Definitions and standards in the diagnosis and treatment of themyelodysplastic syndromes: Consensus statements and
report from a working conference
Peter Valent a,∗, Hans-Peter Horny b, John M. Bennett c, Christa Fonatsch d, Ulrich Germing e,Peter Greenberg f, Torsten Haferlach g, Detlef Haase h, Hans-Jochen Kolb i, Otto Krieger j,
Michael Loken k, Arjan van de Loosdrecht l, Kiyoyuki Ogata m, Alberto Orfao n,Michael Pfeilstocker o, Bjorn Ruter p, Wolfgang R. Sperr a,
Reinhard Stauder q, Denise A. Wells k
a Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna,Waehringer Guertel 18-20, A-1090 Vienna, Austria
b Klinikum Ansbach, Institute of Pathology, Ansbach, Germanyc James P. Wilmot Cancer Center, University of Rochester Medical Center, Rochester, NY, USA
d Institute of Human Genetics (KIMCL), Medical University of Vienna, Vienna, Austriae Department of Hematology Oncology and Clinical Immunology, Heinrich-Heine-University, Dusseldorf, Germany
f Stanford University Cancer Center, Stanford, CA, USAg Munich Leukemia Laboratory (MLL), Munich, Germany
h Department of Hematology and Oncology, Georg-August-University, Gottingen, Germanyi Department of Medicine III, University of Munich, GSF-National Research Centre for Environment and Health, Munich, Germany
j First Department of Internal Medicine, Elisabethinen Hospital, Linz, Austriak Hematologics, Inc., Fred Hutchinson Cancer Research Center, Seattle, WA, USA
l Department of Hematology, VU University Medical Center, Amsterdam, The Netherlandsm Division of Hematology, Department of Medicine, Nippon Medical School, Tokyo, Japan
n Servicio Central de Citometrıa, Centro de Investigacion del Cancer and Department of Medicine, Universidad de Salamanca, Spaino Ludwig-Boltzmann Institute for Leukemia Research and Hematology, Vienna, Austria
p Department of Hematology/Oncology, Albert-Ludwigs University (ALU), Freiburg, Germanyq Division of Hematology and Oncology, Innsbruck Medical University, Innsbruck, Austria
Accepted 14 November 2006Available online 25 January 2007
bstract
The classification, scoring systems, and response criteria for myelodysplastic syndromes (MDS) have recently been updated and haveecome widely accepted. In addition, several new effective targeted drugs for patients with MDS have been developed. The current articlerovides a summary of updated and newly proposed markers, criteria, and standards in MDS, with special reference to the diagnostic interfacend refinements in evaluations and scoring. Concerning the diagnostic interface, minimal diagnostic criteria for MDS are proposed, andor patients with unexplained cytopenia who do not fulfill these criteria, the term ‘idiopathic cytopenia of uncertain significance’ (ICUS) isuggested. In addition, new diagnostic and prognostic parameters, histopathologic and immunologic determinants, proposed refinements incoring systems, and new therapeutic approaches are discussed. Respective algorithms and recommendations should facilitate diagnostic and
rognostic evaluations in MDS, selection of patients for therapies, and the conduct of clinical trials.
Myelodysplastic syndromes (MDS) represent a hetero-eneous group of myeloid neoplasms characterized bybnormal differentiation and maturation of myeloid cells,one marrow (bm) failure, and a genetic instability withnhanced risk to transform to acute myeloid leukemiaAML). MDS are classified according to their etiology (pri-ary = de novo; or following a known mutagenic event =
econdary), cytologic features of bm and blood cells, andpecific karyotypes.
A most useful classification system, that has been applieduccessfully, was the proposal of the French–American–ritish (FAB) cooperative study group [1]. This proposal
s primarily based on morphologic criteria. More recently,he World Health Organization (WHO) has worked out anpdated classification that represents an extension of theAB proposal, with several modifications, which include theemoval of RAEB-T (now considered to belong to the AMLection) and of chronic myelomonocytic leukemia (now in
DS/MPD-interface group), recognition of the impact ofultilineage dysplasia in RA and RARS, and delineation of a
ytogenetically defined subvariant, the 5q− syndrome [2,3].However, in any particular WHO category, the progno-
is and clinical course vary among patients. Whereas someransform to leukemia or die from complications of bm fail-re within a short time, other MDS patients survive for yearsithout major clinical problems. Therefore, during the past
ew decades, a number of attempts have been made to estab-ish scoring systems that can more accurately predict therognosis concerning survival and evolution to AML [3–5].hese systems were based on multiple prognostic parame-
ers such as the percentage of blasts, karyotype, and numberf cytopenias. In 1997, the International Prognostic Scoringystem (IPSS) has been introduced [4]. This score system hasecome the gold standard for risk assessment in patients withe novo MDS, and is widely used for stratification in clinicalrials as well as for patient-selection in clinical practice.
However, despite the availability of the WHO classifica-ion and the IPSS, there remains a need to further improveiagnostic and prognostic scores and to define standards forvaluations, patient selection, and for the use of targeted drugsn the various subgroups of MDS. This is important becausef the complexity of the disease and the increasing numberf emerging targets and therapeutic approaches. In addition,any concepts and algorithms are based on FAB variants, anday not count in the same way when patients are evaluated
sing the WHO or IPSS score.To address these issues, a number of efforts and projects
re currently in progress—many of them conducted inell-recognized expert panels, such as the US Nationalomprehensive Cancer Network (NCCN), the International
orking Group (IWG), or the European Leukemia Net
ELN). We report on a Working Conference on MDS, con-ened in the Year 2006, which included representatives fromhese groups. In this workshop, current criteria and standards
(maR
rch 31 (2007) 727–736
n MDS were discussed and are presented as a consensuserein. In addition, potential forthcoming standards wereiscussed.
. Definition of MDS and minimal diagnostic criteria
MDS are defined as a group of myeloid neoplasms charac-erized by bm failure with peripheral cytopenia and morpho-ogic dysplasia in one or more of the following hematopoieticell lineages: (i) erythroid cells (also ringed sideroblasts15% considered diagnostic), (ii) neutrophils and their pre-ursors, and (iii) megakaryocytes. Respective criteria wereriginally established by the FAB study group [1] and laterere adopted with modifications by the WHO [2].In most patients, it is thus straightforward to diagnose
DS on the basis of WHO criteria. However, in manyases with cytopenia(s), it may be quite difficult to estab-ish (or exclude) the diagnosis MDS. These may be patientsithout a cytogenetic abnormality and only mild cytopenia,atients with a typical karyotype and cytopenia but only slightr absent dysplasia, or patients with transfusion-dependentacrocytic anemia without karyotype abnormalities andithout diagnostic dysplasia.To assist in these situations, minimal diagnostic cri-
eria sufficient to call a condition MDS, were discussednd presented as a consensus-proposal. This proposal isased on two ‘prerequisite-type criteria’ (both must beulfilled), at least one (out of 3) additional MDS-relateddecisive) criterion, and several co-criteria (Table 1). Diag-ostic prerequisites are (a) marked and constant cytopenia≥6 months unless cytogenetic studies reveal MDS) in at leastne of the following hematopoietic cell lineages: erythroidells (<11 g dL−1), neutrophil granulocytes (<1500 �L−1),latelets (<100,000 �L−1) and (b) exclusion of another clonalr non-clonal hematopoietic disease or non-hematopoieticisease as primary reason for cytopenia or/and dysplasia. Inddition, at least one of the following decisive criteria (i)–(iii)ust be fulfilled to call a condition MDS: (i) morphologic
ysplasia in at least 10% of all cells in one or more of theollowing cell lineages in the bm smear: (a) erythroid cells>15% ringed sideroblasts also counts as criterion of ery-hroid dysplasia), (b) neutrophils and their precursors, (c)egakaryocytes; (ii) typical cytogenetic abnormality (recur-
ently reported to occur in MDS); (iii) a constant blast cellount of 5–19%. In patients with ‘subdiagnostic’ or question-ble results in (i)–(iii) (e.g. atypical chromosome aberration,ysplasia in <10% of cells, 4% blasts, etc.) but otherwise typi-al MDS-related clinical findings (e.g. transfusion-dependentacrocytic anemia), additional tests (co-criteria) can be
pplied and may help in reaching the conclusion the patientas a clonal myeloid neoplasm with bm failure resembling
highly suspective of) MDS (Table 2). Such additional testsay include flow cytometry, HUMARA-assay, gene chip
nalysis, colony-forming assay, and mutation analysis (e.g.AS mutations). The likelihood of MDS may increase with
P. Valent et al. / Leukemia Research 31 (2007) 727–736 729
Table 1Minimal diagnostic criteria in MDSa
(A) Prerequisite criteriaConstant cytopenia in one or more of the following cell lineages:
erythroid (hemoglobin <11 g dL−1); neutrophilic(ANC < 1500 �L−1) or megakaryocytic (platelets <100,000 �L−1)
Exclusion of all other hematopoietic or non-hematopoietic disorders asprimary reason for cytopenia/dysplasiab
(B) MDS-related (decisive) criteriaDysplasia in at least 10% of all cells in one of the following lineages in
the bone marrow smear: erythroid; neutrophilic; or megakaryocyticor >15% ringed sideroblasts (iron stain)
5–19% Blast cells in bone marrow smearsTypical chromosomal abnormality (by conventional karyotyping or
FISH)c
(C) Co-criteriad (for patients fulfilling ‘A’ but not ‘B’, and otherwiseshow typical clinical features, e.g. macrocytic transfusion-dependentanemia)
Abnormal phenotype of bone marrow cells clearly indicative of amonoclonal population of erythroid or/and myeloid cells,determined by flow cytometry
Clear molecular signs of a monoclonal cell population in HUMARAassay, gene chip profiling, or point mutation analysis (e.g. RASmutations)
Markedly and persistently reduced colony-formation (±clusterformation) of bone marrow or/and circulating progenitor cells(CFU-assay)
a The diagnosis MDS can be established when both prerequisite criteriaand at least one decisive criterion are fulfilled. If no decisive criterion isfulfilled, but the patient is likely to suffer from a clonal myeloid disease,co-criteria should be applied and may help in reaching the conclusion thepatient has MDS or a condition called ‘highly suspective of MDS’.
b As more patients with two co-existing bone marrow neoplasms are diag-nosed it is important to state that in a few cases, MDS can be diagnosed evenif another co-existing disease potentially causing cytopenia was detected.
c Typical chromosome abnormalities are those that are recurrently foundin MDS (+8, −7, 5q−, 20q−, others). If the abnormal karyotype is the onlydecisive criterion, the condition should be considered as ‘highly suspectiveof MDS’.
d Co-criteria are not considered to be used as standard in the routine hema-tmi
ta(lsl(st
3s
c(
Table 2Idiopathic cytopenia of uncertain (undetermined) significance (ICUS)
(A) DefinitionCytopenia in one or more of the following cell lineages (for ≥ 6
MDS excluded (see ‘B’ and ‘C’)All other causes of cytopenia also excluded (see ‘B’ and ‘C’)
(B) Initial investigations required to establish the diagnosis of ICUSDetailed case history (toxins, drugs, mutagenic events, etc.)Thorough clinical investigations including X-ray and sonography of
spleenDifferential blood count (microscopic) and complete serum chemistryBone marrow histology and immunohistochemistryBone marrow smear including an iron stainFlow cytometry of bone marrow and peripheral blood cellsChromosome analysis including FISHa
Molecular analysis where appropriate (e.g. T cell receptorrearrangement—neutropenia)
Exclusion of viral infections (HCV, HIV, CMV, EBV, others)
(C) Recommended investigations in the follow-upBlood count and differential count as well as serum chemistry in 1–6
months intervalsIn those in whom suspicion for MDS becomes evident: bone marrow
C
(hwppcMices
cbhs
4
bt[teo
ologic work up in all centers. If not available, questionable cases should beonitored and repeated tests be performed to establish the diagnosis MDS
n the follow-up.
he number of abnormalities found in such assays, but in thebsence of morphologic dysplasia or an increase in blastsin the follow-up), the diagnosis MDS should not be estab-ished. If such assays (for co-criteria) are not available orhow negative results, the recommended standard is to fol-ow the clinical course and to repeat diagnostic tests after ain) certain time interval(s). Patients with an increase in blastshould also be followed carefully after diagnosis as some ofhese patients may rapidly progress into AML.
. Idiopathic cytopenia of uncertain (undetermined)ignificance (ICUS)
Cytopenia in one or more myeloid lineages (erythro-ytes, neutrophils, platelets) that is (i) constant (≥6 months),ii) does not meet the (minimal) criteria of an MDS and
iii) cannot be explained by any other hematologic or non-ematologic disease is termed ICUS (Table 2), a term thatas also proposed by Dr. G. Mufti (8th International Sym-osium on MDS, Nagasaki, Japan, 2005). In some of theseatients, the type of cytopenia (transfusion-dependent macro-ytic anemia) may point to the potential of an MDS or anDS-prephase. These patients should then be carefully mon-
tored and repeated tests be performed in the follow-up toonfirm or exclude MDS. If suspicion for MDS becomesvident from the routine follow-up, a repeat bm examinationhould be performed.
At initial presentation, it is standard to perform a suffi-ient hematologic investigation in all patients, including am trephine biopsy with appropriate histology and immuno-istochemistry, bm smear-examinations with Romanowskytain and iron stain as well as cytogenetics (Table 2).
. The bone marrow and peripheral blood smear
The examination of an appropriately prepared and stainedm and peripheral blood smear remains the most impor-ant diagnostic approach in patients with (suspected) MDS1–3]. For proper morphologic assessment, well-preparedhin films (bm films containing particles at the feathereddge) are required. An excellent Romanowsky stain (MGGr WG stain) should be utilized that has a good balance
etween the azur dyes to identify the cytoplasmic gran-les and basophilic cytoplasm. Overstaining on thick smearsesults in all cells resembling each other, and understainingrevents the separation of the major cell lines as well (and
Table 3AValue of bone marrow histology in MDS (and recommended test)
Separation from AML when smears are contaminated with blood cells(CD34-IHC)
Separation from hypoplastic AML (CD34-IHC)Separation from Aplastic AnemiaMultifocal accumulations of (CD34+) progenitor cells (CD34-IHC)a
Abnormal distribution/localization of CD34+ progenitor cells, ALIP(CD34-IHC)a
Abnormal accumulation and morphology of megakaryocytes (IHC: CD31,CD42, or CD62)
Demonstration of bone marrow fibrosis (Gomori’s silver impregnation)Demonstration of increased angiogenesis (CD34-IHC)Diagnosis of a second (concomitant) myelogenous neoplasmDiagnosis of hypocellular MDSDiagnosis of MDS-U and SM-MDSDemonstration of cytogenetic markers by in situ-FISH when no
a Since abnormal distribution/localization cannot be discriminated fromrandom multifocal accumulation of CD34+ cells, the proposal is to mergebt
M
i8rtimm
oTftca
eTtaaCt
mseie
30 P. Valent et al. / Leukemi
ay mimic hypogranulated neutrophils). An iron stain of thespirate (Perl’s reagent) with a nuclear counterstain should beerformed in all cases to identify sideroblasts. For an accu-ate differential count, at least 500 nucleated cells should beounted in the bm smear. In each case, the cellularity of themear, erythroid-to-myeloid (E–M) ratio, and the percentagef blasts should be reported. In cases where the E–M ratios 1:1 or greater, one should count 500 non-erythroid cells,liminating lymphocytes, plasma cells, and mast cells. Also,hen the E–M ratio is 1:1 or greater, the percentage of blasts
s based on the non-erythroid component.If more than 10% of cells in the erythroid, neutrophil
ranulocytic, or megakaryocytic lineage in the bm smearhow dysplasia, the diagnosis MDS can be established pro-ided that cytopenia is present and other diseases have beenxcluded as sole reason for dysplasia/cytopenia (note, how-ver, that a co-existing myelogenous disease per se does notxclude MDS!). The demonstration of >15% ringed sider-blasts is also considered a diagnostic sign of erythroidysplasia [1]. The diagnosis MDS can be established in suchases even if morphologic dysplasia is found in less than 10%f cells.
A number of morphologic criteria for the various cellsecorded in MDS are available. Myeloblasts can be dividednto non-granulated blast cells and blast cells with granules.n routine diagnostics, it is not required to report on thearious subtypes of blast cells.
Apart from the bm, it is also important to review theeripheral blood smear in all cases with MDS and to reportorphologic features of myeloid cells (Pseudo-Pelger-Huet
orms, hypogranulated neutrophils, others) and the differen-ial count in all cases.
. Bone marrow histology andmmunohistochemistry in MDS: standards andecommendations
A histologic examination of the bm is recommended inll patients with suspected MDS [6–9]. In those in whomCUS is diagnosed, the bm histology is essential to exclude annderlying ‘occult’ myelogenous neoplasm (e.g. mastocyto-is, lymphoma, others) or other non-hematopoietic disorderse.g. gelatinous transformation of the bone marrow; certainnfectious diseases such as leishmaniosis; metastasis).
In patients with established MDS, the bm histology mayield important diagnostic information and features, such asm fibrosis, small clusters of immature (CD34+) progeni-or cells, increased angiogenesis, or a hypocellular marrowTable 3A) [6–12]. The IHC-based determination of the per-entage of CD34+ progenitor cells in the bm is importanthen the bm smear is contaminated with peripheral blood
ells.For diagnostic evaluation, the bm biopsy specimen is usu-
lly obtained from the posterior iliac spine and should be ofdequate length (≥1.5 cm). The specimen should be fixed
otCa
oth terms into ‘multifocal accumulation’ of CD34+ cells and to avoid theerm ‘ALIP’.
b Currently, in situ-FISH is not a standard in the evaluation of (suspected)DS.
n neutral formalin, decalcified in editic acid for at leasth, and embedded in paraffin-wax. Recommended standard
outine stains include H&E, Giemsa, Prussian blue, naph-ol AS-D chloroacetate esterase (CAE), and Gomori’s silvermpregnation. CAE is of superior value for detection of even
inor alterations of the microarchitecture of the bm includinginute infiltrates of CAE-negative cells (e.g. blasts).The bm cellularity should be determined as percentage
f bm section-area according to the standard proposed byuzuner and Bennett with recognition of age-dependent dif-erences in cellularity [13,14]. It is therefore recommendedhat the pathologist determines the cellularity as ‘normo-ellular’, ‘hypocellular’, or ‘hypercellular’, based on ange-adapted estimate.
The application of immunohistochemical (IHC) mark-rs is recommended in all patients with (suspected) MDS.he minimal panel recommended includes CD34 (progeni-
or cells), a megakaryocyte marker (CD31, CD42, or CD61),nd tryptase (mast cell-related antigen). In difficult cases,dditional lineage-specific antibodies such as CD3, CD20,D25, CD117, or others, should be employed depending on
he differential diagnosis (Table 3B).When employing CD34 as a progenitor-related IHC
arker in MDS [8–10], the additional labelling of larger andmaller blood vessels has to be taken into account, whichnables reporting on angiogenesis. If the microvessel densitys high, it may then be difficult to differentiate blast cells fromndothelium, i.e. to give an exact estimate on the percentage
f CD34+ progenitor cells. Another limitation of CD34 ishat in a few patients with MDS, progenitor cells may beD34-negative. In such cases, CD117 can be applied as anlternative (Table 3B). Nevertheless, in most cases, it is a
Table 3BRecommended immunohistochemical markers in MDS
Marker(s) Cell type(s)
(A) Minimal panelCD34a Blast cells, progenitors, endothelial cellsCD31 or CD42 or CD62 MegakaryocytesTryptasea Mast cells, basophils, myeloid progenitors
(B) Extended panel—according to the cell lineage to be examinedCD3 T cellsCD15b Monocytes, granulocytesCD20 B cellsCD25 T and B cell subset, atypical mast cellsCD38 Plasma cellsCD68, CD68Rb Monocytes, macrophages, myeloid cellsLysozymeb Monocytes, macrophagesCD117a Progenitor cells, mast cells2D7, BB1 Basophils
a In a very few cases of MDS, blasts cell may be CD34-negative cells.In such situation, CD117 can be applied as an alternative, whereas tryptaseusually is negative or shows only a weak reactivity with blast cells.
im
sucicbkio
niiCibterdc
ecIsom
cmlIC
pi[
6r
sauaio
ltrc
caodtFtadcaabapisbtp
otccTcuseo
b Monocyte/macrophage markers may be helpful to discriminate betweenmmature monocytic cells and blast cells (CMML vs. AML). Otherwise,
onocytic markers are not recommended in MDS.
traightforward approach to count progenitor cells (blasts)sing antibodies against CD34 [8–10]. Thus, such antibodiesan be used for detection of even a slight diffuse increasen blast cells, and for assessment of small compact blastell infiltrates that may escape cytological investigation inm smears. The estimated percentage of CD34+ progenitors,nown to be of prognostic significance, should be reportedn each case. This is also of importance when investigationsf bm aspirates did not show conclusive results.
A number of previous studies have reported on the diag-ostic and prognostic value of an ‘atypical localization ofmmature progenitor cells’ (ALIP) in MDS [7]. These stud-es have recently been confirmed using antibodies againstD34. Thus, antibodies against CD34 can assist in report-
ng on ALIP. However, the term ALIP may not be optimalecause contrasting the initial definition of ALIP (no vicinityo vessels or endosteal surfaces), the vicinity of a vessel orndosteal surface can usually not be excluded. Therefore, weecommend to avoid the term ‘ALIP’, and to replace it byescribing ‘multifocal accumulations of CD34+ progenitorells’ in pathology reports.
Megakaryocyte markers (e.g. CD31, CD42, or CD62)nable the detection of an atypical accumulation (grouping orlustering) and cytomorphological atypia of megakaryocytes.n fact, in almost all patients with MDS, megakaryocyteshow cell atypia and abnormal distribution [6]. In contrast tother bm cells, it is possible to assess cytological atypia ofegakaryocytes in adequately processed bm sections.Tryptase IHC is useful to detect loosely scattered mast
ells which are increased in almost all cases of MDS and
ay show spindle-shape appearance [15,16]. Serum tryptase
evels are also elevated in a group of patients with MDS [17].f mast cells form compact clusters in the bm and/or expressD25, or tryptase levels are very high, it is appropriate to
i[o
rch 31 (2007) 727–736 731
erform mutation analysis of KIT. In such cases, a coex-sting mastocytosis (occult mastocytosis) may be detected15,16].
. Karyotyping in MDS: current standards andecommended procedures
Conventional karyotyping employing different chromo-ome-banding techniques (G-, Q-, and R-banding) remainsn integral component and standard in the diagnostic workp of patients with (suspected) MDS [18–20]. By consensus,t least 20–25 bm metaphases should be examined. In certainnstances (clear-cut demonstration of clonal aberrations), 20r even 10 metaphases may be sufficient.
Karyotypes should be reported according to ISCN guide-ines [21]. Based on these guidelines, a clone is defined bywo bm cells showing the same gain of chromosomal mate-ial or the same structural aberration, or by at least three bmells showing loss of the same chromosome [21].
In questionable cases (e.g. low number of metaphases inonventional karyotyping; or ICUS versus low risk MDS),dditional fluorescence in situ hybridization (FISH) is rec-mmended as a second step and should then count in theemonstration of a clone [22–24] with the same diagnos-ic criteria that are used for conventional karyotyping. SuchISH investigations should include probes covering (at least)
he following regions: 5q31, CEP7, 7q31, CEP8, 20q, CEPY,nd p53. Clonality by FISH is proven on the basis of theiagnostic cut off defined by the sensitivity of the probe. Inase of small percentages (5–10%) of ‘FISH-positive’ cells,repeat analysis of the bm should be recommended. If avail-ble, multicolor FISH (mFISH; 24-color FISH, SKY) cane performed to better characterize marker chromosomesnd complex aberrations [24]. However, mFISH must beerformed on metaphases after culturing bm cells, whereasnterphase FISH can also be performed on bm smears. Inelect cases, i.e. if no bm material is available, peripherallood cells may be examined. Note, however, that if a nega-ive result is obtained from the blood, this does not exclude theresence of karyotype abnormalities in bone marrow cells.
In a group of patients, clonal evolution with developmentf one or more subclones is reported. A subclone is defined byhe presence (occurrence) of additional (so-called secondary)hromosome aberrations in at least 2 or 3 cells (of the entirelone) according to the definition of clonality (see above).he occurrence of a population of bm cells with independenthromosomal abnormalities is rarely seen. In these cases it issually impossible to define whether these cells represent aubclone (of an original neoplastic stem cell clone that did notxhibit any of the later acquired chromosomal abnormalities)r represent a new clone.
A complex aberrant karyotype is defined by at least threendependent chromosome aberrations in at least two cells18–21]. The complex karyotype may also include subclonesr even independent clones which by themselves may show
aIiCmpmvcdachanges may help in discriminating a normal/reactive bmfrom a clonal myeloid malignancy (e.g. ICUS versus low riskMDS/RA). Whereas a single phenotypic abnormality shouldnot be regarded as indicative, the likelihood of a myeloid
Table 4Recurrent phenotypic abnormalities detected by flow cytometry in MDS
CD34+ myeloid progenitorsAbsolute and relative increase in CD34+ cellsExpression of CD11ba and/or CD15Lack of expression of CD13, CD33, or HLA-DRExpression of ‘lymphoid’ antigens: CD5, CD7, CD19, or CD56Decreased CD45 expressionAbnormal increased or decreased intensity of CD34Abnormally decreased CD38 expression
CD34+ B cell progenitors (CD34+/CD10+)Absolute and relative (to all CD34+) decrease in CD34+/CD10+ cells
Maturing myeloid (neutrophil) cellsHypogranularity as evidenced by decreased right angle light scatterAbnormalities in relationship patterns of myeloid antigensAsynchronous maturationLack of expression of CD13 or CD33Expression of CD34Expression of ‘lymphoid’ antigensDecreased CD45 expression
MonocytesAbnormalities in relationship patterns of HLA-DR, CD11b, CD13,
CD14, CD33Lack of expression of CD13, CD14, CD16, or CD33Expression of CD34Expression of ‘lymphoid’ antigens (with the exception of CD4)
Erythroid precursor cells
32 P. Valent et al. / Leukemi
complex chromosome pattern (three or more abnormali-ies). In this regard it is also noteworthy that the ‘complexaryotype group’ of MDS patients may consist of severalubgroups reflecting different ‘degrees of complexity’, andhus a variable prognosis.
During the follow-up of patients with MDS, karyotyp-ng should be considered in case of suspected progression.n certain instances (e.g. when it is important to recognizedrogression as soon as possible) it may be preferable to per-orm karyotyping every 6–12 months. A comparison withhe original karyotype may reveal cytogenetic evidence oflonal evolution. Although the exact prognostic impact ofach of the acquired chromosomal defect in MDS remainsnknown, it is generally appreciated that karyotype evolutions associated with disease progression.
Moreover, karyotyping at diagnosis is a most importantrognostic approach and therefore has been included in sev-ral prognostic scoring systems including the IPSS.
The use of new effective drugs has recently led to anpdated formulation of response criteria in MDS, includ-ng a ‘complete cytogenetic response’ that may be seen inq− patients treated with lenalidomide or those who receiventensive chemotherapy.
. Molecular typing and point mutation analysis inDS
In recent years, gene expression profiling (GEP) based onicroarray analysis has been introduced as a powerful new
ool in leukemia research. However, little is known so farbout the potential value of gene chip profiling in MDS. Firstata suggest that microarray-based GEP (performed withD34+ or CD133+ cells) can define specific and prognosti-ally relevant gene signatures that may correlate with FAB-,
HO-, or IPSS subtypes [25,26]. However, there may be aonsiderable overlap in gene expression profiles, when highisk MDS are compared with secondary AML, or low risk
DS with control samples (normal bm). Nevertheless, in aroup of patients, microarray analysis may help in reachinghe conclusion the patient is suffering from a clonal myeloidisorder. In patients with otherwise typical clinical featurese.g. transfusion-dependent macrocytic anemia), such ‘mon-clonal’ pattern together with other co-criteria may lead tohe conclusion the condition is ‘highly suspective of MDS’.n addition, GEP may help to predict responses to therapiesn MDS in the future. All in all, GEP is an exciting new toolnd may become a future diagnostic approach in MDS, buturther studies are required to define the exact diagnostic andrognostic impact of GEP.
In certain clinical situations, mutation analysis seems use-ul as a diagnostic approach in MDS. Examples for such
nvestigations are suspected associated systemic mastocy-osis (screen for KIT mutation D816V) [15,16] or MDSith marked thrombocytosis, where molecular analysis may
eveal the V617F Jak-2 mutation [27,28]. This mutation has C
rch 31 (2007) 727–736
een described to occur in a few patients with MDS includ-ng a small subgroup of 5q− patients [28]. In other cases, theetection of Jak-2 V617F (together with other features) mayead to the conclusion the patient is suffering from an overlapyndrome (MDS/MPD).
. Flow cytometry in MDS
A number of recent data suggest that flow cytometry canssist in the diagnosis and prognostication in MDS [29–32].n the diagnostic work up in suspected MDS, flow cytometrys of value in the quantitative and qualitative assessment ofD34+ progenitor cells (blasts), maturing myeloid cells, andonocytes. Results from quantitative assessments may be of
articular value when bm smears are of suboptimal quality orissing, or monocytic cells are extremely immature (CMML
ersus AML). Qualitative features may help in reaching theonclusion the patient is suffering from a clonal myeloidisorder [29–32]. In fact, although no marker-abnormalitynd no abnormal marker profile is specific for MDS, such
Abnormal expression of CD45Expression of CD34Abnormal expression of CD71, CD117, or CD235a
a Note: (immature) basophils may also co-express some CD34 withD11b.
eoplasm increases with the number of phenotypic devia-ions. However, the final diagnosis of MDS has to be basedn additional (clinical and laboratory) features/criteria. Aummary of repeatedly described phenotypic abnormalitiesn the various myeloid lineages in MDS is depicted inable 4.
Apart from the value of flow cytometry as a diagnosticool, phenotyping may also assist in prognostication in MDS30–32]. In particular, a number of recent studies have shownhat phenotypic abnormalities in MDS correlate with prog-osis. In addition, flow cytometry may improve currentlyvailable prognostic scoring systems [30]. Larger prospec-ive multicenter studies are required, however, to define therecise value of flow cytometry as a generally applicable stan-ard of prognostication in MDS. Thus, a current disadvantagef flow cytometry in MDS is that no generally accepted con-ensus on uniformly used standard protocols and techniquess available. Therefore, the most important aim for the futures to develop multi-center projects with the aim to standard-ze and harmonize methodologies and reagents, in order toncrease the general impact and awareness of this importantpproach, and to facilitate its use as a general standard inlinical practice and trials.
. Risk scoring systems in MDS: proposedefinement of the IPSS and forthcoming scores
A number of risk factors concerning survival and AML-evelopment have been identified in the past [1–5]. Forome of these factors, like age, the prognostic impact onurvival may be quite different from the impact on AMLevelopment. Still, however, all score approaches in use rep-esent unidirectional systems without evaluating these twond points separately. In 1997, the international prognos-ic scoring system (IPSS) was introduced [4]. This scoringystem represents the gold standard in prognostication in
DS. However, despite the generally accepted value of thePSS, additional refinements have been proposed. Here, onemportant aspect is that additional well-established prognos-ic variables, such as the lactate dehydrogenase (LDH), haveot been included in the IPSS. Interestingly, an elevated LDHplits each IPSS-category into two prognostically differentubgroups [33,34].
So far, it also remains unknown whether the IPSS scoringystem can be applied to all groups of patients diagnosedccording to the WHO classification in the same way as itas been described for patients diagnosed according to FABriteria.
A potential new forthcoming scoring system may behe recently proposed WHO-adjusted (WPSS) scoring sys-em that includes transfusion dependence as an important
ariable. However, all these proposed refinements and newcores have to be validated against the IPSS in forth-oming studies before they can be generally accepted astandard.
wMQa
rch 31 (2007) 727–736 733
0. Non-intensive therapy in MDS, predictive scores,nd response criteria
In patients with low risk MDS who are not consideredor intensive therapy, the most important goal is to maintainuality of life (QOL) [35–38] and to prevent transfusion-elated morbidity and mortality, mostly resulting from ironverload, which may become apparent when the number ofBC transfusions exceeds 20–40 and serum ferritin levelsxceed 1500–2000 ng mL−1. In patients with high risk MDSho are not considered for intensive therapy, major goals are
o counteract disease progression using palliative, targeted,r experimental drugs and to manage the consequences ofhrombocytopenia and neutropenia [35–38]. Again, main-enance of QOL is a most important goal in these patients35–38].
Erythropoietin (EPO) with or without additional G-CSFs considered standard for treatment of low risk or INT-
patients with transfusion-dependent anemia in whomndogenous EPO levels and the frequency of transfusionsre low [39–42]. Respective criteria for patient selection arevailable [39–41]. Recently, long-acting EPO (darbepoetin-lpha) has been introduced in the therapy of MDS withncouraging first results [42].
In chronically transfused MDS patients, the directpproach to counteract iron overload is continuous treat-ent with iron-chelating agents such as desferoxamine,
eferiprone (L1), or deferasirox (ICL670), the latter tworugs being administered orally [43].
In patients with recurrent or refractory neutropenic infec-ions, therapy with G-CSF is usually recommended. GM-CSF
ay be considered as alternative. In special situations (highisk for recurrent infections), G-CSF or GM-CSF may alsoe considered as prophylactic drug(s). In addition, as men-ioned above, G-CSF is administered together with EPOn low/intermediate risk patients to augment the erythroidesponse, which may be particularly effective in those suffer-ng from RARS. Otherwise, CSFs are not used routinely in
DS. Recently, thrombopoietic cytokines such as TPO or IL-1 have been introduced in clinical trials in MDS patients withariable effects. However, these cytokines are not consideredtandard of therapy in MDS.
Treatment response criteria defining hematologicmprovement in one or more myeloid lineages (erythroidesponse, neutrophil response, platelet response) are avail-ble and should be applied as standard [44,45]. The initiallyroposed response criteria have recently been updated andodified with important simplifications [45].In low risk patients, response evaluation for iron overload
ay be of importance. Finally, the changes (improvement) inuality of life (QOL) during non-intensive therapy is consid-red a most important parameter to be evaluated in patients
ith (low risk) MDS [38]. Notably, for most patients withDS, the most important effect of therapy is improvement ofOL. Therefore, it is recommended to evaluate QOL before
nd during therapy using appropriate questionnaires and to
nclude QOL scores and response evaluations in clinical prac-ice as well as in investigational trials.
1. Intensive therapy in MDS: current standards
One of the most important question to be addressed inatients with MDS is whether a curative treatment approachhould be considered. When planning intensive therapy, sev-ral important aspects have to be considered:
. For most patients with MDS, the only curative treat-ment approach is hematopoietic stem cell transplantation(SCT). However, this therapy can only be offered to asmall number of patients and is associated with a relativelyhigh risk of transplant-related morbidity and mortality.
. Intensive polychemotherapy can restore normal poly-clonal hematopoiesis in a subset of patients, but can inducelong term disease-free survival in only a few patients,whereas most of them will relapse after a variable timeperiod.
. The natural course of MDS is variable, with survival timesranging from a few months to several years sometimeseven in those who have high risk MDS.
. Comorbidity, age, and other individual factors may influ-ence the outcome of SCT (and of intensive chemotherapy)in patients with MDS. In patients with advanced MDS(IPSS HIGH; >5% blasts), the probability of post-transplant relapse ranges between 10% and 40% [46].
Thus, many different factors may count, and the final deci-ion must always be based on multiple parameters and thendividual situation in each case.
A number of different chemotherapy protocols have beenroposed for the treatment of patients with high risk MDS.ost of these protocols are similar compared to those applied
o patients with AML [46,47]. Using such protocols, a sub-roup of patients with MDS (roughly 50%) enter completeematologic remission (CR). In (young) patients who havechieved CR and have a suitable donor, SCT should then beonsidered as appropriate consolidation.
The optimal timing of SCT (±preceding chemotherapy) inatients with MDS is unknown. Recent data suggest that forOW and INT-1 patients, overall survival can be maximizedhen SCT is delayed, whereas for INT-2 and HIGH patients,
arly SCT is associated with improved survival [48]. In selectatients with low risk MDS, the 3-year survival amounts topproximately 70% using HLA-matched related or unrelatedonors [46]. In unselected, high risk, and comorbid patients,he outcome is clearly worse [48,49]. In many cases, a rea-onable approach may be to start with polychemotherapyn order to reduce the disease-burden and to explore theesponsiveness of the clone and the possibility to introduce
ntensive therapy in the individual patient (tolerability againstntensive therapy). In addition, comorbidity scores are avail-ble that may help to select patients who can benefit fromCT. Regarding age, recent data suggest that in selected
ifau
rch 31 (2007) 727–736
atients over 60 years of age (even up to 70 years), SCTay be performed as a relatively safe approach [46,48–50].nother important issue is optimal conditioning. Here, both
onventional and reduced-intensity/non-myeloablative regi-ens have been used successfully [48,49]. Reduced-intensity
onditioning is associated with a decrease in non-relapseortality and may allow for SCT in older patients [46].Another interesting (albeit experimental) approach is
utologous SCT. This therapy is an option for patients whore young and have entered CR after induction chemotherapy,ut do not have a suitable transplant donor.
Once disease-relapse has occurred in a patient with MDSfter SCT, treatment options are limited. In some patients,e-induction followed by donor lymphocyte infusion may beonsidered [50]. However, if at all seen, remissions usuallyre short lived.
2. Immunosuppressive drugs, new targeted drugs,nd palliative therapy
A number of new drugs and therapeutic concepts haveeen introduced in MDS in the past few decades. Thesenclude low dose chemotherapy, immunosuppressive ther-py, demethylating agents, anti-apoptotic strategies, targetedrugs, anti-cytokine therapy, and differentiation-inducingherapy [51–59]. However, of the many drugs tested, only
few are considered potential standard in MDS. Theserugs include 5-azacytidine (5-Aza), 5-aza-2-deoxycytidinedecitabine), lenalidomide (revlimid), anti-thymocyte globu-in (ATG), and cyclosporin A (CSA). Most of these drugsave been shown to produce major responses in MDS insubgroup of patients. Likewise, lenalidomide has been
escribed to produce major clinical and even cytogeneticesponses in most patients with the 5q− abnormality [59].herefore, today, in 5q− patients with symptomatic ane-ia, lenalidomide is considered first line therapy after a
rial of erythropoietin. ATG ± CSA may work in a sub-roup of (younger) patients with low risk MDS (RA; IPSSNT-1 group) [57,58]. Those presenting with HLADR15,
PNH subclone, or hypoplastic MDS, may have a betterhance to respond [57,58]. Decitabine and 5-azacytidine havehown encouraging results in a group of MDS patients, oftenith major and long-lasting responses [52–56]. In low riskatients, these drugs are only considered when signs of pro-ression occur. In several centers, demethylating agents arelready considered as forthcoming standard of therapy inigh risk MDS, although these drugs did not yet receive reg-lar approval in all countries. An important aspect is thatesponses to demethylating agents are often seen only afterlatency period of several months. Therefore, at least three
ycles of decitabine or 5-azacytidine should be administered
n each case, and thereafter the response be evaluated as basisor the decision to continue therapy. In all patients and withll drugs applied, treatment responses should be measuredsing available response-criteria and respective guidelines.
Apart from the above-mentioned drugs, general supportiveherapy is essential to help maintaining QOL in patients with
DS. Palliative cytoreduction (for patients with leukocyto-is) is usually performed using hydroxyurea. In such cases,he use of experimental drugs and the conduct of clinical tri-ls has to balanced against the overall clinical situation of theatient, age, and QOL.
3. Concluding remarks and future perspectives
The increasing number of tests, markers, targets, and ther-peutic options in MDS is a challenge for the physician.ased on such developments, it is important to revisit and
efine criteria and standards. The current article reports theutcomes of a Working Conference in which these issuesere discussed, with special focus on the diagnostic inter-
ace, minimal diagnostic criteria (potential) refinements inurrent scoring systems, and emerging new diagnostic andherapeutic approaches. It is the hope for the future that theseoncepts will result in the formulation of updated recommen-ations and guidelines, and thus improvement of diagnosisnd treatment in patients with MDS.
cknowledgement
Contributions. All persons listed as co-authors contributedo pre-conference and post-conference discussions (October005 until September 2006) and actively participated in thetandardization Conference (Vienna, 7–9 July 2006). All co-uthors contributed equally by discussing criteria, standards,lgorithms, and recommendations at the Working Confer-nce. In addition, all persons listed as co-authors providedssential input by drafting parts of the manuscript and bypproving the final version of the document.
eferences
[1] Bennett JM, Catovsky D, Daniel MT, Flandrin G, Galton DA, Gral-nick HR, et al. Proposals for the classification of the myelodysplasticsyndromes. Br J Haematol 1982;51:189–99.
[2] Brunning RD, Bennett JM, Flandrin G, Matutes E, Head D, Vardi-man JW, et al. Myelodysplastic syndromes. In: Jaffe ES, Harris NL,Stein H, Vardiman JW, editors. World Health Organization classifica-tion of tumours. Pathology & genetics. Tumours of haematopoietic andlymphoid tissues, vol. 1. Lyon: IARC Press; 2001. p. 62–73.
[3] Bennett JM. A comparative review of classification systems inmyelodysplastic syndromes (MDS). Semin Oncol 2005;32:S3–10.
[4] Greenberg P, Cox C, LeBeau MM, Fenaux P, Morel P, Sanz G, et al.International scoring system for evaluating prognosis in myelodysplas-tic syndromes. Blood 1997;89:2079–88.
[5] Bennett JM, Komrokji RS. The myelodysplastic syndromes: diag-
nosis, molecular biology and risk assessment. Hematology 2005;10:258–69.
[6] Thiele J, Quitmann H, Wagner S, Fischer R. Dysmegakaryopoiesis inmyelodysplastic syndromes (MDS): an immunomorphometric study ofbone marrow trephine biopsy specimens. J Clin Pathol 1991;44:300–5.
[
rch 31 (2007) 727–736 735
[7] Tricot G, De Wolf-Peeters C, Vlietinck R, Verwilghen RL. Bone mar-row histology in myelodysplastic syndromes. II. Prognostic value ofabnormal localization of immature precursors in MDS. Br J Haematol1984;58:217–25.
[8] Horny HP, Wehrmann M, Schlicker HU, Eichstaedt A, Clemens MR,Kaiserling E. QBEND10 for the diagnosis of myelodysplastic syn-dromes in routinely processed bone marrow biopsy specimens. J ClinPathol 1995;48:291–4.
[9] Oriani A, Annaloro C, Soligo D, Pozzoli E, Cortelezzi A, LambertenghiDeliliers G. Bone marrow histology and CD34 immunostaining inthe prognostic evaluation of primary myelodysplastic syndromes. BrJ Haematol 1996;92:360–4.
10] Baur AS, Meuge-Moraw C, Schmidt PM, Parlier V, Jotterand M, Delac-retaz F. CD34/QBEND10 immunostaining in bone marrow biopsies: anadditional parameter for the diagnosis and classification of myelodys-plastic syndromes. Eur J Haematol 2000;64:71–9.
11] Verburgh E, Achten R, Maes B, Hagemeijer A, Boogaerts M, DeWolf-Peeters C, et al. Additional prognostic value of bone marrowhistology in patients subclassified according to the International Prog-nostic Scoring System for myelodysplastic syndromes. J Clin Oncol2003;21:273–82.
12] Lambertenghi-Deliliers G, Annaloro C, Oriani A, Soligo D. Myelodys-plastic syndrome associated with bone marrow fibrosis. LeukLymphoma 1992;8:51–5.
13] Tuzuner N, Bennett JM. Reference standards for bone marrow cellu-larity. Leuk Res 1994;18:645–7.
14] Tuzuner N, Cox C, Rowe JM, Bennett JM. Bone marrow cellularityin myeloid stem cell disorders: impact of age correction. Leuk Res1994;18:559–64.
15] Horny HP, Greschniok A, Jordan JH, Menke DM, Valent P. Chymaseexpressing bone marrow mast cells in mastocytosis and myelodysplas-tic syndromes: an immunohistochemical and morphometric study. JClin Pathol 2003;56:103–6.
17] Sperr WR, Stehberger B, Wimazal F, Baghestanian M, SchwartzLB, Kundi M, et al. Serum tryptase measurements in patients withmyelodysplastic syndromes. Leuk Lymphoma 2002;43:1097–105.
18] Fenaux P. Chromosome and molecular abnormalities in myelodysplas-tic syndromes. Int J Hematol 2001;73:429–37.
19] Steidl C, Steffens R, Gassmann W, Hildebrandt B, Hilgers R, GermingU, et al. Adequate cytogenetic examination in myelodysplastic syn-dromes: analysis of 529 patients. Leuk Res 2005;29:987–93.
20] Haase D, Fonatsch C, Freund M, Wormann B, Bodenstein H, BartelsH, et al. Cytogenetic findings in 179 patients with myelodysplasticsyndromes. Ann Hematol 1995;70:171–87.
21] ISCN. An international system for human cytogenetic nomenclature.Cytogenet Cell Genet 1981;31:5.
22] Cherry AM, Brockman SR, Paternoster SF, Hicks GA, Neuberg D,Higgins RR, et al. Comparison of interphase FISH and metaphase cyto-genetics to study myelodysplastic syndrome: an Eastern CooperativeOncology Group (ECOG) study. Leuk Res 2003;27:1085–90.
23] Bernasconi P, Cavigliano PM, Boni M, Calatroni S, Klersy C, Giardini I,et al. Is FISH a relevant prognostic tool in myelodysplastic syndromeswith a normal chromosome pattern on conventional cytogenetics? Astudy on 57 patients. Leukemia 2003;17:2107–12.
24] Babicka L, Ransdorfova S, Brezinova J, Zemanova Z, Sindelarova L,Siskova M, et al. Analysis of complex chromosomal rearrangementsin adult patients with MDS and AML by multicolor FISH. Leuk Res2007;31:39–47.
25] Hofmann WK, de Vos S, Komor M, Hoelzer D, Wachsman W, Koeffler
HP. Characterization of gene expression of CD34+ cells from normaland myelodysplastic bone marrow. Blood 2002;100:3553–60.
26] Pellagatti A, Esoof N, Watkins F, Langford CF, Vetrie D, CampbellLJ, et al. Gene expression profiling in the myelodysplastic syndromesusing cDNA microarray technology. Br J Haematol 2004;125:576–83.
27] Szpurka H, Tiu R, Murugesan G, Aboudola S, Hsi ED, Theil KS, etal. Refractory anemia with ringed sideroblasts associated with markedthrombocytosis (RARS-T), another myeloproliferative condition char-acterized by JAK2 V617F mutation. Blood 2006;108:2173–81.
28] Ingram W, Lea NC, Cervera J, Germing U, Fenaux P, Cassinat B, etal. The JAK2 V617F mutation identifies a subgroup of MDS patientswith isolated deletion 5q and a proliferative bone marrow. Leukemia2006;20:1319–21.
29] Ogata K, Nakamura K, Yokose N, Tamura H, Tachibana M, TaniguchiO, et al. Clinical significance of phenotypic features of blasts in patientswith myelodysplastic syndrome. Blood 2002;100:3887–96.
30] Wells DA, Benesch M, Loken MR, Vallejo C, Myerson D, LeisenringWM, et al. Myeloid and monocytic dyspoiesis as determined by flowcytometric scoring in myelodysplastic syndrome correlates with theIPSS and with outcome after hematopoietic stem cell transplantation.Blood 2003;102:394–403.
31] Benesch M, Deeg HJ, Wells D, Loken M. Flow cytometry for diag-nosis and assessment of prognosis in patients with myelodysplasticsyndromes. Hematology 2004;9:171–7.
32] Ogata K, Kishikawa Y, Satoh C, Tamura H, Dan K, Hayashi A. Diag-nostic application of flow cytometric characteristics of CD34+ cells inlow-grade myelodysplastic syndromes. Blood 2006;108:1037–44.
33] Wimazal F, Sperr WR, Kundi M, Meidlinger P, Fonatsch C, Jordan JH,et al. Prognostic value of lactate dehydrogenase activity in myelodys-plastic syndromes. Leuk Res 2001;25:287–94.
34] Germing U, Hildebrandt B, Pfeilstocker M, Nosslinger T, Valent P,Fonatsch C, et al. Refinement of the international prognostic scoringsystem (IPSS) by including LDH as an additional prognostic variableto improve risk assessment in patients with primary myelodysplasticsyndromes (MDS). Leukemia 2005;19:2223–31.
35] Valent P, Wimazal F, Schwarzinger I, Sperr WR, Geissler K. Pathogene-sis, classification, and treatment of myelodysplastic syndromes (MDS).Wien Klin Wochenschr 2003;115:515–36.
36] Steensma DP, Bennett JM. The myelodysplastic syndromes: diagnosisand treatment. Mayo Clin Proc 2006;81:104–30.
37] Malcovati L, Porta MG, Pascutto C, et al. Prognostic factors andlife expectancy in myelodysplastic syndromes classified accordingto WHO criteria: a basis for clinical decision making. J Clin Oncol2005;23:7594–603.
38] Thomas ML. Health-related quality of life for those with myelodys-plastic syndrome: conceptualization, measurement and implications.In: Greenberg PL, editor. Myelodysplastic syndromes: clinical and bio-logical advances. Cambridge, UK: Cambridge University Press; 2006.p. 263–95.
39] Hellstrom-Lindberg E, Ahlgren T, Beguin Y, Carlsson M, Carneskog J,Dahl IM, et al. Treatment of anemia in myelodysplastic syndromes withgranulocyte colony-stimulating factor plus erythropoietin: results froma randomized phase II study and long-term follow-up of 71 patients.Blood 1998;92:68–75.
40] Jadersten M, Montgomery SM, Dybedal I, Porwit-MacDonald A, Hell-strom-Lindberg E. Long-term outcome of treatment of anemia in MDSwith erythropoietin and G-CSF. Blood 2005;106:803–11.
41] Bowen D, et al. Guidelines for the diagnosis and therapy of adultmyelodysplastic syndromes. Br J Haematol 2003;120:187–200.
42] Musto P, Lanza F, Balleari E, Grossi A, Falcone A, Sanpaolo G, et
al. Darbepoetin alpha for the treatment of anaemia in low-intermediaterisk myelodysplastic syndromes. Br J Haematol 2005;128:204–9.
43] Greenberg PL. Myelodysplastic syndromes: iron overload conse-quences and current chelating therapies. J Natl Compr Canc Netw2006;4:91–6.
[
rch 31 (2007) 727–736
44] Cheson BD, Bennett JM, Kantarjian H, Pinto A, Schiffer CA,Nimer SD, et al. Report of an international working group tostandardize response criteria for myelodysplastic syndromes. Blood2000;96:3671–4.
45] Cheson BD, Greenberg PL, Bennett JM, Lowenberg B, WijermansPW, Nimer SD, et al. Clinical application and proposal for modifi-cation of the International Working Group (IWG) response criteria inmyelodysplasia. Blood 2006;108:419–25.
46] Deeg HJ. Optimization of transplant regimens for patients withmyelodysplastic syndrome (MDS). Hematol Am Soc Hematol EducProgram 2005:167–73.
47] Hofmann WK, Heil G, Zander C, Wiebe S, Ottmann OG, BergmannL, et al. Intensive chemotherapy with idarubicin, cytarabine, etopo-side, and G-CSF priming in patients with advanced myelodysplasticsyndrome and high-risk acute myeloid leukemia. Ann Hematol2004;83:498–503.
48] Cutler CS, Lee SJ, Greenberg P, Deeg HJ, Perez WS, Anasetti C,et al. A decision analysis of allogeneic bone marrow transplanta-tion for the myelodysplastic syndromes: delayed transplantation forlow-risk myelodysplasia is associated with improved outcome. Blood2004;104:579–85.
49] de Witte T, Hermans J, Vossen J, Bacigalupo A, Meloni G, Jacob-sen N, et al. Haematopoietic stem cell transplantation for patientswith myelodysplastic syndromes and secondary leukemias: a reporton behalf of the Chronic Leukaemia Working Party of the EuropeanGroup for Blood and Marrow Transplantation (EBMT). Br J Haematol2000;110:620–30.
50] Kolb HJ, et al. Graft-versus-leukemia effect of donor lympho-cyte transfusions in marrow grafted patients. Blood 1995;86:2041–50.
51] List AF. New agents in the treatment of MDS. Clin Adv Hematol Oncol2005;3:832–4.
52] Silverman LR, Demakos EP, Peterson BL, et al. Randomized controlledtrial of azacitidine in patients with the myelodysplastic syndrome: astudy of the CALGB. J Clin Oncol 2002;20:2429–40.
53] Ruter B, Wijermans PW, Lubbert M. DNA methylation as a thera-peutic target in hematologic disorders: recent results in older patientswith myelodysplasia and acute myeloid leukemia. Int J Hematol2004;80:128–35.
54] Lubbert M, Wijermans PW. Epigenetic therapy in MDS and acute AML:focus on decitabine. Ann Hematol 2005;84:1–2.
55] Kantarjian H, Issa JP, Rosenfeld CS, et al. Decitabine improves patientoutcomes in myelodysplastic syndromes: results of a phase III random-ized study. Cancer 2006;106:1794–803.
56] Kantarjian H, Oki Y, Garcia-Manero G, Huang X, O’brien S, CortesJ, et al. Results of a randomized study of three schedules of low-dose decitabine in higher risk myelodysplastic syndrome and chronicmyelomonocytic leukemia. Blood 2007;109:52–7.
57] Sloand EM, Greenberg PL, Wu C, Young NS, Barrett AJ. Immunosup-pressive treatment is associated with durable responses and a survivaladvantage in younger patients with Int-1 myelodysplastic syndrome.Proceedings of the American Society of Hematology meeting. Blood2005;106:707a.
58] Saunthararajah Y, Nakamura R, Nam JM, Robyn J, LoberizaF, Maciejewiski JP, et al. HLA-DR15 (DR2) is overexpressed
in myelodysplastic syndrome and aplastic anemia and predicts aresponse to immunosuppression in myelodysplastic syndrome. Blood2002;100:1570–4.
59] List A, et al. Lenalidomide in the myelodysplastic syndrome with chro-mosome 5q deletion. N Engl J Med 2006;355:1456–65.
