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Background: Peptide receptor radionuclide therapy (PRRT) has shown favorable results in neuroendocrine tumors (NETs). Long-term safety and efficacy data for 177 Lu-octreotate PRRT, particularly in combination with chemotherapy, is lacking., Methods: The authors conducted a retrospective review of the long-term toxicity and survival outcomes of 104 patients with advanced NETs treated on 4 phase 2 clinical trials with Lutetium-177-octreotate ( 177 Lu-octreotate) PRRT, mostly in combination with chemotherapy. Median follow-up was 68 months, which represents the longest follow-up study of 177 Lu-octreotate PRRT for NETs to date., Results: Median progression-free survival (PFS) was 37 months, and median overall survival (OS) was 71 months. Five- and 10-year OS were 62% and 29%, and 5- and 10-year PFS were 36% and 21%, respectively, demonstrating 177 Lu-octreotate can provide durable responses. PRRT was well tolerated with 1.9% of patients developing chronic renal impairment and 1% of patients developing long-term thrombocytopenia. Interestingly, there was a relatively high rate of myelodysplasia (MDS)/leukemia (6.7%), possibly attributable to the longer follow-up (with all except 1 case occurring more than 4 years after PRRT treatment) or to the addition of concurrent chemotherapy., Conclusions: Lutetium-177-Octreotate PRRT remains an efficacious and well tolerated treatment in long-term follow-up. For clinicians deciding on the timing of PRRT for individual patients, the 6.7% long-term risk of MDS/leukemia needs to be balanced against the 21% PFS at 10 years., (© 2022 American Cancer Society.)

This review aims to provide an expert consensus statement to address the role of gene-panel testing in the diagnosis, prognosis and management of adult myelodysplastic syndrome/myeloproliferative neoplasm overlap syndromes (MDS/MPN) in Australia. This consensus statement was developed by an expert group, actively involved in gene panel testing in the area of MDS/MPN in Australia. This work was led by the chairs of the MDS (A/Prof A. Enjeti) and MPN (A/Prof D. Ross) working parties of the Australasian Leukaemia and Lymphoma Group (ALLG). The authors were selected after an expression of interest process on the basis of active laboratory involvement in gene panel testing, a specific demonstrated interest in MDS/MPN and/or publication record in this field. The authors were then allocated sections for literature review to identify the specific genes of interest for each MDS/MPN entity. At least two authors reviewed each section and an overarching diagnostic algorithm was developed by a consensus amongst all authors., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by bone marrow dysfunction and increased risk of transformation to leukemia. MDS represent complex and diverse diseases that evolve from malignant hematopoietic stem cells and involve not only the proliferation of malignant cells but also the dysfunction of normal bone marrow. Specifically, the marrow microenvironment-both hematopoietic and stromal components-is disrupted in MDS. While microenvironmental disruption has been described in human MDS and murine models of the disease, only a few current treatments target the microenvironment, including the immune system. In this review, we will examine current evidence supporting three key interdependent pillars of microenvironmental alteration in MDS-immune dysfunction, cytokine skewing, and stromal changes. Understanding the molecular changes seen in these diseases has been, and will continue to be, foundational to developing effective novel treatments that prevent disease progression and transformation to leukemia.

Aims: Spliceosome genes ( SF3B1 , SRSF2 , U2AF1 and ZRSR2 ) are commonly mutated in myeloid neoplasms, particularly in myelodysplastic syndromes (MDS). JAK2 , MPL and CALR mutations are associated with myeloproliferative neoplasms (MPN). Although SF3B1 and MPN-associated mutations frequently co-occur in the rare entity MDS/MPN with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T), myeloid neoplasms with concurrent spliceosome and MPN-associated mutations encompass many disease entities and are not well characterised., Methods: Specimens from 2016 to 2019 with concurrent spliceosome and MPN-associated mutations were identified, and the clinicopathologic features were assessed., Results: The 36 cases were divided into mutational categories based on their spliceosome mutation. At diagnosis, cases with concurrent U2AF1 and MPN-associated mutations had lower leucocyte counts and platelet counts than did the other groups. Cases with mutant SRSF2 were more likely to have ASXL1 and IDH2 mutations, while U2AF1- mutated neoplasms were more likely to have an abnormal karyotype. The most common SF3B1 K700 and U2AF1 S34 mutational hotspots were underrepresented in our cohort of myeloid neoplasms with concurrent spliceosome and MPN-associated mutations, as SF3B1 and U2AF1 mutations tended to involve other codons. Numerous WHO-defined disease entities were represented in each spliceosome gene category; although MDS/MPN-RS-T were only identified in the group with SF3B1 mutations, they constituted only 1/4 of the neoplasms in the category., Conclusions: Myeloid neoplasms with different mutant splicing factor and concurrent MPN-associated mutations demonstrate somewhat different clinical and pathologic features, but t he association between genotypes and phenotypes in these overlapping neoplasms is not straightforward., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Allogeneic hematopoietic cell transplantation (HCT) is a curative option for patients with acute leukemia and myelodysplastic syndromes (MDS) but is associated with significant cost. Compared with children (age <15 years), adolescents and young adults (AYA; age 15 to 39 years) undergoing HCT have an increased risk for transplantation-related complications. However, whether such complications translate into increased resource utilization and costs during HCT remains unknown. Therefore, we conducted a multicenter database study using the Pediatric Health Information System database, an administrative database containing resource utilization data from 49 US tertiary children's hospitals to compare inpatient costs and resource utilization in children and AYA undergoing HCT for acute leukemia and MDS. The International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify HCT recipients and transplantation-related complications occurring up to 1 year post-HCT. We identified 1693 HCT recipients at pediatric centers between January 2010 and September 2014. Eighty percent of the total costs (from admission for HCT up to 1 year post-HCT) occurred during the initial transplantation admission. During initial admission, although AYA and children had a similar median length of stay (LOS) of 43 days, AYA incurred significantly greater adjusted costs ($338,458 versus $275,723; P < .001) and costs per hospital day ($7122 versus $5838; P < .001). Median total costs and costs per day during subsequent time periods post-HCT were also significantly greater in the AYA group. In multivariable analysis, increasing age at HCT, LOS, use of cord blood or an unrelated donor, occurrence of any graft-versus-host disease, infection, and use of dialysis or mechanical ventilation were significant drivers of increased cost at initial admission. In conclusion, allogeneic HCT for acute leukemia and MDS is associated with higher costs in AYA recipients than in children. Therefore, directing efforts and resources aimed at reducing HCT-related costs may be advantageous in this high-risk group., (Copyright © 2019 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Aims: Chromosome 11q23 translocations, resulting in MLL (KMT2A ) rearrangement, have been well characterised in acute myeloid leukaemia (AML) and acute lymphoblastic leukaemia (ALL). However, little is known of haematopoietic neoplasms associated with 11q23 translocation but without MLL rearrangement (11q23+/ MLL -). The aim of this study is to characterise such cases with 11q23+/ MLL -., Methods and Results: We retrospectively searched our database for cases with haematopoietic malignancies with 11q23+/ MLL -. We identified nine patients, two with AML, two with B-lymphoblastic leukaemia (B-ALL); two with T-lymphoblastic leukaemia (T-ALL), two with myelodysplastic syndrome (MDS) and one with chronic myelomonocytic leukaemia (CMML). The translocations included t(X;11)(p11.2;q23), t(2;11)(p21;q23), t(6;11)(q27;q23), t(8;9;11)(q13;q13;q23), t(11;11)(p15;q23), t(11;14)(q23;q24) and t(11;15)(q23;q14). Five of six patients with acute leukaemia had received chemotherapy and detection of 11q23 translocation occurred at time of disease relapse. Both patients with MDS and the patient with CMML had 11q23 translocation detected at time of initial diagnosis, all three patients progressed to AML after >1 year on hypomethylating agent therapy. All patients received risk-adapted therapies, including stem cell transplant in five patients. At the last follow-up, eight patients died with a median overall survival of 14 months., Conclusions: 11q23+/ MLL - occurs rarely, involving different partner chromosomes and showing clinical and pathological features and disease subtypes different from those cases with MLL rearrangement. 11q23+/ MLL - appears to be associated with clonal evolution/disease progression in acute leukaemia, a high risk for AML progression in MDS/CMML and a high incidence of disease relapse., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Health-related quality of life (HRQOL) and other patient-reported outcomes (PROs) are crucial for a comprehensive evaluation of treatment effectiveness. A systematic review of randomized controlled trials (RCTs) with a PRO endpoint conducted in patients with leukemia and myelodysplastic syndromes (MDS) was performed. Eligible studies were evaluated independently, according to a pre-defined coding scheme, by two reviewers. Thirteen RCTs, enrolling overall 3380 patients were identified. There were four RCTs involving acute myeloid leukemia patients (AML), one with acute lymphoid leukemia (ALL), five with chronic lymphocytic leukemia (CLL) and three with MDS. Six RCTs accurately documented PRO methodology assessment and were thus considered likely to robustly inform clinical decision-making. Of these, three RCTs dealt with AML, two with CLL, one with MDS. A growing number of RCTs in leukemia and MDS have included a PRO component in recent years. Inclusion of PROs in RCTs is feasible and can provide unique information to facilitate clinical decision-making., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Simple Summary: Obesity is epidemiologically and likely, causally related to various hematological cancers, while both conditions may predispose to severe SARS-CoV-2 infection. The COVID-19 pandemic brought about a variety of obstacles with respect to numerous aspects in the management of hematological malignancies. In the present overview, the evidence linking obesity with the development of hematological cancers and their role as risk factors for severe COVID-19 is critically appraised. Furthermore, the various challenges which emerged during the the pandemic are reviewed, regarding not only the treatment of the underlying hematological malignancies themselves, but also the prevention and therapeutic management of SARS-CoV-2 infection in this patient group. Lastly, we discuss further unresolved issues which need to be addressed in order to optimize the management of patients with hematologic cancers in the course of ongoing COVID-19 pandemic. The COVID-19 pandemic brought about an unprecedented societal and healthcare system crisis, considerably affecting healthcare workers and patients, particularly those with chronic diseases. Patients with hematologic malignancies faced a variety of challenges, pertinent to the nature of an underlying hematologic disorder itself as well as its therapy as a risk factor for severe SARS-CoV-2 infection, suboptimal vaccine efficacy and the need for uninterrupted medical observation and continued therapy. Obesity constitutes another factor which was acknowledged since the early days of the pandemic that predisposed people to severe COVID-19, and shares a likely causal link with the pathogenesis of a broad spectrum of hematologic cancers. We review here the epidemiologic and pathogenetic features that obesity and hematologic malignancies share, as well as potential mutual pathophysiological links predisposing people to a more severe SARS-CoV-2 course. Additionally, we attempt to present the existing evidence on the multi-faceted crucial challenges that had to be overcome in this diverse patient group and discuss further unresolved questions and future challenges for the management of hematologic malignancies in the era of COVID-19. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) can become dysfunctional in patients with hematological disorders. An unanswered question is whether age-linked disruption of the bone marrow (BM) microenvironment is secondary to hematological dysfunction or vice versa. We therefore studied MSC function in patients with different hematological disorders and found decreased MHC-II except from one sample with acute myeloid leukemia (AML). The patients' MSCs were able to exert veto properties except for AML MSCs. While the expression of MHC-II appeared to be irrelevant to the immune licensing of MSCs, AML MSCs lost their ability to differentiate upon contact and rather, continued to proliferate, forming foci-like structures. We performed a retrospective study that indicated a significant increase in MSCs, based on phenotype, for patients with BM fibrosis. This suggests a role for MSCs in patients transitioning to leukemia. NFĸB was important to MSC function and was shown to be a potential target to sensitize leukemic CD34+/CD38− cells to azacitidine. This correlated with their lack of allogeneic stimulation. This study identified NFĸB as a potential target for combination therapy to treat leukemia stem cells and showed that understanding MSC biology and immune response could be key in determining how the aging BM might support leukemia. More importantly, we show how MSCs might be involved in transitioning the high risk patient with hematological disorder to AML. [ABSTRACT FROM AUTHOR]

Cytogenetics is essential in myeloid neoplasms (MN) and pre-analytical variables are important for karyotyping. We assessed the relationship between pre-analytical variables (time from collection to sample processing, material type, sample cellularity, and diagnosis) and failures of karyotyping. Bone marrow (BM, n=352) and peripheral blood (PB, n=69) samples were analyzed from acute myeloid leukemia (n=113), myelodysplastic syndromes (n=73), myelodysplastic syndromes/myeloproliferative neoplasms (n=17), myeloproliferative neoplasms (n=137), and other with conclusive diagnosis (n=6), and reactive disorders/no conclusive diagnosis (n=75). The rate of unsuccessful karyotyping was 18.5% and was associated with the use of PB and a low number of nucleated cells (≤7×103/µL) in the sample. High and low cellularity in BM and high and low cellularity in PB samples showed no metaphases in 3.9, 39.7, 41.9, and 84.6% of cases, respectively. Collecting a good BM sample is the key for the success of karyotyping in MN and avoids the use of expensive molecular techniques.

The interaction of hematopoietic stem and progenitor cells with their direct neighboring cells in the bone marrow (the so called hematopoietic niche) evolves as a key principle for understanding physiological and malignant hematopoiesis. Significant progress in this matter has recently been achieved making use of emerging high-throughput techniques that allow characterization of the bone marrow microenvironment at single cell resolution. This review aims to discuss these single cell findings in the light of other conventional niche studies that together define the current notion of the niche’s implication in (i) normal hematopoiesis, (ii) myeloid neoplasms and (iii) disease-driving pathways that can be exploited to establish novel therapeutic strategies in the future.

Background Therapy related myeloid neoplasm (t-MN) is an emerging challenge in the current era. However, real world data on its incidence and survival at the population level remains sparse. Methods Using Surveillance Epidemiology and End Results (SEER-18) database, we identified patients aged ≥20 years with pathologically confirmed t-MN diagnosed between the years 2001–2014 and actively followed. Incidence rate per 100,000 population and incidence rate ratio (IRR) were calculated. Overall survival (OS) was calculated by Kaplan-Meier method with determinants analyzed by Cox proportional hazard regression method. Results A total of 1093 patients with a median age of 65 years were identified. Overall incidence of t-MN was 0.13 cases/100,000 population and showed significant variations with age, race and the period of diagnosis. Two year OS significantly declined with increasing age (51.3% in age group 20–39, 33.9% in age group 40–59, 19.3% in age group 60–79 and 0% in age ≥ 80, p < 0.01). OS has improved over period (year 2001–2007 − 22.1% vs. year 2008–2014 −26.9%, p = 0.01). On multivariate analysis, increasing age was associated with significantly higher mortality. Compared to the period 2001–2007, a significantly lower risk for mortality was seen in the period 2008–2014 (HR 0.73, CI 0.58–0.92, p < 0.01). Conclusions Incidence of t-MN has significantly increased in the last decade. Although OS at the population level is improving over time, outcomes of this disorder continue to remain poor, highlighting the need for novel therapies. [ABSTRACT FROM AUTHOR]

Objective: Therapy-related myeloid neoplasms (t-MN) account for approximately 10% to 20% of all cases of AML (acute myeloid leukemia), MDS (myelodysplastic syndrome) and MDS/MPN (myelodysplastic syndrome/myeloproliferative neoplasms), MDS, and MDS/MPN. In our study, we evaluated peripheral blood smear samples and hemogram values in breast cancer patients who were receiving adjuvant anthracycline regimens and were in remission. Materials and Methods: A total of 78 patients receiving anthracycline-based adjuvant chemotherapy treatment from Kayseri Research and Training Hospital and Mersin State Hospital were enrolled in the study. Their adjuvant treatments had been completed at least 18 months prior to the study. Results: Two patients complained of anemia (2.2%) (Hb

Jumping translocations (JT) have been identified in numerous malignancies, including leukemia, but infrequently in patients with myelodysplastic syndromes (MDS). The responsible genetic region has been mapped to the JTB gene at 1q21, but breakpoints involving other chromosomal loci, such as 3q and 11q, have been described as well. We have characterized the pathological and mutational landscape, and the clinical course of 6 new MDS patients with jumping mutations using chromosome genomic array testing (CGAT) and target gene panel next generation sequencing. In addition, we have performed a literature review for other MDS cases with JTs as defined by ISCN 2013. Results support the concept that MDS in patients with jumping translocations has a poor prognosis with a high risk of progression to leukemia, and suggest that these patients warrant aggressive therapy, including HCT, early in the disease course. [ABSTRACT FROM AUTHOR]

Objective: Therapy-related myeloid neoplasms (t-MN) account for approximately 10% to 20% of all cases of AML (acute myeloid leukemia), MDS (myelodysplastic syndrome) and MDS/MPN (myelodysplastic syndrome/myeloproliferative neoplasms), MDS, and MDS/MPN. In our study, we evaluated peripheral blood smear samples and hemogram values in breast cancer patients who were receiving adjuvant anthracycline regimens and were in remission. Materials and Methods: A total of 78 patients receiving anthracycline-based adjuvant chemotherapy treatment from Kayseri Research and Training Hospital and Mersin State Hospital were enrolled in the study. Their adjuvant treatments had been completed at least 18 months prior to the study. Results: Two patients complained of anemia (2.2%) (Hb<11 mg/dl), leukopenia was observed in seven patients (7.7%) (leukocytes<4000/mm3), and thrombocytopenia was observed in four patients (4.4%) (PLT<150.000/mm3). In the blood smear samples, the following were observed: ovalomacrocytes (14%), macrocytes (37%), acanthocytes (1%), stomatocytes (12%), teardrops (12%), nucleated erythrocytes (1%), basophilic stippling (14%), and Howell-Jolly bodies (1%). Additionally, hypo-granulation (38%), Pelger-Huet abnormalities (26%), hypersegmentation (20%), immature granulocytes (8%), and blasts (6%) were observed. We also confirmed the presence of giant platelets (50%) and platelet hypogranulation (19%). Conclusion: According to the peripheral blood smear assessments in our study, we suggest that breast cancer patients should be evaluated for MDS in the early stages, starting from month 18, even if the automated blood counts are normal. [ABSTRACT FROM AUTHOR]

Leukemia-initiating cells (LICs) or leukemia stem cells (LSCs) are defined by their ability to form tumors after xenotransplantation in immunodeficient mice and appear to be rare in most human leukemias. In various leukemias, only small subpopulations of cells can transfer disease upon transplantation into immunocompromised NOD/SCID mice, and markers that distinguish the leukemogenic cancer cells from the bulk populations of non-leukemogenic cells have been identified. However, the phenotype of LICs is heterogeneous: it is variable for the different types of acute myeloid leukemias; cells with different membrane phenotype can act as LICs in each B-acute lymphoid leukemia; LICs change during the evolution of chronic myeloid leukemia from the chronic to the acute phase. There is a general consensus that the identification and characterization of leukemic stem cells might lead to the identification of new therapeutic targets and, through this way, to more effective treatments by focusing therapy on the most malignant cells. [ABSTRACT FROM AUTHOR]

This paper describes the methodology used to develop a consensual glossary for haematopoietic cells within Diagnostics-WP10 of European-LeukemiaNet EU-project. This highly interactive work was made possible through the use of the net, requiring only a single two-day meeting of actual confrontation and debate. It resulted in the production of a freely accessible tool that could be useful for training as well as harmonization of morphological reports in onco-haematology especially, without geographic limitation, not limited to European countries. Moreover, this collective work resulted in the production of a consensus statement, taking into account individual practices, collegial agreement and literature data. [ABSTRACT FROM AUTHOR]

Lenalidomide is a functional and structural analogue of thalidomide with a relatively benign toxicity profile and pleiotropic anti-tumor activity, exhibiting anti-angiogenic and immunomodulatory effects. Lenalidomide has already been approved for the management of low or intermediate-1 risk myelodysplastic syndrome with chromosome 5q31 deletion and relapsed/refractory multiple myeloma in combination with dexamethasone. During the last five years, multiple clinical trials have been conducted to explore its potential efficacy in hematologic as well as in solid malignancies, revealing a significant benefit in clinical outcomes. This review outlines the mechanisms of action, the toxicity profile and the efficacy of lenalidomide, reviewing the current literature and focusing on the current status of the compound in cancer management. The determination of molecular biomarkers, predictive of clinical response to lenalidomide may reveal a more substantial role of this agent in the treatment of hematologic as well as solid malignancies. [ABSTRACT FROM AUTHOR]

A total of 50 consecutive patients (median age, 57.5 years) with AML (n=30) or myelodysplasia (MDS, n=20) underwent HLA matched related donor (MRD, n=27) or unrelated donor (MUD, n=23) peripheral blood hematopoietic cell transplantation after nonmyeloablative CY/fludarabine (Flu) conditioning. GVHD prophylaxis included CsA (n=19)±mycophenolate mofetil (n=31). At a median follow-up of 59 months, 21 patients (42%) were alive without evidence of disease. By Kaplan–Meier analysis, year 1–4 disease-free survival (DFS) and OS estimates were 0.50/0.58, 0.40/0.46, 0.37/0.43 and 0.37/0.41. MUD recipients were engrafted quickly (13.5 days) compared to MRD recipients (16 days) and relapsed/progressed less frequently (P=0.005). Overall grade 3/4 acute GVHD (aGVHD) occurred in 26% in the absence of antecedent mucositis and was associated with chronic GVHD (cGVHD) and poor OS. Extensive cGVHD developed in 51.2% of 100 day survivors. Rates of aGVHD, cGVHD and survival were similar between MRD and MUD recipients. Of 14 survivors with cGVHD, 5 (35.7%) experienced resolution off immunosuppression, suggesting that tolerance with HLA matched grafts is possible at an advanced age by this method. This study provides further evidence for prolonged DFS after CY/Flu MRD allotransplantation for AML/MDS, and extends the findings to older patients and those with unrelated donors. [ABSTRACT FROM AUTHOR]

Peripheral blood (PB) is sometimes used in place of bone marrow (BM) for cytogenetic studies during the evaluation of hematologic malignancies. A total of 242 PB cytogenetic studies from adult patients were performed: clinical diagnosis was a myeloid neoplasm in 169 patients (70%), lymphoid or plasma cell neoplasm in 50 (21%), and a benign/reactive cytopenia or leukocytosis in 23 (9%). PB cytogenetic studies resulted in at least two analyzable metaphases in 142 of the 242 study cases (59%); in univariate analysis, this was predicted by the specific clinical diagnosis ( P < 0.0001), presence and degree of circulating myeloid progenitor cells or blasts of any lineage ( P < 0.0001), higher leukocyte count ( P < 0.001), lower platelet count ( P = 0.003), lower hemoglobin level ( P = 0.002), and presence of palpable splenomegaly ( P = 0.002). In multivariable analysis, only the presence of circulating myeloid progenitor cells or blasts sustained significance and this was consistent with the high yield rates seen in primary myelofibrosis (PMF) (80%), post-PV/ET PMF (85%), acute myeloid leukemia (76%), and acute lymphoblastic leukemia (80%) in contrast with the low rates seen in ET (0%) and PV (2%). In 104 cases, BM cytogenetic studies were performed within 1 month of the PB cytogenetic studies; an abnormal BM cytogenetic finding was another independent predictor of a successful PB study ( P = 0.002). PB cytogenetic studies are most appropriate in diseases of adults characterized by presence of circulating myeloid progenitors or blasts; the yield otherwise is too small to be cost-effective. [ABSTRACT FROM AUTHOR]

Abstract: This review details major new observations in the diagnosis and treatment of leukemias and plasma cell dyscrasias that have been communicated since the last version of this work. This review is not exhaustive and may appear to some to be rather superficial. However, it should serve as an accurate index of current thinking and accomplishments. The review clearly demonstrates a trend away from traditional chemotherapeutic approaches to the leukemias and related diseases in favor of the more rational design of treatments for specific diseases based on laboratory observations. Some refer to the agents that have resulted from such an approach as targeted therapy and suggest that they represent a new era in cancer treatment, although one of the first targeted therapy agents to be conceived, synthesized and tested was 6-mercaptopurine decades ago. Furthermore, there is no cancer therapy more targeted than surgery, which has been practiced longer than any of us has lived. At any rate, whatever slogan may be used to describe current cancer treatment, it is clear that it is based on more preclinical science and more rational design than ever before. This chapter demonstrates that is certainly true for the leukemias and plasma cell dyscrasias. What has not been demonstrated yet is that better rationale has led to better results. That remains to be proven or disproven by continued observation of our treated patients. [Copyright &y& Elsevier]

Granulocyte colony-stimulating factor (GCSF) administration has been linked to the development of monosomy 7 in severe congenital neutropenia and aplastic anemia. We assessed the effect of pharmacologic doses of GCSF on monosomy 7 cells to determine whether this chromosomal abnormality developed de novo or arose as a result of favored expansion of a preexisting clone. Fluorescence in situ hybridization (FISH) of chromosome 7 was used to identify small populations of aneuploid cells. When bone marrow mononuclear cells from patients with monosomy 7 were cultured with 400 ng/ml GCSF, all samples showed significant increases in the proportion of monosomy 7 cells. In contrast, bone marrow from karyotypically normal aplastic anemia, myelodys-plastic syndrome, or healthy individuals did not show an increase in monosomy 7 cells in culture. In bone marrow CD34 cells of patients with myelodysplastic syndrome and monosomy 7, GCSF receptor (GCSFR) protein was increased. Although no mutation was found in genomic GCSFR DNA, CD34 cells showed increased expression of the GCSFR class IV mRNA isoform, which is defective in signaling cellular differentiation. GCSFR signal transduction via the Jak/Stat system was abnormal in monosomy 7 CD34 cells, with increased phosphorylated signal transducer and activation of transcription protein, STAT1-P, and increased STAT5-P relative to STAT3-P. Our results suggest that pharmacologic doses of GCSF increase the proportion of preexisting monosomy 7 cells. The abnormal response of monosomy 7 cells to GCSF would be explained by the expansion of undifferentiated monosomy 7 clones expressing the class IV GCSFR, which is defective in signaling cell maturation. [ABSTRACT FROM AUTHOR]

Human leukocyte antigen G (HLA-G) molecules corresponding to nonclassic class I genes of the major histocompatibility complex exhibit immunomodulatory properties. They are either membrane-bound or solubly expressed during certain tumoral malignancies. Soluble human leukocyte antigen G (sHLA-G) molecules seem more frequently expressed than membrane-bound isoforms during hematologic malignancies, such as lymphoproliferative disorders. Assay of these molecules by enzyme-linked immunosorbent assay in patients suffering from another hematologic disorder (acute leukemia) highlights increased sHLA-G secretion. This increased secretion seems more marked in acute leukemia subtypes affecting monocytic and lymphoid lineages such as FABM4 and FABM5, as well as both B and T acute lymphoblastic leukemia (ALL). Moreover, this study uses in vitro cytokine stimulations and reveals the respective potential roles of granulocyte--macrophage colony-stimulating factor and interferon-γ in increasing this secretion in FABM4 and ALL. Correlations between sHLA-G plasma level and clinical biologic features suggest a link between elevated sHLA-G level and 1) the absence of anterior myelodysplasia and 2) high-level leukocytosis. All these findings suggest that sHLA-G molecules could be a factor in tumoral escape from immune survey during acute leukemia. [ABSTRACT FROM AUTHOR]

Spontaneous remission of acute myeloid leukemia (AML) in adults is a rare but well documented phenomenon. This study reports on a 64-year-old male patient with acute myelogenous leukemia (AML-M4, according to the French-American-British classification) that was developed on a background of chronic myelomonocytic leukemia (CMML) and then underwent remission after treatment with the gonadotropin-releasing hormone agonist (GnRH agonist) triptorelin for presumed prostate cancer. Remission persisted for at least 4 years before the patient was lost to follow-up. To the author' knowledge, this is the first report of remission in an AML-M4 case associated with hormone manipulation. Possible mechanisms of this phenomenon are discussed. [ABSTRACT FROM AUTHOR]

An 8-year retrospective study of bone marrow reports was conducted to evaluate the incidence and classification of feline bone marrow disorders. Bone marrow reports from 203 cats were reviewed. Blood smears, bone marrow aspiration smears, bone marrow core biopsy specimens, and case records were reviewed for all cats with the exception of those bone marrows reported to be nondiagnostic or cytologically normal. Bone marrows with nonneoplastic/nonmyelodysplastic pathologic changes ( n=96) were subclassified into 16 categories. Frequently observed disorders included erythroid hyperplasia, nonregenerative immune-mediated anemia, pure red cell aplasia, aplastic anemia, bone marrow necrosis, myelofibrosis, and lymphocytosis. Dysmyelopoiesis ( n=27) was subcategorized into myelodysplastic syndromes ( n=20) and secondary ( n=7) dysmyelopoiesis. Thirty-four cases of acute leukemia, 3 cases of chronic lymphocytic leukemia, and 14 cases of other neoplasia were identified. These results indicate that a relatively small group of disorders account for the majority of the feline bone marrow disorders. Routine evaluation of blood and bone marrow aspiration smears and core biopsy specimens is needed for proper classification of bone marrow disorders. Ancillary testing, including flow cytometry and immunophenotyping, are useful in some circumstances. [ABSTRACT FROM AUTHOR]

The investigation of the mechanism(s) of benzene toxicity/leukemogenesis over the past 50 years has been contemporaneous with developments in the study of xenobiotic metabolism. Research on the cytochrome P450(CYP) enzyme system, and related systems in vivo and in vitro, which culminated in the isolation and reconstitution of the many CYPs, established pathways for the study of xenobiotic metabolism and its relationship to the biological activity of many chemicals. The essential role for metabolism of benzene as a precursor to the demonstration of benzene toxicity led to extensive studies of benzene metabolism, many of which will be reviewed here. Benzene toxicity/leukemogenesis, however, is a function of the bone marrow, a site remote from the liver where most benzene metabolism occurs. Studies of benzene metabolism have delineated the array of metabolites which appear to play a role in bone marrow damage, but further studies, both in vivo and in vitro, using appropriate animal models, will be needed to fully understand the impact of benzene and its metabolites on bone marrow function. [ABSTRACT FROM AUTHOR]

Patients with acute myelogenous leukemia or myelodysplastic syndrome may respond to farnesyl transferase inhibitors (FTIs) with partial or complete response rates noted in about 30% of such patients. FTIs prevent the attachment of a lipid farnesyl moiety to dependent proteins prior to their insertion into the plasma membrane and thereby prevent activity of these prenylation-dependent proteins, but their mechanism of tumor suppression remains unknown. Many patients receiving FTIs do experience myelosuppression. In this work, the in vitro effects of the FTI, R115777 on normal and leukemic hematopoiesis have been examined as have its effects on apoptosis induction and cell cycle profile in both leukemic blasts and normal CD34+ cells. R115777 was inhibitory to normal CD34+ cell proliferation and to leukemic blast cells, but did not affect long-term culture initiating cell frequency nor NOD-SCID reconstituting capacity. No induction of apoptosis or cell cycle changes were noted in AML blasts. These data suggest that myelosuppression with R115777 occurs largely at the intermediate to late progenitor stage of hematopoiesis and that cyclic use might avoid long-term marrow suppression. [ABSTRACT FROM AUTHOR]