survival, occurring in about 15% to 20% of all relapsed patients (Ding et al., 2017; Sun et al., 2018). The central nervous system (CNS) and the testes are the most common sites of extramedullary relapse of B-ALL. In addition, extramedullary leukemia can appear in the skin, eyes, breasts, bones, muscles, and abdominal organs. The prognosis of relapsed extramedullary B-ALL after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is extremely poor (Spyridonidis et al., 2012; Dahlberg et al., 2019). Conventional chemotherapy or radiation is often ineffective in such patients. At present, there are no optimal treatment strategies for treating extramedullary leukemia after allo-HSCT.