Subacute myeloid leukemia: a clinical review

A case-control study of chronic myelomonocytic leukemia (CMML) in Shanghai, China: evaluation of risk factors for CMML, with special focus on benzene

The authors report the results of a hospital-based case-control study of all patients diagnosed with chronic myelomonocytic leukemia (CMML) (n = 36) from 28 participating hospitals over a 4-year period. Diagnoses were made by a single laboratory using 2001 World Health Organization (WHO) criteria. Subjects were matched to 2 control patients and interviewed concerning previous diseases, work histories, and exposures to potential etiologic agents. Peripheral blood and bone marrow findings revealed clinical features of both myelodysplastic syndromes (MDSs) and myeloproliferative neoplasms (MPNs), consistent with hematopoietic disease category of MDS/MPN. The frequency of clonal cytogenetic abnormalities in all CMML cases was 31%, with no consistent pattern identified. A select number of risk factors associated with occupational exposure, nonoccupational exposure, and prior medical or family history of disease were extracted from the questionnaire. The results were compared between the case and control subjects. A total of 5 study subjects (2 CMML cases and 3 control subjects) were determined to have had some benzene exposure. In addition, none of the highlighted risk factors associated with nonoccupational exposure to etiologic agents was significantly different among the study subjects. These results do not support an increased risk for developing CMML associated with historical exposures to benzene.

The role of low-dose cytosine arabinoside and aggressive chemotherapy in advanced myelodysplastic syndromes

The efficacy of low-dose cytosine arabinoside (Ara-C) and aggressive chemotherapy was assessed in 67 patients with advanced myelodysplastic syndromes (MDS). In most cases, treatment was started because of worsening peripheral cytopenia, increase in bone marrow blasts, or transition of MDS to acute myeloid leukemia (AML). Of 51 patients (age range, 18-82 years) receiving low-dose Ara-C by subcutaneous bolus injection (10 mg/m2 every 12 hours) or continuous intravenous infusion (20 mg/m2/day), nine (18%) entered complete remission (CR) and four (8%) had a partial response (PR). Duration of CR varied from 4 to 25+ months. Overall survival of patients treated with Ara-C was not superior to that of a historical control receiving supportive care only. Hematologic toxicity of low-dose Ara-C was considerable, with 12 patients (24%) dying of hemorrhage or infection during the initial treatment course. Sixteen patients (age range, 17-65 years) who presented with a Karnofsky score of more than 80% were chosen for aggressive chemotherapy using standard AML protocols. In this group, nine CR and two PR were obtained. Early death from pneumonia occurred in two patients, and three patients had refractory disease. The factors most strongly associated with successful remission induction were (1) presence of Auer rods in granulocyte precursors, and (2) a comparatively low medullary blast count (less than 30%) at the start of treatment. Median duration of bone marrow aplasia for patients entering CR was 21 days (range, 6-51). Prolonged remissions (22+, 27+, and 29 months, respectively) could be achieved in three of four patients receiving consolidation and maintenance chemotherapy after induction of CR. From these data we conclude that aggressive chemotherapy should not generally be considered contraindicated in advanced MDS. In patients with a good Karnofsky score, this form of treatment may be more advantageous than the currently favored low-dose Ara-C, which is also myelotoxic, but induces remissions in only a minority of patients.

Chronic myelomonocytic leukemia--clinicobiological characteristics: a multivariate analysis in a series of 70 cases

In a series of 70 patients diagnosed according to the FAB criteria, 42 clinical and biological disease characteristics were analyzed in order to identify significant prognostic factors by means of univariate and multivariate analysis. The univariate analysis identified ten parameters associated with poor prognosis: Symptoms of anemia, WBC over 10 x 10(9)/l, presence of blast cells, myeloid precursors or erythroblasts in peripheral blood (PB), high bone marrow (BM) cellularity, severe dysthrombopoiesis, percent of blast cells in BM and high serum levels of bilirubin and LDH. The Cox proportional hazards regression method revealed that the combination of high leukocyte counts and BM percentage of blast cells had the strongest predictive relation to survival length (p = 0.002 and p = 0.060 respectively). A new multivariate analysis treating the presence of myeloid and erythroid precursors in PB as a single variable selected only this as the most significant prognostic factor (p = 0.001). Both regression models allowed us to discriminate two significantly different risk groups of patients.

Acute transformation of chronic myelomonocytic leukaemia: a multivariate study of predictive factors

In an attempt to determine the possible predictive value of the main clinical and haematological initial features of chronic myelomonocytic leukaemia (CMML) on the evolution to acute leukaemia, as well as the real impact of such an event on survival, 35 such patients were submitted to multiple regression analyses. At the time of the study 30 out of the 35 patients had died, with a median survival of 8.2 months for the whole series. 12 patients (34%) developed acute leukaemia, between 1.5 and 42.1 months from diagnosis of CMML, the actuarial median time of acute transformation being 29.4 months. The initial bone marrow blast cell percentage was the only factor influencing the development of acute leukaemia. On the other hand, the multivariate survival study showed that acute transformation introduced in the model as a time-dependent variable had a clear-cut unfavourable influence on the outcome of CMML patients, as did palpable spleen, advanced age and marked monocytosis.

Treatment of "poor risk" acute nonlymphocytic leukemia with continuously infused low-dose cytosine arabinoside

There is currently little experience using a continuous intravenous infusion of low-dose cytosine arabinoside (LDARA-C) in the treatment of acute nonlymphocytic leukemia (ANLL). We report the results in 12 patients with ANLL described as either relapsed ANLL, ANLL with a preceding myelodysplastic phase, or ANLL in the elderly treated with 14 days of continuous intravenous LDARA-C (20 mg/m2/day). Complete responses (CR) were seen in five patients (42%) and partial responses (PR) in three patients (25%). Treatment resulted in overall and clonal cytoreduction, which was evident by serial bone marrow exams and bone marrow cytogenetic analysis. The ability to obtain a CR correlated with the finding of a low initial marrow cellularity (P less than .05). This study finds that continuous intravenous infusion of LDARA-C for ANLL can achieve response rates comparable to standard induction programs in a subset of patients traditionally defined as having a poor prognosis.

Effects of recombinant human granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndromes

The myelodysplastic syndromes are characterized by ineffective hematopoiesis and refractory cytopenias. In an attempt to improve hematopoiesis, we administered recombinant human granulocyte--macrophage colony-stimulating factor (GM-CSF) to eight patients with myelodysplastic syndrome, as part of a Phase I trial. The GM-CSF was given by continuous intravenous infusion daily for two weeks and then again after a two-week rest period. Over the entire dose range tested (30 to 500 micrograms per square meter of body-surface area), treatment was associated with marked increases in peripheral-blood leukocytes (5- to 70-fold), including granulocytes (5- to 373-fold), in all eight patients. The absolute number of monocytes, eosinophils, and lymphocytes increased in all patients. Three of eight patients also had 2- to 10-fold increases in platelet counts and improvement in erythropoiesis, with the result that two of three patients who had required red-cell and platelet transfusions no longer needed them (at 20 to 27 weeks of follow-up). Treatment was also associated with increased marrow cellularity and a decreased percentage of blasts in the bone marrow of patients with excess blasts, resulting in an increase in the ratio of differentiated myeloid cells to immature myeloid cells. We observed relatively few side effects, but bone pain was dose-limiting when it was associated with high white-cell counts. Our results showed that GM-CSF is a potent stimulator of hematopoiesis in vivo and may produce hematologic improvement in the short term (8 to 32 weeks of observation) in patients with myelodysplastic syndrome. More experience, with longer follow-up periods, will be necessary to assess the long-term safety and efficacy of this new treatment.

Successful oral chemotherapy with idarubicin in refractory anaemia with excess blasts

6 patients with refractory anaemia with excess blasts (RAEB) were treated with a new oral anthracycline, idarubicin. 3 patients achieved complete remission, and the remaining 3 achieved partial remission. These responses were maintained for 8-60 wk, the longer durations being in the patients who achieved complete remission. Treatment was given on an outpatient basis, and all but 1 patient remained at home for most of the disease course. Unwanted effects were mild. It would thus appear that oral idarubicin is an effective treatment for RAEB, in addition to allowing outpatient management. Larger studies are required for further evaluation.

Myelodysplastic syndromes: analysis of 131 cases according to the FAB classification

The clinical and haematological findings in 131 patients with myelodysplastic syndromes (MDS), none of which had previously received chemotherapy or radiotherapy, classified according to the FAB criteria, were analysed. The distribution among the 5 subgroups was: RA 31 patients, RAS 19, RAEB 23, CMML 29 and RAEBT 29 patients. There were difficulties in the classification of 24 patients. These included, first, 8 cases with myeloid hyperplasia of the bone marrow (BM) but without monocytosis or excess of blasts of the BM. They were classified as RA. Second, 8 cases with sideroblastosis but with monocytosis or excess of blasts of the BM were classified 3 as RAEB, 2 as CMML and 3 as RAEBT. Finally, 8 cases with absolute monocytosis and BM blasts 15-30% were classified as CMML. 37 of 82 dead patients (45.1%) had transformed to acute non-lymphoblastic leukaemia (ANLL). The incidence of evolution to ANLL was low for RA and RAS (6.30% and 12.5% respectively), while it was 37.5% for RAEB, 57.1% for CMML and 77.2% for RAEBT. The median survival for each subgroup was: RA 18 months; RAS 25; RAEB 13; CMML 14 and RAEBT 10 months. It is concluded that the FAB classification with some modifications recognises group of MDS with different prognosis.

A multivariate analysis of prognostic factors in chronic myelomonocytic leukaemia according to the FAB criteria

In an attempt to characterize the prognostic significance of the main initial clinical, haematological and biochemical features of chronic myelomonocytic leukaemia according to the FAB criteria, 29 such patients were analysed by means of univariate and multivariate statistical methods. At the time of the analysis 21 patients had died, with a median survival for the overall series of 8.2 months. The univariate analysis identified three parameters associated with poor prognosis: high monocyte counts, low platelet counts and splenomegaly. When all the initial features were included in a multiple regression model, only high monocyte counts and spleen enlargement retained their unfavourable prognostic influence (P = 0.002 and P = 0.02, respectively). Based on the presence or not of these prognostic factors, two populations of patients with different survival (median survival 5.6 and 16.5 months, respectively, P less than 0.005) could be identified. It seems therefore that monocytic proliferation serves not only as the diagnostic marker for chronic myelomonocytic leukaemia but also as the most important feature in the assessment of the patient's prognosis.

Chronic myelomonocytic leukemia following refractory anemia with sideroblasts: report of two cases

We report 2 patients with idiopathic refractory sideroblastic anemia who developed chronic myelomonocytic leukemia 1 to 5 yr later. This observation supports the decision of the FAB cooperative group to include both conditions in the category of myelodysplastic syndrome.

Chronic and subacute myelomonocytic leukaemia in the adult: a report of 60 cases with special reference to prognostic factors

We report 60 cases of chronic and subacute myelomonocytic leukaemias (CMML and SMML) in the adult, using the FAB group criteria. The M/F sex ratio was 3.3 and the mean age 67.5 years. Splenomegaly was found in 32% of cases, hyperleucocytosis in 52% of cases and mean blood monocytosis was 4.3 X 10(9)/l. Marrow smears showed an excess of blasts in 57% of patients, a moderate increase in monocytes in most cases and frequent myelodysplastic features. An increase in serum lysozyme and polyclonal hypergammaglobulinaemia were usual and clonal cytogenetic anomalies found in about half of the patients tested. Treatment was usually palliative and the median survival was 28 months, a blastic transformation being responsible for a third of the deaths. Prognostic factors at diagnosis were analysed retrospectively in the 46 patients who had sufficient follow up. Percentage of marrow blasts haemoglobin level and blood monocytosis at diagnosis, were subject to multivariate analysis, resulting in a discriminant 'score'. This allowed assignment of each patient into one of two prognostic subgroups (10.9% probability of error): a poor prognosis one, with a life expectancy of less than 1 year and a high risk of acute transformation (subgroup termed SMML) and a better prognosis subgroup (termed CMML), with some CMML patients surviving over 5 years.

Hypoplastic acute leukemia: review of 70 cases with multivariate regression analysis

Between 1971 and 1984, 22 of 190 adult patients (11.6 per cent) with acute leukemia seen at the University of Arizona had hypocellular acute leukemia (HAL), defined as lymphoblasts or myeloblasts (plus atypical promyelocytes) of greater than or equal to 30 per cent, but marrow cellularity of the core biopsy or clot section of less than or equal to 50 per cent based on a 1000 point count. These 22 patients with HAL plus the 48 previously published patients with well documented HAL (combined series of 70 patients) were evaluated in detail with multivariate analysis. The median leukocyte count was 2700/microL, hemoglobin of 8.2 g/dl, and platelet count 63,000/microL. Circulating blasts were noted in 27 of 52 patients (52 per cent). Twenty-seven of 34 patients (79 per cent) had abnormal cytogenetics. The overall median survival was 8 months (range: 0.1-48). The median survival for the 22 patients managed with supportive care alone was 4 months, 6 months for the 16 patients treated with non-aggressive induction therapy, and 13 months for the 32 patients treated with aggressive induction therapy (p less than 0.02 versus other categories). Multivariate analysis confirmed that aggressive induction therapy was a major favourable prognostic factor (p = 0.016). Multivariate analysis of the aggressively induced patients revealed that younger patients (less than or equal to 65; p = 0.04) and patients with no AHD (p = 0.09) lived longer. Thus, aggressive remission induction can be attempted in HAL and appears to contribute to prolonged survival especially under age 65 years.

Prognostic factors for survival of 194 patients with low infiltrate leukemia

Prognostic factors were identified from the histories of 194 patients diagnosed as having low infiltrate leukemia (LIL) between 1973 and 1981, when the policy was to delay treatment until there was evidence of progressive disease or life-threatening morbidity. Their median age was 59 yr; 63% were male; 30 had had a malignant disease previously. Presenting symptoms included anemia, 82%; infections, 15%; and hemorrhage, 16%. The group's median survival was 42 weeks, with high marrow cellularity and percentage of blasts, impairment of bone marrow, liver or renal function, age over 65 yr and performance status less than 80% associated with poorer survival. Cytogenetic changes associated with poor survival included loss of chromosome 5 or 7, additional chromosome 8, karyotypic instability, and presence of 100% abnormal metaphases. A regression model including terms for blood and bone marrow features, and age at hospital admission was able to stratify patients into prognostic groups in the same population and in an independent population admitted prior to 1973. Further prospective testing of the model is required. Twenty-six of the 78 patients who were eventually treated with combination chemotherapy achieved complete remission. The presence of Auer rods, diagnosis of acute leukemia or refractory anemia with excess blasts, rapid increase in marrow infiltrate and favorable cytogenetic karyotype were associated with response. Delaying treatment in all patients was found to have improved only modestly the survival of patients with LIL.

The concept of preleukemia: clinical and laboratory studies

Thirty-five years ago, a handful of astute clinical hematologists began to notice that some of their patients with acute nonlymphocytic leukemia had a history of a preceding ill-defined hemopathy. This "preleukemic" hemopathy was increasingly reported anecdotally and through careful retrospective analyses. In more recent prospective studies, this syndrome has been relatively well defined. Indeed, it is widely accepted that there exists a hematopoietic abnormality not recognizable as classical, overt, acute nonlymphocytic leukemia, which, nonetheless, can represent an early phase of leukemia. In this manuscript, the author reviews the original case reports, the initial retrospective studies, and the prospective studies which have clarified some of the clinical and laboratory features of the preleukemic syndrome. The notion that the preleukemic syndrome represents an established neoplastic process will be reviewed with special attention to assessment of clonal hematopoiesis, cytogenetic studies, and clonal evolution. Studies on induced leukemia and preleukemia in experimental animals and humans will be reviewed as will be the semantic issues which have complicated our ability to compare interinstitutional studies. A simple classification scheme of the myelodysplastic syndromes will be presented as will be a framework agenda for future studies on the pathophysiology of these syndromes.

Myelodysplastic syndromes. A clinical and pathologic analysis of 109 cases

A total of 109 patients with myelodysplastic syndromes (MDS) was analyzed to determine the clinical and pathologic features of the five recently defined French-American-British Cooperative Group (FAB) subtypes, and to assess the utility of this classification system in predicting survival, evolution to acute nonlymphocytic leukemia (ANLL), and cause of death. All patients with MDS presented with anemia; additional cytopenias were present in patients with refractory anemia with excess blasts (RAEB), chronic myelomonocytic leukemia (CMML) and refractory anemia with excess blasts in transformation to ANLL (RAEB/Tr). Thirty-two patients received some form of antileukemic therapy for MDS. ANLL developed in 16 of the 77 remaining untreated patients, including 18% (2/11), 0% (0/21), 22% (5/23), 33% (2/6), and 44% (7/16) of patients with refractory anemia (RA), refractory anemia with ring sideroblasts (RARS), RAEB, CMML, and RAEB/Tr, respectively (P = 0.02). The FAB subtype was highly predictive of survival with median survivals ranging from 71 months for RARS to 5 months for RAEB/Tr (P = less than 0.0001). Patients with RAEB, CMML, and RAEB/Tr frequently died of direct consequences of MDS, while patients with RA and especially RARS generally survived or died from unrelated disorders (P = less than 0.0001). MDS encompass a spectrum of disorders. RA and RARS, are relatively indolent and often do not lead to the patient's demise. RAEB, CMML, and RAEB/Tr are aggressive disorders which are often responsible for the patient's death whether or not actual progression to overt leukemia occurs. FAB subtype predicts survival, evolution to ANLL, and cause of death, although the five morphologic subtypes appear to separate into only two disease groups, especially with regard to survival and cause of death.

Chronic myelomonocytic leukemia: clinical features, cytogenetics, and prognosis in 30 consecutive cases

A retrospective analysis of 30 patients with chronic myelomonocytic leukemia (CrMML) was performed to define the natural history of the disease and the risk of acute transformation. Our patients fulfilled the following criteria of diagnosis: blood monocytosis over 1 X 10(9)/l, blast cell percentage in bone marrow up to 30, and in peripheral blood less than 5. The most common presenting feature was anemia; seven patients had fever; three patients complained of purpura and bleeding. Anysopoikilocytosis and macrocytosis were frequent. Abnormal granulocyte morphology, defective granulation and abnormal leukocyte alkaline phosphatase were often observed. Blast cells in peripheral blood smears were found in 14 patients. Serum and urine lysozyme levels were increased in 82 per cent and 93 per cent, respectively. Dysplastic changes involving erythroid, granulocytic and megakaryocytic lineages were constant features in all cases. Agranulated blasts above 5 per cent of marrow nucleated cells were seen in 13 patients (43 per cent). Seven of the 20 patients showed non-specific chromosomal abnormalities at diagnosis. Median survival from diagnosis was 18 months (range, 3-112). Evolution into acute myeloid leukemia occurred in 11 patients. No difference in survival was found between patients who developed acute leukemia and patients who did not. A shorter survival has correlated to the following parameters: leukocytes greater than 10 X 10(9)/l, the presence of blasts in peripheral blood and agranulated blasts in the marrow above 5 per cent.

Evolution of oligoleukemia

Chronic lithium administration to 22 patients with oligoleukemia did not alleviate cytopenia or stimulate bone marrow proliferative activity. The authors identified, however, pretreatment characteristics discriminating two evolutionary endpoints of oligoleukemia (marrow failure, 10 patients; overt acute leukemia, 12 patients): higher marrow leukemic infiltrate, normal myeloid precursor proportion, platelet count, and female sex all favored eventual transition to overt leukemia which, in comparison with marrow failure, was associated with a significantly longer survival duration from symptoms. For patients developing overt leukemia, survival from diagnosis was inversely correlated with the degree of marrow leukemic infiltrate. The lack of lithium responsiveness in oligoleukemia is consistent with the concept of differentiated leukemia with abnormalities either at the level of a lithium-responsive adherent cell elaborating colony stimulating activity (CSA) or at the level of CSA-responsive CFUs.

Response of preleukemic syndromes to continuous infusion of low-dose cytarabine

Preleukemic syndromes are a group of acquired bone-marrow disorders characterized by dysplastic maturation of hematopoietic cells and peripheral-blood cytopenias. Although the clinical course is variable, most patients succumb to hemorrhage, infection, or acute leukemia. These syndromes are generally considered untreatable. We administered low doses of cytarabine by continuous intravenous infusion for 7 to 21 days in eight patients with preleukemia or with preleukemia in evolution to acute leukemia. Eight of 13 courses were associated with marked increases in peripheral-blood granulocyte, platelet, and red-cell counts, with the result that six of the eight patients needed no transfusions for 2 to over 14 months. These preliminary results demonstrate that continuous infusion of low-dose cytarabine can offer patients with preleukemic syndromes hematologic improvement with limited toxicity.

Remission of acute myelogenous leukemia in elderly patients with prior refractory dysmyelopoietic anemia

Refractory dysmyelopoietic anemia (RDA) is a myeloproliferative disorder usually of elderly patients which often evolves into acute myelogenous leukemia (AML). AML in such patients is usually considered untreatable with standard aggressive chemotherapy in part because these patients are often elderly, but primarily because of the concern that the bone marrow of these patients no longer has a residual stem cell to repopulate the bone marrow following chemotherapy-induced aplasia. The authors treated three patients (ages 72, 69, and 62 years, respectively) with intensive chemotherapy after RDA evolved into AML. Each patient had been pancytopenic for 3 to 15 months prior to their transition to AML. At the onset of therapy for AML, all were severely pancytopenic with greater than 50% myeloblasts in the bone marrow. All patients had bone marrow aplasia by day 14 after chemotherapy with a complete bone marrow remission and normal peripheral counts by day 26. These data suggest that intensive chemotherapy of AML with prior RDA may result in complete bone marrow remission.

Dysmyelopoietic syndromes. A search for prognostic factors in 193 patients

Dysmyelopoietic syndromes cover sideroblastic or nonsideroblastic refractory anemia with or without excess of blasts, subacute or chronic myelomonocytic leukemia. The evolution of 193 patients was studied with regard to the initial hematologic picture. A certain number of variables of prognostic value have then been isolated: excess of marrow blasts (more than 5%); presence of circulating blasts or karyotypic anomalies; reduction in the number of polymorphonuclear leukocytes (less than 1.043 10(9)/l, of monocytes (less than 0.136 10(9)/l), of platelets (less than 140 10(9)/l), of in vitro granulopoietic progenitors (less than 5 per 10(5) nucleated cells plated), of erythrocytic incorporation of 59Fe at day 14 (less than 12%), of hemoglobin level (less than 92 g/l); previous exposure to radiation or chemotherapy; early hemolysis in 51Cr-labeled erythrocytes study; marrow heterogeneity in histology; less than 20% of ringed sideroblasts. The correlation between these variables and adjustments related to the length of survival and the order of magnitude of the critical level of the log-rank test show that the most significant variables in descending order are: excess of marrow blasts, neutropenia, thrombopenia, presence of circulating blasts, the type of erythropoietic insufficiency, and decrease of in vitro growth.

Cytogenetic findings in the dysmyelopoietic syndrome

Cytogenetic studies of bone marrow specimens from 15 patients with dysmyelopoietic syndrome are presented. The group consists of nine patients with refractory anemia with excess of blasts (RAEB), three patients with chronic myelomonocytic leukemia (CMMoL), and three patients with acquired idiopathic sideroblastic anemia (AISA). None of these patients had a prior history of therapeutic or occupational exposure to potential carcinogenic agents, G(TG)-banding revealed clonal abnormalities in nine of the 15 patients. Five of these patients exhibited one or more of the following cytogenetic abnormalities: 5q deletion, -7, +8, or +21. The AISA group appeared to be unique as chromosome abnormalities were seen in two of the three patients and the clinical course in these patients had been prolonged without progression to acute leukemia. No other clinical correlation could be made in the blast RAEB and CMMoL groups, except for possible survival benefit in patients with normal karyotypes.

A phase II study of prednimustine in acute non-lymphocytic leukemia, smouldering leukemia, and refractory anemia with excess blasts

Prednimustine, an ester of chlorambucil and prednisolone, was evaluated for efficacy and toxicity in a selected group of leukemia patients with a poor prognosis. Disease subsets consisted of patients with acute non-lymphocytic leukemia (ANLL) over age 60; ANLL refractory to standard therapy; smouldering leukemia; and refractory anemia with excess blasts (RAEB). In agreement with previous studies, toxicity from Prednimustine was relatively mild, consisting primarily of infrequent myelosuppression, gastrointestinal side-effects, and mild hyperglycemia. This study did not, however, confirm previously reported remission rates in ANLL: in 41 evaluable patients only two complete remissions were achieved. Both occurred in the subset of patients with smouldering leukemia. We conclude that Prednimustine has limited activity in this patient population.

Natural history of smouldering leukaemia

The natural history of 45 cases of smouldering leukaemia has been studied. Males and females were equally represented, with a median age of 60.5. The median survival of the whole group was only 20 months, but rare cases lived 10 years or longer. 38% developed acute leukaemia; the remainder usually died of the results of marrow failure. Although it was possible to divide these marrow dysplasias morphologically into 3 major subgroups (refractory anaemia with excess of myeloblasts, chronic myelomonocytic leukaemia and chronic erythraemic myelosis), several displayed transitional features. Many showed refractory macrocytosis at diagnosis. The survival of the 3 groups was similar, though patients with high monocyte counts tended to present with less anaemia and fared rather better than the others. Statistical analysis suggests that increasing age, severe anaemia, thrombocytopenia and hepatomegaly are associated with a poor prognosis. Chemotherapy, when attempted, was usually unsuccessful.

Preleukemia in children

Six children who developed acute myelomonocytic leukemia presented with a preleukemic syndrome. The incidence of preleukemic presentation of AMML was 17% of children with acute nonlymphocytic leukemia, or 2.9% of all children with acute leukemia at this institution, incidences similar to those in adults. During the preleukemic phase, which lasted from three to 35 months, all children had anemia, all had infectious complications, and three of six had hemorrhagic tendencies. Three received steroids before the diagnosis of AMML, and all had some objective response. Two patients died before receiving therapy for AMML. Four children who received AMML therapy with combinations including cytosine arabinoside and an anthracycline achieved complete remission. Ultimately, all patients died. Clues to diagnosis of preleukemia include unexplained cytopenias, either absolute or functional, peripheral blasts, progressive megaloblastosis with an elevated B12 value, dyserythropoiesis, abnormalities of nuclear segmentation, nonrandom chromosomal alterations, and reduced marrow colony to cluster ratio in vitro. Until there is a highly effective therapy for ANLL, precisely when to treat the child with preleukemia remains uncertain. However, treatment should be started before infectious complications or hemorrhagic tendencies become life-threatening.

Adult acute nonlymphocytic leukemias

For the first two decades, leukemic chemotherapy had little impact on survival. In the past 10 years, however, remission induction therapy has generated complete remissions which last approximately one year in about half to three fourths of those treated, with a seventh in some series alive at 5 years.