Superior outcomes and high-risk features with carfilzomib, lenalidomide, and dexamethasone combination therapy for patients with relapsed and refractory multiple myeloma: Results of the multicenter KMMWP2201 study.

Carfilzomib, lenalidomide, and dexamethasone (KRd) combination therapy improves the survival of patients with relapsed and/or refractory multiple myeloma (RRMM). Nonetheless, evidence on the use of KRd in Asian populations remains scarce. Accordingly, this study aimed at investigating this regimen's efficacy in a large group of patients. This retrospective study included patients with RRMM who were treated with KRd at 21 centers between February 2018 and October 2020. Overall, 364 patients were included (median age: 63 years). The overall response rate was 90% in responseevaluable patients, including 69% who achieved a very good partial response or deeper responses. With a median follow-up duration of 34.8 months, the median progression-free survival (PFS) was 23.4 months and overall survival (OS) was 59.5 months. Among adverse factors affecting PFS, highrisk cytogenetics, extramedullary disease, and doubling of monoclonal protein within 2 to 3 months prior to start of KRd treatment significantly decreased PFS and overall survival (OS) in multivariate analyses. Patients who underwent post-KRd stem cell transplantation (i.e.delayed transplant) showed prolonged PFS and OS. Grade 3 or higher adverse events (AEs) were observed in 56% of the patients, and non-fatal or fatal AE's that resulted in discontinuation of KRd were reported in 7% and 2% of patients, respectively. Cardiovascular toxicity was comparable to that reported in the ASPIRE study. In summary, KRd was effective in a large real-world cohort of patients with RRMM with long-term follow-up. These findings may further inform treatment choices in the treatment of patients with RRMM.

Clinical characteristics and treatment outcomes of Asian patients with T-cell large granular lymphocytic Leukemia: a single-center analysis of 67 cases.

Large granular lymphocytic (LGL) leukemia is a clonal lymphoproliferative disorder of LGLs derived from cytotoxic T lymphocytes or natural killer cells. However, the clinical features and treatment responses are still not fully understood because of the rarity of the disease. To describe and assess a cohort of patients with T-cell large granular lymphocytic leukemia (T-LGLL). Single-center, retrospective, observational study. We retrospectively collected the clinical data of patients diagnosed with T-LGLL at Seoul National University Hospital since 2006. We included 67 patients in this study. The median age at diagnosis was 60 years. Additionally, 37 patients (55%) were symptomatic, and 25 (37%) had splenomegaly; 54 patients (81%) required treatment. Cyclophosphamide (n = 35), methotrexate (n = 25), and cyclosporin A (n = 19) were used most frequently for treatment, and their overall response rates were similar: cyclophosphamide (77%), methotrexate (64%), and cyclosporin A (63%). Splenomegaly was associated with an increased response rate to first-line therapy and a decreased complete response rate. Thrombocytopenia was associated with decreased response rates to cyclophosphamide, methotrexate, cyclosporin A, and steroids. In contrast, a high LGL number (> 2000/µL) in the peripheral blood smear was associated with increased response rates to cyclophosphamide, methotrexate, cyclosporin A, and steroids. This study describes the clinical features and treatment outcomes of patients with T-LGLL, providing valuable information for clinical decision-making regarding T-LGLL treatment.

Real-world outcome of patients with extensively pretreated multiple myeloma who were treated with selinexor and dexamethasone: a Korean multicenter retrospective analysis.

The outcomes of patients with myeloma after exposed to penta-classes are extremely poor. Selinexor is the first approved exportin inhibitor for those patients, but intractable toxicities may limit its use. This retrospective study evaluated the real-world efficacy and safety of selinexor plus dexamethasone (XD) and involved 48 patients with multiple myeloma, who were treated from November 2020 to October 2022. Their median age was 64 years, and the median number of prior lines of therapy was 6. The overall response rate was 25%, and the median progression-free survival (PFS) was 2.1 months (95% confidence interval (CI), 1.7-2.5). Patients on a reduced initial dose, delayed treatment, and dose reduction had better PFS. After XD treatment failure, 17 patients received subsequent therapy and had a median PFS of 2.4 months. The median overall survival was 4.6 months (95% CI, 2.3-6.9). Among the patients, 12 (25%) and 17 (35%) experienced dose reduction and delayed treatment, respectively. Our data show that the real-world efficacy of XD treatment in heavily pretreated patients was modest and that improving treatment adherence through reducing initial doses or delaying treatments may improve patient outcomes.

Effects of tertiary palliative care on the pattern of end-of-life care in patients with hematologic malignancies in Korea.

INTRODUCTION: Patients with hematologic malignancies (HMs) often face challenges in accessing palliative care (PC) and receiving quality end-of-life (EOL) care. We examined factors associated with referrals to tertiary PC and the effects of tertiary PC on EOL care in patients with HMs. METHOD: We included patients with HMs who were admitted to a university-affiliated hospital and died during hospitalization between January 2018 and December 2021. We investigated the receipt of PC consultations, patient characteristics, and EOL care indicators. RESULTS: Overall, 487 patients were included in the analysis, with 156 (32%) undergoing PC consultation. Sex, residence, disease status, and admission purpose were factors associated with the likelihood of PC consultation, and there has been an increasing trend in the frequency of consultations in recent cases. A higher proportion of patients who received PC completed advance statements and life-sustaining treatment documents. Patients who received PC had lower rates of aggressive EOL care, including chemotherapy and intensive care unit admission, than those who did not receive PC. Notably, PC reduced the number of blood transfusions. CONCLUSION: Tertiary PC aims to reduce aggressive EOL care through patient-centered goal-of-care discussions. Therefore, there is an imperative need for concerted efforts toward seamless integration of PC.

Risk factors for resistant gram-positive bacteremia in febrile neutropenic patients with cancer.

BACKGROUND: Gram-positive bacteria are frequently resistant to empirical beta-lactams in febrile neutropenic patients with cancer. As microbiology and antibiotic susceptibility changes, we reevaluated the risk factors for resistant Gram-positive bacteremia in febrile neutropenic patients with cancer. METHODS: Episodes of bacteremic febrile neutropenia in Seoul National University Hospital from July 2019 to June 2022 were reviewed. Resistant Gram-positive bacteria were defined as a pathogen susceptible only to glycopeptide or linezolid in vitro (e.g., methicillin-resistant staphylococci, penicillin-resistant viridans streptococci, and ampicillin-resistant enterococci). Episodes were compared to identify independent risk factors for resistant Gram-positive bacteremia. RESULTS: Of 225 episodes, 78 (34.7%) involved resistant Gram-positive bacteremia. Multivariate analysis revealed that breakthrough bacteremia while being administered antibiotics (adjusted odds ratio [aOR], 6.794; 95% confidence interval [95% CI], 3.130-14.749; P < 0.001) and catheter-related infection (aOR 4.039, 95% CI 1.366-11.946; P = 0.012) were associated with resistant Gram-positive bacteremia. Chronic liver disease (aOR 0.231, 95% CI 0.059-0.905; P = 0.035) and hypotension at bacteremia (aOR 0.454, 95% CI 0.218-0.945; P = 0.035) were inversely associated with resistant Gram-positive bacteremia. CONCLUSIONS: Resistant Gram-positive bacteria should be considered in breakthrough bacteremia and catheter-related infection in febrile neutropenic patients with cancer.

ITDetect: a method to detect internal tandem duplication of FMS-like tyrosine kinase (FLT3) from next-generation sequencing data with high sensitivity and clinical application.

Internal tandem duplication (ITD) of the FMS-like tyrosine kinase (FLT3) gene is associated with poor clinical outcomes in patients with acute myeloid leukemia. Although recent methods for detecting FLT3-ITD from next-generation sequencing (NGS) data have replaced traditional ITD detection approaches such as conventional PCR or fragment analysis, their use in the clinical field is still limited and requires further information. Here, we introduce ITDetect, an efficient FLT3-ITD detection approach that uses NGS data. Our proposed method allows for more precise detection and provides more detailed information than existing in silico methods. Further, it enables FLT3-ITD detection from exome sequencing or targeted panel sequencing data, thereby improving its clinical application. We validated the performance of ITDetect using NGS-based and experimental ITD detection methods and successfully demonstrated that ITDetect provides the highest concordance with the experimental methods. The program and data underlying this study are available in a public repository.

Comparison of the effect of DLI according to cell sources in relapsed AML after allogeneic stem cell transplantation.

For relapsed acute myeloid leukemia (AML) patients who received allogeneic hematopoietic stem cell transplantation, donor lymphocyte infusion (DLI) is an effective therapy. However, the cell source of DLI remains a topic of debate. In this study, we aimed to compare the efficacy and safety of G-CSF mobilized cells (G-DLI) with conventionally collected DLI (C-DLI). A total of 81 patients (50 C-DLI vs. 31 G-DLI) were assessed for clinical outcomes. There were no statistically significant differences in the baseline characteristics between the two groups including AML risk, donor types, interval from relapse to DLI, and infused CD3+ cell count. Although not statistically significant, complete remission (CR) and chimerism conversion rates were higher in G-DLI than in C-DLI: 51.6% vs. 28.0%, P = 0.057 and 42.3% vs. 28.2%, P = 0.363, respectively. There was no difference in acute graft-versus-host disease (GVHD) incidence and severity of acute GVHD between the two groups. The median overall survival (OS) of the G-DLI and C-DLI groups was 139 days and 106 days, respectively (P = 0.58). In conclusion, G-DLI appears to be a safe and an equally efficacious substitute for C-DLI, which is more readily available.

Clinical outcomes after incomplete cycles of R-CHOP for diffuse large B-cell lymphoma: 10 years' real-world experience in a single institute.

Although the current standard of care for diffuse large B-cell lymphoma (DLBCL) is six cycles of rituximab/cyclophosphamide/doxorubicin/vincristine/prednisolone combination chemotherapy (R-CHOP), a larger than expected number of patients cannot complete planned six cycles for various reasons in the real world. We aimed to evaluate the prognosis of patients with DLBCL after incomplete treatment by analyzing the chemotherapy response and survival according to the cause of discontinuation and the number of cycles. We analyzed a retrospective cohort of patients diagnosed with DLBCL who underwent incomplete cycles of R-CHOP at Seoul National University Hospital and Boramae Medical Center from January 2010 to April 2019. A total of 1183 patients were diagnosed with DLBCL, of which 260 (22%) did not complete six cycles of R-CHOP. The most common cause of discontinuation of chemotherapy was life-threatening infection, and the most common pathogen was Pneumocystis jirovecii. Overall survival (OS) and progression-free survival (PFS) were significantly better in patients who achieved complete response (CR) or partial response (PR) at the first response evaluation. Patients underwent three or more cycles of chemotherapy had a longer OS than those who did not. In patients with limited-stage disease, consolidative radiotherapy showed a significant improvement in OS and PFS. Advanced stage, high comorbidity score, and poor primary response to chemotherapy were poor prognostic factors in patients with unplanned treatment shortening. This study provides real-world outcomes for patients who could not complete the planned six cycles of R-CHOP.

A randomized phase II study of acyclovir for the prevention of chemotherapy-induced oral mucositis in patients undergoing autologous hematopoietic stem cell transplantation.

OBJECTIVES: To prove our hypothesis that acyclovir prophylaxis in autologous hematopoietic stem cell transplantation (AHSCT) recipients with hematologic malignancies (HM) reduces the incidence of chemotherapy-induced oral mucositis (CIOM) by inhibiting the intraoral HSV reactivation during the neutropenic period, we conducted a randomized phase II study of acyclovir for the prevention of CIOM in adult HSV sero-positive AHSCT recipients. METHODS: Patients were randomized to either the study group (acyclovir 400 mg PO bid until neutrophil engraftment) or the control group (no prophylaxis) and received AHSCT. Oral examination and sampling for HSV were performed at three timepoints of AHSCT. RESULTS: In 54 patients who were randomized (for intention-to-analysis), the incidence of CIOM was 16.0% (4/25 patients) and 58.6% (17/29 patients) in the study group and the control group, respectively (P = 0.001). In 49 patients who completed the study (for per-protocol analysis), the incidence of CIOM was 13.0% (3/23 patients) and 61.5% (16/26 patients) in the study group and the control group, respectively (P = 0.001). In addition, HSV-1 PCR positivity in the study group was significantly lower than that the control group (4.3% vs. 46.2%, P = 0.001). A strong association between the HSV-1 reactivation status and CIOM was reconfirmed. CONCLUSIONS: Prophylactic use of oral acyclovir effectively reduced the incidence of CIOM in patients with HM who were undergoing AHSCT. TRIAL REGISTRATIONS: This trial was registered at the Clinical Research Information Service in the Republic of Korea under the number KCT0003885 (registration date 03/05/2019).

Characteristics of Sweet syndrome in patients with or without malignancy.

Sweet syndrome is a neutrophilic dermatosis occasionally associated with malignancies. Due to its rarity, the clinical features of Sweet syndrome are still unclear. Thus, we aimed to analyze clinical features, treatment, and outcomes of these patients according to associated disease. We conducted a retrospective, longitudinal cohort study from January 2000 to August 2020. We reviewed the medical records of 52 patients with Sweet syndrome. The median age of patients was 57.5 years old (range, 17-84), and 48.1% were female. Of the 52 patients analyzed, 27 patients (51.9%) had malignancy-associated Sweet syndrome. Sweet syndrome was diagnosed concurrently with (N = 8), before (N = 5), and after (N = 14) the diagnosis of malignancy. The idiopathic Sweet syndrome was most common in the non-malignancy group (56.0%). Myelodysplastic syndrome was the most common malignancy associated with Sweet syndrome (47.6%). Leukopenia (p = 0.005), anemia (p < 0.001), and thrombocytopenia (p = 0.008) were significantly associated with malignancy. The majority of patients showed rapid improvement of symptoms after steroid administration. The symptoms of some patients with malignancy did not improve with steroid alone; however, their symptoms often improved when steroids were combined with a treatment for the associated malignancy. Relapse and aggravation of Sweet syndrome were common in the malignancy group. Sweet syndrome showed a broad spectrum of clinical features related to various diseases. Sweet syndrome often occurred as a paraneoplastic feature. Therefore, active systemic evaluation is needed in the first diagnosis of Sweet syndrome without clear etiology.

Eltrombopag for Post-Transplant Poor Graft Function in East Asian Patients.

Poor graft function (PGF) is a serious, potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation. Eltrombopag has shown multilineage responses in patients with refractory severe aplastic anemia, supporting the idea that it may improve cytopenia in patients with PGF. This retrospective, single center analysis included 8 Korean patients receiving eltrombopag for PGF. Median interval between transplant and eltrombopag treatment was 73 days, and the median duration treatment was 3.5 weeks. With median maximum daily dose of 50 mg, the time to best response was 93 days. Median hemoglobin increased from 8.2 g/dL to 10.9 g/dL, platelet from 18.5 × 109/L to 54 × 109/L, and absolute neutrophil count from 1.25 × 109/L to 3.32 × 109/L. In conclusion, eltrombopag is a good option for PGF in Korean patients, even at a lower dose compared to western patients.

Population-based study on the association between autoimmune disease and lymphoma: National Health Insurance Service-National Sample Cohort 2002-2015 in Korea.

BACKGROUND: We aimed to evaluate the association between autoimmune disease (AID) and lymphoma incidence in the Korean population. We also aimed to compare the overall survival (OS) in patients with AID-associated lymphoma (AAL) with that in patients with lymphoma without AID. MATERIAL AND METHODS: We used National Sample Cohort 2002-2015 provided by National Health Insurance Service. Among 1,011,638 patients, 994,496 were recruited for the final cohort: 130,987 patients (13.2%) in the AID group and 863,509 (86.8%) in control. Lymphoma was diagnosed in 1162 patients and 322 patients with accompanying AID, irrespective of the time point of diagnosis, were defined as AAL. Of those, patients who experienced lymphoma development at least one year after AID diagnosis were defined as post-AID lymphoma (N = 155). RESULTS: The median follow-up duration was 13.7 years. AAL accounted for 0.03% of total and 27.7% of lymphoma cases. AID patients experienced more Epstein-Barr virus (0.02 vs. 0.01%, P = 0.027) or Helicobacter pylori infection (63.9 vs. 41.4%, P < 0.001) than the control group did. AID was associated with a 1.45-fold increased risk of lymphoma. The median time interval from AID to AAL was 10.9 months. The risk of lymphoma increased in the order of: psoriasis (adjusted odds ratio [AOR] 1.61), systemic lupus erythematosus (AOR 3.99), multiple sclerosis (AOR 4.52), and sarcoidosis (AOR 26.37). Sjogren syndrome was not related to lymphoma in this cohort. The 5-year OS in AAL was not different from that in lymphoma patients without AID (60.9 vs. 61.5%, P = 0.970). CONCLUSIONS: The association patterns in AAL in Korean population were different from those of Western countries. Further studies on lymphomatogenesis from distinct baseline characteristics (e.g. chronic infection status) would elucidate the difference based on race and ethnicity.

Preconditioning Absolute Lymphocyte Count and Transplantation Outcomes in Matched Related Donor Allogeneic Hematopoietic Stem Cell Transplantation Recipients with Reduced-Intensity Conditioning and Antithymocyte Globulin Treatment.

The integration of antithymocyte globulin (ATG) into therapy has significantly reduced the incidence of graft-versus-host disease (GVHD) and is being actively used in allogeneic hematopoietic stem cell transplantation (allo-HSCT). The ATG dosage is determined by the recipient's body weight, but some insist that this approach does not reflect the actual target of ATG. In this respect, weight-based dosing may lead to ATG overdose, particularly in recipients with a relatively low absolute lymphocyte count (ALC). We retrospectively analyzed 84 patients with acute leukemia or myelodysplastic syndrome who underwent matched related donor (MRD) allo-HSCT with reduced-intensity conditioning (RIC) at a single institution. Patients were dichotomized according to the ALC measured on the first day of conditioning (day -7) to investigate the associations of the ALC with GVHD and survival outcomes. The median duration of follow-up was 29 months. The preconditioning ALC was closely correlated with the ALC at the first ATG administration (day -3). The cumulative incidences of both acute GVHD and chronic GVHD were significantly lower in the preconditioning ALC <500/µL group compared with the ALC ≥500/µL group. There was no significant difference in disease relapse incidence between the 2 groups; however, mortality was significantly higher in the ALC <500/µL group. Multivariate analysis including disease status, modified European Blood and Marrow Transplantation score, and preconditioning ALC (≥500/µL versus <500/µL) identified disease status and ALC as being independently associated with overall survival (OS). In particular, infection was the most common cause of death in the ALC <500/µL group. Our data suggest that uniform weight-based ATG dosing in MRD allo-HSCT with RIC is associated with an increase in nonrelapse mortality and a relatively inferior OS in patients with a significantly low preconditioning ALC. Therefore, alternative strategies for the integration of ATG should be considered in allo-HSCT, at least for patients with a substantially low preconditioning ALC.

Clinical features and treatment outcomes of limited-stage mantle cell lymphoma: Consortium for Improving Survival of Lymphoma report.

Limited-stage (Ann Arbor stage I or II) mantle cell lymphoma (MCL) is an extremely rare disease. Thus, there is little data on the clinical features and treatment outcomes of patients with early-stage MCL. We examined consecutive stage I or II MCL 41 cases diagnosed between 2000 and 2016 in 16 institutions of the Consortium for Improving Survival of Lymphoma group. All cases were pathologically confirmed and systemic evaluation was performed for staging. The clinical features were reviewed, and the treatment outcomes were analyzed. The median age of patients was 66 years (range 19-85 years); there were more men (n = 31, 75.6%) than women. Most patients (n = 28, 68.3%) had stage 2 disease, and 29 (70.7%) were symptomatic. The elevation of lactate dehydrogenase (n = 2, 4.9%) was not common; thus, 39 patients (95.1%) had a low-risk score (0 or 1) for the International Prognostic Index, and 28 (68.3%) had a low-risk score (1-3) for the MCL International Prognostic Index. Most patients (n = 37, 90.1%) received chemotherapy as the first therapeutic strategy, while some received radiotherapy (n = 2), surgical resection (n = 1), or no treatment (n = 1). Of the patients who received chemotherapy, 23 (56.9%) received a rituximab-containing regimen, and R-CHOP (n = 17) and R-bendamustine (n = 5) were commonly used. The best response was noted in 97.4% (n = 38) of patients, including 32 who showed a complete response (78%). With a median follow-up duration of 40.6 months, the 42 months relapse-free survival was 59.1%, and the 5-year overall survival rate was 80.4%. Limited-state MCL showed indolent clinical and low-risk prognostic features. Chemotherapy could be effective for controlling localized MCL lesions, with high complete response rates.

Epidemiology of Congenital Bleeding Disorders: a Nationwide Population-based Korean Study.

BACKGROUND: Except for data in the Korea Hemophilia Foundation Registry, little is known of the epidemiology of congenital bleeding disorders in Korea. METHODS: Data were obtained from the Korean Health Insurance Review and Assessment Service (HIRA) database. RESULTS: From 2010 to 2015, there were 2,029 patients with congenital bleeding disorders in the Korean HIRA database: 38% (n = 775) of these patients had hemophilia A (HA), 25% (n = 517) had von Willebrand disease (vWD), 7% (n = 132) had hemophilia B (HB), and 25% (n = 513) had less common factor deficiencies. The estimated age-standardized incidence rate (ASR) of HA and HB was 1.78-3.15/100,000 and 0.31-0.51/100,000, respectively. That of vWD was 1.38-1.95/100,000. The estimated ASR of HA showed increase over time though the number of new patients did not increase. Most patients with congenital bleeding disorders were younger than 19 years old (47.8%), and most were registered in Gyeonggi (22.1%) and Seoul (19.2%). CONCLUSION: This is the first nationwide population-based study of congenital bleeding disorders in Korea. This study provides data that will enable more accurate estimations of patients with vWD. This information will help advance the comprehensive care of congenital bleeding disorders. We need to continue to obtain more detailed information on patients to improve the management of these diseases.

Comparison of quality of life and health behaviors in survivors of acute leukemia and the general population.

We aimed to compare the health-related quality of life and health behaviors of acute leukemia (AL) survivors with that of the general population from two cohorts. AL survivors (n = 149) completed a set of questionnaires to evaluate quality of life, mental status, and health behaviors. AL survivors had more physical and mental difficulties (problems with usual activities, 15% vs. 5%, p < 0.001; anxiety or depression, 24% vs. 9%, p < 0.001; pain, 35% vs. 20%, p = 0.002) and more financial difficulties (p < 0.001) than the general population. Survivors who received stem cell transplantation (SCT) had significantly worse problems with role functioning, fatigue, pain, dyspnea, and insomnia, and had higher depression scores than chemotherapy group (p = 0.024). In terms of health behaviors, AL survivors had lower rates of smoking and drinking and higher influenza vaccination rates than the general population. However, only 17% of survivors had been recommended to receive screening for other cancers from health-care providers, and 67% thought their risk for other cancers was equal or lower than that of the general population. Cancer screening rates were even lower in the SCT group than in the chemotherapy group (p = 0.041). Our study indicates that clinicians should establish more appropriate survivorship care plans.

Hemoglobin Concentration Reference Interval Revisited: a Nationwide Study from Korea.

BACKGROUND: Anemia is a common cause among the elderly for increased mortality. Hemoglobin concentration can be affected by many factors, but the reference interval defined by the World Health Organization has not been adjusted for the previous half century. METHODS: Through using the dataset generated by the National Health Insurance (NHI) health screening program of Republic of Korea, here we attempt to present a close to actual hemoglobin concentration of the Korean population. Between January 2009 and December 2013, a total of 57,409,872 health screening events were registered in the NHI database. Following the exclusion criteria, 6,759,566 participants were enrolled for analyses. RESULTS: Significant portion of the study population was considered 'anemic', while the mean value (2.5% ~ 97.5%) of hemoglobin concentration from the study was 14.8 (12.5 ~ 16.8) g/dL in men and 12.8 (10.6 ~ 14.7) g/ dL in women. Concordant results of hemoglobin concentration declining with age were observed as previous studies have described, supporting the need for separate, possibly lower cutoff in the elderly. CONCLUSIONS: A considerable portion of the participants being categorized as anemia contests the accuracy of the current lower cutoff for anemia. From a large representative dataset, the need for adjustment to the lower cutoff for anemia is suggested.

Real world epidemiology of myeloproliferative neoplasms: a population based study in Korea 2004-2013.

Myeloproliferative neoplasms (MPNs), with an expected increment in number, impose substantial economic and social burdens. To this end, we conducted a nationwide population-based descriptive epidemiology study. We also investigated medical cost associated with MPNs. Prevalence was the highest for essential thrombocythemia (ET) (range 4.1-9.0 per 100,000), followed by polycythemia vera (PV) (range 2.8-5.4 per 100,000) and primary myelofibrosis (PMF) (range 0.5-0.9 per 100,000). ET incurred the highest cumulative total cost at US$35 million and the most frequent hospital visits, while PMF incurred the highest average cost per person at US$5000. The mean hemoglobin level was 16.9 ± 2.2 g/dL for PV males and 15.5 ± 2.7 g/dL for PV females. Further analyses on hemoglobin levels showed the true positive rate of PV from the significantly elevated hemoglobin group (defined as >18.5 g/dL for men and >16.5 g/dL for women) was 3.01% and that of MPNs was 3.1%. Here, we provide the biggest population-based report on MPN epidemiology that can readily be used as a representative Asian data.