The incidence of trisomy 8 as a sole chromosomal aberration in myeloid malignancies varies in relation to gender, age, prior iatrogenic genotoxic exposure, and morphology

A real-world study of adverse drug reactions of two isocitrate dehydrogenase inhibitor based on the US FDA adverse event reporting system and VigiAccess databases

Background and objectives

Isocitrate dehydrogenase (IDH) inhibitor drugs (Enasidenib, Ivosidenib) restore normal metabolism and epigenetic regulation in cells, offering a precision-targeted therapeutic option for acute myeloid leukemia (AML) patients with IDH mutations by specifically inhibiting mutated IDH enzymes. This research evaluates the relationship between adverse drug reactions (ADR) and the use of two isocitrate dehydrogenase inhibitors by using the database from the World Health Organization (WHO) VigiAccess and compares the characteristics of ADRs of the two drugs.

Methods

This study design used the retrospective descriptive analysis. We calculated the ratio of ADRs recorded in reports to compare the same points and different points in ADRs between two medications. Proportional reporting ratio (PRR) and reported odds ratio were used to evaluate the relationship between these two isocitrate dehydrogenase inhibitor medications and adverse events.

Results

Overall, during the search, 4,072 adverse events related to two types of isocitrate dehydrogenase inhibitors were reported in VigiAccess. The results revealed that the top 10 most common AEs were off label use, death, fatigue, nausea, diarrhea, acute myeloid leukemia, drug ineffective, differentiation syndrome, platelet count decreased and decreased appetite. Compared two drugs, enasidinib had the highest adverse reaction reporting rate in general disorders and administration site conditions while ivosidenib had the highest adverse drug reactions reporting rate in injury, poisoning and procedural complications.

Conclusion

Based on the current comparative observational studies, the ADR reports received by the World Health Organization, Food and Drug Administration for these drugs list common and specific adverse drug reactions. Clinical doctors should develop individualized treatment plans based on the adverse reactions of different drugs and the specific conditions of patients to promote the rational use of these expensive medications.

Comprehensive Recommendations for the Clinical Management of Pregnant Women With Noninvasive Prenatal Test Results Suspicious of a Maternal Malignancy

In this article, we defined comprehensive recommendations for the clinical follow-up of pregnant women with a malignancy-suspicious NIPT result, on the basis of the vast experience with population-based NIPT screening programs in two European countries complemented with published large data sets. These recommendations provide a tool for classifying NIPT results as malignancy-suspicious, and guide health care professionals in structured clinical decision making for the diagnostic process of pregnant women who receive such a malignancy-suspicious NIPT result.

Mutational Profile Enables the Identification of a High-Risk Subgroup in Myelodysplastic Syndromes with Isolated Trisomy 8

Trisomy 8 (+8) is the most frequent trisomy in myelodysplastic syndromes (MDS) and is associated with clinical heterogeneity and intermediate cytogenetic risk when found in isolation. The presence of gene mutations in this group of patients and the prognostic significance has not been extensively analyzed. Targeted deep sequencing was performed in a cohort of 79 MDS patients showing isolated +8. The most frequently mutated genes were: TET2 (38%), STAG2 (34.2%), SRSF2 (29.1%) and RUNX1 (26.6%). The mutational profile identified a high-risk subgroup with mutations in STAG2, SRSF2 and/or RUNX1, resulting in shorter time to acute myeloid leukemia progression (14 months while not reached in patients without these mutations, p < 0.0001) and shorter overall survival (23.7 vs. 46.3 months, p = 0.001). Multivariate analyses revealed the presence of mutations in these genes as an independent prognostic factor in MDS showing +8 isolated (HR: 3.1; p < 0.01). Moreover, 39.5% and 15.4% of patients classified as low/intermediate risk by the IPSS-R and IPSS-M, respectively, were re-stratified as a high-risk subgroup based on the mutational status of STAG2, SRSF2 and RUNX1. Results were validated in an external cohort (n = 2494). In summary, this study validates the prognosis significance of somatic mutations shown in IPSS-M and adds STAG2 as an important mutated gene to consider in this specific subgroup of patients. The mutational profile in isolated +8 MDS patients could, therefore, offer new insights for the correct management of patients with a higher risk of leukemic transformation.

Routine clinical parameters and laboratory testing predict therapy-related myeloid neoplasms after treatment for breast cancer

We aim to identify predictors of therapy-related myeloid neoplasms (t-MN) in patients with breast cancer (BC) and cytopenias to determine the timing of bone marrow biopsy (BMBx). Patients with BC and cytopenias who were referred for BMBx between 2002-2018 were identified using the Memorial Sloan Kettering Cancer Center institutional database. Characteristics associated with the risk of t-MN were evaluated by multivariable logistic regression and included in a predictive model. The average area under the receiver operating characteristic curve (AUC) was estimated by 5-fold cross-validation. Of the 206 BC patients who underwent BMBx included in our study, 107 had t-MN. By multivariable analysis, white blood cell count 4-11 K/mcL, absolute neutrophil count (ANC) ≥1.5 K/mcL, hemoglobin ≥12.2 g/dL, red cell distribution width 11.5-14.5%, the presence of bone metastasis and a time from BC diagnosis to BMBx <15 months significantly decreased the likelihood of t-MN. The average AUC was 0.88. We stratified our cohort by bone metastasis and by findings on peripheral smear. In both the subset without bone metastasis (n=159) and in the cohort with no blasts or dysplastic cells on peripheral smear (n=96) our variables had similar effects on the risk of t-MN. Among the 47 patients with bone metastasis, an ANC ≥1.5 K/mcL was the only variable associated with a decreased risk of t-MN. Our findings show that in patients with BC and unexplained cytopenias, clinical and laboratory parameters can predict t-MN and assist clinicians in determining the timing of a BMBx.

Clinical impacts of genome-wide noninvasive prenatal testing for rare autosomal trisomy

BACKGROUND

Genome-wide noninvasive prenatal testing identifies several rare autosomal trisomies in the general obstetrical population, but its use is questioned by its low positive predictive value. Furthermore, the origin of rare autosomal trisomies and the clinical effect of reporting them has not been sufficiently investigated. In addition, professional societies express their need for data assessing the clinical use of genome-wide noninvasive prenatal testing for rare autosomal trisomies for years.

OBJECTIVE

This study aimed to investigate the origin of rare autosomal trisomies and the clinical effect of disclosing rare autosomal trisomies in clinical settings.

STUDY DESIGN

Women who received noninvasive prenatal testing between March 2021 and March 2022 were prospectively enrolled. Clinical follow-up and cytogenetic and molecular investigations were performed. Posthoc analysis was performed to investigate the association between placental mosaicism and clinical outcomes.

RESULTS

Overall, 154 rare autosomal trisomies were identified in 89,242 pregnancies (0.17%) through noninvasive prenatal testing. In the 120 cases in which cytogenetic and molecular investigations were carried out, the rare autosomal trisomies were found to originate from true fetal mosaicism (n=5), uniparental disomy (n=5), maternal mosaic trisomy (n=3), maternal malignancy (n=1), and confined placental mosaicism (n=106). Clinical follow-up showed that 40% of all rare autosomal trisomy cases had adverse perinatal outcomes. In women with false-positive noninvasive prenatal testing results originating from confined placental mosaicism, the frequency of adverse perinatal outcomes was 26%. More importantly, the placental mosaicism ratio revealed by noninvasive prenatal testing was significantly higher in women who experienced adverse perinatal outcomes than those who did not (0.688 vs 0.332; P<.001).

CONCLUSION

Women with noninvasive prenatal testing results indicative of rare autosomal trisomies are at risk of adverse perinatal outcomes, and that risk can be stratified using chromosomes and the mosaicism ratio revealed by noninvasive prenatal testing. Our data are valuable for obstetrical caregivers advising a patient with a noninvasive prenatal testing result indicative of a rare autosomal trisomy and a false-positive diagnosis and for managing risks during pregnancy.

Comprehensive genome-wide analysis of routine non-invasive test data allows cancer prediction: A single-center retrospective analysis of over 85,000 pregnancies

BACKGROUND

Implausible false positive results in non-invasive prenatal testing (NIPT) have been occasionally associated with the detection of occult maternal malignancies. Hence, there is a need for approaches allowing accurate prediction of whether the NIPT result is pointing to an underlying malignancy, as well as for organized programs ensuring efficient downstream clinical management of these cases.

METHODS

Using a data set of 88,294 NIPT performed at University Hospital Leuven (Belgium) between November 2013 and March 2020, we retrospectively evaluated the positive predictive value (PPV) of our NIPT approach for cancer detection. In this approach, whole-genome cell-free DNA (cfDNA) data from NIPT were scrutinized for the presence of (sub)chromosomal copy number alterations (CNAs) predictive for a malignancy, using an unbiased NIPT analysis pipeline coined GIPSeq. For suspected cases, the presence of a maternal cancer was evaluated via subsequent multidisciplinary clinical follow-up examinations. The cancer-specificity of the identified CNAs in cfDNA was assessed through genetic analyses of a tumor biopsy.

FINDINGS

Fifteen women without a cancer history were identified with a GIPSeq result suggestive of a malignant process. Their cfDNA profiles showed either genome-wide aberrations or a single trisomy 8. Upon clinical examinations, a solid or hematological cancer was identified in 4 and 7 cases, respectively. Three women were identified as having a clonal mosaicism. For one case no underlying condition was found. These numbers add to a PPV of 73%. Based on this experience, we presented a multidisciplinary care path for efficient clinical management of these cases.

INTERPRETATION

The presented approach for analysing NIPT results has a high PPV, yet unknown sensitivity, for detecting asymptomatic malignancies upon routine NIPT. Given the complexity of diagnosing a pregnant woman with cancer, clinical follow-up should occur in a well-designed multidisciplinary setting, such as via the care model that we presented here.

FUNDING

This work was supported by Research Foundation Flanders and KU Leuven funding.

Prognostic Markers of Myelodysplastic Syndromes

Myelodysplastic syndrome (MDS) is a clonal disease characterized by multilineage dysplasia, peripheral blood cytopenias, and a high risk of transformation to acute myeloid leukemia. In theory, from clonal hematopoiesis of indeterminate potential to hematologic malignancies, there is a complex interplay between genetic and epigenetic factors, including miRNA. In practice, karyotype analysis assigns patients to different prognostic groups, and mutations are often associated with a particular disease phenotype. Among myeloproliferative disorders, secondary MDS is a group of special entities with a typical spectrum of genetic mutations and cytogenetic rearrangements resembling those in de novo MDS. This overview analyzes the present prognostic systems of MDS and the most recent efforts in the search for genetic and epigenetic markers for the diagnosis and prognosis of MDS.

Retrospective analysis of the clinical features of 172 patients with BCR-ABL1-negative chronic myeloproliferative neoplasms

Background

To explore the clinical features of the patients with BCR-ABL1-negative chronic myeloproliferative neoplasms (MPNs) in our hospital and to reveal the unique features of BCR-ABL1-negative MPNs patients in our center.

Methods

Retrospective analysis of routine karyotype analysis results, driver gene mutations and other related clinical parameters of 172 patients with newly diagnosed BCR-ABL1-negative MPNs who were admitted to our hospital between October 2013 and June 2018.

Results

(1) The rate of karyotypic abnormalities were 25, 6.3 and 2.9% in primary myelofibrosis (PMF), polycythemia vera (PV) and essential thrombocythemia (ET) patients, respectively. (2) The mutation rate of JAK2-V617F was 62.5%, and that of the CALR, MPL and EZH2 genes was 4.2% in PMF. The mutation rates of JAK2-V617F and JAK2-12exon were 91.3 and 1.3% in PV, respectively. The mutation rates of JAK2-V617F and CALR were 69.1 and 11.8% in ET, respectively. (3) Patients with JAK2-V617F mutation than with the wild-type gene were more often female in PMF (P = 0.027); had higher peripheral blood white blood cell (WBC) counts (P = 0.006), platelet (PLT) count (P = 0.001) and splenomegaly (P < 0.05) in PV; and had higher WBC (P = 0.001), hemoglobin concentrations (P = 0.001), lower PLT (P = 0.037), splenomegaly and endogenous coagulopathy (P < 0.05) in ET. (4) Among the PV and ET patients, those with thrombus were older than those in the nonthrombotic group.

Conclusion

PMF patients have more chromosomal abnormalities than PV and ET patients, and the effect of driver mutations on the clinical features of patients with MPNs differs among the three subtypes.

Karyotyping and prenatal diagnosis of 47,XX,+ 8[67]/46,XX [13] Mosaicism: case report and literature review

BACKGROUND

Trisomy 8 mosaicism has a wide phenotypic variability, ranging from mild dysmorphic features to severe malformations. This report concluded a female pregnant woman with trisomy 8 mosaicism, and carefully cytogenetic diagnoses were performed to give her prenatal diagnostic information. This report also provides more knowledge about trisomy 8 mosaicism and the prenatal diagnostic for clinicians.

CASE PRESENTATION

In this present study, we reported one case of pregnancy woman with trisomy 8 mosaicism. Noninvasive prenatal testing prompted an abnormal Z-score, but further three dimension color ultrasound result suggested a single live fetus with no abnormality. The phenotypic of the pregnant woman was normal. Based on our results, there were no abnormal initial myeloid cells (< 10^- 4), which suggested that the patient had no blood diseases. The peripheral blood karyotype of the patient was 47,XX,+ 8[67]/46,XX [13], and karyotype of amniotic fluid was 46, XX. The next generation sequencing (NGS) result suggested that the proportions of trisomy 8 in different tissues were obviously different; and 0% in amniotic fluid. Last, the chromosomes of the patient and her baby were confirmed using chromosome microarray analysis (CMA), and the results were arr[GRCh37](8) × 3,11p15.5p13(230750-33,455,733) × 2 hmz and normal.

CONCLUSIONS

This pregnancy woman was trisomy 8 mosaicism, but the phenotypic was normal, and also the fetus was normal. Carefully cytogenetic diagnoses should be performed for prenatal diagnose.

Recurrent Cytogenetic Abnormalities in Acute Myeloid Leukemia

The spectrum of chromosomal abnormality associated with leukemogenesis of acute myeloid leukemia (AML) is broad and heterogeneous when compared to chronic myeloid leukemia and other myeloid neoplasms. Recurrent chromosomal translocations such as t(8;21), t(15;17), and inv(16) are frequently detected, but hundreds of other uncommon chromosomal aberrations from AML also exist. This chapter discusses 22 chromosomal abnormalities that are common structural, numerical aberrations, and other important but infrequent (less than 1 %) translocations emphasized in the WHO classification. Brief morphologic, cytogenetic, and clinical characteristics are summarized, so as to provide a concise reference to cancer cytogenetic laboratories. Morphology based on FAB classification is used together with the current WHO classification due to frequent mentioning in a vast number of reference literatures. Characteristic chromosomal aberrations of other myeloid neoplasms such as myelodysplastic syndrome and myeloproliferative neoplasm will be discussed in separate chapters-except for certain abnormalities such as t(9;22) in de novo AML. Gene mutations detected in normal karyotype AML by cutting edge next generation sequencing technology are also briefly mentioned.

Trisomy 8 in pediatric acute myeloid leukemia: A NOPHO-AML study

Trisomy 8 (+8) is a common cytogenetic aberration in acute myeloid leukemia (AML); however, the impact of +8 in pediatric AML is largely unknown. We retrospectively investigated 609 patients from the NOPHO-AML database to determine the clinical and cytogenetic characteristics of +8 in pediatric AML and to investigate its prognostic impact. Complete cytogenetic data were available in 596 patients (98%) aged 0-18 years, diagnosed from 1993 to 2012, and treated according to the NOPHO-AML 1993 and 2004 protocols in the Nordic countries and Hong Kong. We identified 86 patients (14%) with +8. Trisomy 8 was combined with other cytogenetic aberrations in 68 patients (11%) (+8 other) and in 18 patients (3%), it was the sole abnormality (+8 alone). Trisomy 8 was associated with FAB M5 (36%) but otherwise clinically comparable with non-trisomy 8 patients. Trisomy 8 was favorable in patients of young age and with t(9;11). Trisomy 8 alone was associated with older age (median age 10.1 years), FAB M2 (33%), and FLT3-ITD mutations (58%). The 5-year event-free survival for patients with +8 alone was 50% and 5-year overall survival was 75%. In conclusion, +8 is one of the most common cytogenetic aberrations in pediatric AML. Trisomy 8 positive AML is a heterogeneous group and the majority of cases have additional cytogenetic aberrations. Patients with +8 alone differed from patients with +8 other and were associated with older age, FAB M2, and FLT3-ITD aberrations. There were no differences in survival despite the more frequent occurrence of FLT3-ITD in +8 alone. © 2016 Wiley Periodicals, Inc.

AML with gain of chromosome 8 as the sole chromosomal abnormality (+8sole) is associated with a specific molecular mutation pattern including ASXL1 mutations in 46.8% of the patients

Trisomy 8 is the most frequent cytogenetically gained aberration in AML. We compared 79 adult de novo AML with trisomy 8 as the sole cytogenetic abnormality (+8sole) to 511 normal karyotype AML patients (NK). +8sole patients were older (p=0.013), presented lower WBC counts (p=0.010), harbored more often ASXL1 mutations (p<0.001) and RUNX1 mutations (p=0.009), but less frequent FLT3-ITD (p=0.038), NPM1 mutations (p<0.001) and double-mutated CEBPA (p=0.038) than NK patients. No prognostic difference was found between +8sole and NK. With respect to genetic stability we found +8sole was instable, and molecular markers were either stable or gained in number and diversity.

Gene expression profiling in the myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a heterogeneous group of haematopoietic malignancies, characterized by blood cytopenias, ineffective hematopoiesis and hypercellular bone marrow. Several genetic alterations have been reported in MDS but these are not MDS-specific and the underlying molecular causes of the disease remain poorly understood. Gene expression microarray technology allows the simultaneous parallel analysis of many thousands of genes and has already provided novel insights into cancer pathogenesis. In this review we discuss the results of several recent studies which utilize the enormous power of microarray technology for the study of MDS. Several exciting findings have emerged from these early studies that highlight the potential of this technology to further our understanding of the molecular pathogenesis of this disorder. It is clear, however, that these findings should be confirmed in larger sets of MDS patients.

Single nucleotide polymorphism array-based karyotyping in acute myeloid leukemia or myelodysplastic syndrome with trisomy 8 as the sole chromosomal abnormality

The clinical heterogeneity of patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) with trisomy 8 as the sole abnormality may result from cytogenetically undetectable genetic changes. The purpose of this study was to identify hidden genomic aberrations not detected by metaphase cytogenetics (MC) using high-resolution single nucleotide polymorphism array (SNP-A)-based karyotyping in AML/MDS patients with a sole trisomy 8. The study group included 8 patients (3 AML and 5 MDS) and array-based karyotyping was done using whole-genome SNP-A (SNP 6.0 and SNP 2.7M). By SNP-A, additional genomic aberrations not detected by MC were identified in 2 patients: 1 AML patient exhibited a copy-neutral loss of heterozygosity (CN-LOH) of 3q21.1-q29 and 11q13.1-q25 and the other patient with MDS (refractory cytopenia with unilineage dysplasia) had CN-LOH of 2p25.3-p15. In particular, the latter patient progressed to AML 18 months after the diagnosis. In 3 patients, aberrations in addition to trisomy 8 were not identified by SNP-A. In the remaining 3 patients, SNP-A could not detect trisomy 8, while trisomy 8 was found in 25-67% of metaphase cells by MC. This study suggests that additional genomic aberrations may in fact be present even in cases of trisomy 8 as sole abnormality by MC, and SNP-A could be a useful karyotyping tool to identify hidden aberrations such as CN-LOH.

Cytogenetics findings in a histiocytic sarcoma case

Histiocytic sarcoma (HS) is a neoplasm derived from histiocytes. Its diagnosis was not clear until its immunohistochemistry profile was correctly established. Not much is known about its genetic properties. We report a case of a 48-year-old male patient whose bone marrow was almost completely occupied by monomorphic medium size neoplastic cellularity. Its immunohistochemical profile was CD68(+), CD4(+), CD45(+) with negativity of other dendritic cells, and other lineage markers. Cytogenetic study showed 4 related clones: one with trisomy 8 and extra material on the short arms of chromosome 4; a second line with tetrasomy of chromosome 8, add(4)(p16); the third clone had the same alterations as the previous and deletion of chromosome 3 at q11; the fourth line had tetrasomy 8 and translocation t(3;5)(q25;q35). To our knowledge this is the first HS case showing chromosome 8 trisomy and tetrasomy and the other described alterations.

Myelodysplastic syndromes

The myelodysplastic syndromes are a diverse group of clonal stem cell disorders characterized by ineffective hematopoiesis, peripheral cytopenias, and an increased propensity to evolve to acute myeloid leukemia. The molecular pathogenesis of these disorders is poorly understood, but recurring chromosomal abnormalities occur in approximately 50% of cases and are the focus of much investigation. The availability of newer molecular techniques has allowed the identification of additional genetic aberrations, including mutations and epigenetic changes of prognostic and potential therapeutic importance. This review focuses on the key role of cytogenetic analysis in myelodysplastic syndromes in the context of the diagnosis, prognosis, and pathogenesis of these disorders.

Cytogenetic evolution correlates with poor prognosis in myelodysplastic syndrome

Clonal chromosomal abnormalities are observed in 30-50% of primary myelodysplastic syndrome (MDS) patients. Although the prognostic relevance of cytogenetics is generally appreciated, the prognostic value of cytogenetic evolution has rarely been evaluated. In this study, we retrospectively analyzed cytogenetic features at diagnosis and during follow-up in 85 patients with primary MDS. Cytogenetic evolution occurred in 18 of the 85 patients (21%), with chromosomes 8, 5, and 1 most often involved. Patients with higher levels of marrow blasts (P = 0.034), more advanced stages of World Health Organization (WHO) subtypes (44% vs. 16%, P = 0.035), and higher risk International Prognostic Scoring System (IPSS) subgroups (47% vs. 16%, P = 0.021) had higher incidences of developing cytogenetic evolution. Furthermore, the median survival of patients in the group with cytogenetic evolution was 25.8 months, compared with 45.4 months for patients in the group without cytogenetic evolution (P = 0.01). The same result was also found for time to progression: patients with cytogenetic evolution progressed more rapidly than those without cytogenetic evolution (P = 0.007). Knowledge of cytogenetic evolution offers useful information for clinicians to make more accurate prognostic assessments for patients with MDS.

Diagnostic tools in the indications for allogeneic stem cell transplantation in myelodysplastic syndromes

The rates of allogeneic stem cell transplantation (SCT) to treat the myelodysplastic syndromes (MDS) is continually increasing. However, given the growing arsenal of therapeutic options in parallel to deeper insight into the heterogeneity of this disorder, determining the indications for SCT in MDS remains a difficult task. The International Prognostic Scoring System (IPSS) serves as a guideline for therapeutic decisions, but many aspects (eg, interpretation of rare cytogenetic abnormalities, combinations of chromosomal alterations and/or molecular markers, variant clinical courses within distinct biological subgroups) remain the subject of continuous investigation. In an effort to achieve a more well-differentiated risk categorization, attempts have been made to perform a more detailed cytogenetic categorization, and the use of various fluorescein in situ hybridization (FISH) techniques has improved the description of aberrations. Multicenter initiatives have standardized multiparameter flow cytometry techniques for diagnosis of MDS. In advanced MDS, screening for molecular mutations can identify cases with a high transformation risk. Finally, the new World Health Organization classification system provides a more homogenous morphological categorization of MDS compared with the former French-American-British system. Consequently, in the near future, risk stratification in MDS might incorporate additional diagnostic tools and categorization systems aimed at improving the timing and indication for SCT in this complex disorder.

Trisomy 8 in two newly diagnosed Chinese patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is one of the most common lymphoid malignancies in Western countries, but is infrequent in Asian populations. To verify the incidence of trisomy 8 in Chinese patients with CLL, fluorescence in situ hybridization (FISH) was used in 140 CLL patients after routine chromosome analysis. Only two patients (1.4%) were found with trisomy 8, and the number of trisomy 8 cells was 8 and 10%, respectively. No other aberrations by "panel" probe FISH were found in these two patients. The chromosome karyotypes of two patients were 47,XY,+8[2]/49,XY,+14,+20,+21[2]/46,XY[16] and 47,XX,+8[2]/46,XX[18], respectively. Neither of the patients' present signs of myelodysplastic or myeloproliferative disorder appeared on the bone marrow aspirates and peripheral blood smear. Our study demonstrates that trisomy 8 is rare in CLL, and its role in prognosis of CLL remains unknown.

Trisomy 8 in an allogeneic stem cell transplant recipient representative of a donor-derived constitutional abnormality

Trisomy 8 is a common cytogenetic abnormality in myeloid malignancies. It can also be present constitutionally and is associated with a wide range of phenotypes. We report a case of a 20-year-old woman with acute myelogenous leukemia associated with the 11q23/MLL translocation who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a healthy, unrelated 26-year-old female. Cytogenetics on a bone marrow biopsy and aspirate performed 71 days after transplant to evaluate pancytopenia identified trisomy 8 in 6 of 7 cells examined. The bone marrow was hypocellular but normal by morphology and flow cytometry. Fluorescent in situ hybridization (FISH) for the original 11q23/MLL translocation was negative. Chimerism analysis using multiplex polymerase chain reaction to amplify an informative short tandem repeat demonstrated 97% donor cells. These findings were confirmed by repeat bone marrow biopsies at Day 110 after transplant and 1 year after transplant. With resolution of comorbid illness, the patient's peripheral blood counts recovered and remained normal at 1 year after HSCT. FISH analysis of a cryopreserved sample of the donor graft showed trisomy 8 in 120 of 200 cells examined. This represents the first reported case of a person with constitutional trisomy 8 mosaicism serving as a stem cell donor. The case illustrates the importance of identifying donor-derived constitutional abnormalities to avoid the assumption that these cytogenetic abnormalities after HSCT are representative of malignant disease.

Bone marrow mononuclear cells of MDS patients are characterized by in vitro proliferation and increased apoptosis independently of stromal interactions

Enhanced proliferation of MDS progenitors is abrogated by increased apoptosis of their progeny in vivo. We investigated whether bone marrow mononuclear cells (BMMNC) of MDS patients also showed enhanced proliferation and apoptosis in vitro in comparison with acute myeloid leukemia (AML) and normal BM (NBM). NBM showed a decrease in the number of clusters in time due to apoptosis of clusters and due to development of clusters into colonies with low apoptotic level. In MDS patients, about two-fold more clusters have developed at day 4, and in contrast with NBM, the total number of clusters at day 7 remained high in spite of an increasing percentage of apoptotic clusters (from 52 to 76%) in combination with more colony formation. The number of clusters and colonies showed a sharp decrease at day 10 because of persistently high apoptosis at cluster level and increasing apoptosis in colonies. BMMNC of AML patients showed a decreased proliferation with enhanced apoptosis at cluster level in contrast to a relatively low apoptotic levels in the colony-forming cells. This data show that increased proliferation is abrogated by enhanced apoptosis in MDS, whereas AML showed decreased proliferation with a low level of apoptosis in colony-forming cells. These growth profiles of BMMNC are independent of stromal influences and may represent intrinsic features of the MDS progenitors and accessory cell interactions.

Chromosomal abnormalities in Philadelphia chromosome negative metaphases appearing during imatinib mesylate therapy in patients with newly diagnosed chronic myeloid leukemia in chronic phase

The development of chromosomal abnormalities (CAs) in the Philadelphia chromosome (Ph)-negative metaphases during imatinib (IM) therapy in patients with newly diagnosed chronic myecloid leukemia (CML) has been reported only anecdotally. We assessed the frequency and significance of this phenomenon among 258 patients with newly diagnosed CML in chronic phase receiving IM. After a median follow-up of 37 months, 21 (9%) patients developed 23 CAs in Ph-negative cells; excluding -Y, this incidence was 5%. Sixteen (70%) of all CAs were observed in 2 or more metaphases. The median time from start of IM to the appearance of CAs was 18 months. The most common CAs were -Y and + 8 in 9 and 3 patients, respectively. CAs were less frequent in young patients (P = .02) and those treated with high-dose IM (P = .03). In all but 3 patients, CAs were transient and disappeared after a median of 5 months. One patient developed acute myeloid leukemia (associated with - 7). At last follow-up, 3 patients died from transplantation-related complications, myocardial infarction, and progressive disease and 2 lost cytogenetic response. CAs occur in Ph-negative cells in a small percentage of patients with newly diagnosed CML treated with IM. In rare instances, these could reflect the emergence of a new malignant clone.

World Health Organization classification in combination with cytogenetic markers improves the prognostic stratification of patients with de novo primary myelodysplastic syndromes

This study correlated chromosomal defects with French-American-British (FAB)/World Health Organization (WHO) classification subtypes, proposed a revised International Prognostic Scoring System (IPSS) cytogenetic grouping; and established which classification, when used with the IPSS cytogenetic categories, best predicted clinical outcome in the myelodysplastic syndromes (MDS). A higher prevalence of chromosomal defects and distinct defects were observed in patients with multi-lineage dysplasia and a blast cell percentage >10%. Abnormalities of the long arm of chromosome 3, del(7)(q31q35), trisomy 8, del(11)(q14q23), del(12p) and 20q- could be segregated from their respective IPSS cytogenetic categories and used to develop new cytogenetic subgroups. Clinical parameters, FAB/WHO classification, IPSS score and standard or revised cytogenetic categories were statistically relevant for overall survival (OS) and progression-free intervals (PFI) and were included within five distinct multivariate models compared by the Akaike Information Criterion. To predict OS, the best models included age, WHO classification and standard or revised IPSS cytogenetic categories; to predict PFI, the best model included the same variables and revised cytogenetic categories. In conclusion, (i) the WHO classification was associated with a more homogeneous cytogenetic pattern than the FAB classification, (ii) WHO classification and standard/revised IPSS cytogenetic categories were much more effective than IPSS for predicting MDS clinical outcome, (iii) revised cytogenetic subgroups predicted PFI more effectively than standard categories.

Trisomy 8 as the sole chromosomal aberration in acute myeloid leukemia and myelodysplastic syndromes

Trisomy 8 as the sole abnormality is the most common karyotypic finding in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), occurring in approximately 5% and 10% of the cytogenetically abnormal cases, respectively. However, despite the high frequency of +8, much remains to be elucidated as regards its epidemiology, etiology, clinical impact, association with other chromosomal abnormalities, cell of origin, and functional and pathogenetic consequences. Here, we summarize and review these various aspects of trisomy 8, focusing on AMLs and MDS harboring this abnormality as a single change.

Chromosomal abnormalities of young multiple myeloma patients (<45 yr) are not different from those of other age groups and are independent of stage according to the International Staging System

Little is known about tumor-related prognostic factors, in particular specific chromosomal abnormalities, in young patients with multiple myeloma (MM). We therefore investigated the chromosomal pattern by interphase fluorescence in situ hybridization (chromosomes 13q14, 14q32-translocations, chromosomes associated with hyperdiploidy) in 38 young patients with MM (age <45 yr) and compared the results with those observed in 69 patients with intermediate age (45-70 yr) and 64 elderly patients (age >70 yr). All chromosomal patterns were not significantly different between the three age cohorts. Similarly, standard MM parameters were equally distributed between these MM patient populations. However, survival by the International Staging System (ISS) for MM revealed marked differences between stage I/II (median survival not yet reached) and stage III (23.4 months; P < 0.0003) among young MM patients. A significant survival difference between ISS-stage I/II and ISS-stage III patients was also noted in the intermediate age group (median 65.4 months vs. 24.6 months; P = 0.0009). However, this difference disappeared among elderly MM patients (39.6 months in ISS-stage I/II vs. 32 months in ISS-stage III patients; P = 0.94), but it was unrelated to the cytogenetic pattern. Our results indicate that MM in young patients does not represent a distinct biologic entity, and that short survival of younger MM patients at ISS-stage III is independent of the molecular cytogenetic pattern.

Trisomy 8 as sole cytogenetic abnormality in a case of chronic lymphocytic leukemia

A 49-year-old man, who had been diagnosed with chronic lymphocytic leukemia (CLL) in 2002, had a normal karyotype in his bone marrow. Trisomy 8 was demonstrated in his peripheral blood in 2005. Fluorescence in situ hybridization using an LSI CEP 8 probe performed on the archival bone marrow specimen showed three hybridization signals in 40% of 200 interphase cells scored. This confirmed that the trisomy 8 abnormality was present in both the blood and bone marrow samples. Trisomy 8 as the sole chromosomal abnormality in CLL is a very rare finding. The prognostic significance of trisomy 8 in CLL remains to be seen.

Impact of trisomy 8 on expression of genes located on chromosome 8 in different AML subgroups

Trisomy 8 is the most frequently observed trisomy in acute myeloid leukemia (AML) occurring as a sole karyotype abnormality or in addition to other chromosome aberrations. It was the aim of this study to analyze the impact of trisomy 8 on the expression of genes located on chromosome 8 in distinct AML subgroups characterized by different chromosome abnormalities in addition to trisomy 8. Gene expression analyses were performed on a total of 567 AML cases comprising the following subgroups: +8 sole, +8 within a complex aberrant karyotype, +8 in addition to t(15;17), inv(16), t(8;21), 11q23/MLL, or other abnormalities, AML with normal karyotype and the before mentioned subgroups without trisomy 8. A significant higher mean expression of genes located on chromosome 8 was observed in subgroups with +8 in comparison to their respective control groups. A varying number of significantly higher expressed genes was identified in all comparisons. No gene was significantly overexpressed in all comparisons, and no distinct gene expression pattern was identified allowing the identification of cases with trisomy 8. In conclusion, the gain of chromosome 8 leads to a higher expression of genes located on chromosome 8. However, no consistent pattern of genes was identified, which shows a higher expression in all AML subtypes with trisomy 8. These data suggest that trisomy 8 rather provides a platform for a higher expression of chromosome 8 genes which are individually up-regulated by the respective primary genetic abnormalities. Therefore, trisomy 8 in AML determines no specific disease characteristic but is a disease modulating secondary event.

High-resolution genome-wide array-based comparative genome hybridization reveals cryptic chromosome changes in AML and MDS cases with trisomy 8 as the sole cytogenetic aberration

Although trisomy 8 as the sole chromosome aberration is the most common numerical abnormality in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), little is known about its pathogenetic effects. Considering that +8 is a frequent secondary change in AML/MDS, cryptic--possibly primary--genetic aberrations may occur in cases with trisomy 8 as the apparently single anomaly. However, no such hidden anomalies have been reported. We performed a high-resolution genome-wide array-based comparative genome hybridization (array CGH) analysis of 10 AML/MDS cases with isolated +8, utilizing a 32K bacterial artificial chromosome array set, providing >98% coverage of the genome with a resolution of 100 kb. Array CGH revealed intrachromosomal imbalances, not corresponding to known genomic copy number polymorphisms, in 4/10 cases, comprising nine duplications and hemizygous deletions ranging in size from 0.5 to 2.2 Mb. A 1.8 Mb deletion at 7p14.1, which had occurred prior to the +8, was identified in MDS transforming to AML. Furthermore, a deletion including ETV6 was present in one case. The remaining seven imbalances involved more than 40 genes. The present results show that cryptic genetic abnormalities are frequent in trisomy 8-positive AML/MDS cases and that +8 as the sole cytogenetic aberration is not always the primary genetic event.

Limited clinical value of regular bone marrow cytogenetic analysis in imatinib-treated chronic phase CML patients monitored by RQ-PCR for BCR-ABL

Real-time quantitative polymerase chain reaction (PCR) for BCR-ABL mRNA in the peripheral blood (RQ-PCR) provides an accurate and reliable measure of response to therapy in chronic myeloid leukaemia (CML). We wanted to determine in what circumstances additional clinically relevant information was provided by simultaneous cytogenetic analysis in RQ-PCR monitored patients receiving imatinib treatment. We analysed 828 simultaneous RQ-PCR and bone marrow cytogenetic analyses from 183 patients with chronic phase CML with a median follow-up of 20 months. Cytogenetic progression was defined as Philadelphia (Ph)-positive clonal evolution, loss of complete cytogenetic response or an increase of > or = 20% Ph-positive cells. Cytogenetic progression occurred in 24/183 (13%) patients. At the time of cytogenetic progression, none of the 24 patients had a major molecular response (MMR; > or = 3-log reduction in BCR-ABL from standardised baseline). There were 320 RQ-PCR results from 95 patients indicating MMR. No abnormality was detected in any of the corresponding cytogenetic analyses. A policy of regular RQ-PCR monitoring with cytogenetic analysis targetted only to patients who have not achieved, or have lost MMR would represent a rational approach to monitoring and spare most patients the discomfort of multiple marrow aspirates. This approach depends upon availability of an accurate, reproducible RQ-PCR assay with ongoing quality assurance.

Population-based demographic study of karyotypes in 1709 patients with adult Acute Myeloid Leukemia

Few large demographic studies of acute myeloid leukemia (AML) are derived from population-based registries. Demographic and karyotypic data were provided for AML cases from two regional leukemia registry databases in Scotland and the Northern Region of England. A population-based dataset was compiled, comprising 1709 patients aged >16 years (1235 North England/474 Scotland patients). The most common cytogenetic abnormalities involved chromosomes 5 and/or 7 (17%). Patients with the following abnormal chromosome 5/7 combinations: -5, del(5q), -5/-7 and del(5q)/-7 represented a significantly older population (P < 0.01, ANOVA). t(8;21) was the only 'favourable' karyotype found in older age. Karyotypic complexity varied within chromosome 5/7 combination groups; those containing -5, -5/-7, -5/del(7q), del(5q)/-7 or del(5q)/del(7q) combinations were significantly more frequently complex than those containing -7 and del(7q) (P < 0.01, chi2 test). Additional recurring cytogenetic abnormalities within complex karyotypes containing chromosome 5/7 combinations included (in order of frequency), abnormalities of chromosomes 17, 12, 3 and 18. Complex karyotypes not involving chromosomes 5 or 7 represented 30% of all complex karyotypes, occurred in younger patients than those involving chromosomes 5 and 7, and frequently included additional trisomy 8 (26%). In conclusion, we describe subgroups within adverse karyotypes, with different demographics, degree of complexity and additional chromosome abnormalities.

Acute leukemia associated with valproic acid treatment: a novel mechanism for leukemogenesis?

Valproic acid has been previously associated with hematologic toxicity, including a reversible myelodysplasia-like syndrome without chromosomal abnormalities. We now report three cases of acute leukemia with features of secondary leukemia associated with valproic acid therapy: two cases of acute myelogenous leukemia with multilineage dysplasia, one with trisomy 8 and one with monosomy 7, and one case of secondary acute lymphoblastic leukemia with del (7) (q22q34), del (9) (q21.11q22), del (11) (q12q23). One patient had a previous myelodysplastic syndrome while on valproic acid. Valproic acid has been previously shown to be a histone deacetylase inhibitor. Inhibition of histone deacetylase causes a relaxation of chromatin structure and thus increases susceptibility to DNA damage and sensitizes cells to radiation. We propose that valproic acid therapy may lead to secondary leukemia by increasing DNA damage through chronic inhibition of histone deacetylase.

Cytogenetic profile in de novo acute myeloid leukemia with FAB subtypes M0, M1, and M2: a study based on 652 cases analyzed with morphology, cytogenetics, and fluorescence in situ hybridization

In about 55% of acute myeloid leukemia (AML) cases, chromosome aberrations are detectable by cytogenetics. Close correlations between cytomorphology and cytogenetics have been reported. To determine a pattern of cytogenetic abnormalities within the French-American-British (FAB) subtypes AML M0, M1, and M2, we analyzed 48 AML M0, 179 AML M1, and 425 AML M2 and compared cytogenetic data to a cohort of 1,062 AML M3/3v, M4, M4eo, M5a/5b, M6, and M7. Cytogenetic abnormalities were significantly more frequent in AML M0 (71%) compared to M1 (49%), M2 (53%), and the total cohort (56%; P < 0.02). While +8 was the most common numeric abnormality in all FAB subtypes, +13, +14, and +11 were associated with AML M0-M2. The only recurring balanced translocation that was associated with one of these FAB subtypes was t(8;21) in M2 (12.5%) and, rarely, M1 (1.7%) (M0, 0% and M3-7, 0.09%; P=0.001). To evaluate the frequency of cytogenetically undetectable abnormalities, we performed fluorescence in situ hybridization (FISH) analyses in 273 AML M0-M2 with normal karyotype using probes for ETO, ABL, MLL, TEL, RB, P53, AML1, and BCR. In two cases we identified numerical aberrations of RB only in interphases nuclei. In seven additional cases, TEL and MLL abnormalities were found. In conclusion, t(8;21), +11, +13, and +14 are strongly associated with AML M0, M1, and M2. The FISH screening analyses identified abnormalities in an additional 3% in normal karyotypes.

Distinctive gene expression profiles of CD34 cells from patients with myelodysplastic syndrome characterized by specific chromosomal abnormalities

Aneuploidy, especially monosomy 7 and trisomy 8, is a frequent cytogenetic abnormality in the myelodysplastic syndromes (MDSs). Patients with monosomy 7 and trisomy 8 have distinctly different clinical courses, responses to therapy, and survival probabilities. To determine disease-specific molecular characteristics, we analyzed the gene expression pattern in purified CD34 hematopoietic progenitor cells obtained from MDS patients with monosomy 7 and trisomy 8 using Affymetrix GeneChips. Two methods were employed: standard hybridization and a small-sample RNA amplification protocol for the limited amounts of RNA available from individual cases; results were comparable between these 2 techniques. Microarray data were confirmed by gene amplification and flow cytometry using individual patient samples. Genes related to hematopoietic progenitor cell proliferation and blood cell function were dysregulated in CD34 cells of both monosomy 7 and trisomy 8 MDS. In trisomy 8, up-regulated genes were primarily involved in immune and inflammatory responses, and down-regulated genes have been implicated in apoptosis inhibition. CD34 cells in monosomy 7 showed up-regulation of genes inducing leukemia transformation and tumorigenesis and apoptosis and down-regulation of genes controlling cell growth and differentiation. These results imply distinct molecular mechanisms for monosomy 7 and trisomy 8 MDS and implicate specific pathogenic pathways.

Systematic screening at diagnosis of −5/del(5)(q31), −7, or chromosome 8 aneuploidy by interphase fluorescence in situ hybridization in 110 acute myelocytic leukemia and high-risk myelodysplastic syndrome patients: concordances and discrepancies with conventional cytogenetics

To assess the contribution of interphase fluorescence in situ hybridization (I-FISH) toward the detection of recurring unbalanced chromosomal anomalies at diagnosis, a systematic screening of -5/del(5)(q31), -7, and chromosome 8 aneuploidy was performed on 110 patients with acute myelocytic leukemia or high-risk myelodysplastic syndrome. We searched for monosomy 5/del(5q) by one-color I-FISH with a probe specific for the 5q31 region and for -7/8 by dual-color I-FISH with centromeric probes for chromosomes 7 and 8. Discrepancies between conventional cytogenetics (CC) and I-FISH were observed in 8 of the 110 patients (7.3%). For -5/del(5)(q31), a discordance was observed in two patients with complex abnormalities involving chromosome 5. Whereas no discordance was observed for -7, I-FISH detected a trisomy 7 unnoticed by CC in two cases. In six patients, I-FISH revealed a chromosome 8 aneuploidy not detected by CC. Our results illustrate that, when using this specific set of probes, I-FISH is of special interest for the detection of minor clones with chromosome 8 aneuploidy, breakpoint assessment, and sequence identification (markers). Also, to avoid misinterpretations, I-FISH should not be used alone at disease presentation, particularly in cases complex changes that have clearly established prognostic significance.

The emergence of Ph-, trisomy -8+ cells in patients with chronic myeloid leukemia treated with imatinib mesylate

OBJECTIVE

To describe clinical and laboratory features of a cohort of patients with chronic myelogenous leukemia (CML) who developed Ph(-), trisomy 8(+) metaphases while on treatment with imatinib mesylate.

PATIENTS AND METHODS

Conventional cytogenetics and triple-color interphase fluorescence in situ hybridization were used to identify 5 of 310 studied patients who, on follow-up analysis, had Ph(-), trisomy 8(+) cells while on therapy.

RESULTS

None of the 5 patients had cytogenetic evidence of clonal evolution at the start of treatment with imatinib. All patients developed grade 3 or 4 neutropenia and thrombocytopenia during treatment. The emergence of Ph(-), trisomy 8(+) metaphases was seen at 3, 6, 13, 16, and 18 months from the start of treatment and was present at multiple time points. The maximum number of trisomy 8 metaphases ranged from 25 to 50%. Concomitantly, all patients had a profound suppression of Ph(+) cells (ranging from 0 to 65%) as well as the appearance of normal metaphases, ranging from 6 to 55%. None of the patients has shown clinical or hematologic signs of progression to a more advanced phase of CML.

CONCLUSIONS

While on treatment with imatinib mesylate a small group (less than 5%) of patients with CML developed Ph(-) trisomy 8(+) clone associated with pancytopenia. None of the patients developed clinical or hematological signs of progression to a more advanced phase of CML. These observations suggest that identification of trisomy 8 cells may represent clonal Ph(-) cells that were uncovered by treatment with a selective and potent inhibitor of Ph(+) cells.

[Chromosomal abnormalities in acute myeloid leukaemias]

Cytogenetic studies of acute myeloid leukaemias reveal non-random chromosomal abnormalities in 50-70% of karyotypes. Some are correlated with morphological and immunological parameters and constitute a prognostic factor independent of the other factors of risk: favourable for acute leukaemias myeloid with translocations t(8;21), t(15;17) and inversion or translocation of the chromosome 16, inv(16)/t(16;16), poor with deletion of the long arm of chromosome 5 del(5q), rearrangement of the 11q23 region and complex karyotypes. The distribution of the anomalies depends on the age: 11q23 and t(8;21) more frequent for the child, del(5q) and complex anomalies more frequent for the adult. The karyotypes are essential for the diagnosis, the follow-up of the patients and the evaluation of the relapse. It plays a fundamental part in the detection of new genes and their partners implied in the leucemogenese. The knowledge of their function is essential to open new therapeutic ways.

Cytogenetic abnormalities in childhood acute myeloid leukaemia: a Nordic series comprising all children enrolled in the NOPHO-93-AML trial between 1993 and 2001

Between 1993 and 2001, 318 children were diagnosed with acute myeloid leukaemia (AML) in the Nordic countries. The patient group comprised 237 children < 15 years of age with de novo AML, 42 children < 15 years with Down syndrome (DS) and de novo AML, 18 adolescents 15-18 years of age with de novo AML, and 21 children < 15 years with treatment-related AML (t-AML). The first group was all-inclusive, yielding an annual childhood de novo AML incidence of 0.7/100 000. Cytogenetic analyses were successful in 288 cases (91%), and clonal chromosomal abnormalities were detected in 211 (73%). The distribution of ploidy levels were pseudodiploidy (55%), hyperdiploidy (34%) and hypodiploidy (11%). The most common aberrations (> 2%) were + 8 (23%) (as a sole change in 6.2%), 11q23-translocations, including cryptic MLL rearrangements (22%) [t(9;11)(p21-22;q23) in 11%], t(8;21)(q22;q22) (9.0%), inv(16)(p13q22) (6.2%), -7/7q- (5.2%), and t(15;17)(q22;q12) (3.8%). Except for +8, these abnormalities were rare in group 2; only one DS patient had a t(8;21) and none had 11q23-translocations, t(15;17) or inv(16). In the t-AML group, three cases displayed 11q23-rearrangements, all t(9;11); and there were no t(8;21), t(15;17) or inv(16). Overall, the observed frequencies of t(8;21) and t(15;17) were lower, and frequencies of trisomy 8 and 11q23-translocations higher, than in previous studies. Furthermore, seven abnormalities that were previously reported as only single AML cases were also seen, meaning that der(4)t(4;11)(q26-27;q23), der(6)t(1;6)(q24-25;q27), der(7)t(7;11)(p22;q13), inv(8)(p23q11-12), t(11;17)(p15;q21), der(16)t(10;16)(q22;p13) and der(22)t(1;22)(q21;q13) are now classified as recurrent abnormalities in AML. In addition, 37 novel aberrations were observed, 11 of which were sole anomalies.

A pooled analysis of karyotypic patterns, breakpoints and imbalances in 783 cytogenetically abnormal multiple myelomas reveals frequently involved chromosome segments as well as significant age- and sex-related differences

The cytogenetic features (ploidy, complexity, breakpoints, imbalances) were ascertained in 783 abnormal multiple myeloma (MM) cases to identify frequently involved chromosomal regions as well as a possible impact of age/sex. The series included MM patients from the Mitelman Database of Chromosome Aberrations in Cancer and from our own laboratory. Hyperdiploidy was most common, followed by hypodiploidy, pseudodiploidy and tri-/tetraploidy. Most cases were complex, with a median of eight changes per patient. The distribution of modal numbers differed between younger and older patients, but was not related to sex. No sex- or age-related differences regarding the number of anomalies were found. The most frequent genomic breakpoints were 14q32, 11q13, 1q10, 8q24, 1p11, 1q21, 22q11, 1p13, 1q11, 19q13, 1p22, 6q21 and 17p11. Breaks in 1p13, 6q21 and 11q13 were more common in the younger age group. The most frequent imbalances were + 9, - 13, + 15, + 19, + 11 and - Y. Trisomy 11 and monosomy 16 were more common among men, while -X was more frequent among women. Loss of Y as the sole change and + 5 were more common in elderly patients, and - 14 was more frequent in the younger age group. The present findings strongly suggest that some karyotypic features of MM are influenced by endogenous and/or exogenous factors.

Trisomy 8 as the sole chromosomal aberration in myelocytic malignancies: a multicolor and locus-specific fluorescence in situ hybridization study

Trisomy 8 is the most common chromosomal aberration in myelocytic malignancies, occurring both as a sole change as well as in addition to other abnormalities. In spite of this, next to nothing is known about its pathogenetic importance or its molecular genetic consequences. Possible mechanisms involved in the transformation process include dosage effects of genes mapping to chromosome 8 and presence of specific mutations or cryptic fusion genes on the duplicated chromosome. In the latter case, +8 would be secondary to a cryptic primary rearrangement and not involved in leukemogenesis as such, but rather in tumor evolution. Although hidden genetic changes have been found in some trisomies, for example, mutations in KIT in acute myelocytic leukemia (AML) with +4 and in MET in hereditary papillary kidney carcinoma with trisomy 7, none associated with +8 have so far been discovered. To address this issue, we have investigated a total of 13 cases of AML, myelodysplastic syndromes, and chronic myeloproliferative disorders with trisomy 8 as the sole chromosomal anomaly. All cases were studied by combined binary ratio multicolor fluorescence in situ hybridization (FISH) and with FISH using locus-specific probes for both arms of chromosome 8, the subtelomeric regions of 8p and 8q, and the leukemia-associated genes FGFR1, MOZ, ETO, and MYC. No cryptic changes were detected, thus excluding the possibility of gross genetic rearrangements or aberrations involving these loci on chromosome 8.

BCR/ABL genes and leukemic phenotype: from molecular mechanisms to clinical correlations

The Philadelphia chromosome (Ph), a minute chromosome that derives from the balanced translocation between chromosomes 9 and 22, was first described in 1960 and was for a long time the only genetic lesion consistently associated with human cancer. This chromosomal translocation results in the fusion between the 5' part of BCR gene, normally located on chromosome 22, and the 3' part of the ABL gene on chromosome 9 giving origin to a BCR/ABL fusion gene which is transcribed and then translated into a hybrid protein. Three main variants of the BCR/ABL gene have been described, that, depending on the length of the sequence of the BCR gene included, encode for the p190(BCR/ABL), P210(BCR/ABL), and P230(BCR/ABL) proteins. These three main variants are associated with distinct clinical types of human leukemias. Herein we review the data on the correlations between the type of BCR/ABL gene and the corresponding leukemic clinical features. Lastly, drawing on experimental data, we provide insight into the different transforming power of the three hybrid BCR/ABL proteins.

Pooled analysis of clinical and cytogenetic features in treatment-related and de novo adult acute myeloid leukemia and myelodysplastic syndromes based on a consecutive series of 761 patients analyzed 1976-1993 and on 5098 unselected cases reported in the literature 1974-2001

To ascertain the frequency of treatment-related acute myeloid leukemias and myelodysplastic syndromes (t-AML/t-MDS) in an unselected series, we have identified all adult cases analyzed in our department from 1976 to 1993. Further aims were to compare karyotypic features of t-AML/t-MDS with de novo AML/MDS, in our material as well as in 5098 unselected, cyto- genetically abnormal, published cases, and to analyze associations between type of prior therapy and karyotype. Among our 372 AML and 389 MDS, 47 (13%) were t-AML and 62 (16%) were t-MDS. Clonal abnormalities were significantly more common in t-AML and t-MDS than in de novo disease (68% vs 50%, P < 0.05 and 84% vs 45%, P < 0.001, respectively). Among the available 4230 AML and 1629 MDS (the present series and published cases), 14% were t-AML and 15% were t-MDS. In t-AML/t-MDS, the number of anomalies and the ploidy levels differed significantly from de novo cases, with complex and hypodiploid karyotypes being more common in t-AML/t-MDS. In t-AML, unbalanced changes in general, t(1;3), der(1;7), 3p-, -5, 5q-, -7, 7q-, t(9;11), t(11;19), t(11q23), der(12p), -17, der(17p), -18, and -21 were significantly more frequent than in de novo AML. In t-MDS, -5, -7, 7q-, 13q-, der(17p), and -18 were significantly more common. Type of prior treatment correlated significantly with number of anomalies in t-AML and with ploidy levels in t-AML/t-MDS. The frequencies of several aberrations varied with type of therapy, eg, 5q- was more frequent in radiotherapy-associated t-MDS, monosomy 7 was more common in t-AML and t-MDS after treatment with alkylators, and t(11q23) in t-AML was associated with topoisomerase II inhibitors. Abnormalities significantly more common in de novo disease were +8 as a sole anomaly, balanced changes in general, t(8;21), t(9;22), t(15;17), inv(16), and t(21q22) in AML, and -Y, 5q-, and 20q- as sole anomalies and +8 in MDS. The results emphasize the strong association between previous genotoxic exposure and karyotypic features.