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

Risk stratification for survival and leukemic transformation in essential thrombocythemia: a single institutional study of 605 patients

Unlike the case with thrombosis, prognostic models for survival and leukemic transformation (LT) in essential thrombocythemia (ET) are not available. Among 605 patients with ET seen at our institution and followed for a median of 84 months, 155 died and LT was documented in 20 patients (3.3%). In a multivariable analysis, hemoglobin level below normal (females<120 g/l; males<135 g/l) was identified as an independent risk factor for both inferior survival and LT. Additional risk factors for survival included age > or =60 years, leukocyte count> or =15 x 10(9)/l, smoking, diabetes mellitus and thrombosis. For LT, platelet count> or =1000 x 10(9)/l but not cytoreductive therapy was flagged as an additional independent risk factor. In fact, four of the 20 patients (20%) with LT were untreated previously. We used the above information to construct prognostic models that effectively discriminated among low-, intermediate- and high-risk groups with respective median survivals of 278, 200 and 111 months (P<0.0001), and LT rates of 0.4, 4.8 and 6.5% (P=0.0009) respectively. Presence of JAK2V617F did not impact either survival or LT and mutational frequency was similar among the different risk groups.

Evaluation of recurring cytogenetic abnormalities in the treatment of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are clinically heterogeneous, but the presence of specific cytogenetic abnormalities can predict disease manifestations, provide a basis for prognosis, and direct treatment. Conventional cytogenetic analysis is instrumental in identifying chromosomal abnormalities in MDS and novel genetic methods may provide supplementary information. Treatment with lenalidomide was recently shown to be effective in MDS, particularly in those cases with del(5q), resulting in durable cytogenetic remission and hematological responses. In this paradigm, diagnosis of the del(5q) abnormality would be essential to predicting response to therapy.

Donor cell-derived acute myeloblastic leukemia after allogeneic peripheral blood hematopoietic stem cell transplantation for juvenile myelomonocytic leukemia

Despite its rarity, donor cell leukemia (DCL) is a most intriguing entity. We report here the case of a 5 year-old girl with juvenile myelomonocytic leukemia and normal female karyotype who developed acute myeloblastic leukemia with a karyotype of 46, X, t(X; 7) (p21; p11.2), der(7) t(3; 7) (q13.3; q22) 5 months after peripheral blood hematopoietic stem cell transplantation from her HLA-matched sister. We performed the analysis of short tandem repeat sequence markers to DNA obtained from donor peripheral blood, patient's peripheral blood including leukemic blasts and patient's hair root. This analysis showed that the leukemic blood DNA matched the donor blood DNA and not the patient's DNA, thus confirming DCL. To our knowledge, this is the first case of DCL after peripheral blood SCT for juvenile myelomonocytic leukemia.

Genomic gain at 6p21: a new cryptic molecular rearrangement in secondary myelodysplastic syndrome and acute myeloid leukemia

Fluorescence in situ hybridization and comparative genomic hybridization characterized 6p rearrangements in eight primary and in 10 secondary myeloid disorders (including one patient with Fanconi anemia) and found different molecular lesions in each group. In primary disorders, 6p abnormalities, isolated in six patients, were highly heterogeneous with different breakpoints along the 6p arm. Reciprocal translocations were found in seven. In the 10 patients with secondary acute myeloid leukemia/myelodysplastic syndrome (AML/MDS), the short arm of chromosome 6 was involved in unbalanced translocations in 7. The other three patients showed full or partial trisomy of the 6p arm, that is, i(6)(p10) (one patient) and dup(6)(p) (two patients). In 5/7 patients with unbalanced translocations, DNA sequences were overrepresented at band 6p21 as either cryptic duplications (three patients) or cryptic low-copy gains (two patients). In the eight patients with cytogenetic or cryptic 6p gains, we identified a common overrepresented region extending for 5-6 megabases from the TNF gene to the ETV-7 gene. 6p abnormalities were isolated karyotype changes in four patients. Consequently, in secondary AML/MDS, we hypothesize that 6p gains are major pathogenetic events arising from acquired and/or congenital genomic instability.

Alternative genetic pathways and cooperating genetic abnormalities in the pathogenesis of therapy-related myelodysplasia and acute myeloid leukemia

Alternative genetic pathways were previously outlined in the pathogenesis of therapy-related myelodysplasia (t-MDS) and acute myeloid leukemia (t-AML) based on cytogenetic characteristics. Some of the chromosome aberrations, the recurrent balanced translocations or inversions, directly result in chimeric rearrangement of genes for hematopoietic transcription factors (class II mutations) which disturb cellular differentiation. Other genetic abnormalities in t-MDS and t-AML comprise activating point mutations or internal tandem duplications of genes involved in signal transduction as tyrosine kinase receptors or genes more downstream in the RAS-BRAF pathway (class I mutations). The alternative genetic pathways of t-MDS and t-AML can now be further characterized by a different clustering of six individual class I mutations and mutations of AML1 and p53 in the various pathways. In addition, there is a significant association between class I and class II mutations possibly indicating cooperation in leukemogenesis, and between mutations of AML1 and RAS related to subsequent progression from t-MDS to t-AML. Therapy-related and de novo myelodysplasia and acute myeloid leukemia seem to share genetic pathways, and surprisingly gene mutations were in general not more frequent in patients with t-MDS or t-AML as compared to similar cases of de novo MDS and AML studied previously.

Secondary myelodysplastic syndrome following long-term treatment with azathioprine in patients with multiple sclerosis

Azathioprine (Aza) is a widely used immunosuppressive drug in multiple sclerosis (MS) treatment. Recently, the incidence of secondary myelodysplastic syndromes (sMDS) associated with a poor prognosis was found to be elevated in patients treated with Aza for non-malign disorders. Three hundred and seventeen MS patients were retrospectively analysed and complete blood counts were examined for those exposed to Aza. We identified one case of sMDS (cumulative dose 627 g) in a young patient and two further malignancies (cumulative doses 27 g and 54 g) in the Aza group (n = 81; 3.7%). In the non-Aza (n = 236) group, five malignancies (2.1%, P = 0.419) were identified. Including our patient, four cases of sMDS after long-term Aza therapy in MS have been reported so far. Cases suggest a time- and dose-dependent risk of sMDS in long-term therapy of MS with Aza. Long-term Aza therapy needs careful monitoring.

Disclosure of candidate genes in acute myeloid leukemia with complex karyotypes using microarray-based molecular characterization

PURPOSE

To identify novel genomic regions of interest in acute myeloid leukemia (AML) with complex karyotypes, we applied comparative genomic hybridization to microarrays (array-CGH), allowing high-resolution genome-wide screening of genomic imbalances.

PATIENTS AND METHODS

Sixty AML cases with complex karyotypes were analyzed using array-CGH; parallel analysis of gene expression was performed in a subset of cases.

RESULTS

Genomic losses were found more frequently than gains. The most frequent losses affected 5q (77%), 17p (55%), and 7q (45%), and the most frequent genomic gains 11q (40%) and 8q (38%). Critical segments could be delineated to genomic fragments of only 0.8 to a few megabase-pairs of DNA. In lost/gained regions, gene expression profiling detected a gene dosage effect with significant lower/higher average gene expression levels across the genes located in the respective regions. Furthermore, high-level DNA amplifications were identified in several regions: 11q23.3-q24.1 (n = 7), 21q22 (n = 6), 11q23.3 (n = 5), 13q12 (n = 3), 8q24 (n = 3), 9p24 (n = 2), 12p13 (n = 2), and 20q11 (n = 2). Parallel analysis of gene expression in critical amplicons displayed overexpressed candidate genes (eg, C8FW and MYC in 8q24).

CONCLUSION

In conclusion, a large spectrum of genomic imbalances, including novel recurring changes in AML with complex karyotypes, was identified using array-CGH. In addition, the combined analysis of array-CGH data with gene expression profiles allowed the detection of candidate genes involved in the pathogenesis of AML.

Derivative (1;7)(q10;p10) in multiple myeloma. A sign of therapy-related hidden myelodysplastic syndrome

Therapy-related myelodysplastic syndrome (MDS) is a major problem in long-term cancer survivors, therefore early detection and prevention of therapy-related secondary neoplasia is an important issue. We searched for therapy-related MDS and analyzed cytogenetic changes in 155 patients with multiple myeloma (MM) from a single institution. Of the total 155 MM patients with cytogenetic results, 7 patients showed de novo appearance of myeloid-related cytogenetic changes, and 5/7 had -7/7q-, including 3 with der(1;7)(q10;p10): 3 patients developed MDS (i.e. 2 patients with der(1;7)(q10;p10) and 1 with a complex abnormality including -5 and 7q-). Among five patients receiving more than 2 g of melphalan, three developed MDS, and two of them showed der(1;7)(q10;p10) before or at the time of MDS diagnosis. Although morphologic identification of MDS was difficult in some cases, we concluded that the presence of 7q-, specifically der(1;7)(q10;p10), during chemotherapy involving melphalan for MM patients might indicate hidden MDS status and appropriate therapeutic options should be considered for such patients.

Etiology of acute myeloid leukemia in the elderly

The biologic and epidemiologic study of acute myeloid leukaemia (AML) in the elderly is in its infancy. Most epidemiologic data attempting to ascertain the etiology of AML have been obtained from younger cohorts or patients with therapy-related AML. The increasing prevalence of deletional and complex karyotypes in elderly AML patients implies a cumulative genotoxicity over time for this subgroup, given the similar spectrum of abnormalities following exposure to known genotoxic agents such as alkylating chemotherapeutic drugs. Exposure to benzene, radiation, and tobacco smoke are clear but weak risk factors for AML. Polymorphic variants in several genes responsible for genomic protection and integrity are now also weak risk factors for AML. Future epidemiologic studies should correlate exposure data with well-defined biologic subtypes of AML.

Clinical management of myelodysplastic syndromes with interstitial deletion of chromosome 5q

Deletions of the long (q) arm of chromosome 5 [del(5q)]occur in patients with myelodysplastic syndromes (MDS) including, but not limited to, those who meet the WHO definition of the 5q- syndrome. Del(5q) MDS patients frequently have symptomatic anemia, and its treatment has traditionally consisted of RBC transfusions and, for some, iron chelation therapy. Erythropoietin, darbepoetin, hypomethylating agents, and lenalidomide can enhance erythropoiesis in MDS patients with anemia, increasing hemoglobin levels and abrogating RBC transfusion requirements. Lenalidomide is particularly active in treating the anemia of del(5q) MDS, which is especially relevant given the low response rate to erythropoietin in this group of patients. In a recent study of 43 MDS patients, 10 of 12 patients (83%) with del(5q) MDS achieved sustained RBC transfusion independence (or a > 2 g/dL increase in hemoglobin), compared with 57% of those with a normal karyotype and 12% of those with other karyotypic abnormalities. Complete cytogenetic remissions were achieved in 75% (nine of 12) of the del(5q) MDS patients, suggesting that lenalidomide targets a fundamental pathogenetic feature of MDS that is more pronounced in the presence of chromosomal 5q deletions. This review highlights some issues about the classification and treatment of del(5q) MDS.

Clustered incidence of acute promyelocytic leukemia during gefitinib treatment for non-small-cell lung cancer: experience at a single institution

Although gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, has been shown a significant activity for recurrent non-small-cell lung cancer (NSCLC), its long-term adverse effect with its continuous usage has hitherto not been clearly elucidated. Subjects were 108 consecutive NSCLC cases who were treated with gefitinib between November 2001 and December 2004 at our single institution. A crude incidence rate ratio was calculated by ratio of crude incidence rate in our subject to population-based incident rate of all leukemia (ICD: C91-95) in the same region. The 95% confidence intervals (CIs) were calculated based upon a Poisson distribution. Three cases of acute promyelocytic leukemia (APL) occurred during gefitinib treatment, and these patients' past treatment histories are presented herein. No other malignancy was identified. All of the cases were diagnosed at the stage of mild-to-moderate cytopenia, especially thrombocytopenia, without disseminated intravascular coagulation. All presented a normal karyotype with positive PML-RARalpha in RT-PCR, indicating submicroscopic translocation. They responded well to APL treatments, including all-trans-retinoic acid. The crude incident rate ratio was 639.9 (95% confidence interval: 131.6-1,878.9, P < 0.0001) when the APL incidence in this cohort was compared to all leukemia cases in the general population in the same district in Japan. Thus we had three cases of secondary APL patients within the gefitinib-treated NSCLC cohort. Although we cannot exclude an effect of past exposure of other cytotoxic agents and radiotherapy as a cause of APL, APL inducibility of gefitinib should be clarified in the further study.

Biological and prognostic significance of chromosome 5q deletions in myeloid malignancies

The presence of del(5q), either as the sole karyotypic abnormality or as part of a more complex karyotype, has distinct clinical implications for myelodysplastic syndromes (MDS) and acute myeloid leukemia. The 5q- syndrome, a subtype of low-risk MDS, is characterized by an isolated 5q deletion and <5% blasts in the bone marrow and can serve as a useful model for studying the role of 5q deletions in the pathogenesis and prognosis of myeloid malignancies. Recent clinical results with lenalidomide, an oral immunomodulatory drug, have shown durable erythroid responses, including transfusion independence and complete cytogenetic remissions in patients with del(5q) MDS with or without additional chromosomal abnormalities. These results indicate that lenalidomide can overcome the pathogenic effect of 5q deletion in MDS and restore bone marrow balance. The data provide important new insights into the pathobiology of 5q chromosomal deletions in myeloid malignancies.

Multipoint interphase FISH analysis of chromosome 3 abnormalities in 28 childhood AML patients

We detected non-random 3p losses and 3q gains on well-determined regions in both murine and human tumors using a microcell hybrid-based model system called 'elimination test'. We suggest that these are general malignancy-associated aberrations not necessarily linked to a particular tissue of origin. To examine chromosome 3 abnormalities, in 28 childhood acute myeloid leukemia bone marrow samples, we performed interphase multipoint-fluorescence in situ hybridization using 84 chromosome 3-specific probes and detected clonal chromosome 3 aberrations in nine cases, which is of a higher frequency than the previously reported one. In 3/28 children, a chromosome 3 abnormality was detected which was not visible using conventional cytogenetic analysis. We did not detect any 3p deletion. Increased copy number of 3q was found in four cases with trisomy of whole chromosome 3 and one case with 3q tetrasomy (isodisomy). We identified rare structural rearrangements in childhood acute myeloblastic leukemia, involving 3q21 and 3q26 loci around RPN1 and MDS1/EVI1 respectively. The poor outcome in pediatric patients with 3q rearrangements appears to be quite uniform.

Multicolor fluorescence in situ hybridization characterization of cytogenetically polyclonal hematologic malignancies

Several different investigations and methodologies have provided data supporting a monoclonal origin of neoplasia. For example, the vast majority of neoplastic disorders are cytogenetically monoclonal. Occasionally, however, clones with unrelated karyotypic anomalies are found, as, for example, in approximately 2% of acute myeloid leukemias (AML), myelodysplastic syndromes (MDS), and chronic myeloproliferative disorders (CMD). Whether such a cytogenetic polyclonality represents a polyclonal origin or whether different clones share a submicroscopic primary change, indicating a monoclonal origin, remains to be elucidated. Our objective was to ascertain if cryptic aberrations can be found in cytogenetically polyclonal hematologic malignancies using multicolor fluorescence in situ hybridization (M-FISH). Fourteen AML, MDS, and CMD cases were investigated. In none of these was a cryptic aberration found, common to all subclones, although the karyotypes were revised in two AMLs and one MDS. Thus, all malignancies were still classified as polyclonal after the M-FISH analyses. Based on the present results, we conclude that M-FISH, in general, does not reveal primary cryptic aberrations supporting a monoclonal origin of cytogenetically polyclonal hematologic malignancies.

Treatment-related myelodysplastic syndrome/acute myeloid leukemia in survivors of childhood cancer--an update

Treatment-related myelodysplastic syndrome/acute myeloid leukemia (t-MDS/t-AML) is a devastating complication of treatment for childhood cancer. However, the major cause of premature death of children treated for cancer remains their primary cancer. The understanding of the presentation, incidence, predisposing risk factors and pathobiology of t-MDS/t-AML is increasing. This increased understanding has not yet been translated into improved outcomes of therapy for t-MDS/t-AML. However, newer approaches are under study.

Secondary acute myeloid leukaemia: results of conventional treatments. Experience of GIMEMA trials

BACKGROUND

The aim of the study was to evaluate the outcome of acute myeloid leukaemia (AML) in patients with a previous malignancy (sAML) treated with chemo- and/or radiotherapy, enrolled in conventional trials.

PATIENTS AND METHODS

In a multicentre setting, a prospective non-concurrent analysis was performed on 2513 new AML patients, aged 12-78 years, consecutively enrolled in EORTC-GIMEMA trials between 1987 and 2001. Thirty-eight patients with sAML were identified and compared with a group of 114 de novo AML patients matched according to age, French-American-British criteria, white blood cell count at diagnosis, trial and time of diagnosis of AML. Induction treatment response, disease-free survival (DFS), duration and overall survival (OS) were evaluated in the two groups.

RESULTS

Comparing the complete remission (CR) rate between 38 sAML patients and 114 de novo AML patients, selected according to the previously reported criteria, we observed no difference in the CR rates [25/38 (66%) versus 66/114 (58%); Pearson chi(2) 0.7393, P=0.390] as well as no differences while comparing the DFS and the OS between the two groups.

CONCLUSION

The results of this study suggest that sAML patients are characterised by a good performance status permitting their recruitment in conventional trials without a previous myelodysplastic phase. Similar to de novo AML patients, sAML patients show good response to treatment and the possibility of cure.

Therapy-related myelodysplastic syndrome in childhood: A retrospective study of 36 patients in Japan

We report here a retrospective analysis of 36 children with therapy-related myelodysplastic syndrome (t-MDS) diagnosed between 1990 and 1999 in Japan. Their median age was 7.7 years and the median latency period for the development of t-MDS was 38.5 months. The primary tumors were hematologic in 15 of the cases and nonhematologic in 21. Chromosomal abnormalities were detected in 32/34(94%) patients: abnormalities of chromosomes 5and/or 7 in 41% and notably, 11q23 abnormalities in 31%. The prognosis of children with t-MDS was very poor as compared to children with primary MDS (5 year survival: 16% versus 54%, p<0.0001).

Long-term outcomes for unselected patients with acute myeloid leukemia categorized according to the World Health Organization classification: a single-center experience

The actual utility of a new classification system of acute myeloid leukemia (AML) recently introduced by the World Health Organization (WHO) has not been thoroughly investigated yet. In this study, we evaluated long-term outcomes of unselected AML patients categorized according to the new WHO classification. Between 1990 and 2002, 109 adult AML cases were referred to our hospital. For the entire population, the median survival duration was 1.2 yr with a 5-yr survival rate of 31%. AML with recurrent genetic abnormalities accounted for 26%, AML with multilineage dysplasia for 29%, therapy-related AML for 13%, and AML not otherwise categorized for 32% of classifiable cases. Among the four groups, a significant difference was observed in terms of overall survival (P < 0.0001). Univariate analysis showed that six variables affected survival: cytogenetic risk, age, multilineage dysplasia, prior chemo/radiotherapy, type of treatment (intensive or palliative), and transplantation. However, in multivariate analysis no adverse prognostic impact of multilineage dysplasia and prior chemo/radiotherapy was detected (P = 0.4979 and 0.8702), whereas cytogenetic risk and patient age maintained their prognostic value (P = 0.0005 and 0.0100). These results indicate that outcomes for AML patients appear to be distinguished on the basis of the WHO classification, but the prognostic significance of multilineage dysplasia and prior therapy is lost after adjusting for cytogenetic risk and age. Our findings suggest that the WHO classification may be strengthened by greater emphasis on genetic/cytogenetic information.

Chronic myelomonocytic leukemia: lost in classification?

Chronic myelomonocytic leukemia (CMML) comprises a spectrum of disease variably considered as a myelodysplastic (MDS) and/or myeloproliferative (MPD) disorder. Now classified by the WHO within a separate nosological group from MDS or MPD, the reality is that there is a dynamic of evolution through increasing monocyte counts in one-third of patients. The principal clinical difference between CMML and other MPD is the presence of ineffective hematopoiesis, manifesting as more frequent anemia and thrombocytopenia in CMML. A fundamental biological characteristic shared with MPD is progenitor hypersensitivity to growth factors, but the pathways mediating this likely differ, as does the lineage specificity. Activation of the STAT pathway in MPD contrasts with frequent RAS pathway activation in CMML. Therapy of CMML is unsatisfactory, with the median age dictating that supportive care and control of myeloproliferation remains the mainstay for the majority. Intensive chemotherapy alone is of little benefit, and stem cell transplantation is the only curative modality in the small number of eligible patients, although outcome remains suboptimal. A deeper understanding of the biological basis of CMML may lead to targeted therapy analogous to the evolving management of MPD best exemplified for chronic myeloid leukemia.

Loss of Hspa9b in zebrafish recapitulates the ineffective hematopoiesis of the myelodysplastic syndrome

Myelodysplastic syndrome (MDS) comprises a heterogeneous group of often fatal hematopoietic stem cell disorders for which neither curative nor standard treatment exists. The complex karyotypes and multistep nature of MDS have severely restricted the identification of causative genetic mutations and thus limited insight into new and more effective therapies. Here we describe a zebrafish mutant crimsonless (crs) with a developmental blood defect that closely recapitulates the ineffective hematopoiesis of MDS including anemia, dysplasia, increased blood cell apoptosis, and multilineage cytopenia. By positional cloning, rescue, and morpholino knockdown experiments, we demonstrate that crs encodes a conserved mitochondrial matrix chaperone HSPA9B containing a glycine-to-glutamate substitution within the substrate-binding domain. This mutation compromises mitochondrial function, producing oxidative stress and apoptosis distinctly in blood cells. Thus, we identify an essential role for Hspa9b in hematopoiesis and implicate both loss of HSPA9B specifically and mitochondrial dysfunction generally in the pathogenesis of the MDS.

WT1 gene expression: an excellent tool for monitoring minimal residual disease in 70% of acute myeloid leukaemia patients - results from a single-centre study

Following induction chemotherapy for acute myeloid leukaemia (AML), sensitive determination of minimal residual disease (MRD) in patients achieving complete remission (CR) should enable the detection of early relapse and allow intervention at a more favourable stage than at overt relapse. We have determined the expression levels of the Wilms' tumour gene (WT1) by real-time quantitative polymerase chain reaction (RQ-PCR) in peripheral blood and bone marrow in 133 newly diagnosed AML patients and compared them with those in healthy volunteers. At diagnosis, the WT1 level exceeded normal expression in 118 of 133 (89%) patients, and was high enough to allow for detection of a WT1 decrease of least 1000-fold in 98 of 133 (74%) patients following induction therapy. Concomitant monitoring of fusion transcripts (PML-RARalpha, AML1-ETO, MLL-MLL, CBFbeta-MYH11, or DEK-CAN) in 38 patients identified different relationships between WT1 and fusion transcript levels, the AML1-ETO group showing remarkably low levels of WT1 compared with fusion transcript. In 32 patients analysed longitudinally there was close concordance between relapse and increased WT1 levels. Parallel longitudinal monitoring of WT1 and fusion transcript showed close correlation in 18 of 18 patients. We conclude that WT1 expression by RQ-PCR may be employed as a tool to detect MRD in the majority of fusion transcript-negative AML patients.

Risk for the development of treatment-related acute myelocytic leukemia and myelodysplastic syndrome among patients with breast cancer: review of the literature and the National Surgical Adjuvant Breast and Bowel Project experience

Regimens of adjuvant chemotherapy for early-stage breast cancer commonly include alkylating agents and anthracyclines. These agents have been associated with treatment-related acute myelocytic leukemia (AML) or myelodysplastic syndrome (MDS). This article reviews the medical literature concerning the incidence, causes, and natural history of treatment-related AML/MDS, with emphasis on the association of these factors with alkylating agents, topoisomerase inhibitors, growth factors, and radiation treatment. Data from 6 completed adjuvant National Surgical Adjuvant Breast and Bowel Project trials that tested regimens containing doxorubicin and cyclophosphamide were reviewed to characterize the incidence of treatment-related AML/MDS. The regimens differed in cyclophosphamide intensity, cumulative cyclophosphamide dose, and the presence or absence of mandated prophylactic support with growth factor and ciprofloxacin. Rates were compared across regimens, by patient age, and by treatment with or without adjuvant in-breast radiation therapy (RT). The relative risk (RR) for the development of treatment-related AML/MDS was greater for patients undergoing the more-intense regimens than for those undergoing standard AC (doxorubicin/cyclophosphamide) regimens (RR, 6.16; P<0.0001). Risk correlated more closely with dose intensity than with cumulative dose, and the data suggested that granulocyte colony-stimulating factor (G-CSF) dose may also be independently correlated with increased risk. Patients who received in-breast RT experienced more secondary AML/MDS than those who did not (RR, 2.38; P=0.006). Patients treated with AC with intensified doses of cyclophosphamide requiring G-CSF support had increased rates of treatment-related AML/MDS, even though the incidence was slight relative to breast cancer relapse. In-breast RT appeared to be associated with an increased risk of AML/MDS.

Karyotype is an independent prognostic parameter in therapy-related acute myeloid leukemia (t-AML): an analysis of 93 patients with t-AML in comparison to 1091 patients with de novo AML

The aim of this study was to compare the pattern of karyotype abnormalities of therapy-related acute myeloid leukemia (t-AML) (n=93) with de novo AML (n=1091), and to evaluate their impact on prognosis. Favorable, intermediate, and unfavorable cytogenetics were observed in 25.8, 28.0, and 46.2% of t-AML, and in 22.2, 57.3, and 20.4% of de novo AML. The median overall survival (OS) was shorter in t-AML than in de novo AML (10 vs 15 months, P=0.0007). Favorable and unfavorable cytogenetics had a prognostic impact with respect to OS in both t-AML (P=0.001 and 0.0001) and de novo AML (P<0.0001 and <0.0001). To define the overall prognostic impact of cytogenetics and t-AML, a multivariate Cox's regression analysis was performed for OS with favorable cytogenetics, unfavorable cytogenetics, t-AML, age, and white blood cell (WBC) count as covariates. All parameters proved to be independently related to OS (P=0.001 for t-AML, P<0.0001 for all other parameters). Within patients with t-AML, there were significant correlations between OS and both unfavorable (P<0.0001) and favorable cytogenetics (P=0.001), while age and WBC count had no impact on OS. In conclusion, these data indicate that cytogenetics are an important prognostic parameter in t-AML. Furthermore, t-AML is an unfavorable factor independent of cytogenetics with respect to survival.

Contemporaneous appearance, 18 years after allogeneic bone marrow transplantation, of myelodysplastic syndrome in the patient and the donor

We report the case of the development of two different stages of the same clonal disorder in two patients sharing the same bone marrow due to a previous bone marrow allotransplant. The transplanted patient developed severe aplasia with myeloid blasts, different from those of the previously cured leukemia. Chimerism evaluated by microsatellite analyses confirmed a full donor phenotype. At the same time, the donor of the bone marrow transplantation developed a refractory anemia with excess blasts. We speculate on the presence of an undetectable pre-existing pathological clone in the transplanted bone marrow, which have evolved in the two patients.

Inversion of chromosome 12 and lineage promiscuity in hematologic malignancies

Rearrangements of the short arm of chromosome 12 are among the most common aberrations found in hematologic malignancies, including myelodysplastic syndromes, acute myelocytic leukemias, acute lymphoblastic leukemias, and non-Hodgkin lymphomas. We report on a group of 46 patients with a variety of myelocytic and lymphoid malignancies, all with an inversion of chromosome 12. Both pericentric and paracentric inversions occurred. The identified hotspots for breakage were p13 and q24. These correspond to gene-rich areas of known chromosome instability. The inv(12) is difficult to detect and may be misinterpreted as a partial deletion by routine cytogenetics. Fluorescence in situ hybridization studies revised the G-banding interpretations of a deleted 12p in some cases to an inversion. The inv(12) may occur as the sole abnormality in both myelocytic and lymphoid malignancies, suggesting lineage promiscuity as seen with MLL and ETV6 gene disruptions. The majority of patients with the inv(12) had complex karyotypic changes that predicted a poor prognosis. Of the 24 patients with known clinical follow-up, many were refractory to chemotherapy and overall survival was short.

Cytogenetic findings in adult de novo acute myeloid leukaemia. A population-based study of 303/337 patients

During a 10-year period (1992-2001) in the region of Southern Denmark, 337 patients aged 15 years or older (range 16-93 years, median 67 years) were diagnosed with acute myeloid leukaemia (AML). Cytogenetic analysis was carried out in 90%, of whom 53% had clonal chromosome aberrations. Some 24% and 31% had only numerical or structural abnormalities respectively. The remaining patients showed both types of abnormalities. Ploidy levels in decreasing order were: pseudodiploidy, 41%; hyperdiploidy, 32%; and hypodiploidy, 27%. Pseudodiploidy characterizes type M3 (70%) and hypodiploidy M6 (56%). Recurrent cytogenetic abnormalities--t(8;21), t(15;17) and inv(16)--were found in 3.3%, 3.3% and 2.0% of all patients respectively. Prognostically intermediate and adverse aberrations were found in 39% and 44%, respectively, of those with an abnormal karyotype. Rare recurrent aberrations were found in two patients in this material. A previously described non-recurrent abnormality was found to be recurrent in one patient [der(20)t(11;20)(q13.2;p13)]. New, previously undescribed abnormalities were found in 41 patients. Statistically significant correlations were found between t(15;17) and young age (P < 0.001), inv(16) and young age (P < 0.006), -17 and M6 (P = 0.007), and M6 and complex karyotype with five or more unrelated aberrations (P = 0.004). We conclude that this truly population-based cytogenetic study of adult AML showed distributions of chromosome abnormalities that differ from those described so far.

[Chromosomal abnormalities in secondary myelodysplastic syndromes and leukemias]

Secondary leukemias group essentially together myelodysplastic syndromes and acute leukemias, therapy-related (chemo- or radio-), or consecutive to environmental factors. It's now proven that some recurrent abnormalities are associated with effects of therapeutic agents, as -5/del(5q), -7/del(7q) linked to alkylating agents, or 11q23 and 21q22 abnormalities linked to inhibitors of Topoisomerase II. Even if important differences between secondary and "de novo" forms exist, the discrimination between these 2 categories is not always obvious: many common chromosomal abnormalities, "de novo" leukemias in older patients having characteristics close to those of postalkylating leukemias, neonatal forms possibly secondary to maternal affect. Recent studies identified some others chromosomal abnormalities in the secondary leukemias and confirmed the poor prognosis of these hemopathies. This review sums up criterions, circumstances and cytogenetic abnormalities.

Two cases of acute myeloblastic leukemia evolving from aplastic anemia

Two cases of acute myeloblastic leukemia (AML) evolving from aplastic anemia are presented. The first case was diagnosed 18 years ago, and treatment with bolus methylprednisolone, prednisolone, and androgens resulted in partial hematological response. Severe pancytopenia recurred, and AML M0 by French-American-British classification developed. The second case was diagnosed 7 years ago. The patient had HLA DRB1*1501, and treatment with granulocyte colony-stimulating factor (G-CSF), cyclosporine, and methenolone resulted in complete hematological response. Thrombocytopenia recurred and did not respond to cyclosporine and methenolone or to later treatment with antithymocyte globulin, and AML M1 developed. Cytogenetic studies demonstrated 7q- in the first patient and +8 in the second patient. No mutations of N-ras or p53 were observed in either patient. These patients were treated with cytosine arabinoside, aclacinomycin, and G-CSF (CAG) chemotherapy, and the number of leukemic cells decreased substantially. However, pancytopenia after CAG chemotherapy persisted, and the first patient died of pneumonia and the second patient of cerebral hemorrhage.

Oxidative stress and the myelodysplastic syndromes

The evolution of higher organisms from anaerobic to aerobic living has promoted an elaborate mechanism of defense against potentially toxic oxidants. Many environmental toxicants implicated in the pathogenesis of myelodysplastic syndromes (MDS), including benzene and ionizing radiation, exert toxicity via pro-oxidant mechanisms. The emerging data suggest a probable genetic susceptibility to environmental carcinogenesis through functional polymorphic variants in enzymes that metabolize toxicants and/or protect against oxidative stress. The most studied enzyme is NAD(P)H:quinone oxidoreductase (NQO1). CD34+ cells from individuals homozygous for the NQO1 C609T nonfunctional allelic variant are incapable of enzyme induction following exposure to benzene, thus potentially increasing the hematotoxicity of benzene metabolites. Serologic and molecular markers of oxidative stress are present in many patients with MDS and include an increased concentration of the lipid peroxidation product malondialdehyde and the presence of oxidized bases in CD34+ cells. Potential mechanisms of oxidative stress include mitochondrial dysfunction via iron overload and mitochondrial DNA mutation, systemic inflammation, and bone marrow stromal defects. The biological activity of the antioxidant aminothiol amifostine in vivo suggests that these pathways may be meaningful targets for future therapy in MDS patients.

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.