Allogeneic Hematopoietic Cell Transplantation in Advanced Systemic Mastocytosis: A retrospective analysis of the DRST and GREM registries.

We identified 71 patients with AdvSM (aggressive SM [ASM], SM with an associated hematologic neoplasm [SM-AHN, e.g., acute myeloid leukemia, SM-AML], mast cell leukemia [MCL]) in two national registries (DRST/GREM) who received an allogeneic hematopoietic cell transplantation (alloHCT) performed in Germany from 1999-2021. Median overall survival (OS) of ASM/SM-AHN (n = 30, 45%), SM-AML (n = 28, 39%) and MCL ± AHN (n = 13, 19%) was 9.0, 3.3 and 0.9 years (P = 0.007). Improved median OS was associated with response of SM (17/41, 41%; HR 0.4 [0.2-0.9], P = 0.035) and/or of AHN (26/43, 60%, HR 0.3 [0.1-0.7], P = 0.004) prior to alloHCT. Adverse predictors for OS included absence of KIT D816V (10/61, 16%, HR 2.9 [1.2-6.5], P < 0.001) and a complex karyotype (9/60, 15%, HR 4.2 [1.8-10.0], P = 0.016). HLA-match, conditioning type or transplantation at centers reporting above-average alloHCTs (≥7) had no impact on OS. Taking into account competing events at years 1, 3 and 5, relapse-related mortality and non-relapse mortality rate were 15%/23%, 20%/30% and 23%/35%, respectively. Irrespective of subtype, subsequent treatment response was achieved in 13/30 (43%) patients and was highest on midostaurin/avapritinib (7/9, 78%). We conclude that outcome of alloHCT in AdvSM is more affected by disease phenotype and treatment response prior to transplant than by transplant characteristics.

Allogeneic hematopoietic stem cell transplantation and pre-transplant strategies in patients with NPM1-mutated acute myeloid leukemia: a single center experience.

Patients with acute myeloid leukemia (AML) and nucleophosmin 1 gene mutations (NPM1mut) show a favorable prognosis with chemotherapy (CT) in the absence of negative prognostic genetic abnormalities. Between 2008 and 2021 64 patients with NPM1mutAML received alloHSCT because of additional adverse prognostic factors (1st line), inadequate response to or relapse during or after CT (2nd line). To expand the evidence in alloTX in NPM1mut AML, clinical and molecular data were retrospectively analyzed with respect to pre-transplant strategies and outcome. Patients with minimal residual disease negative (MRD-) CR at transplant had better 2-y-PFS and 2-y-OS (77% and 88%) than patients with minimal residual disease positive (MRD+) CR (41% and 71%) or patients with active disease (AD) at transplant (20% and 52%). The 2nd line patients with relapse after completing CT responded well to high dose cytarabine based salvage chemotherapy (salvage CT) in contrast to patients relapsing while still on CT (90% vs 20%, P = 0.0170). 2-y-PFS and 2-y-OS was 86% in patients who achieved a 2nd MRD- CR pre alloHSCT. Outcome in NPM1mutAML depends on disease burden at alloHSCT. Time and type of relapse in relation to CT are predictive for response to salvage CT.

Clinical and Cytogenetic Characterization of Early and Late Relapses in Patients Allografted for Myeloid Neoplasms with a Myelodysplastic Component.

An improved understanding of relapse kinetics is required to optimize detection and treatment strategies for the post-transplant relapse of myeloid neoplasms. Therefore, we retrospectively analyzed data from 91 patients allografted for MDS (n = 54), AML-MRC (n = 29) and chronic myelomonocytic leukemia (CMML, n = 8), who relapsed after transplant. Patients with early (<12 months, n = 56) and late relapse (>12 months, n = 35) were compared regarding patient-, disease- and transplant-related factors, including karyotype analyses at diagnosis and relapse. After a median follow-up of 17.4 months after relapse, late relapses showed improved outcomes compared with early relapses (2-yr OS 67% vs. 32%, p = 0.0048). Comparing frequency of distinct patient-, disease- and transplant-related factors among early and late relapses, complex karyotype (p = 0.0004) and unfavorable disease risk at diagnosis (p = 0.0008) as well as clonal evolution at relapse (p = 0.03) were more common in early than in late relapses. Furthermore, patients receiving transplant without prior cytoreduction or in complete remission were more frequently present in the group of late relapses. These data suggest that cytogenetics rather than disease burden at diagnosis and transplant-related factors determine the timepoint of post-transplant relapse and that upfront transplantation may be favored in order to delay relapse.

Feasibility of Wearable-Based Remote Monitoring in Patients During Intensive Treatment for Aggressive Hematologic Malignancies.

PURPOSE: Intensive treatment protocols for aggressive hematologic malignancies harbor a high risk of serious clinical complications, such as infections. Current techniques of monitoring vital signs to detect such complications are cumbersome and often fail to diagnose them early. Continuous monitoring of vital signs and physical activity by means of an upper arm medical wearable allowing 24/7 streaming of such parameters may be a promising alternative. METHODS: This single-arm, single-center observational trial evaluated symptom-related patient-reported outcomes and feasibility of a wearable-based remote patient monitoring. All wearable data were reviewed retrospectively and were not available to the patient or clinical staff. A total of 79 patients (54 inpatients and 25 outpatients) participated and received standard-of-care treatment for a hematologic malignancy. In addition, the wearable was continuously worn and self-managed by the patient to record multiple parameters such as heart rate, oxygen saturation, and physical activity. RESULTS: Fifty-one patients (94.4%) in the inpatient cohort and 16 (64.0%) in the outpatient cohort reported gastrointestinal symptoms (diarrhea, nausea, and emesis), pain, dyspnea, or shivering in at least one visit. With the wearable, vital signs and physical activity were recorded for a total of 1,304.8 days. Recordings accounted for 78.0% (63.0-88.5; median [interquartile range]) of the potential recording time for the inpatient cohort and 84.6% (76.3-90.2) for the outpatient cohort. Adherence to the wearable was comparable in both cohorts, but decreased moderately over time during the trial. CONCLUSION: A high adherence to the wearable was observed in patients on intensive treatment protocols for a hematologic malignancy who experience high symptom burden. Remote patient monitoring of vital signs and physical activity was demonstrated to be feasible and of primarily sufficient quality.

Guidelines for Myelodysplastic Syndromes: Converting Evidence into Action?

The heterogeneous group of myelodysplastic syndromes (MDS) needs an individualized and patient-tailored therapeutic approach. Consensus-based guidelines for diagnosis and treatment provide a basis for clinical decision making. MDS guidelines are issued by expert panels. Our main objective was to examine how guidelines influence patients' adherence to expert recommendations and how they ensure healthcare quality. To approach this question, we reviewed the most common guidelines for diagnosing and treating MDS in adult patients. Furthermore, we critically looked at quality indicators for everyday practice and studied adherence in an everyday outpatient setting. Finally, we also paid close attention to patient-reported outcome measures and studied how they are used as endpoints in clinical trials. We can conclude that the combination of evidence-based diagnostic tools, standardized treatment recommendations, and patient-centered shared decision making will eventually lead to a healthcare standard that will significantly improve outcomes in adult patients with MDS.

Influence of platelet count at diagnosis and during the course of disease on prognosis in MDS patients.

Thrombocytopenia at diagnosis and platelet drop within the first 6 months have an adverse effect on prognosis of MDS patients. We therefore were interested in the association and impact on prognosis of morphologic findings of megakaryocytes and platelets with platelet count at diagnosis, bleeding complications, and the drop of platelets during the course of disease. This retrospective analysis was based on 334 MDS patients from the Duesseldorf MDS registry that were followed up for blood counts, bleeding, transfusion dependency, and AML evolution and correlated with morphology of the megakaryocytes and platelets. Thrombocytopenia was found more frequently in higher risk MDS and was associated with hypocellularity of the megakaryocytes in the bone marrow. Signs of bleeding were present at diagnosis in 14% and occurred during the disease in 48% of all MDS patients. Death due to bleeding was ranked third behind infections and AML. A decrement of platelets during the first 6 months was associated with an inferior overall survival of 21 vs. 49 months and with a higher cumulative 2-year AML rate of 22.2% vs. 8.3% (p = 0.001). In a multivariate analysis, besides bone marrow blasts and karyotype, decreasing platelets were also associated with an inferior outcome. Signs of bleeding are present in a relevant number of MDS patients and account for significant morbidity and mortality in MDS. We could demonstrate the prognostic importance of decreasing platelets during the course of disease in all MDS patients, identifying patients at higher risk for death or AML progression.

Eligibility for clinical trials is unsatisfactory for patients with myelodysplastic syndromes, even at a tertiary referral center.

Participation in clinical trials may allow patients with MDS to gain access to therapies not otherwise available. However, access is limited by strict inclusion and exclusion criteria, reflecting academic or regulatory questions addressed by the respective studies. We performed a simulation in order to estimate the average proportion of MDS patients eligible for participation in a clinical trial. The simulation drew upon 1809 patients in the Düsseldorf MDS Registry whose clinical data allowed eligibility screening for a wide range of clinical trials. This cohort was assumed to be alive and available for study participation. The simulation also posited that all MDS trials (n = 47) conducted in our center between 1987 and 2016 were open for recruitment. In addition, study activities in the year 2016 were analyzed to determine the proportion of patients eligible for at least one of the 9 MDS trials open at that time. On average, each clinical trial was suitable for about 18 % of patients in the simulation cohort. Conversely, 34 % of the patients were eligible for at least one of the 9 clinical studies in 2016. Inclusion/exclusion criteria of studies initiated by the pharmaceutical industry excluded more than twice the fraction of patients compared with investigator initiated trials (potential inclusion of 10 % vs. 21 %, respectively). Karyotype (average exclusion rate 58 %), comorbidities (40 %), and prior therapies (55 %) were the main reasons for exclusion. We suggest that in- and exclusion criteria should be less restrictive, in order to meet the needs of the real-life population of elderly MDS patients.

Prognostic impact of pretransplant measurable residual disease assessed by peripheral blood WT1-mRNA expression in patients with AML and MDS.

OBJECTIVE: As peripheral blood (PB) Wilm's Tumor 1 (WT1)-mRNA expression is established as MRD-marker during conventional AML chemotherapy, impact of pretransplant WT1 expression remains unclear. Therefore, we aimed to assess prognostic impact of pretransplant WT1 expression on post-transplant outcome in patients with AML/MDS. METHODS: In 64 AML/MDS patients, pretransplant WT1 expression was retrospectively analyzed using a standardized assay offering high sensitivity, specificity, and a validated cut-off. Patients were divided into three groups determined by pretransplant remission and WT1 expression. Post-transplant outcome of these groups was compared regarding cumulative incidence of relapse (CIR), relapse-free (RFS), and overall survival (OS). RESULTS: Pretransplant forty-six patients (72%) showed hematologic remission, including 21 (46%) MRD-negative and 25 (54%) MRD-positive patients indicated by WT1 expression, while 18 refractory patients (28%) showed active disease. Two-year estimates of post-transplant CIR, RFS, and OS were similar in MRD-positive (61%, 37%, 54%) and refractory patients (70%, 26%, 56%), but significantly inferior compared with MRD-negative patients (10%, 89%, 90%). After multivariable adjustment, pretransplant MRD negativity measured by WT1 expression retained its prognostic impact on CIR (P = .008), RFS (P = .005), and OS (P = .049). CONCLUSIONS: PB WT1 expression represents a useful method to estimate pretransplant MRD, which is highly predictable for post-transplant outcome and may help improving peri-transplant management in AML/MDS patients.

Outcomes of patients with chronic myelomonocytic leukaemia treated with non-curative therapies: a retrospective cohort study.

BACKGROUND: Approval of hypomethylating agents in patients with chronic myelomonocytic leukaemia is based on trials done in patients with myelodysplastic syndromes. We aimed to investigate whether hypomethylating agents provide a benefit in subgroups of patients with chronic myelomonocytic leukaemia compared with other treatments. METHODS: For this retrospective cohort study, data were retrieved between Nov 30, 2017, and Jan 5, 2019, from 38 centres in the USA and Europe. We included non-selected, consecutive patients diagnosed with chronic myelomonocytic leukaemia, who received chronic myelomonocytic leukaemia-directed therapy. Patients with acute myeloid leukaemia according to 2016 WHO criteria at initial diagnosis (ie, ≥20% blasts in the bone marrow or peripheral blood) or with unavailability of treatment data were excluded. Outcomes assessed included overall survival, time to next treatment, and time to transformation to acute myeloid leukaemia. Analyses were adjusted by age, sex, platelet count, and Chronic myelomonocytic leukaemia-Specific Prognostic Scoring System (CPSS). Patients were grouped by first received treatment with either hydroxyurea, hypomethylating agents, or intensive chemotherapy, and stratified by risk according to blast count, French-American-British subtype, CPSS, WHO 2016 subtype, and the eligibility criteria of the DACOTA trial (NCT02214407). FINDINGS: 949 patients diagnosed with chronic myelomonocytic leukaemia between April 13, 1981, and Oct 26, 2018, were included. Median follow-up was 23·4 months (IQR 11·5-42·3) from diagnosis and 16·2 months (6·6-31·6) from start of first-line treatment. 412 (43%) of 949 patients received hypomethylating agents as first treatment, 391 (41%) hydroxyurea, and 83 (9%) intensive chemotherapy. Adjusted median overall survival for patients treated with hydroxyurea versus hypomethylating agents was 15·6 months (95% CI 13·1-17·3) versus 20·7 months (17·9-23·4); hazard ratio (HR) 1·39 (1·17-1·65; p=0·0002) and 14·0 months (9·8-17·2) versus 20·7 months (17·9-23·4; HR 1·55 [1·16-2·05]; p=0·0027) for those treated with intensive chemotherapy versus hypomethylating agents. In patients with myeloproliferative chronic myelomonocytic leukaemia (myeloproliferative CMML), median overall survival was 12·6 months (10·7-15·0) versus 17·6 months (14·8-21·5; HR 1·38 [1·12-1·70]; p=0·0027) for patients treated with hydroxyurea versus hypomethylating agents, and 12·3 months (8·4-16·6) versus 17·6 months (14·8-21·5; HR 1·44 [1·02-2·03]; p=0·040) for intensive chemotherapy versus hypomethylating agents. Hypomethylating agents did not confer an overall survival advantage for patients classified as having lower-risk disease (ie, myelodysplastic chronic myelomonocytic leukaemia with <10% blasts, CMML-0, or lower-risk CPSS). INTERPRETATION: These data suggest hypomethylating agents as the preferred therapy for patients with higher-risk chronic myelomonocytic leukaemia and those with myeloproliferative CMML. Our findings also suggest that CPSS is a valuable tool to identify patients who are most likely to benefit from hypomethylating agents. Further evidence from prospective cohorts would be desirable. FUNDING: The Austrian Group for Medical Tumor Therapy.

Treatment of myeloid malignancies relapsing after allogeneic hematopoietic stem cell transplantation with venetoclax and hypomethylating agents-a retrospective multicenter analysis on behalf of the German Cooperative Transplant Study Group.

Treatment of relapse after allogeneic hematopoietic stem cell transplantation (alloHSCT) remains a great challenge. Aiming to evaluate the combination of venetoclax and hypomethylating agents (HMAClax) for the treatment of relapse of myeloid malignancies after alloHSCT, we retrospectively collected data from 32 patients treated at 11 German centers. Venetoclax was applied with azacitidine (n = 13) or decitabine (n = 19); 11 patients received DLI in addition. HMAClax was the first salvage therapy in 8 patients. The median number of cycles per patient was 2 (1-19). All but 1 patient had grade 3/4 neutropenia. Hospital admission for grade 3/4 infections was necessary in 23 patients (72%); 5 of these were fatal. In 30 evaluable patients, overall response rate (ORR) was 47% (14/30, 3 CR MRDneg, 5 CR, 2 CRi, 1 MLFS, 3 PR). ORR was 86% in first salvage patients versus 35% in later salvage patients (p = 0.03). In 6 patients with molecular relapse (MR), ORR was 67% versus 42% in patients with hematological relapse (HR) (n = 24, p = n.s.). After a median follow-up of 8.4 months, 25 patients (78%) had died and 7 were alive. Estimated median overall survival was 3.7 months. Median survival of patients with HMAClax for first versus later salvage therapy was 5.7 and 3.4 months (p = n.s.) and for patients with MR (not reached) compared to HR (3.4 months, p = 0.024). This retrospective case series shows that venetoclax is utilized in various different combinations, schedules, and doses. Toxicity is substantial and patients who receive venetoclax/HMA combinations for MR or as first salvage therapy derive the greatest benefit.

Prediction of Response and Survival Following Treatment with Azacitidine for Relapse of Acute Myeloid Leukemia and Myelodysplastic Syndromes after Allogeneic Hematopoietic Stem Cell Transplantation.

To provide long-term outcome data and predictors for response and survival, we retrospectively analyzed all 151 patients with relapse of myeloid neoplasms after allogeneic hematopoietic stem cell transplantation (allo-HSCT) who were uniformly treated with first-line azacitidine (Aza) salvage therapy at our center. Patients were treated for molecular (39%) or hematologic relapse (61%), with a median of 5 cycles of Aza and at least one donor lymphocyte infusion in 70% of patients. Overall response was 46%, with 41% achieving complete (CR) and 5% achieving partial remission. CR was achieved after a median of 4 cycles and lasted for a median of 11 months (range 0.9 to 120 months). With a median follow-up of 22 months (range: 1 to 122 months), the 2-year survival rate was 38% ± 9%, including 17 patients with ongoing remission for >5 years. Based on results from multivariate analyses, molecular relapse and time to relapse were integrated into a score, clearly dividing patients into 3 subgroups with CR rates of 71%, 39%, and 29%; and 2-year survival rates of 64%, 38%, and 27%, respectively. In the subgroup of MDS and secondary AML, receiving upfront transplantation was associated with superior response and survival, and therefore pretransplant strategy was integrated together with relapse type into a MDS-sAML-specific score. Overall, Aza enables meaningful responses and long-term survival, which is a predictable with a simple-to-use scoring system.

Improving the accuracy of prognostication in chronic myelomonocytic leukemia.

INTRODUCTION: Chronic myelomonocytic leukemia (CMML) is a hematological malignancy that is extremely variable regarding its clinical course. It may present either as a chronic disorder with mild symptoms and low disease burden for several years, thereby justifying a watch-and-wait-strategy, or may soon progress to acute myeloid leukemia (AML) leaving allogeneic stem cell transplantation as the only curative treatment option. AREAS COVERED: Attempts have been made to integrate clinical, cytogenetic, and molecular parameters into scoring systems aiming at providing reliable prognostic information. In this article, we discuss several prognostic parameters and validate prognostic scores in a cohort of 645 patients with CMML. EXPERT OPINION: We show that the CPSS (CMML prognostic scoring system) is a useful prognostic tool. The integration of molecular data into the new CPSS-mol will further improve prognostic accuracy, primarily by identifying an increased proportion of higher-risk patients.

EASIX for prediction of survival in lower-risk myelodysplastic syndromes.

Patients with myelodysplastic syndromes (MDS) are at risk of early death from cardiovascular complications due to the link between clonal hematopoiesis and endothelial dysfunction. EASIX (Endothelial Activation and Stress Index) has been established to predict endothelial complications after allogeneic transplantation. We investigated the impact of EASIX measured at first diagnosis on survival of patients with lower- and higher-risk MDS (no allogeneic transplantation) in two independent institutions: n = 192 (training cohort) and n = 333 (validation cohort). Serum markers of endothelial cell distress were measured and correlated to EASIX. While no effects of EASIX on survival were observed in higher-risk patients, EASIX was associated with shorter survival in patients with lower-risk MDS in both cohorts (univariate: Cohort I: hazard ratio (HR): 1.46; 95% confidence interval (CI) 1.24-1.71; p-value < 0.001/Cohort II: HR 1.31 [1.17-1.48]; p-value < 0.001). Multivariate Cox regression analysis and prediction error analyses confirmed that EASIX remained a significant predictor of survival after adjustment for age, sex, cytogenetic abnormalities and bone marrow blasts in lower-risk patients. The model of the training cohort could be validated. Serum levels of Angiopioetin-2 correlated significantly with EASIX. We introduce EASIX as an easily accessible and independent predictor for survival in patients with lower-risk MDS.

Lymphopenia at diagnosis is highly prevalent in myelodysplastic syndromes and has an independent negative prognostic value in IPSS-R-low-risk patients.

Lymphopenia is associated with an increased mortality in several medical conditions. Its prognostic impact in myelodysplastic syndromes (MDS) is less well studied. Hence, we analyzed 1023 patients from the Düsseldorf MDS-registry with regard to the absolute lymphocyte count (ALC) at diagnosis. An ALC below the median of the population (1.2 × 109/l) was associated with lower counts of neutrophils (median 1.35 vs. 1.92 × 109/l, p < 0.001) and platelets (median 100 vs. 138 × 109/l, p < 0.001) and with a significant lower overall survival in univariate analysis (whole cohort: median 36 vs. 46 months, p = 0.016; 721 patients without hematopoietic stem cell transplantation or induction chemotherapy: median 36 vs. 56 months, p = 0.001). For low-risk MDS according to IPSS-R, an ALC < 1.2 × 109/l was of additional prognostic value in a multivariate Cox regression model together with age (< or ≥65 years) and LDH (< or ≥normal value of 240 U/l; HR 1.46, 95% CI: 1.03-2.08, p = 0.033). These data support the hypothesis of subtle but clinical relevant changes of the adaptive immune system in MDS. Further studies are necessary to identify the ALC cut-off best suitable for prognostication and the mechanisms responsible for the impairment of lymphoid homeostasis in MDS.

Molecular genetics in allogeneic blood stem cell transplantation for myelodysplastic syndromes.

Introduction: Myelodysplastic Syndromes (MDS) are a heterogeneous group of myeloid neoplasms arising in a multipotent hematopoietic stem cell. In about 50% of cases, chromosomal aberrations are detected, which can serve as clonal markers as well as important prognostic factors. In recent years, many somatic mutations have been recognized to be involved in the initiation and clonal evolution of MDS. They provide prognostic information, not only regarding the natural course of disease but also regarding the outcome of allogeneic stem cell transplantation (aSCT) and can be used to monitor the depth of treatment response and enable early detection of relapse. Areas covered: The authors describe current methods for mutation detection in MDS and highlight their prognostic significance. In addition, the authors discuss whether molecular findings should influence the approach to aSCT and how they can be used for minimal residual disease (MRD) detection and guidance for preemptive treatment of relapse. Expert opinion: Molecular genetics give insight into the pathophysiology of MDS, provide prognostic information on the natural course of disease and help to predict the success of several therapeutic approaches including aSCT. MRD monitoring based on next-generation sequencing will soon become the standard of care to guide treatment before and after aSCT.

Novel therapies in low- and high-risk myelodysplastic syndrome.

Introduction: Myelodysplastic syndromes (MDS) comprise a heterogeneous group of myeloid neoplasms with diverse clinical courses. The revised version of the international prognostic scoring system (IPSS-R) provides risk stratification into 5 different groups. Areas covered: For lower-risk patients, red blood cell transfusions and iron chelation are the backbone of supportive care. In addition, erythropoiesis-stimulating agents (ESA) are used to ameliorate anemia. Lenalidomide is approved for the treatment of lower-risk patients with del(5q) who are transfusion-dependent. Patients with higher-risk disease should be offered allogeneic stem cell transplantation whenever possible. If they are unfit for transplantation or an appropriate donor cannot be found, hypomethylating agents may be used. Expert opinion: New therapeutic options for lower-risk patients include thrombopoietin analogues, the TGF-beta family ligand trapping drug Luspatercept, and the telomerase inhibitor Imetelstat. Combinations of hypomethylating agents (HMA) with other compounds, and inhibitors of bcl2, such as venetoclax are being developed for higher-risk patients. Finally, hypomethylating agents in combination with donor lymphocytes may lead to long-term remission following molecular or hematological relapse after allogeneic SCT.

Spontaneous remission in a patient with very late relapse of acute myeloid leukemia 17 years after allogeneic blood stem cell transplantation.

Spontaneous remission (SR) of acute myeloid leukemia (AML) represents a rare phenomenon and is usually of short duration although long-term remissions are reported. Indeed, mechanisms underlying SR remain unclear, but it is suggested that immunactivation, e.g. caused by infections, plays an important role. Here we report on a patient who suffered from pneumonia and simultaneously experienced very late hematologic AML relapse seventeen years after allogeneic blood stem cell transplantation (allo-BSCT). Surprisingly in parallel to recovery from pneumonia peripheral blood count which previously showed pancytopenia, had normalized and bone marrow (BM) aspiration revealed spontaneous remission of AML. To the best of our knowledge we here report on the latest AML relapse after allo-BSCT experiencing SR.

Cytogenetic clonal evolution in myelodysplastic syndromes is associated with inferior prognosis.

BACKGROUND: The karyotype of bone marrow cells at the time of diagnosis is a strong prognostic parameter for overall survival as well as acute myeloid leukemia (AML) progression in patients with myelodysplastic syndromes (MDS). However, to the authors' knowledge, few data exist regarding the prognostic impact of cytogenetic clonal evolution during the course of MDS. METHODS: The authors evaluated follow-up karyotype analyses in 549 patients from the Dusseldorf MDS Registry. RESULTS: Clonal evolution was detectable in 24% of the entire cohort and in 18% of 294 patients receiving best supportive care. The authors noted a clear adverse effect of clonal evolution on the risk of leukemic transformation (hazard ratio, 2.233; P = .036) and overall survival (hazard ratio, 3.677; P<.001). The authors also analyzed the prognostic influence of subclones detectable at the time of diagnosis. Again, such a finding was associated with a significantly shorter overall survival and a higher 5-year-probability of acute myeloid leukemia progression (30% vs 22%). CONCLUSIONS: The results of the current study support the belief that follow-up karyotype analyses should be performed, especially in patients with lower-risk and intermediate-risk MDS, to identify those patients who are at higher risk of disease progression and therefore might benefit from earlier or more intensive treatment. Cancer 2017;123:4608-4616. © 2017 American Cancer Society.