Mar Mallo

New Comprehensive Cytogenetic Scoring System for Primary Myelodysplastic Syndromes (MDS) and Oligoblastic Acute Myeloid Leukemia After MDS Derived From an International Database Merge

PURPOSE The karyotype is a strong independent prognostic factor in myelodysplastic syndromes (MDS). Since the implementation of the International Prognostic Scoring System (IPSS) in 1997, knowledge concerning the prognostic impact of abnormalities has increased substantially. The present study proposes a new and comprehensive cytogenetic scoring system based on an international data collection of 2,902 patients. PATIENTS AND METHODS Patients were included from the German-Austrian MDS Study Group (n = 1,193), the International MDS Risk Analysis Workshop (n = 816), the Spanish Hematological Cytogenetics Working Group (n = 849), and the International Working Group on MDS Cytogenetics (n = 44) databases. Patients with primary MDS and oligoblastic acute myeloid leukemia (AML) after MDS treated with supportive care only were evaluated for overall survival (OS) and AML evolution. Internal validation by bootstrap analysis and external validation in an independent patient cohort were performed to confirm the results. RESULTS In total, 19 cytogenetic categories were defined, providing clear prognostic classification in 91% of all patients. The abnormalities were classified into five prognostic subgroups (P < .001): very good (median OS, 61 months; hazard ratio [HR], 0.5; n = 81); good (49 months; HR, 1.0 [reference category]; n = 1,809); intermediate (26 months; HR, 1.6; n = 529); poor (16 months; HR, 2.6; n = 148); and very poor (6 months; HR, 4.2; n = 187). The internal and external validations confirmed the results of the score. CONCLUSION In conclusion, these data should contribute to the ongoing efforts to update the IPSS by refining the cytogenetic risk categories.

Cytogenetic risk stratification in chronic myelomonocytic leukemia

Background The prognostic value of cytogenetic findings in chronic myelomonocytic leukemia is unclear. Our purpose was to evaluate the independent prognostic impact of cytogenetic abnormalities in a large series of patients with chronic myelomonocytic leukemia included in the database of the Spanish Registry of Myelodysplastic Syndromes. Design and Methods We studied 414 patients with chronic myelomonocytic leukemia according to WHO criteria and with a successful conventional cytogenetic analysis at diagnosis. Different patient and disease characteristics were examined by univariate and multivariate methods to establish their relationship with overall survival and evolution to acute myeloid leukemia. Results Patients with abnormal karyotype (110 patients, 27%) had poorer overall survival (P=0.001) and higher risk of acute myeloid leukemia evolution (P=0.010). Based on outcome analysis, three cytogenetic risk categories were identified: low risk (normal karyotype or loss of Y chromosome as a single anomaly), high risk (presence of trisomy 8 or abnormalities of chromosome 7, or complex karyotype), and intermediate risk (all other abnormalities). Overall survival at five years for patients in the low, intermediate, and high risk cytogenetic categories was 35%, 26%, and 4%, respectively (P<0.001). Multivariate analysis confirmed that this new CMML-specific cytogenetic risk stratification was an independent prognostic variable for overall survival (P=0.001). Additionally, patients belonging to the high-risk cytogenetic category also had a higher risk of acute myeloid leukemia evolution on univariate (P=0.001) but not multivariate analysis. Conclusions Cytogenetic findings have a strong prognostic impact in patients with chronic myelomonocytic leukemia.

Impact of adjunct cytogenetic abnormalities for prognostic stratification in patients with myelodysplastic syndrome and deletion 5q.

This cooperative study assessed prognostic factors for overall survival (OS) and risk of transformation to acute myeloid leukemia (AML) in 541 patients with de novo myelodysplastic syndrome (MDS) and deletion 5q. Additional chromosomal abnormalities were strongly related to different patients’ characteristics. In multivariate analysis, the most important predictors of both OS and AML transformation risk were number of chromosomal abnormalities (P<0.001 for both outcomes), platelet count (P<0.001 and P=0.001, respectively) and proportion of bone marrow blasts (P<0.001 and P=0.016, respectively). The number of chromosomal abnormalities defined three risk categories for AML transformation (del(5q), del(5q)+1 and del(5q)+⩾2 abnormalities) and two for OS (one group: del(5q) and del(5q)+1; and del(5q)+⩾2 abnormalities, as the other one); with a median survival time of 58.0 and 6.8 months, respectively. Platelet count (P=0.001) and age (P=0.034) predicted OS in patients with ‘5q−syndrome’. This study demonstrates the importance of additional chromosomal abnormalities in MDS patients with deletion 5q, challenges the current ‘5q−syndrome’ definition and constitutes a useful reference series to properly analyze the results of clinical trials in these patients.

Role of casein kinase 1A1 in the biology and targeted therapy of del(5q) MDS.

The casein kinase 1A1 gene (CSNK1A1) is a putative tumor suppressor gene located in the common deleted region for del(5q) myelodysplastic syndrome (MDS). We generated a murine model with conditional inactivation of Csnk1a1 and found that Csnk1a1 haploinsufficiency induces hematopoietic stem cell expansion and a competitive repopulation advantage, whereas homozygous deletion induces hematopoietic stem cell failure. Based on this finding, we found that heterozygous inactivation of Csnk1a1 sensitizes cells to a CSNK1 inhibitor relative to cells with two intact alleles. In addition, we identified recurrent somatic mutations in CSNK1A1 on the nondeleted allele of patients with del(5q) MDS. These studies demonstrate that CSNK1A1 plays a central role in the biology of del(5q) MDS and is a promising therapeutic target.

Complex, Not Monosomal, Karyotype Is the Cytogenetic Marker of Poorest Prognosis in Patients With Primary Myelodysplastic Syndrome

PURPOSE Complex karyotype (CK) is the poorest risk factor in patients with myelodysplastic syndrome (MDS). It has recently been reported that monosomal karyotype (MK) worsens the prognosis of patients with CK. PATIENTS AND METHODS; We analyzed 1,054 adult patients with MDS with an abnormal karyotype from the Spanish Registry of MDS. The aim of the study was to describe the incidence, characteristics, and prognosis of MK; the main end points were overall survival (OS) and leukemia-free survival. RESULTS MK was identified in 172 patients (16%), most of whom (88%) presented with CK. Variables significantly associated with OS were age (hazard ratio [HR], 1.90; P < .001), bone marrow (BM) blast percentage (HR, 1.05; P < .001), hemoglobin level (HR, 1.71; P < .001), platelet count (HR, 1.41; P < .001), karyotype complexity (CK [three abnormalities]: HR, 1.81; P = .003; very CK [> three abnormalities]: HR, 2; P < .001), and abnormalities of chromosome 5 and/or 7 (HR, 1.89; P < .001). Variables significantly related to the risk of transformation to acute myeloid leukemia (AML) were higher BM blast percentage (HR, 1.12; P < .001) and karyotype complexity (CK: HR, 2.53; P = .002; very CK: HR, 2.77; P < .001). CONCLUSION After accounting for karyotype complexity, MK was not associated with OS or evolution to AML. In conclusion, these results demonstrate that the prognostic value of MK in MDS is not independent and is mainly the result of its strong association with number of chromosomal abnormalities.

Response to lenalidomide in myelodysplastic syndromes with del(5q): influence of cytogenetics and mutations

Lenalidomide is an effective drug in low‐risk myelodysplastic syndromes (MDS) with isolated del(5q), although not all patients respond. Studies have suggested a role for TP53 mutations and karyotype complexity in disease progression and outcome. In order to assess the impact of complex karyotypes on treatment response and disease progression in 52 lenalidomide‐treated patients with del(5q) MDS, conventional G‐banding cytogenetics (CC), single nucleotide polymorphism array (SNP‐A), and genomic sequencing methods were used. SNP‐A analysis (with control sample, lymphocytes CD3+, in 30 cases) revealed 5q losses in all cases. Other recurrent abnormalities were infrequent and were not associated with lenalidomide responsiveness. Low karyotype complexity (by CC) and a high baseline platelet count (>280 × 109/l) were associated with the achievement of haematological response (P = 0·020, P = 0·013 respectively). Unmutated TP53 status showed a tendency for haematological response (P = 0·061). Complete cytogenetic response was not observed in any of the mutated TP53 cases. By multivariate analysis, the most important predictor for lenalidomide treatment failure was a platelet count <280 × 109/l (Odds Ratio = 6·17, P = 0·040). This study reveals the importance of a low baseline platelet count, karyotypic complexity and TP53 mutational status for response to lenalidomide treatment. It supports the molecular study of TP53 in MDS patients treated with lenalidomide.

Monosomal karyotype in MDS: explaining the poor prognosis?

Monosomal karyotype (MK) is associated with an adverse prognosis in patients in acute myeloid leukemia (AML). This study analyzes the prognostic impact of MK in a cohort of primary, untreated patients with myelodysplastic syndromes (MDS). A total of 431 patients were extracted from an international database. To analyze whether MK is an independent prognostic marker in MDS, cytogenetic and clinical data were explored in uni- and multivariate models regarding overall survival (OS) as well as AML-free survival. In all, 204/431 (47.3%) patients with MK were identified. Regarding OS, MK was prognostically significant in patients with ⩽4 abnormalities only. In highly complex karyotypes (⩾5 abnormalities), MK did not separate prognostic subgroups (median OS 4.9 months in MK+ vs 5.6 months in patients without MK, P=0.832). Based on the number of abnormalities, MK-positive karyotypes (MK+) split into different prognostic subgroups (MK+ and 2 abnormalities: OS 13.4 months, MK+ and 3 abnormalities: 8.0 months, MK+ and 4 abnormalities: 7.9 months and MK+ and ⩾5 abnormalities: 4.9 months; P<0.01). In multivariate analyses, MK was not an independent prognostic factor. Our data support the hypothesis that a high number of complex abnormalities, associated with an instable clone, define the subgroup with the worst prognosis in MDS, independent of MK.

Fluorescence in situ hybridization improves the detection of 5q31 deletion in myelodysplastic syndromes without cytogenetic evidence of 5q

The findings of this study indicate that fluorescence in situ hybridization improves the detection of deletion 5q31–32 in patients with myelodysplastic syndrome without cytogenetic evidence of del(5q). See related perspective on page 967. Background More than 50% of patients with myelodysplastic syndromes present cytogenetic aberrations at diagnosis. Partial or complete deletion of the long arm of chromosome 5 is the most frequent abnormality. The aim of this study was to apply fluorescence in situ hybridization of 5q31 in patients diagnosed with de novo myelodysplastic syndromes in whom conventional banding cytogenetics study had shown a normal karyotype, absence of metaphases or an abnormal karyotype without evidence of del(5q). Design and Methods We performed fluorescence in situ hybridization of 5q31 in 716 patients, divided into two groups: group A patients (n=637) in whom the 5q deletion had not been detected at diagnosis by conventional banding cytogenetics and group B patients (n=79), in whom cytogenetic analysis had revealed the 5q deletion (positive control group). Results In group A (n=637), the 5q deletion was detected by fluorescence in situ hybridization in 38 cases (5.96%). The majority of positive cases were diagnosed as having the 5q- syndrome. The deletion was mainly observed in cases in which the cytogenetics study had shown no metaphases or an aberrant karyotype with chromosome 5 involved. In group B (n=79), the 5q deletion had been observed by cytogenetics and was confirmed to be present in all cases by fluorescence in situ hybridization of 5q31. Conclusions Fluorescence in situ hybridization of 5q31 detected the 5q deletion in 6% of cases without clear evidence of del(5q) by conventional banding cytogenetics. We suggest that fluorescence in situ hybridization of 5q31 should be performed in cases of a suspected ‘5q- syndrome’ and/or if the cytogenetic study shows no metaphases or an aberrant karyotype with chromosome 5 involved (no 5q- chromosome).

Acquisition of cytogenetic abnormalities in patients with IPSS defined lower-risk myelodysplastic syndrome is associated with poor prognosis and transformation to acute myelogenous leukemia

We hypothesized that the dynamic acquisition of cytogenetic abnormalities (ACA) during the follow up of myelodysplastic syndromes (MDS) could be associated with poor prognosis. We conducted a retrospective analysis of 365 patients with IPSS low or intermediate‐1 risk MDS who had at least two consecutive cytogenetic analyses during the follow up. Acquisition of cytogenetic abnormalities was detected in 107 patients (29%). The most frequent alteration involved chromosome 7 in 21% of ACA cases. Median transformation‐free and overall survival for patients with and without ACA were 13 vs. 52 months (P = 0.01) and 17 vs. 62 months (P = 0.01), respectively. By fitting ACA as a time‐dependent covariate, multivariate Cox regression analysis showed that patients with ACA had increased risk of transformation (HR = 1.40; P = 0.03) or death (HR = 1.45; P = 0.02). Notably, female patients with therapy‐related MDS (t‐MDS) had an increased risk of developing ACA (OR = 5.26; P < 0.0001), although subgroup analysis showed that prognostic impact of ACA was not evident in t‐MDS. In conclusion, ACA occurs in close to one third of patients with IPSS defined lower risk MDS, more common among patients with t‐MDS, but has a significant prognostic impact on de novo MDS. Am. J. Hematol. 88:831–837, 2013.

Single nucleotide polymorphism array karyotyping: A diagnostic and prognostic tool in myelodysplastic syndromes with unsuccessful conventional cytogenetic testing

Cytogenetic aberrations identified by metaphase cytogenetics (MC) have diagnostic, prognostic, and therapeutic implications in myelodysplastic syndromes (MDS). However, in some MDS patients MC study is unsuccesful. Single nucleotide polymorphism array (SNP‐A) based karyotyping could be helpful in these cases. We performed SNP‐A in 62 samples from bone marrow or peripheral blood of primary MDS with an unsuccessful MC study. SNP‐A analysis enabled the detection of aberrations in 31 (50%) patients. We used the copy number alteration information to apply the International Prognostic Scoring System (IPSS) and we observed differences in survival between the low/intermediate‐1 and intermediate‐2/high risk patients. We also saw differences in survival between very low/low/intermediate and the high/very high patients when we applied the revised IPSS (IPSS‐R). In conclusion, SNP‐A can be used successfully in PB samples and the identification of CNA by SNP‐A improve the diagnostic and prognostic evaluation of this group of MDS patients.