Ex vivo platelet morphology assessment of chronic myeloid leukemia patients before and after Imatinib treatment.

Chronic myeloid leukemia (CML) is a myeloproliferative disease and the first line treatment is through the administration of Imatinib, a first generation tyrosine kinase inhibitor. Thrombocytosis and bleeding irregularities are common in CML, however, the morphological variations in CML patients' platelets are not well documented. In this study, ex vivo platelet morphology of control participants, as well as CML patients were assessed before and after Imatinib treatment. The topographical and structural morphology of platelets were determined via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Qualitative data of SEM and TEM revealed that CML patient's platelets were prone to aggregation and coagulation at time of diagnosis; the samples that were not aggregated at time of diagnosis showed typical discoid shaped platelets, which was comparable to control participants' platelets. TEM results of CML patients' platelets at diagnosis showed that internal granular constituents including dense bodies were decreased in comparison to control participants. In all CML patients, platelets appeared activated after 6 months of treatment with Imatinib with membrane structure abnormalities and constituent variations. Research to date has primarily focused on the effects of CML on leukocyte populations, however, the results of the current study implicate the impact of CML pathogenesis on platelets, seemingly as a result of alterations in normal hematopoiesis. In addition, the impact of Imatinib treatment on platelet morphology was also established, indicating an increase in platelet activation. Recognizing and understanding the impact of CML disease progression on platelets is of importance to aid improved patient treatment. RESEARCH HIGHLIGHTS: In the study, results from SEM and TEM indicated that CML patient's platelets were prone to aggregation at time of diagnosis, and activation after Imatnib treatment. Platelet samples that did not aggregate had decreased internal granular constituents.

Comparison of 3-month cytogenetic and molecular assays for early assessment of long-term clinical impact after BCR-ABL1 tyrosine kinase inhibitor treatment in chronic myeloid leukemia.

To compare the clinical significance of 3-month cytogenetic and molecular monitoring, we analyzed 1,410 paired cytogenetic and molecular data from 705 chronic-phase chronic myeloid leukemia patients. Based on early cytogenetic response (ECyR, Ph+≤35 %) and molecular response (EMR, BCR-ABL1IS≤10 %) at 3 months, the patients were divided into four groups (group 1: ECyR + EMR, n = 560; group 2: no ECyR + EMR, n = 27; group 3: ECyR + no EMR, n = 55; group 4: no ECyR + no EMR, n = 63). By 10 years, major molecular response (MMR), deep molecular response (MR4.5), overall survival (OS), and progression-free survival (PFS) rates were significantly high in group 1 (P < 0.001). Comparing groups 2 and 3, the MMR (P = 0.096), MR4.5 (P = 0.945), OS (P = 0.832), and PFS (P = 0.627) rates tended to be higher in group 2, although not significantly. Thus, the cytogenetic assay can not only be useful but its addition may also provide a more precise prediction of MR4.5.

Assessment of individual molecular response in chronic myeloid leukemia patients with atypical BCR-ABL1 fusion transcripts: recommendations by the EUTOS cooperative network.

PURPOSE: Approximately 1-2% of chronic myeloid leukemia (CML) patients harbor atypical BCR-ABL1 transcripts that cannot be monitored by real-time quantitative PCR (RT-qPCR) using standard methodologies. Within the European Treatment and Outcome Study (EUTOS) for CML we established and validated robust RT-qPCR methods for these patients. METHODS: BCR-ABL1 transcripts were amplified and sequenced to characterize the underlying fusion. Residual disease monitoring was carried out by RT-qPCR with specific primers and probes using serial dilutions of appropriate BCR-ABL1 and GUSB plasmid DNA calibrators. Results were expressed as log reduction of the BCR-ABL1/GUSB ratio relative to the patient-specific baseline value and evaluated as an individual molecular response (IMR). RESULTS: In total, 330 blood samples (2-34 per patient, median 8) from 33 CML patients (19 male, median age 62 years) were analyzed. Patients expressed seven different atypical BCR-ABL1 transcripts (e1a2, n = 6; e6a2, n = 1; e8a2, n = 2; e13a3, n = 4; e14a3, n = 6; e13a3/e14a3, n = 2; e19a2, n = 12). Most patients (61%) responded well to TKI therapy and achieved an IMR of at least one log reduction 3 months after diagnosis. Four patients relapsed with a significant increase of BCR-ABL1/GUSB ratios. CONCLUSIONS: Characterization of atypical BCR-ABL1 transcripts is essential for adequate patient monitoring and to avoid false-negative results. The results cannot be expressed on the International Scale (IS) and thus the common molecular milestones and guidelines for treatment are difficult to apply. We, therefore, suggest reporting IMR levels in these cases as a time-dependent log reduction of BCR-ABL1 transcript levels compared to baseline prior to therapy.

Assessment of Cell Cycle in Primitive Chronic Myeloid Leukemia Cells by Flow Cytometry After Coculture with Endothelial Cells.

From the knowledge that hematopoiesis does not occur randomly in the bone marrow but is regulated by the different components of the microenvironment, the use of in vitro coculture systems has been used as a powerful tool in the analysis of different processes that are involved in the maintenance of blood cells. In this chapter, we describe a methodological strategy to perform a coculture between primitive hematopoietic cells and endothelial cells to evaluate cell cycle, an aspect of relevant importance in the permanence of primitive leukemic cells.

Investigating the cytotoxic and apoptotic effects of sunitinib upon K-562 chronic myelogenous leukemia cell line and assessment of gene profiling.

OBJECTIVE: Tyrosine kinase inhibitors (TKIs) which efficiently inhibit BCR-ABL are highly effective for clinical treatment of chronic myeloid leukemia (CML), but development of resistance to TKIs is a big challenge to treatment. Sunitinib is a multitargeted TKI targeting vascular endothelial growth factor receptor and is defined a safe and effective candidate target, but its effect on other signaling pathways is unknown. To investigate the cytotoxic and apoptotic effect of sunitinib in CML cell model K-562 on JAK-STAT signaling pathway components, suppressor genes and oncogenes, hematopoiesis-related genes, cell cycle and VEGF pathway components, and mRNA level expression changes was aimed. MATERIALS AND METHODS: Sunitinib's effective dose cytotoxic IC50 was determined by trypan blue and WST-1 cell proliferation assay tests. Expression levels of target genes were determined by quantitative reverse transcriptase polymerase chain reaction simultaneously after sunitinib application. Protein expression analysis was determined by "WesternBreeze Chromogenic Kit-Anti-Rabbit" based on the principles of the application kit by Western blot analysis. RESULTS: Assessing the cytotoxicity of K-562 cells following sunitinib treatment revealed that sunitinib decreased cell proliferation in a time- and dose-dependent manner. According to the sunitinib inhibition curve, IC50 dose was calculated as 3.5 µM at 48th h for K-562 cells and apoptosis assays pointed that sunitinib induces apoptotic cell death of leukemic cells at moderate levels. CONCLUSION: Our study supports that sunitinib might be used as a novel therapeutic target to trigger apoptosis in CML cells which in turn might accelerate therapeutic response in regard to inhibiting oncogenes and enhancing tumor suppressors in cooperation with cell cycle regulatory genes.

Comparison of BCR-ABL1 quantification in peripheral blood and bone marrow using an International Scale-standardized assay for assessment of deep molecular response in chronic myeloid leukemia.

Background Monitoring of molecular response (MR) using quantitative polymerase chain reaction (PCR) for BCR-ABL1 is a pivotal tool for guiding tyrosine kinase inhibitor therapy and the long-term follow-up of patients with chronic myeloid leukemia (CML). Results of MR monitoring are standardized according to the International Scale (IS), and specific time-dependent molecular milestones for definition of optimal response and treatment failure have been included in treatment recommendations. The common practice to use peripheral blood (PB) instead of bone marrow (BM) aspirate to monitor the MR monitoring in CML has been questioned. Some studies described differences between BCR-ABL1 levels in paired PB and BM specimens. Methods We examined 631 paired PB and BM samples from 283 CML patients in a retrospective single-center study using an IS normalized quantitative reverse transcription (qRT)-PCR assay for quantification of BCR-ABL1IS. Results A good overall concordance of BCR-ABL1IS results was found, a systematic tendency towards higher BCR-ABL1IS levels in PB was observed in samples of CML patients in a major MR. This difference was most pronounced in patients treated with imatinib for at least 1 year. Importantly, the difference resulted in a significantly lower rate of deep MR when BCR-ABL1IS was assessed in the PB compared to BM aspirates. Conclusions In summary, our data suggest that the classification of deep MR in patients with CML is more stringent in PB than in BM. Our study supports the current practice to primarily use PB for long-term molecular follow-up monitoring in CML.

Paediatric chronic myeloid leukaemia: Is it really a different disease?

Paediatric chronic myeloid leukaemia (CML) has biological and clinical differences from adult CML. Management of paediatric CML presents unique challenges in growing children, and there are no specific guidelines for paediatric CML. This review focusses on the clinical characteristics, diagnostic issues and management of paediatric CML. Major studies that provide the basis of managing paediatric CML are summerized here. Studies conducted on adult CML patients were used to guide the management of places where studies were lacking in paediatric CML. Recently, dasatinib and nilotinib have been approved for treatment of paediatric CML, and their role has been discussed in the current management perspective. Allogeneic transplant, fertility and vaccination in paediatric CML, have also been discussed.

Treatment value of second-generation BCR-ABL1 tyrosine kinase inhibitors compared with imatinib to achieve treatment-free remission in patients with chronic myeloid leukaemia: a modelling study.

BACKGROUND: Treatment-free remission in chronic myeloid leukaemia-ie, achievement of a sustained deep molecular response leading to discontinuation of BCR-ABL1 tyrosine kinase inhibitor (TKI) therapy-has become a potential aim of therapy. Highly priced second-generation TKIs might offer deep molecular response status more quickly and for more patients than imatinib; however, with the availability and lower cost of generic imatinib, the value of second-generation TKIs as frontline therapy for this particular treatment endpoint remains unknown. We aimed to assess the potential value of second-generation TKIs used as frontline therapy in patients with chronic myeloid leukaemia in chronic phase in relation to the probability of achieving sustained deep molecular responses compared with generic imatinib, and the associated cost of each modality. METHODS: We used a decision analytic model to consider the value of different TKI approaches from the payer's perspective. The proportion of patients achieving sustained deep molecular response after 5 years of treatment in chronic phase was estimated at 26% with imatinib and 44% with second-generation TKIs. We also modelled more favourable scenarios of the proportion of patients achieving such response with second-generation TKIs at 66%, 88%, and a near-perfect response of 99%. For each scenario, we examined the impact of the combination of health utilities for chronic-phase chronic myeloid leukaemia (base case 0·89, range 0-1) and the annual cost of second-generation TKIs (base case US$152 814 [ie, the price of nilotinib in the USA], range 0-240 000) on the cost-effectiveness of second-generation TKIs compared with generic imatinib. We used different price scenarios for generic imatinib in the USA (average price $35 000 per year; lowest price $4400 per year), Europe ($4000 per year), and developing countries ($2100 per year). We calculated incremental cost-effectiveness ratios (ICERs) and assessed cost-effectiveness by considering two societal willingness-to-pay thresholds: $50 000 per quality-adjusted life-year (QALY) in all markets and $200 000 per QALY in the USA. FINDINGS: In the base case, we obtained an ICER of $22 765 208, meaning that second-generation TKIs as frontline therapy to achieve sustained deep molecular response was not cost-effective under either of the societal willingness-to-pay thresholds. In our sensitivity analyses, none of the explored scenarios showed potential treatment value for use of second-generation TKIs at the current prices in the USA or at the price of $30 000-40 000 per year elsewhere. For example, considering a scenario in the USA using second-generation TKIs versus imatinib (annual price $4400 per year) with the potential benefit in favour of second-generation TKI (willingness to pay $200 000 per QALY, 66% of patients achieving sustained deep molecular response, and health utility of the chronic phase of 0·1), the cost of second-generation TKIs would need to be less than $25 000 per year to be a cost-effective option. Under the same conditions in developing nations, with a price of generic imatinib of $2100 per year and a willingness to pay of $50 000 per QALY, the annual price of second-generation TKIs should not exceed $10 000 per year of therapy. INTERPRETATION: Considering the current prices of second-generation TKIs and of generic imatinib under different pricing scenarios in the USA, Europe, and developing countries, second-generation TKIs at current prices do not offer good value as frontline therapy in chronic myeloid leukaemia in order to achieve sustained deep molecular response and treatment-free remission. FUNDING: National Cancer Institute.

Bone marrow core biopsy in 508 consecutive patients with chronic myeloid leukemia: Assessment of potential value.

BACKGROUND: The diagnosis of chronic myeloid leukemia (CML) is based on characteristic clinical and laboratory findings and the presence of BCR/ABL1 in the blood and/or bone marrow (BM). The utility of BM core biopsy in the workup of patients with CML has been questioned. METHODS: The potential added value of BM biopsy versus aspiration in the workup of a single-institution series of 508 patients with CML at their initial presentation was systematically assessed. BM biopsy was considered essential when it was needed to establish the disease phase, often because blast counts derived from aspirate smears were misleading because the biopsy specimen was more representative of the disease. BM biopsy was considered helpful if it was needed for other nonessential reasons. RESULTS: In 127 patients (25%), BM biopsy was either essential (109 patients) or helpful (18 patients). Patients with accelerated-phase (AP) or blast-phase (BP) disease often required a biopsy related to essential reasons. High-grade myelofibrosis (MF) was more frequent in patients with AP/BP disease than patients with chronic-phase disease (P = .0005), and the identification of BP disease required a BM biopsy assessment in 75% of the patients (P = .001). A follow-up BM evaluation more often yielded inadequate aspirates in patients with inadequate BM aspirates at the time of their initial diagnosis. CONCLUSIONS: BM core biopsy remains valuable in the workup of 25% of patients with CML because it facilitates identification of the disease phase or MF. The initial grade of MF is associated with the disease stage and outcome after therapy. BM biopsy is, therefore, indicated for patients with CML who have AP/BP disease or other findings suggestive of progressive disease.

Real-time quantitative PCR: a reliable molecular diagnostic and follow-up tool for 'minimal residual disease' assessment in chronic myeloid leukemia.

Molecular monitoring of BCR-ABL transcript levels by real-time quantitative PCR is increasingly being used to diagnose the disease and assess treatment response in patients with chronic myeloid leukemia (CML). This has become particularly relevant when residual levels of leukemia usually fall below the level of detection by cytogenetic analysis. Forty-two CML patients, including 18 males (42.86%) and 24 females (57.14%) aged 7-75 years, were enlisted for the study and followed-up for the response to imatinib treatment. Patients were subjected to Multiplex RT-PCR (reverse-transcriptase PCR) and were all found to harbor either e13a2 or the e14a2, which could be analyzed by a single Taqman probe based quantitation kit (Geno-Sen's) to quantitate the BCR-ABL transcript load. The Multiplex RT-PCR and peripheral blood cytogenetics providing specific and sensitive detection of BCR-ABL fusion transcripts and metaphase signal load respectively were used as parallel reference tools to authenticate the q-PCR findings. There was 100% concordance between the multiplex RT-PCR and the q-PCR as every positive RT-PCR assay for a transcript reflected as q-PCR load of above 0% for that transcript. q-PCR also demonstrated a strong Pearson correlation with the cytogenetic response.

Medication adherence, molecular monitoring, and clinical outcomes in patients with chronic myelogenous leukemia in a large HMO.

OBJECTIVE: Our objective was to examine the association between adherence to tyrosine kinase inhibitors (TKIs) and molecular monitoring and the risk of disease progression or mortality among patients with chronic phase chronic myeloid leukemia (CML). DESIGN: We assembled a retrospective cohort of patients with CML (chronic phase, no prior cancer history, and confirmed to be Philadelphia chromosome positive) using data from electronic health records and chart reviews. Medication possession ratio (MPR) was used to measure drug adherence. SETTING: A large, community-based, integrated health plan in Southern California. PARTICIPANTS: The cohort consisted of 245 adult patients (≥18 years old) with Philadelphia positive chronic phase CML diagnosed from 2001 to 2012 and followed through 2013. MAIN OUTCOME MEASURES: In survival analyses, we examined the association of TKI adherence (MPR) and polymerase chain reaction (PCR) monitoring test frequency with the composite clinical outcome, progression to accelerated phase disease-blast crisis or mortality (progression-free survival). The cohort was followed for a maximum of 13 years (median 4.6 years). RESULTS: Over 90% of the cohort initiated TKI therapy within 3 months of diagnosis, and the mean MPR was 88% (SD 18%). Virtually all patients (96%) started on imatinib. The rates of progression to accelerated phase-blast crisis and mortality were lower in patients with greater TKI adherence (20.4/1000 person-years) versus lower adherence (27.0/1000 person-years). Patients who underwent PCR monitoring had a significantly reduced risk of progression or mortality, which was seen in patients with high and low TKI adherence status from both the groups (hazard ratio [HR] 0.07 [95% CI 0.03-0.19 if MPR >90%] and HR 0.70 [95% CI 0.02-0.21 if MPR<90%]). CONCLUSION: Our results suggest that close clinical monitoring, which includes PCR monitoring in patients with high and low TKI drug adherence, is associated with a lower risk of progression or mortality.

Estimation of the prevalence and direct medical costs of chronic myeloid leukemia in the I.R. of Iran in the era of tyrosine kinase inhibitors.

BACKGROUND: After the introduction of tyrosine kinase inhibitors for chronic myeloid leukemia (CML), the survival of these patients has increased significantly. However, these new drugs are expensive and impose considerable expense to patients and governments. Epidemiologic and economic evaluation studies provide good information for resource allocation and decision making. We estimated the incidence, prevalence and direct medical cost of CML in Iran. METHODS: We used the National Cancer Registry (NCR) data from 2006 to 2009 to estimate the incidence rate of CML (ICD-10 code C92.1). After adjustment for the underestimation of incidence rates, we used survival rates of CML and estimated the 5-year prevalence for these patients. In addition, we used clinical practice guideline, expert opinions and medical tariffs to estimate the direct medical costs through the prevalence approach. RESULTS: After an adjustment for the underestimation, the incidence rate of CML was 0.5 per 100 000 in the I.R. of Iran. The 5-year prevalence was about 2263 cases (2.98 per 100 000). The total direct medical cost of CML was $23 089 323 and the majority of the cost (97%) was related to drug costs. The total cost will increase considerably to $40 728 869 if all patients use the new drug nilotinib (800 mg/day) as a second-line treatment. CONCLUSIONS: The increased survival of CML patients and a possible increase in incidence of CML in Iran will most likely lead to a considerable rise in its prevalence and economic burden.

Assessment of the Number and Phenotype of Macrophages in the Human BMB Samples of CML.

Macrophages have emerged as a key player in tumor biology. However, their number and phenotype in human bone marrow of biopsy (BMB) samples of chronic myeloid leukemia (CML) and their association with disease progression from an initial chronic phase (CP) to accelerated phase (AP) to advanced blast phase (BP) are still unclear. BMB samples from 127 CML patients and 30 patients with iron-deficiency anemia (IDA) as control group were analyzed by immunohistochemistry. The expression levels of CD68, CD163, and CD206 in BMB samples of CML patients were significantly higher than those in the patients of control group (P < 0.01), and we observed that their positive expression was gradually elevated during the transformation of CML-CP to AP to BP (P < 0.01). However, the expressions of CD68, CD163, and CD206 in released group were downregulated and contrasted to these in control group; there exists statistical significance (P < 0.01). The percentage ratio of CD163 and CD206 to CD68 was pronounced to be increasing from CML-CP to AP to BP (P < 0.01). Hence, the higher proportion of CD68+, CD163+ and CD206+ macrophages in BMB samples can be considered a key factor for disease progression of CML patients. Targeting macrophages, especially the M2 phenotype may help in designing therapeutic strategies for CML.

Quantitative assessment of the CD26+ leukemic stem cell compartment in chronic myeloid leukemia: patient-subgroups, prognostic impact, and technical aspects.

Little is known about the function and phenotype of leukemic stem cells (LSCs) in chronic myeloid leukemia (CML) or about specific markers that discriminate LSCs from normal hematopoietic stem cells (HSCs). CD26 has recently been described as a specific marker of CML LSCs. In the current study, we investigated this marker in a cohort of 31 unselected CML patients. BCR/ABL1 positivity was analyzed in highly enriched stem cell fractions using fluorescence in situ hybridization (FISH) and reverse transcription PCR (RT-PCR). The proportion of CD26+ LSCs and CD26- HSCs varied considerably among the patients analyzed, and the percentage of CD26+ cells correlated with leukocyte count. The CD26 expression robustly discriminated LSCs from HSCs. This required a strict gating of the stem cell compartment. Thus, in patients with very low LSC or HSC numbers, only the highly sensitive RT-PCR method discriminated between clonal and non-clonal cells, while a robust FISH analysis required larger numbers of cells in both compartments. Finally, our data show that the numbers of CD26+ CML LSCs correlate with responses to treatment with BCR-ABL1 inhibitors.

The treatment of CML at an environment with limited resources.

OBJECTIVES: This article reviews clinical experiences in the treatment of chronic myeloid leukemia (CML) in an environment of limited resources. METHODS: We reviewed recent publications on Pub med and abstracts from mayor congresses relevant to the disease. RESULTS: CML is a hematological neoplasm observed more frequently in adults, regardless of their socioeconomic status. Until recently, available treatments improved patients' quality of life but did not modify survival. It was not until interferon appeared that patients received a drug that reduced and even eliminated Philadelphia chromosome-positive (Ph+) cells. DISCUSSION: With the start of the new millennium, the International Randomized Study of Interferon-α plus cytarabine versus STI571 (IRIS) trial demonstrated a dramatic improvement in survival by comparing imatinib versus interferon alpha plus cytarabine. The Food and Drug Administration (FDA) approved imatinib as first-line treatment for newly diagnosed CML in 2001 due to its outstanding effectiveness. Years later, three second-generation (dasatinib, nilotinib, bosutinib) and one third-generation (ponatinib) tyrosine-kinase inhibitors (TKIs) were developed and approved. These highly effective treatment options, however, are not affordable for many low-income patients. Additionally, the use of drugs that effectively treat but do not cure the disease has resulted in an important economic impact for patients and health care systems worldwide, especially those in developing countries. Imatinib is the least expensive and a very effective TKI in many low-income countries. Early allogeneic stem cell transplantation must be considered in the management of selected patients before CML transformation.

Assessment of bone marrow lymphocytic status during tyrosine kinase inhibitor therapy and its relation to therapy response in chronic myeloid leukaemia.

PURPOSE: Tyrosine kinase inhibitors (TKIs) used in the treatment of chronic myeloid leukaemia have been reported to induce immunomodulatory effects. We aimed to assess peripheral blood (PB) and bone marrow (BM) lymphocyte status at the diagnosis and during different TKI therapies and correlate it with treatment responses. METHODS: BM and PB samples were acquired from 105 first-line TKI-treated patients. Relative number of BM lymphocytes was evaluated from MGG-stained BM aspirates, and immunophenotypic analyses were performed with multicolour flow cytometry. RESULTS: Early 3-month expansion of BM lymphocytes was found during all different TKIs (imatinib n = 71, 20 %; dasatinib n = 25, 21 %; nilotinib n = 9, 22 %; healthy controls n = 14, 12 %, p < 0.0001). Increased PB lymphocyte count was only observed during dasatinib therapy. The BM lymphocyte expansion was associated with early molecular response; patients with 3-month BCR-ABL1 <10 % showed higher lymphocyte counts than patients with BCR-ABL1 >10 % (23 vs. 17 %, p < 0.05). Detailed phenotypic analysis showed that BM lymphocyte expansion consisted of various lymphocyte subclasses, but especially the proportion of CD19+ B cells and CD3negCD16/56+ NK cells increased from diagnostic values. During dasatinib treatment, the lymphocyte balance in both BM and PB was shifted more to cytotoxic direction (increased CD8+CD57+ and CD8+HLA-DR+ cells, and low T regulatory cells), whereas no major immunophenotypic differences were observed between imatinib and nilotinib patients. CONCLUSIONS: Early BM lymphocytosis occurs with all current first-line TKIs and is associated with better treatment responses. PB and BM immunoprofile during dasatinib treatment markedly differs from both imatinib- and nilotinib-treated patients.

The use of medical claims to assess incidence, diagnostic procedures and initial treatment of myelodysplastic syndromes and chronic myelomonocytic leukemia in the Netherlands.

Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) may be underreported in cancer registries such as the Netherlands Cancer Registry (NCR). Analysis of Dutch medical claims can complement NCR data on MDS and CMML. We analyzed data on 3681 MDS patients and 235 CMML patients aged ≥18 years with initial claims for MDS or CMML from the Dutch nationwide medical claims-based Diagnosis Treatment Combination Information System (DIS) between 2008 and 2010. Clinical information was available in the DIS. MDS and CMML were diagnosed without a bone marrow (BM) examination in almost half of the patients. The age-standardized incidence rate (ASR) per 100,000 in the cohort that underwent BM examinations compared with NCR data was 2.8 vs. 3.3 for MDS and 0.2 vs. 0.4 for CMML in 2008-2010. A conservative treatment approach was associated with increasing age and absence of BM examination in MDS (p<0.001 for both) and CMML patients (p<0.033 for both). In conclusion, the ASR of MDS in the cohort that underwent BM examinations was comparable with the NCR. The majority of elderly patients, either with or without BM examinations, received no therapy. Together, MDS and CMML may be misdiagnosed and inappropriately managed without a BM confirmation.