Prognostic factors in the myelodysplastic syndromes: a review

Myelodysplastic syndromes (MDS): prognostic factors and scoring systems

OBJECTIVE

To evaluate the score systems of Cassano and Sanz and suggest a new one.

DESIGN

Case series.

LOCATION

Teaching hospitals: EPM UNIFESP and Faculdade de Medicina de Botucatu.

PARTICIPANTS

59 patients diagnosed from 1979 to 1992.

INTERVENTION

Evaluation of clinical-laboratorial data.

MEASUREMENT

Statistical comparison, uni and multivariate analysis and actuarial survival curves.

RESULTS

Cassano's system divided the patients into high and low risk (p = 0.0966) while Sanz's gave high, intermediate and low risk (p = 0.0108). The univariate analysis showed hemoglobin, WBC count, E/M ratio, liver size and blast percentage in BM as statistically significant. The multivariate analysis showed blast percentage in BM (p = 0.004) and Hb (p = 0.050) as significant. Our system, considering the multivariate analysis data, divided the patients into high, intermediate and low risk (p = 0.0038).

CONCLUSIONS

Sanz's system was more functional than Cassano's, while ours showed predictive survival value and ease of use in clinical practice.

Mode of disease progression in primary myelodysplastic syndromes: a Japanese co-operative study. The Refractory Anemia Study Group of The Ministry of Health and Welfare, Japan

Chronological changes in hematological findings were analyzed in 225 patients with myelodysplastic syndromes (MDS). They were diagnosed between 1990 and 1992. Their hematological findings, i.e. hemoglobin levels, leukocyte and platelet counts, proportions of peripheral blood (PB) blasts and monocytes, and proportion of blasts in bone marrow (BM), were recorded for up to 42 months after diagnosis, when available. BM was examined regularly in only a few patients. Therefore, it was impractical to use the French-American-British Cooperative Group criteria for subtype classification during the disease course. Thus, we used the percentage of PB blasts as the only indicator of stage evolution. We classified the disease into four stages: stage 1, less than 1% PB blasts; stage 2, 1-5% PB blasts; stage 3, 5-30% PB blasts; and stage 4, 30% or more PB blasts. There were 171 patients initially in stage 1, 37 initially in stage 2, and 17 initially in stage 3. Less than half (45%) of the patients initially in stage 1 progressed to stage 2, while 91% of the patients initially in stage 2 and all of the patients initially in stage 3 showed stage evolution. Eight variables, i.e. BM blasts 5% or more, male sex, karyotypic abnormalities, micromegakaryocytes, mononuclear large megakaryocytes, platelet counts 50 x 10(9)/l or higher, abnormal nucleus of granulocytes, and abnormal granules of granulocytes, were found to be significant risk factors for evolution from stage 1 to 2. Evolution from stage 1 to a higher stage within 15 months of diagnosis was associated with impending poor prognosis in most patients. However, of the 67 patients initially in stage 1 who died, 30 did not show stage evolution. Evolution from stage 2 to a higher stage and from stage 3 to stage 4 was also associated with impending poor prognosis. Higher levels of cytopenia were not associated with poorer prognosis in the stage 1 patients. In conclusion, our grading system proved to be useful in evaluating the chronological changes in MDS patients.

The rate of disease progression predicts the quality of remissions following intensive chemotherapy for myelodysplastic syndromes

The use of intensive chemotherapy in the treatment of myelodysplastic syndromes (MDS) has met with some disappointment, although subgroups of patients have been identified in which the response approaches that of de novo acute myeloid leukaemia (AML). We hypothesized that it is not the FAB classification per se, but the biological behaviour of the blasts as shown by their rate of accumulation that influences the response. We have, therefore, included AML with trilineage dysplasia (AML/TLD) as it represents one extreme of the evolution of MDS to AML. We have analysed the results of intensive chemotherapy in 22 patients (median age 60 years; range 26-77 years) with MDS (14) and AML/TLD (8). Response to treatment was analysed by age, interval from diagnosis to treatment, the number of cytopenias, bone marrow blasts and karyotype. Patients were also divided according to the rate of disease progression, shown by the time from diagnosis to treatment (group A = < 3 months; group B = > 3 months). The overall response rate was 87%; 13 (60%) complete responses (CR) and 6 (27%) partial responses. The rate of disease progression was identified as the most significant predictive factor of achieving CR (p = 0.003) (group A 10/12; group B 3/10). Patients presenting with more than 20% blasts also had a better response (p = 0.031). The combined response rates, however, did not differ significantly between the two groups (group A 92%; group B 80%) as 50% of group B achieved a PR. The failure to normalize blood counts was not related to the number of cytopenias before starting treatment. In all cases, PR was associated with persistence of dysplastic morphology and cytogenetic abnormalities. CR was associated with complete morphological and cytogenetic response except in two patients in group B. Dysplastic morphology re-emerged in patients who achieved CR and of these, all but one acquired a new cytogenetic abnormality. Patients in group B who achieved CR all needed two courses compared with a mean of 1.1 for the other group. The median survival from treatment for both groups was 10 months, however, no patient in group B survived more than 20 months. In comparison 33% in group A were alive at 5 years. The rate of accumulation of blasts predicts the response to chemotherapy and the quality of remissions achieved. Patients with rapidly increasing blasts can achieve complete morphological and cytogenetic remissions, although they eventually have a dysplastic relapse. In contrast, intensive chemotherapy for patients with a slow accumulation of blasts may reduce the blast population but with much less benefit on haemopoiesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Long-term survivors in myelodysplastic syndromes: a report on 63 cases and comparison with short and intermediate survivors

Sixty-three of 373 patients (17%) with de novo myelodysplastic syndrome (MDS) survived more than 5 yr (long survivors). At diagnosis, they usually had no or only moderate cytopenias; 63% of them had marrow blasts < 5%; only 1 patient had circulating blasts; 60% had refractory anaemia (RA) or refractory anaemia with ringed sideroblasts (RARS); 19% of the 43 patients who were karyotyped had an abnormal clone, and only 2 patients had complex cytogenetic findings. Only 4 of the 63 patients progressed to another FAB type within 5 yr of diagnosis, from RA to refractory anaemia with excess of blasts (RAEB) or chronic myelomonocytic leukaemia (CMML). After 5 yr, 9 patients showed progression (including progression to AML in 5 patients). The other patients remained stable (43 cases) or died from cytopenias or unrelated disorders (11 cases). Except for 3 patients who achieved prolonged complete remission with intensive chemotherapy, and possibly 3 patients who responded to low dose Ara C, prolonged survival seemed to result mainly from the low natural course of the disease. Although, as expected, significant differences for age, cytopenias, circulating and bone marrow blasts, and karyotype were seen between short (< 2 yr) and long (> 5 yr) very few significant differences were seen between intermediate and long survivors. These 2 subgroups only differed by significantly lower age and higher haemoglobin level in long survivors. Multivariate scoring systems (Bournemouth, Sanz's and Lille scores) proved of relatively limited value in differentiating them.(ABSTRACT TRUNCATED AT 250 WORDS)

Extended cytogenetic follow-up of patients with myelodysplastic syndrome (MDS)

The prognostic significance of clonal karyotype status in myelodysplastic syndrome (MDS) is assessed after an extended follow-up period of 5 years. There are three karyotype, single abnormalities or multiple abnormalities at the time of referral. However, there is no correlation between the size of the abnormal clone and prognosis. Karyotype status has independent prognostic significance in 'high risk' MDS so that patients with a refractory anaemia with excess of blasts (RAEB)/RAEB in transformation (RAEB-t) and a normal karyotype survive significantly longer than those with an abnormal karyotype (P < 0.001) and do not differ significantly from patients with refractory anaemia (RA). Significant differences in survival according to karyotype status are also seen in patients with chronic myelomonocytic leukaemia (P < 0.001) but not in those with primary acquired sideroblastic anaemia and RA. Among patients studied sequentially, those who retained a normal karyotype survived significantly longer than those who developed an abnormality on follow-up (P < 0.001). The risk of leukaemic transformation was also increased in patients who presented with or subsequently developed a clonal karyotype abnormality compared with those who remained normal (P < 0.05).

Epidermal Langerhans cells in myelodysplastic syndromes are abnormal

The myelodysplastic syndromes (MDS) represent clonal disorders of the hematopoietic stem cell that are associated with quantitative and qualitative disturbances of the peripheral blood cells and a high risk for the transition to overt leukemia. As epidermal Langerhans cells (LC) are bone-marrow-derived cells, we were interested to see whether they are altered in patients with MDS. Epidermal sheets were prepared from biopsies taken from the thighs of nine patients with MDS and five control persons and processed for immunoperoxidase staining of CD1a antigens. The density and morphology of CD1a+ cells (i.e., LC) was evaluated by visual assessment as well as automatic image analysis. The density of LC was reduced in seven of nine patients (range, 30-75% of normal), whereas the morphology of LC appeared to be altered in all MDS patients in that the LC displayed large and bizarre cell bodies with only a few and often abnormally long dendrites. The HLA-DR expression by LC was not altered, as shown by double immunofluorescence staining of CD1a and HLA-DR antigens. Ultrastructurally, LC again appeared enlarged and often presented with bizarre nuclei, yet displayed no other abnormalities. Our findings suggest that LC are abnormal in MDS and might even indicate a more wide-spread involvement of the dendritic cell lineage in this syndrome.

Colony-cluster ratio and cluster number in cultures of circulating myeloid progenitors as indicators of high-risk myelodysplasia

Circulating myeloid progenitors were assayed in 172 normal subjects and 147 patients with myelodysplastic syndrome (MDS). Patients whose cultures had colony/cluster ratios (CCR) less than 0.3 had significantly shorter survival periods than comparable patients with CCR greater than 0.3. A second prognostic indicator, which complemented CCR, was identified in patients with less than 5% blasts. Median survival was significantly reduced in patients with greater than 15 clusters/ml blood despite colony and cluster numbers being predominantly within the normal range. Characteristic differences were found in three FAB groups large enough to allow statistical analysis. Survival amongst patients with refractory anaemia with excess of blasts (RAEB) was related to CCR and was independent of cluster number. Amongst sideroblastic patients (SA) survival related only to cluster number. Refractory anaemia (RA) patients included individuals in both high-risk groups with only three patients out of 64 showing both features. Amongst all the MDS patients, those with CCR greater than 0.3 and less than 15 clusters/ml blood formed a low-risk group (n = 60) with a relatively good prognosis of whom 85% survived the study period (median duration 938 d) including 94% of those in this group with less than 5% marrow blast cells.

Clonal karyotype abnormalities and clinical progress in the myelodysplastic syndrome

Clonal karyotype abnormalities in 124 patients with myelodysplastic syndrome are reviewed. 36% of patients had abnormalities at referral, the most common being 5q-, +8 and lesions of chromosomes 7 and 20. Reduced survival was associated with the presence of either single or multiple clonal abnormalities at referral, abnormalities of chromosome 7 or 8 (either alone or with other lesions) and exclusively abnormal metaphases. The presence of 5q- alone did not appear to affect survival. Sequential studies were carried out in 77 patients of whom 12 showed karyotypic evolution. Reduced survival was observed in patients with an evolving karyotype but appeared to be due almost entirely to evolution in those patients whose initial karyotype was normal. Leukaemic transformation occurred more commonly in patients with an abnormal karyotype, particularly those with multiple abnormalities, and in patients with an evolving karyotype. Although the first appearance of an abnormal karyotype or an apparent evolution are important phenomena, it is probable that in some cases they merely represent expansion of a previously existing clone that has escaped detection. The distinction between true karyotypic evolution or clonal expansion and statistical variations due to small sample size and variability of samples may be difficult but needs to be taken into account in considering clinical significance.

Chromosome study of 85 patients with myelodysplastic syndrome

We studied bone marrow chromosomes in 85 consecutive patients with myelodysplastic syndrome (MDS). Fifty-seven (67%) had a clone with an abnormal karyotype at diagnosis. Eight had secondary MDS, all with abnormal karyotypes. The frequency of abnormal karyotypes in the primary MDS was 64.9%. During subsequent follow-up, five patients acquired chromosome abnormalities; thus, at the end of the study, 72.0% of patients had an abnormal karyotype. The most frequent chromosome abnormalities were 5q-, +8, -7, -5, and -22. Forty patients (i.e., 70% of those with an abnormal karyotype and 47% of the whole group) had one of the karyotype abnormalities associated with secondary MDS or acute nonlymphocytic leukemia; in other words, 5q- or -5, or -7. Of all patients, 21.1% progressed into ANLL. Unfavorable prognostic factors associated with the risk of evolution into ANLL and with shorter overall survival were the presence of greater than 5% of bone marrow blasts, major chromosome abnormalities, and monosomy 7.

Mechanisms and prognostic value of cell kinetics in the myelodysplastic syndromes

Cell kinetics were studied by quantitative autoradiography in 29 patients with myelodysplastic syndromes (MDS) and in four with smouldering leukaemia (SML) in a prospective 6-year study. Cellular turnover in all FAB groups was characterized by reduced labelling index and prolonged DNA synthesis time indicating reduced proliferative activity. Two more parameters were derived from the measurements. (1) The relative cell production rate, which is increased in proerythroblasts and myeloblasts in most cases. This could be attributed to an increased number of divisions in early recognizable precursors in the absence of maturation, and (or) an increased influx from the progenitor compartments. (2) The maturation index of a cell lineage was determined by the ratio of relative cell production rate increase from the first to the last proliferative compartment over the corresponding normal value. It showed a high degree of abnormality in all FAB subgroups, indicating premature cell death in the bone marrow. None of the kinetic parameters proved to be of value in predicting the evolution of leukaemia. In contrast, an excellent correlation was found between the myeloid maturation index and survival (P less than 0.0001). No correlation, however, was found between survival and the erythroid maturation index, which was relatively normal in the worst prognostic group. These findings indicate that although in vitro cell kinetic studies can not predict the evolution of overt leukaemia, the myeloid maturation index is a useful predictor of survival in patients with MDS and SML.

Myelodysplastic syndromes: evolution of overt leukaemia by one or several steps of transformation

The evolution of leukaemia was studied prospectively in 29 patients with myelodysplastic syndrome (MDS) followed for 2-6 years by sequential blast counts, cell kinetics derived from quantitative 14C-autoradiography and karyotype analysis. Overt leukaemia developed in seven patients. Two distinct patterns of leukaemic evolution were identified. The first was characterized by a gradual increase in blast cell count and in the frequency of labelled blasts, and a corresponding reduction in myeloid maturation index indicating increased intracompartmental myeloblast divisions and premature myeloid cell death. A second pattern of leukaemic evolution was marked by a sudden rise in the blast cell population in a previously stable MDS. This rise was attributed both to an increased rate of blast proliferation, and the accumulation of non-proliferating blasts. In an additional patient with smouldering ANLL and multiple karyotype abnormalities, transient clinical remission took place following prednisone and oxymetholone therapy, characterized by a sideroblastic morphology, normal karyotype, and persistence of a highly abnormal myeloid maturation index. The sudden emergence of overt leukaemia in previously stable MDS in some of our patients and the temporary reversal of overt leukaemia into sideroblastic anaemia in one case, lend support to the notion of leukaemic evolution by several steps of transformation. On the other hand, the gradual transition of MDS into overt leukaemia in other patients is compatible with a single step leukaemia transformation, although the possibility of clonal disease prior to the development of MDS cannot be excluded with certainty.

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.