[Two cases of systemic mastocytosis with RUNX1-RUNX1T1 positive acute myeloid leukemia treated with sequential avapritinib after allogeneic hematopoietic stem cell transplantation and literature review].

Systemic mastocytosis (SM) with RUNX1-RUNX1T1 positive acute myeloid leukemia (AML) is a rare myeloid tumor with no standard treatment. Two cases of SM patients with RUNX1-RUNX1T1 positive AML treated with sequential avapritinib after allogeneic hematopoietic stem cell transplantation (allo-HSCT) were reported in Henan Cancer Hospital. Mast cell in bone marrow disappeared, C-KIT mutation and RUNX1-RUNX1T1 fusion gene remained negative. Allo-HSCT sequential avapritinib is an effective treatment for SM patients with RUNX1-RUNX1T1 positive AML.

[The prognostic factors of extramedullary relapse after allogeneic hematopoietic stem cell transplantation in patients with acute lymphoblastic leukemia].

To analyze the prognostic factors of extramedullary relapse (EMR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute lymphoblastic leukemia (ALL).The clinical data of 33 relapsed patients in 95 ALL patients receiving allo-HSCT were analyzed retrospectively. The median time of relapse was 5.7 (0.7-52.3) months. Extramedullary relapse was recorded in 10 cases (10.5%), bone marrow relapse in 15 cases (15.8%), and both extramedullary and marrow relapse were seen in 8 cases (8.4%). The median time of EMR was 7.4(0.7-52.3) months. The most commonly involved organ was central nervous system, followed by testis and bone. The 3-year OS rate in EMR patients was (33.3±11.1) %. Univariate analysis showed that disease state before transplantation (P=0.026), extramedullary infiltration before transplantation (P=0.005), conditioning regimens (P=0.033) and acute graft-versus-host disease(aGVHD) (P=0.013) were significantly correlated with EMR. Multivariate analysis suggested that extramedullary infiltration (RR=5.067, 95%CI1.542-16.645, P=0.007) and aGVHD(RR=3.585, 95%CI1.245-10.320, P=0.018) were independent predictive factors of EMR in ALL patients after allo-HSCT.

[Risk factors of extramedullary relapse after allogeneic hematopoietic stem cell transplantation in patients with myeloid leukemia].

Objective: To evaluate risk factors and available treatments of extramedullary relapse (EMR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myeloid leukemia. Methods: A total of 280 patients were retrospectively analyzed from January 2008 to December 2018 in Affiliated Cancer Hospital of Zhengzhou University. Clinical data were collected including disease patterns, pre-transplantation status, chromosome karyotype, conditioning regimen, types of donor, extramedullary disease before transplantation and graft-versus-host disease (GVHD). The log-rank test and Cox proportional hazard model were uesd for univariate analysis and multivariate analysis, respectively. Results: Twenty patients developed EMR (7.14%). The median time of EMR was 7.5 (1-123) months after allo-HSCT. The mortality of EMR was 80% (16/20). Univariate analysis identified disease patterns, second complete remission (CR2) or progressive disease before transplantation, extramedullary disease, abnormal karyotype and conditioning regimen without total body radiation as significant factors correlated to EMR (P<0.05). Multi-variable analysis revealed that CR2 or progressive disease (RR=3.468,95%CI 2.189-7.786), abnormal karyotype (RR=1.494,95%CI 1.020-2.189) and extramedullary disease before transplantation (RR=8.627,95%CI 3.921-18.452) were independent risk factors of EMR. Conclusions: The clinical outcome of EMR after allo-HSCT is poor.It is crucial to comprehensively assess and identify EMR as early as possible.

Phase-field lattice Boltzmann model for interface tracking of a binary fluid system based on the Allen-Cahn equation.

A lattice Boltzmann (LB) model is proposed to track the interface of binary fluid system based on the conservative-form Allen-Cahn (A-C) equation for phase field. Utilizing an equilibrium distribution function and a modified LB equation, this model is able to correctly recover the conservative A-C equation through the Chapman-Enskog analysis. A series of two-dimensional (2D) and three-dimensional (3D) phase-capturing benchmark tests have been conducted for validation, which include the diagonal translation of a circular interface, the rigid-body rotation of a Zalesak disk, and the deformation of 2D circular interface and 3D spherical interface in shear flows, all illustrating better accuracy and stability of the proposed model than the previous models tested. By coupling the incompressible hydrodynamic equation, a stationary droplet, a spinodal decomposition, and the Rayleigh-Taylor instability are simulated as well, showing the satisfying performance of the model in dealing with complex interfaces of binary fluid systems.

[The influence of additive clonal chromosome abnormalities in Ph negative cells on the efficacy of chronic myeloid leukemia].

Objective: To investigate the influence of additional clonal chromosome abnormalities in Ph negative cells (CCA/Ph(-)) on the efficacy of chronic myeloid leukemia (CML) after tyrosine kinase inhibitors (TKI) treatment. Methods: The clinical data of 28 CML patients with CCA/Ph(-) treated in Henan Cancer Hospital from July 2014 to December 2017 were analyzed retrospectively. The univariate analysis was carried out by Kaplan-Meier method. Multivariate analysis was done by Cox proportional risk model. Results: A total of 28 CCA/Ph(-)patients were recruited including 17 males and 11 females with median age of 42.5 years old. The most common CCA/Ph(-)were trisomy 8 (60.7%), monosomy 7 (14.3%). 64.3% CCA/Ph(-)were transient and 35.7% recurrent (more than 2 times). Cytopenia in two or three lineages of peripheral blood was seen in 42.9% patients. As to the efficacy, 89.3% patients achieved major cytogenetic response (MCyR), 25% with major molecular response (MMR). The median follow-up time was 26.5 months. Treatment failure (TF) of TKI occurred in 32.1% patients with median duration of response 8 (1-41) months. Univariate analysis showed that TF rate was significantly correlated with the frequency of CCA/Ph(-)and cytopenia (all P<0.05). The MMR rate was also significantly correlated with cytopenia (P<0.05). Cytopenia of two lineages or pancytopenia was an independent risk factor related to MMR rate (RR=3.868, 95%CI 1.216-12.298, P=0.022) . Conclusions: Cytopenia in CCA/Ph(-)appears to be an independent risk factor of MMR in CML patients with TKI treatment. The recurrent CCA/Ph(-)may link to higher treatment failure rate. Drug withdrawal or alternative strategy should be considered according to response and the ABL kinase mutations.

[Clinical analysis of 9 patients with transplant-related thrombotic microangiopathy].

Objective: To analyze the clinical features, efficacy and outcomes in patients with transplantation associated thrombotic microangiopathy (TA-TMA). Methods: The clinical data of 9 patients who developed TA-TMA after allogeneic hematopoietic stem cell transplantation (allo-HSCT) were retrospectively analyzed from January 2011 to August 2018 in Affiliated Tumor Hospital of Zhengzhou University. Results: There were 6 male and 3 female patiens with a median age of 31 (12-38) years. The median time from transplantation to TA-TMA was 76 (24-155) days. The baseline blood and biochemical parameters at diagnosis of TA-TMA included median hemoglobin (Hb) 66 (58-77) g/L,platelet (PLT) count 22 (4-38) × 10(9)/L,serum lactic dehydrogenase (LDH) 655 (305-4 238) U/L,blood urine nitrogen (BUN) level 15.9 (4.8-26.2) mmol/L,blood creatinine (Cr) level 118 (24-380) µmol/L. The proportion of median peripheral blood schistocytes was 2.6%(1.2%-9%). All patients had positive urinary occult blood tests,and urinary protein was seen in 4 patients. Three patients had mental symptoms. Coombs tests were all negative. The main treatments of TA-TMA composed of reduction and withdrawal of calcineurin inhibitor,steroids and plasma exchange. Response was seen in 4 patients. Patients who did not response to the treatment had a higher proportion of schistocytes,more severe acute graft-versus-host disease (aGVHD),more elevated serum LDH and other transplant-related complications. Conclusions: TA-TMA after allo-HSCT is a serious complication with high mortality rate. The proportion of schistocytes in peripheral blood, serum LDH level and comorbidities are prognostic factors of clinical outcome.

[Prognosis of clonal chromosomal abnormalities in Philadelphia negative metaphases cells in chronic myeloid leukemia with tyrosine kinase inhibitor therapy].

Objective: To investigate the characteristics and prognosis of clonal chromosomal abnormalities appearing in Philadelphia negative metaphases (CCA/Ph(-)) cells in chronic myeloid leukemia (CML) with tyrosine kinase inhibitor (TKI) therapy. Methods: The clinical data of 30 cases with CCA/Ph(-) during TKI treatment in Henan Cancer Hospital from August 2007 to July 2017 were retrospectively analyzed. The univariate factor was analyzed by Kaplan-Meier method. Multiple-factor was analyzed by Cox proportional risk model. Results: Of the 30 cases, 19 (63.3%) were males. At the first detection of CCA/Ph(-) the median age was 44 (rang 14-68) years old and the median treatment of TKI was 13 (rang 2-94) months. The clones proportion of first detected CCA/Ph(-)≥ 50% was found in 18 (60.0%) cases. TKI treatment for 3 months with BCR-ABL(IS) less than 10% was seen in 14 (46.7%) patients. 63.3% (19/30) of CCA/Ph(-) was transient (only one time) and 36.7% (11/30) was repeated (≥2 times) . Trisomy 8 dominant accounted for 60.0% (18/30) , -7/7q- for 13.3% (4/30) , loss of chromosome Y 6.7%. With a median of follow-up 50 months, 76.7% (23/30) cases were in complete cytogenetic response (CCyR) ; 63.3% (19/30) in major molecular response (MMR) , 43.3% (13/30) in undetectable minimal residual disease (UMRD) . The median event-free survival rate of (EFS) were 44 months, and 2-year and 5-year EFS were (82.1±7.3) % and (52.4±12.8) %, respectively. The median overall survival (OS) were 50 months, and 2-year and 5-year OS rates were (92.6±5.0) % and (77.2±14.7) %, respectively. Univariate analysis shows that the 2-year EFS of who in males, more than 2 times CCA/Ph(-), BCR-ABL(IS)>10% at 3 months after TKI were significantly lower than women, transient CCA/Ph(-), and BCR-ABL(IS)≤10% (P<0.05) . The 2-year OS rate in whom the occurrence frequency of CCA/Ph(-) more than twice was significantly lower than those with transient CCA/Ph(-) (P<0.05) . Multivariate analysis showed that CCA/Ph(-) was an independent risk factor (RR=4.741, 95%CI 1.21-18.571, P=0.018) for EFS in CML patients. Conclusion: Trisomy 8, -7/7q-, and -Y were the most common CCA/Ph(-) during TKI treatment, with high clones proportion of ≥50%. CCA/Ph(-) mainly occurred transiently or was permanent occasionally. CCA/Ph(-) recurrence (≥2 times) was an independent risk factor for EFS and OS in CML with TKI.

[Effect of nilotinib on pregnancy outcome in female patients with chronic myeloid leukemia].

Objective: To observe the pregnancy outcome among patients with chronic myeloid leukemia (CML) treated with Nilotinib (NIL) . Methods: Clinical data of pregnancy delivery in CML patients treated with NIL from March 2015 to January 2019 were retrospectively collected. Results: A total of 11 patients were recruited with median pregnancy age 28 (25-40) years. The median duration of NIL treatment before pregnancy was 34 (3-48) months. There were 12 pregnancies, included 2 planned ones and 10 (83.3%) unplanned. In the 10 unplanned patients, 9 (90.0%) received NIL 600 mg/d. The median exposure time were 4 (4-7) weeks. In eight patients with delivery outcomes, 5 cases had well-developed babies, 2 had spontaneous abortion and 1 case with an baby of syndactyly deformity, whose mother was exposed to NIL 600 mg/d for 7 weeks in the early trimester of pregnancy. Seven infants were 4 boys and 3 girls with the median height at birth 50 (41-54) cm and median weight 3.2 (3.0-4.6) kg. They all grew with a normal pattern and well developed. Now the median age is 19 (4-41) months. The disease status during 12 pregnancies included 3 cases in CMR, 2 cases in MR(4.0), 3 cases in MMR, 4 cases not acquiring MMR. The median time of drug discontinuation was 35 (15-36) weeks during pregnancy. No patient lost CHR during this period. Conclusions: Female CML patients exposed to NIL 600 mg/d for 4 weeks in early pregnancy can give birth to normal babies, but there is still a risk of spontaneous abortion and congenital malformations.

[Clinical analysis of six cases with the de novo glomerulitis after allogeneic hematopoietic stem cell transplantation].

Objective: To explore the occurrence, clinical characteristics, diagnosis and treatment of glomerulitis after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: Analysis were carried out based on the clinical data of 6 patients with de novo glomerulitis following allo-HSCT hospitalized in Henan Tumor Hospital from January 2008 to December 2016, and the clinical manifestation, pathology, diagnosis, treatment and outcome were investigated. Results: The occurrence of glomerulitis was 1.26% (6/478). The median time was 447(272-1 495) d after allo-HSCT. Proteinuria and varying degrees of edema were present in all patients. Of the 6 patients, 4 patients with impaired renal function, 3 cases of hypertension, 5 cases of urine occult blood positive, 2 cases of hyperlipidemia. 5 patients underwent acute graft-versus-host disease (GVHD), 4 patients accompanied with chronic GVHD at diagnosis. Kidney pathology showed typical features of minimal change diseases in 1 patient, membranous nephropathy in 4 patients and mesangial proliferative glomerulonephritis in 1 case. Immunohistochemistry of glomerular lesions revealed that the immune complex deposition included IgG in 4 patients, C3 in 3 patients, IgM and C1q in 1 patient. Serum ANA was positive in 2 patients and serum IgG and IgM were in high level in 1 patient, respectively. Only 1 case was effective on glucocorticoid. 5 cases treated by low dose cyclophosphamide combined with mycophenolate mofetil (MMF), 2 cases achieved complete remission, and 3 cases were partial remission. Up to now, 2 cases died with lung infection, and 4 patients survived. Conclusion: The predominant pathological type of glomerulitis was membranous nephropathy. Low-dose cyclophosphamide combined with MMF was an effective treatment.

[Effect of stopping tyrosine kinase inhibitors during pregnancy on disease status and reproductive outcomes among patients with chronic myeloid leukemia].

Objective: To explore the pregnancy outcome and disease status among patients with chronic myeloid leukemia (CML) treated with tyrosine kinase inhibitor (TKI) when they stopped TKI treatment during pregnancy. Methods: The clinical characteristics, reproductive outcomes and disease status of the patients who stopped TKI due to pregnancy between November 2004 to November 2017 were retrospectively collected. Results: A total of 14 CML patients in chronic phase (CML-CP), 12 patients were Sokal-low-risk. The median time of TKI treatment was 46.5 (15-123) months before the drug was stopped. The median age at the time of pregnancy was 29 (24-32) years. The median time of TKI exposure was 4 (0-9) weeks in 12 accidental pregnancies. Outcomes were available for 13 pregnancies, 9 cases (69.2%) delivered healthy babies, 1 case (7.7%) delivered polydactylia malformation baby, 3 cases (23.1%) had spontaneous abortion. The last one was still in pregnancy (no organ malformations were observed in color Doppler ultrasound). At the end of the follow up date, 10 children developed normal, the median age was 14 (0.7-65) months. Of the 14 patients who stopped TKI, 7 in complete molecular response (CMR), 3 in MR(4) (BCR-ABL(IS) <0.01%, ABL transcript >10 000), 2 in major molecular response (MMR), 2 in complete cytogenetic response (CCyR). The median time of TKI discontinuation during pregnancy was 33.5 (4-40) weeks. At the end of pregnancy, 4 cases were in CMR, 4 in MR(4), 1 in MMR and 4 in CCyR. No patients lost CCyR and complete hematologic remission. Conclusions: During the treatment of imatinib and Nilotinib, unplanned pregnancy may have a normal infant, but may lead to spontaneous abortion and congenital malformations. Female of CML-CP who had sustained and stable MMR at least 24 months and Sokal-low-risk had higher safety factor discontinued TKI during pregnancy, but still had a risk of increasing tumor load, so monitored the level of BCR-ABL of peripheral blood monthly during pregnancy is necessary.

[Clinical outcome of allogeneic hematopoietic stem cell transplantation in the treatment of 9 myeloid leukemia patients with granulocytic sarcoma].

To explore the efficacy and influencing factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myeloid leukemia and granulocytic sarcoma (GS). Clinical outcome including hematopoietic reconstitution, transplant-related complications, survival and relapse were collected and retrospectively analyzed in 9 patients with myeloid leukemia and GS after allo-HSCT. Hematopoiesis reconstitution was achieved in all the 9 recipients. Four cases developed acute graft-versus-host disease (GVHD), and 1 with chronic GVHD. The median follow-up time after transplantation was 10(4-81) months. Only 2 cases survived, the other 7 died of relapse. The median time of relapse after transplantation was 5(3-19) months. Allo-HSCT is relatively effective treatment for patients with myeloid leukemia and GS. Relapse after transplantation remains the major factor of mortality.

[The molecular-cytogenetic characterization and tyrosine kinase inhibitors efficacy in newly diagnosed chronic phase CML patients with variant Philadelphia chromosomes].

Objective: To investigate the molecular-cytogenetic characterization and impact on tyrosine kinase inhibitors (TKIs) therapy in chronic phase of chronic myeloid leukemia (CML-CP) patients with variant Ph chromosome (vPh). Methods: The clinical data of 32 patients with vPh chromosomes were collected and compared with 703 patients with typical Ph chromosome in newly diagnosed CML-CP who were on first-line imatinib (IM) and with BCR-ABL transcript of P210. Results: There was no significant difference in demographic and hematological characteristics between vPh and classic Ph patients. 3(9.4%) of the 32 vPh cases were simple variant translocations. Among the remaining 29 cases with complex variant translocations, 28 cases (87.5%) involved 3 chromosomes, and only 1 (3.1%) involved 4 chromosomes. Except for 8, 15, 18, X, and Y chromosomes, the other chromosomes were involved. The frequency of chromosome 12q(15.5%) and 1p (12.1%) were higher involved. The most common FISH signal pattern was 2G2R1Y (74.1%), followed by 1G1R2F (14.8%), 2G1R1Y (3.7%), 1G2R1Y (3.7%), 1G1R1Y (3.7%). The comparison of complete cytogenetic response (CCyR) (P=0.269), major molecular response (MMR) (P=0.391) were carried out between simple and complex mechanisms, without difference. Compared with the classic Ph, the patients with vPh had higher IM primary resistance rate (χ2=3.978, P=0.046), especially primary hematological resistance (χ2=7.870, P=0.005), but the difference of CCyR (χ2=0.192, P=0.661), MMR (χ2=0.822, P=0.365), EFS (χ2=0.509, P=0.476), OS (χ2=3.485, P=0.062) were not statistically significant, and multivariate analysis showed that the presence of vPh did not affect OS (RR=0.692, 95%CI 0.393-1.765, P=0.658)、EFS (RR=0.893, 95%CI 0.347-2.132, P=0.126) and PFS (RR=1.176, 95%CI 0.643-2.682, P=0.703). Conclusion: CML-CP patients with vPh and classic Ph had similar demographic and hematological characteristics. Except for 22q11, 9q34, the frequency of chromosome 12q and 1p were higher involved. The most common FISH signal pattern was 2G2R1Y, and different mechanisms had no impact on TKIs therapy. Compared with cases with classic Ph chromosomes, the patients with vPh chromosomes had higher risk of IM primary resistance, especially primary hematological resistance, which can obtain deeper molecular response quickly after changing to second-generation TKIs and didn't affect long-term outcomes and OS.

[Effect of polydimethylsiloxane matrix elasticity on osteogenic differentiation of rat marrow stromal cells].

Objective: To investigate the effect of polydimethylsiloxane (PDMS) matrix elasticity on osteogenic differentiation of rat marrow stromal cells (rBMSC). Methods: A series of PDMS composite substrates with different elastic modulus were constructed by adjusting the relative concentrations of cross-linking agent. The Young's modulus was used to describe the elasticity of PDMS after measurement by atomic force microscope (AFM). After surface modification, rBMSC was seeded on PDMS matrix, and 7 days after rBMSC was cultured on the five different Young's moduli matrix, the differences of osteogenic differentiation of rBMSC were observed by the method of real-time PCR, Western blotting, and alkaline phosphatase assay. Results: The PDMS was suitable for cell culture after surface modification, and by altering the concentration of cross-linking agent, PDMS could mimic the majority of the tissues' elasticity in vivo. The related osteogenic differentiation markers expression showed significant difference between the five matrixes (P<0.05), including type Ⅰ collagen (Col-Ⅰ), osteocalcin (OCN), osteopontin (OPN) and bone morphogenetic protein 2 (BMP2). The expression of osteogenic markers was up-regulated in the group that the Young's modulus was (354.1±40.9) kPa (P<0.05). Conclusions: PDMS is a tunable elasticity matrix which could be used in the investigation of inducing rBMSCs into osteoblastic lineages. PDMS substrate stiffness has an obvious influence on rBMSC osteogenic differentiation.

Preclinical study of rAAV2-sTRAIL: pharmaceutical efficacy, biodistribution and safety in animals.

The recombinant sTRAIL has been in clinical trial for various human malignancies. However, the half-life time of sTRAIL is very short, which might be an important factor influencing its clinical efficacy for cancer therapy. We previously reported the recombinant adeno-associated virus (AAV)-encoding sTRAIL95-281-mediated sTRAIL expression in vivo up to 8 months and suppressed tumor growth markedly in mouse xenografts. In the present study, we further evaluated the clinical potency for cancer gene therapy and the safety in mouse and non-human primates. The mouse models with HCT-116, NCI-H460 and BEL-7402 cancers were injected intraperitoneally with a single dose of 1.0 × 1011, 1.0 × 1010 and 1.0 × 109 vg of rAAV2-sTRAIL95-281 virus, respectively. The cynomolgus monkeys were injected (i.m.) with a single dose of rAAV2-sTRAIL95-281 of 1 × 1011, 3 × 1011 and 1 × 1012 vg, corresponding to 6-, 20- and 60-fold of intended use dosage for humans, respectively. The efficacy, pharmacology and toxicity of rAAV-sTRAIL in the animals were analyzed accordingly. The tumor inhibitory rates reached 44-76%, 48-52% and 55-74% in the three tumor models, respectively, and they had no influence on mouse spontaneous activity. Administration (s.c.) of a single dose of rAAV2-sTRAIL95-281 virus of 1.0 × 109 or 1.0 × 1010 vg in mice with implanted tumor led to mainly distribution in the spleen, liver, implanted tumor, blood, injected site of muscle and bone marrow. Two weeks later, there was no rAAV2-sTRAIL95-281 detected in blood and bone marrow, and it significantly decreased in other tissues and organs and then gradually cleared away in 4-12 weeks after administration. There was no rAAV2-sTRAIL accumulation in the animal's body and no influence on the body weights. Administration (i.v.) did not cause animal death, and no dose-related abnormal clinical symptoms were found in the mice. There were no abnormal tissue and organ found in all animals. Long-term toxicity test in cynomolgus monkeys did not cause rAAV2-sTRAIL95-281-related toxic and side effects, except that anti-AAV and anti-sTRAIL antibodies were generated. In conclusion, these data demonstrated that administration of rAAV2-sTRAIL95-281 in mice and in cynomolgus monkeys is safe without obvious toxic and side effects to the animals, and throw light on pharmacokinetics and safety in human clinical trials for cancer gene therapy.

Cytogenetic landscape and impact in blast phase of chronic myeloid leukemia in the era of tyrosine kinase inhibitor therapy.

The landscape of additional chromosomal alterations (ACAs) and their impact in chronic myeloid leukemia, blast phase (CML-BP) treated with tyrosine kinase inhibitors (TKIs) have not been well studied. Here, we investigated a cohort of 354 CML-BP patients treated with TKIs. We identified +8, an extra Philadelphia chromosome (Ph), 3q26.2 rearrangement, -7 and isochromosome 17q (i(17q)) as the major-route changes with a frequency of over 10%. In addition, +21 and +19 had a frequency of over 5%. These ACAs demonstrated lineage specificity: +8, 3q26.2 rearrangement, i(17q) and +19 were significantly more common in myeloid BP, and -7 more common in lymphoid BP; +Ph and +21 were equally distributed between two groups. Pearson correlation analysis revealed clustering of common ACAs into two groups: 3q26.2 rearrangement, -7 and i(17q) formed one group, and other ACAs formed another group. The grouping correlated with risk stratification of ACAs in CML, chronic phase. Despite the overall negative prognostic impact of ACAs, stratification of ACAs into major vs minor-route changes provided no prognostic relevance in CML-BP. The emergence of 3q26.2 rearrangement as a major-route change in the TKI era correlated with a high frequency of ABL1 mutations, supporting a role for TKI resistance in the changing cytogenetic landscape in CML-BP.