The impact of chelation therapy on survival in transfusional iron overload: a meta-analysis of myelodysplastic syndrome

Risk of transfusion-related iron overload varies based on oncologic diagnosis and associated treatment: Retrospective analysis from a single pediatric cancer center

BACKGROUND

Transfusion-related iron overload (TRIO) is a widely acknowledged late effect of antineoplastic therapy in pediatric cancer survivors, but firm guidelines as to screening protocols or at-risk populations are lacking in the literature.

PROCEDURE

We performed retrospective analysis of all oncology patients diagnosed at our center from 2014 to 2019, who underwent TRIO screening as part of an internal quality improvement project. Correlations of MRI-confirmed TRIO with patient-, disease-, and treatment-specific features were evaluated.

RESULTS

We show that a tiered screening algorithm for TRIO, when followed as intended, led to the identification of the highest proportion of patients with TRIO. We confirm that cardiac TRIO is quite rare in the oncology patient population. However, accepted surrogate markers including red blood cell transfused volume and ferritin only modestly correlated with TRIO in our patient cohort. Instead, we found that older age, leukemia diagnosis, anthracycline exposure, and receipt of stem cell transplant were most strongly associated with risk for TRIO.

CONCLUSIONS

We describe associations between TRIO and patient, disease, and treatment characteristics in a multivariate risk model that could lead to an improved risk stratification of off-therapy patients, and which should be validated in a prospective manner.

The Role of Hepcidin in Myelodysplastic Syndromes (MDS): A Systematic Review of Observational Studies

Iron overload emerges as a serious complication in myelodysplastic syndromes (MDS), particularly associated with frequent transfusions during the course of the disease. The discovery and description of hepcidin's mechanisms of action have contributed to a deeper understanding of iron metabolism. The existing literature reports a potential role of hepcidin in MDS, yet these data are fragmented and presented in an unstructured, somewhat chaotic manner. Hence, to address the existing data, we performed a systematic review of observational studies examining hepcidin levels in MDS. An extensive review of three bibliographic databases (Pubmed, Web of Science, and Scopus) enabled us to identify 12 observational studies. These studies focused primarily on adult patients with low-risk MDS who underwent transfusions and chelation therapy. An in-depth analysis of these manuscripts led to four main conclusions: (1) although high serum hepcidin levels are associated with MDS, most studies generally have not found a significant difference in these levels between patients and healthy individuals; (2) serum hepcidin levels are specific to MDS type; (3) serum hepcidin levels in MDS are strongly associated with transfusions and the genetic status of patients; and (4) high-risk MDS is associated with high serum hepcidin levels. While we have furnished a comprehensive summary of the significance of hepcidin in MDS, there are still gaps that future research should address. This pertains primarily to the capacity of hepcidin in predicting adverse outcomes for MDS patients and evaluating the efficacy of chelation therapy or the need for transfusion.

Supportive Care for Patients With Myelodysplastic Syndromes

ABSTRACT

Myelodysplastic syndromes are a heterogeneous group of bone marrow disorders characterized by ineffective hematopoiesis, progressive cytopenias, and an innate capability of progressing to acute myeloid leukemia. The most common causes of morbidity and mortality are complications related to myelodysplastic syndromes rather than progression to acute myeloid leukemia. Although supportive care measures are applicable to all patients with myelodysplastic syndromes, they are especially essential in patients with lower-risk disease who have a better prognosis compared with their higher-risk counterparts and require longer-term monitoring of disease and treatment-related complications. In this review, we will address the most frequent complications and supportive care interventions used in patients with myelodysplastic syndromes, including transfusion support, management of iron overload, antimicrobial prophylaxis, important considerations in the era of COVID-19 (coronavirus infectious disease 2019), role of routine immunizations, and palliative care in the myelodysplastic syndrome population.

Exploring the rationale for red cell transfusion in myelodysplastic syndrome patients: emerging data and future insights

INTRODUCTION

Anemia is often present in mostly elderly patients with myelodysplastic syndromes (MDS), and is associated with a poorer outcome. Although Red blood cell (RBC) transfusions are the most immediate treatment, waiting for the response to disease-specific therapy, or in case of non-response, the choice of the optimal transfusion regimen is still controversial.

AREAS COVERED

The main objectives of RBC transfusion are the control of anemia-related symptoms and complications and the improvement of functional status and of health-related quality of life (HRQoL). However, RBC transfusions are associated with several negative clinical consequences, mainly adverse transfusion reactions and iron overload, which can be counteracted by iron chelation therapy. Recent few pilot prospective trials have shown a benefit, in terms of HRQoL, of more liberal transfusion regimens, with higher haemoglobin (Hb) targets, compared to conventional restrictive regimens, but these results need confirmation by larger studies.

EXPERT OPINION

: A patient-oriented RBC transfusion therapy in MDS patients must take into account several laboratory (Hb), clinical (age, comorbidities), psychological, family and social factors, and evaluation of HRQoL should become a fundamental parameter in assessing the clinical benefit of therapy. Many questions remain to be clarified, including why some patients report little benefit from transfusions.

Prognostic Factors and Clinical Considerations for Iron Chelation Therapy in Myelodysplastic Syndrome Patients

Iron chelation therapy (ICT) is an important tool in the treatment of transfusion-dependent lower-risk myelodysplastic syndrome (MDS) patients. ICT is effective in decreasing iron overload and consequently in limiting its detrimental effects on several organs, such as the heart, liver, and endocrine glands. Besides this effect, ICT also proved to be effective in improving peripheral cytopenia in a significant number of MDS patients, thus further increasing the clinical interest of this therapeutic tool. In the first part of the review, we will analyze the toxic effect of iron overload and its mechanism. Subsequently, we will revise the clinical role of ICT in various subsets of MDS patients (low, intermediate, and high risk MDS, patients who are candidates for allogeneic stem cell transplantation).

From Biology to Clinical Practice: Iron Chelation Therapy With Deferasirox

Iron chelation therapy (ICT) has become a mainstay in heavily transfused hematological patients, with the aim to reduce iron overload (IOL) and prevent organ damage. This therapeutic approach is already widely used in thalassemic patients and in low-risk Myelodysplastic Syndrome (MDS) patients. More recently, ICT has been proposed for high-risk MDS, especially when an allogeneic bone marrow transplantation has been planned. Furthermore, other hematological and hereditary disorders, characterized by considerable transfusion support to manage anemia, could benefit from this therapy. Meanwhile, data accumulated on how iron toxicity could exacerbate anemia and other clinical comorbidities due to oxidative stress radical oxygen species (ROS) mediated by free iron species. Taking all into consideration, together with the availability of approved oral iron chelators, we envision a larger use of ICT in the near future. The aim of this review is to better identify those non-thalassemic patients who can benefit from ICT and give practical tips for management of this therapeutic strategy.

Management of the Older Patient with Myelodysplastic Syndrome

No two diagnoses of myelodysplastic syndrome are genuinely alike, owing to differing and dynamic mutational topography and epigenetic aberrancy. Consequently, no two patients with myelodysplastic syndrome are identical and disease-specific and patient-specific factors are considered in formulating the optimal treatment, which includes few that are disease modifying. Age itself should not be an absolute contraindication to therapy, including intensive therapy such as allogeneic hematopoietic stem cell transplantation, which is the only curative therapy. However, age associates with an increased prevalence of frailty and comorbidities that must be considered and may preclude a path to cure. Palliative therapies are the mainstay for many patients with myelodysplastic syndrome, which is a disease of older adults with the majority of patients diagnosed at age ≥ 75 years. The older patient requires heightened attention to end organ function/reserve and drug-drug interactions as well as insurance, income, cost, and socioeconomic and psychosocial issues that influence management. Many prior studies have included relatively younger populations or have not specifically performed high-quality subgroup analyses of older patients. In this review, we discuss the available standard-of-care therapies for myelodysplastic syndrome as they specifically relate to the older population and assess the emerging therapeutics that may further the pursuit for personalized treatment and improve both the outcomes and quality of life of the older patient with myelodysplastic syndrome.

Iron overload-induced oxidative stress in myelodysplastic syndromes and its cellular sequelae

The myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders. MDS patients often require red blood cell transfusions, resulting in iron overload (IOL). IOL increases production of reactive oxygen species (ROS), oxygen free radicals. We review and illustrate how IOL-induced ROS influence cellular activities relevant to MDS pathophysiology. ROS damage lipids, nucleic acids in mitochondrial and nuclear DNA, structural proteins, transcription factors and enzymes. Cellular consequences include decreased metabolism and tissue and organ dysfunction. In hematopoietic stem cells (HSC), consequences of ROS include decreased glycolysis, shifting the cell from anaerobic to aerobic metabolism and causing HSC to exit the quiescent state, leading to HSC exhaustion or senescence. ROS oxidizes DNA bases, resulting in accumulation of mutations. Membrane oxidation alters fluidity and permeability. In summary, evidence indicates that IOL-induced ROS alters cellular signaling pathways resulting in toxicity to organs and hematopoietic cells, in keeping with adverse clinical outcomes in MDS.

Myelodysplastic syndromes: moving towards personalized management

The myelodysplastic syndromes (MDS) share their origin in the hematopoietic stem cell but have otherwise very heterogeneous biological and genetic characteristics. Clinical features are dominated by cytopenia and a substantial risk for progression to acute myeloid leukemia. According to the World Health Organization, MDS is defined by cytopenia, bone marrow dysplasia and certain karyotypic abnormalities. The understanding of disease pathogenesis has undergone major development with the implementation of next-generation sequencing and a closer integration of morphology, cytogenetics and molecular genetics is currently paving the way for improved classification and prognostication. True precision medicine is still in the future for MDS and the development of novel therapeutic compounds with a propensity to markedly change patients' outcome lags behind that for many other blood cancers. Treatment of higher-risk MDS is dominated by monotherapy with hypomethylating agents but novel combinations are currently being evaluated in clinical trials. Agents that stimulate erythropoiesis continue to be first-line treatment for the anemia of lower-risk MDS but luspatercept has shown promise as second-line therapy for sideroblastic MDS and lenalidomide is an established second-line treatment for del(5q) lower-risk MDS. The only potentially curative option for MDS is hematopoietic stem cell transplantation, until recently associated with a relatively high risk of transplant-related mortality and relapse. However, recent studies show increased cure rates due to better tools to target the malignant clone with less toxicity. This review provides a comprehensive overview of the current status of the clinical evaluation, biology and therapeutic interventions for this spectrum of disorders.

Iron chelation therapy for myelodysplastic syndrome: a systematic review and meta-analysis

Iron overload remains a concern in myelodysplastic syndrome (MDS) patients especially those requiring recurrent blood transfusions. Whether iron chelating therapy (ICT) is beneficial to the long-term survival of myelodysplastic syndrome is still a controversial issue. Therefore, we conducted a systematic review and meta-analysis to clarify the relationship between ICT and long-term survival in patients with MDS. A total of 14 studies involving 7242 participants were identified; the outcomes revealed that for patients with MDS, ICT resulted in a lower risk of mortality compared to those with no ICT (HR 0.57; 95% CI 0.44-0.70; P < 0.001); what is more, ICT led to a lower risk of leukemia transformation (HR 0.70; 95% CI 0.52-0.93; P = 0.016). Results of subgroup analyses based on adequate ICT or any ICT, low/int-1 IPSS or unclassified IPSS and study types indicated that the ICT had a beneficial role in all these groups of patients.

Allogeneic stem cell transplant in myelodysplastic syndrome-factors impacting survival

OBJECTIVES

The primary aim of this study was to evaluate survival outcomes following allo-HCT in myelodysplastic syndrome (MDS), and the secondary aim was to study variables impacting survival.

METHODS

This analysis describes patient characteristics, treatment, and outcomes in 125 consecutive adult patients with MDS transplanted from 2005 to 2018.

RESULTS

The median age was 61 years, and median follow-up in patients alive at last follow-up was 29 months. The 2-year OS and RFS were 39% (95%CI 30%-48%) and 35.3% (95% CI: 27%-44%), respectively. Transfusion dependence, high-risk cytogenetics, and high serum ferritin were independent risk factors for death. The cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) at 2 years were 23% and 41.6%, respectively. High serum ferritin was significantly associated with NRM. There was no association between the percentage of bone marrow blasts (either at diagnosis or at pretransplant evaluation), on relapse or survival. Induction chemotherapy did not offer any survival advantage in MDS RAEB-2 patients compared to cytoreduction with azacytidine alone.

CONCLUSION

Our results highlight the importance of karyotype on survival after allo-HCT and identify serum ferritin and transfusion dependence as important surrogate markers of outcome. In addition, our results demonstrate the efficacy of azacytidine for pretransplant cytoreduction.

Impact of treatment with iron chelation therapy in patients with lower-risk myelodysplastic syndromes participating in the European MDS registry

Iron overload due to red blood cell (RBC) transfusions is associated with morbidity and mortality in lower-risk myelodysplastic syndrome (MDS) patients. Many studies have suggested improved survival after iron chelation therapy (ICT), but valid data are limited. The aim of this study was to assess the effect of ICT on overall survival and hematologic improvement in lower-risk MDS patients in the European MDS registry. We compared chelated patients with a contemporary, non-chelated control group within the European MDS registry, that met the eligibility criteria for starting iron chelation. A Cox proportional hazards model was used to assess overall survival (OS), treating receipt of chelation as a time-varying variable. Additionally, chelated and non-chelated patients were compared using a propensity-score matched model. Of 2,200 patients, 224 received iron chelation. The hazard ratio and 95% confidence interval for OS for chelated patients, adjusted for age, sex, comorbidity, performance status, cumulative RBC transfusions, Revised-International Prognostic Scoring System (IPSS-R), and presence of ringed sideroblasts was 0.50 (0.34-0.74). The propensity-score analysis, matched for age, sex, country, RBC transfusion intensity, ferritin level, comorbidity, performance status, and IPSS-R, and, in addition, corrected for cumulative RBC transfusions and presence of ringed sideroblasts, demonstrated a significantly improved OS for chelated patients with a hazard ratio of 0.42 (0.27-0.63) compared to non-chelated patients. Up to 39% of chelated patients reached an erythroid response. In conclusion, our results suggest that iron chelation may improve OS and hematopoiesis in transfused lower-risk MDS patients. This trial was registered at clinicaltrials.gov identifier: 00600860.

Systematic review and meta-analysis of the effect of iron chelation therapy on overall survival and disease progression in patients with lower-risk myelodysplastic syndromes

The impact of iron chelation therapy (ICT) on overall survival (OS) and progression to acute myeloid leukemia (AML) in patients with iron overload and International Prognostic Scoring System low- or intermediate-risk myelodysplastic syndromes (MDS) is not well understood. We conducted a systematic review and meta-analysis of published studies of ICT in patients with MDS to better elucidate these relationships. We searched PubMed, EMBASE, Cochrane databases, and the World Health Organization Clinical Trial Registry for studies reporting the impact of ICT on OS in patients with low- or intermediate-risk MDS. Studies were examined for demographics, effect measures, and potential bias risk. Fixed and random-effects models were used to calculate adjusted OS and adjusted hazards ratio (aHR) estimates, respectively, among the different studies. Nine observational studies (four prospective and five retrospective) were identified. For patients with MDS, ICT was associated with an overall lower risk of mortality compared with no ICT (aHR 0.42; 95% confidence interval (CI) 0.28-0.62; P < 0.01); however, there was significant heterogeneity across the studies. In studies reporting progression to AML, ICT was not associated with decreased risk of progression (odds ratio 0.68; 95% CI 0.31-1.43; P < 0.030). This systematic review and meta-analysis of nine nonrandomized trials demonstrated significant reduction in risk of mortality in patients with iron overload and low- or intermediate-risk MDS treated with ICT; however, a causal relationship cannot be established. Randomized, controlled trials are needed to more definitively evaluate the relationship between ICT and survival in patients with iron overload and low- or intermediate-risk MDS.

Iron overload in myelodysplastic syndromes: Evidence based guidelines from the Canadian consortium on MDS

In 2008 the first evidence-based Canadian consensus guideline addressing the diagnosis, monitoring and management of transfusional iron overload in patients with myelodysplastic syndromes (MDS) was published. The Canadian Consortium on MDS, comprised of hematologists from across Canada with a clinical and academic interest in MDS, reconvened to update these guidelines. A literature search was updated in 2017; topics reviewed include mechanisms of iron overload induced cellular damage, evidence for clinical endpoints impacted by iron overload including organ dysfunction, infections, marrow failure, overall survival, acute myeloid leukemia progression, and endpoints around hematopoietic stem-cell transplant. Evidence for an impact of iron reduction on the same endpoints is discussed, guidelines are updated, and areas identified where evidence is suboptimal. The guidelines address common questions around the diagnosis, workup and management of iron overload in clinical practice, and take the approach of who, when, why and how to treat iron overload in MDS. Practical recommendations for treatment and monitoring are made. Evidence levels and grading of recommendations are provided for all clinical endpoints examined.

Ferritin level changes and erythroid improvement in a group of adult polytransfused patients treated with Deferasirox

Background and aims

Chelating agents therapy is recommended for polytransfused patients that have evidence of iron overload (an elevated serum ferritin or received over 20 units of red blood cell transfusions). Deferasirox showed efficacy and safety in maintaining or reducing body iron. Iron chelation therapy was associated with hematopoiesis improvement in transfusion-dependent patients.Our objectives were to analyze differences in ferritin level in adult polytransfused patients treated with Deferasirox, to estimate the erythroid improvement and variation of the number of red blood cell transfusion after introducing Deferasirox, to evaluate the side effects of the treatment.

Methods

Retrospective study including all the adult polytransfused patients treated with Deferasirox in Hematology Departments of three county hospitals in the North-West of Romania.

Results

We included 40 polytransfused patients treated with Deferasirox in standard doses. There was a significant reduction in serum ferritine from baseline for all the patients (Friedman test, χ2(2)=26.82, p<0.001). Safety profile of Deferasirox was good (three digestive side effects). RBCT were administered before (mean 2.43±1.09 units/month) and after starting Deferasirox (mean 1.40±0.97 units/month), the difference is statistically significant (Student Test, t(39)=6.98, p<0.001).

Conclusions

Deferasirox proves to be an effective iron chelator, the serum level of ferritine decreased for all the patients during the treatment and 22.5 % of the patients developed an erythroid improvement. Safety and compliance were good.

Clinical consequences of iron overload in patients with myelodysplastic syndromes: the case for iron chelation therapy

INTRODUCTION

Patients with myelodysplastic syndromes (MDS) are at increased risk of iron overload due to ineffective erythropoiesis and chronic transfusion therapy. The clinical consequences of iron overload include cardiac and/or hepatic failure, endocrinopathies, and infection risk. Areas covered: Iron chelation therapy (ICT) can help remove excess iron and ultimately reduce the clinical consequences of iron overload. The authors reviewed recent (last five years) English-language articles from PubMed on the topic of iron overload-related complications and the use of ICT (primarily deferasirox) to improve outcomes in patients with MDS. Expert commentary: While a benefit of ICT has been more firmly established in other transfusion-dependent conditions, such as thalassemia, its role in reducing iron overload in MDS remains controversial due to the lack of prospective controlled data demonstrating a survival benefit. Orally administered chelation agents (e.g. deferasirox) are now available, and observational and/or retrospective data support a survival benefit of using ICT in MDS. The placebo-controlled TELESTO trial (NCT00940602) is currently examining the use of deferasirox in MDS patients with iron overload, and is evaluating specifically whether use of ICT to alleviate iron overload can also reduce iron overload-related complications in MDS and improve survival.

To chelate or not to chelate in MDS: That is the question!

Myelodysplastic syndromes (MDS) are a heterogeneous group of hemopathies that exhibit physical manifestations with clinical consequences of bone marrow failure and inherent risk of progression to acute myeloid leukemia. Iron overload (IO) is common in MDS due to chronic transfusion support and disease-related alterations in iron metabolism. IO has been conclusively associated with inferior outcomes among MDS patients. Despite lack of randomized trials showing a survival impact of iron chelation therapy (ICT), ICT is recommended by experts and guidelines for select MDS patients with IO and is often used. The availability of effective oral ICT agents has reignited the controversy regarding ICT use in patients with MDS and IO. Here we summarize the studies evaluating the value of ICT in MDS and suggest a practical approach for use of these therapies. We also highlight controversies regarding use of ICT in MDS and discuss some ongoing efforts to answer these questions.

Iron overload in lower international prognostic scoring system risk patients with myelodysplastic syndrome receiving red blood cell transfusions: Relation to infections and possible benefit of iron chelation therapy

BACKGROUND

An increased incidence of infections and infectious mortality has been reported in myelodysplastic syndromes (MDS) patients receiving red blood cell (RBC) transfusions.

METHODS

We examined incidence of infections requiring antibiotics, antifungal or antiviral medications in transfused lower International Prognostic Scoring System (IPSS) risk MDS patients and whether this differed with iron chelation therapy (ICT).

RESULTS

138 transfused MDS patients were lower IPSS risk. 59 received ICT; median duration was 13 months. There was no significant difference between groups in neutrophil count at first RBC transfusion or first infection. Infections included: bacterial, n = 88; viral; fungal; and mycobacterial; n = 2 each. In ICT and non-ICT patients, respectively, infections were (number [%]): patients, 23 (40.0%) and 22 (27.8%); episodes (median [range]), 2 (1-6) and 2 (1-5); hospitalizations, 16 (27.1%) and 8 (10.1%); and deaths, 0 (0%) and 1 (1.3%), p = NS for all. Median overall survival (OS) from first RBC transfusion was superior in ICT patients, p = 0.01, and remained significant in a multivariate analysis (MVA), p = 0.003. Median time to first infection (TTI) was 27 and 7.8 months, respectively, p < 0.0001, and ICT remained significant for TTI in an MVA, p = 0.02, hazard ratio 0.3. For ICT patients with blast count <5%, TTI was significantly superior (p = 0.004).

CONCLUSIONS

In this retrospective analysis, for lower IPSS risk MDS patients receiving RBC transfusions, though number and type of infections were similar between groups and despite similar neutrophil counts, time to first infection was significantly longer in ICT patients (p < 0.0001). These results should be confirmed in larger, prospective analyses.

Iron Overload in Myelodysplastic Syndromes: Pathophysiology, Consequences, Diagnosis, and Treatment

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic neoplasms varying in severity affecting one or more lines of hematopoiesis. Ineffective erythropoiesis results in dysregulation of iron metabolism. Most MDS patients have anemia, and some require regular red blood cell transfusions. These transfusions, in addition to factors of the disease itself, can result in iron overload (IO). Retrospective analyses suggest that MDS patients with IO have reduced overall survival and poorer outcomes following allogeneic stem cell transplant vs. those without IO. Iron chelation therapy (ICT; deferoxamine, deferasirox, or deferiprone) has been used to alleviate IO in other transfusion-dependent hematologic conditions (e.g., thalassemia), but its role in MDS has not been firmly established. A growing body of evidence suggests that ICT in MDS patients is an effective means for reducing transfusional IO and may significantly improve outcomes such as survival. The orally administered iron chelator deferasirox has been widely studied in MDS, and available studies have shown it to be generally well tolerated and effective in reducing IO in this population. The pathophysiology and clinical consequences of IO in MDS, as well as current methods for diagnosing and treating IO in these patients, are discussed.

Observational Monitoring of Patients with Aplastic Anemia and Low/Intermediate-1 Risk of Myelodysplastic Syndromes Complicated with Iron Overload

BACKGROUND

This study focuses on the iron overload (IOL) of patients with transfused aplastic anemia (AA) or a low/intermediate-1 risk of myelodysplastic syndrome (MDS).

METHODS

Ninety-two AA or MDS patients with IOL were prospectively recruited. Clinical data were collected every 6 months, and organ magnetic resonance imaging T2* values were collected annually. Patients with IOL were chelated.

RESULTS

Serum ferritin was correlated with liver T2* and pancreatic T2* in the AA and MDS groups. Transfusion amounts were correlated with serum ferritin values, liver T2*, and pancreatic T2* in the AA group. At the 6-month and 1-year evaluations, patients with sufficient chelation experienced significant decreases in serum ferritin, and those with decreased serum ferritin experienced an obvious increase in hemoglobin. At their 1-year-follow-up, patients with adequate chelation showed significant increases in hepatic T2*, cardiac T2*, and left ventricular ejection fraction (LVEF). Patients with decreased serum ferritin (including those without chelation) experienced an increase in hemoglobin, hepatic T2*, cardiac T2*, and LVEF.

CONCLUSION

The transfusion amount was more reliable at predicting IOL in patients with AA than in those with MDS. Adequate iron chelation can decrease serum ferritin levels and may improve hepatic T2*, cardiac T2*, and LVEF levels. A decrease in serum ferritin, even in the absence of chelation, may also benefit patients.

Management of iron overload in hemoglobinopathies: what is the appropriate target iron level?

Patients with thalassemia become iron overloaded from increased absorption of iron, ineffective erythropoiesis, and chronic transfusion. Before effective iron chelation became available, thalassemia major patients died of iron-related cardiac failure in the second decade of life. Initial treatment goals for chelation therapy were aimed at levels of ferritin and liver iron concentrations associated with prevention of adverse cardiac outcomes and avoidance of chelator toxicity. Cardiac deaths were greatly reduced and survival was much longer. Epidemiological data from the general population draw clear associations between increased transferrin saturation (and, by inference, labile iron) and early death, diabetes, and malignant transformation. The rate of cancers now seems to be significantly higher in thalassemia than in the general population. Reduction in iron can reverse many of these complications and reduce the risk of malignancy. As toxicity can result from prolonged exposure to even low levels of excess iron, and survival in thalassemia patients is now many decades, it would seem prudent to refocus attention on prevention of long-term complications of iron overload and to maintain labile iron and total body iron levels within a normal range, if expertise and resources are available to avoid complications of overtreatment.

Overcoming barriers to treating iron overload in patients with lower-risk myelodysplastic syndrome

Myelodysplastic syndromes (MDS) constitute a group of heterogeneous hematopoietic neoplasms characterized by ineffective erythropoiesis, anemia, and/or cytopenias. Supportive care for patients with MDS involves frequent red blood cell transfusions, which places patients with ongoing transfusional dependence (TD) at risk for iron overload (IO). Development of IO and tissue iron deposition can increase the risk of cardiac, hepatic, and endocrine toxicities, infection, and progression to acute myeloid leukemia. Iron chelation therapy (ICT) is an option for lower-risk MDS patients to reduce their degree of IO and possibly improve survival; use of these agents in thalassemia patients with TD and IO has been associated with reduced IO-associated complications and better survival. At present, there are several barriers to the regular use of ICT, such as a lack of randomized trial evidence and consistent guidance on diagnosis of IO and when to implement ICT, as well as barriers in adherence to/tolerability of ICT.

Overall survival in lower IPSS risk MDS by receipt of iron chelation therapy, adjusting for patient-related factors and measuring from time of first red blood cell transfusion dependence: an MDS-CAN analysis

Analyses suggest iron overload in red blood cell (RBC) transfusion-dependent (TD) patients with myleodysplastic syndrome (MDS) portends inferior overall survival (OS) that is attenuated by iron chelation therapy (ICT) but may be biassed by unbalanced patient-related factors. The Canadian MDS Registry prospectively measures frailty, comorbidity and disability. We analysed OS by receipt of ICT, adjusting for these patient-related factors. TD International Prognostic Scoring System (IPSS) low and intermediate-1 risk MDS, at RBC TD, were included. Predictive factors for OS were determined. A matched pair analysis considering age, revised IPSS, TD severity, time from MDS diagnosis to TD, and receipt of disease-modifying agents was conducted. Of 239 patients, 83 received ICT; frailty, comorbidity and disability did not differ from non-ICT patients. Median OS from TD was superior in ICT patients (5·2 vs. 2·1 years; P < 0·0001). By multivariate analysis, not receiving ICT independently predicted inferior OS, (hazard ratio for death 2·0, P = 0·03). In matched pair analysis, OS remained superior for ICT patients (P = 0·02). In this prospective, non-randomized analysis, receiving ICT was associated with superior OS in lower IPSS risk MDS, adjusting for age, frailty, comorbidity, disability, revised IPSS, TD severity, time to TD and receiving disease-modifying agents. This provides additional evidence that ICT may confer clinical benefit.

Iron-chelating therapy with deferasirox in transfusion-dependent, higher risk myelodysplastic syndromes: a retrospective, multicentre study

Iron chelation is controversial in higher risk myelodysplastic syndromes (HR-MDS), outside the allogeneic transplant setting. We conducted a retrospective, multicentre study in 51 patients with transfusion-dependent, intermediate-to-very high risk MDS, according to the revised international prognostic scoring system, treated with the oral iron chelating agent deferasirox (DFX). Thirty-six patients (71%) received azacitidine concomitantly. DFX was given at a median dose of 1000 mg/day (range 375-2500 mg) for a median of 11 months (range 0·4-75). Eight patients (16%) showed grade 2-3 toxicities (renal or gastrointestinal), 4 of whom (8%) required drug interruption. Median ferritin levels decreased from 1709 μg/l at baseline to 1100 μg/l after 12 months of treatment (P = 0·02). Seventeen patients showed abnormal transaminase levels at baseline, which improved or normalized under DFX treatment in eight cases. One patient showed a remarkable haematological improvement. At a median follow up of 35·3 months, median overall survival was 37·5 months. The results of this first survey of DFX in HR-MDS are comparable, in terms of safety and efficacy, with those observed in lower-risk MDS. Though larger, prospective studies are required to demonstrate real clinical benefits, our data suggest that DFX is feasible and might be considered in a selected cohort of HR-MDS patients.

Myelodysplastic Syndromes and Iron Chelation Therapy

Over recent decades we have been fortunate to witness the advent of new technologies and of an expanded knowledge and application of chelation therapies to the benefit of patients with iron overload. However, extrapolation of learnings from thalassemia to the myelodysplastic syndromes (MDS) has resulted in a fragmented and uncoordinated clinical evidence base. We’re therefore forced to change our understanding of MDS, looking with other eyes to observational studies that inform us about the relationship between iron and tissue damage in these subjects. The available evidence suggests that iron accumulation is prognostically significant in MDS, but levels of accumulation historically associated with organ damage (based on data generated in the thalassemias) are infrequent. Emerging experimental data have provided some insight into this paradox, as our understanding of iron-induced tissue damage has evolved from a process of progressive bulking of organs through high-volumes iron deposition, to one of ‘toxic’ damage inflicted through multiple cellular pathways. Damage from iron may, therefore, occur prior to reaching reference thresholds, and similarly, chelation may be of benefit before overt iron overload is seen. In this review, we revisit the scientific and clinical evidence for iron overload in MDS to better characterize the iron overload phenotype in these patients, which differs from the classical transfusional and non-transfusional iron overload syndrome. We hope this will provide a conceptual framework to better understand the complex associations between anemia, iron and clinical outcomes, to accelerate progress in this area.

Relation between chelation and clinical outcomes in lower-risk patients with myelodysplastic syndromes: Registry analysis at 5 years

Prospective data are needed to ascertain the impact of iron chelation therapy in patients with myelodysplastic syndromes. The present 5-year prospective registry analysis was conducted to compare clinical outcomes between chelated and nonchelated patients with lower-risk myelodysplastic syndromes and transfusional iron overload. In an interim analysis at 24 months, we previously reported that chelation therapy was associated with longer median overall survival and a tendency toward longer leukemia-free survival and fewer cardiac events. In the present report, we detail findings from the final analysis at 5 years. We confirm, at the conclusion of this 5-year, prospective, non-interventional study, that overall survival was significantly longer in patients who received iron chelation therapy vs those who did not. Causes of death in the overall population were predominantly myelodysplastic syndromes/acute myeloid leukemia followed by cardiac disease. Time to progression to acute myeloid leukemia was also significantly longer in patients receiving chelation therapy, and significantly fewer patients progressed to leukemia vs those not receiving chelation therapy. Limitations of the study include a potential for clinical bias, as patients with longer predicted survival may have been chosen for chelation therapy, the differences present in concomitant conditions at baseline, and the possibility that some high-risk patients were not identified due to limited cytogenetic classification.

High pretransplant hepcidin levels are associated with poor overall survival and delayed platelet engraftment after allogeneic hematopoietic stem cell transplantation

Iron overload is considered a risk factor for mortality in patients with hematopoietic malignancies. Hepcidin is a key regulator of systemic iron balance. We previously reported dynamic changes of serum hepcidin‐25 levels in patients with hematologic malignancies after allogeneic hematopoietic stem cell transplantation (allo‐HSCT). In this study, we retrospectively analyzed the association of pretransplant hepcidin‐25 levels with overall survival (OS), engraftment, and other clinical outcomes of allo‐HSCT in patients with hematologic malignancies. A total of 166 patients were divided into two groups depending on their pretransplant serum hepcidin‐25 levels; their median age was 49.5 years, and the median follow‐up time was 46.8 months. At 3 years, the patients in the high‐hepcidin group had a significantly lower OS than those in the low‐hepcidin group (49.2 vs. 69.0%, respectively; P = 0.006). Multivariate analysis revealed that pretransplant serum hepcidin‐25 level, sex, and disease status were independently associated with OS. The incidence of platelet engraftment was significantly lower in the high‐hepcidin group than in the low‐hepcidin group, whereas no significant differences were observed in neutrophil and reticulocyte engraftments between these groups. Hence, pretransplant serum hepcidin levels can be a marker for predicting delayed platelet recovery after allo‐HSCT.

Optimizing Communication and Adherence to Iron Chelation Therapy From Diagnosis to Treatment in Patients With Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS), a heterogeneous group of blood diseases, are usually diagnosed in older individuals, with a median age at diagnosis of more than 70 years. Anemia is a common symptom in patients with MDS and may require frequent red blood cell transfusions, which can lead to iron overload. Iron chelation therapy is recommended to decrease iron concentrations in tissue and minimize organ dysfunction. However, the currently available iron chelation therapies are associated with side effects, financial constraints, and dosing issues, which may affect patient adherence. Moreover, many patients with MDS lack an understanding of the disease and their prognosis and treatments. This review can be used in the advanced practice setting to discuss the importance of communicating with patients about MDS from the time of diagnosis and will explore strategies to enhance adherence to iron chelation therapy. An individualized approach that weighs the risks and benefits of treatment for older patients with MDS will allow advanced practitioners to set expectations while developing adherence strategies to optimize outcomes. This approach provides a platform for advanced practitioners to communicate with patients to ensure they understand the natural history of MDS, their individual prognoses, and the goals of both active treatment and supportive care.

Red blood cell transfusion for hematologic disorders

Randomized clinical trials (RCTs) have determined, in surgical and critically ill patients, relatively safe hemoglobin (Hb) thresholds of 7-8 g/dL to guide restrictive transfusion of red blood cells (RBCs). However, in patients with various hematologic disorders, strong evidence in support of such an approach is sparse and the optimal transfusion practice is yet to be defined. This review focuses on RBC transfusion practice in three hematologic diseases and a treatment strategy, including autoimmune hemolytic anemia, thalassemia, myelodysplastic syndrome, and hematopoietic stem cell transplantation. These entities manifest in a broad spectrum of anemia, acute or chronic, in patients with different comorbidities and degrees of transfusion requirement. Thus the nuances in the indications of RBC transfusion and the goals to achieve in these specific situations may have been underappreciated. The limited data available highlight the importance of titrating RBC transfusion based on the clinical context and patient characteristics. Future RCTs are necessary to firmly establish the Hb thresholds associated with improved outcomes relevant to these specific patient populations, which will facilitate the personalized decision-making in RBC transfusion.

Early Cardiac Iron Overload in a Child on Treatment of Acute Lymphoblastic Leukemia

An 11-year-old boy with Down syndrome and acute lymphoblastic leukemia developed hepatic dysfunction after only 10 months of treatment. MRI revealed severe iron deposition in the liver, pancreas, and heart. In stark contrast to what is seen in hemoglobinopathies, pancreatic and cardiac iron overload occurred with relatively low transfusion exposure and in a very short time period in this patient. Although extensive experience managing iron overload in hemoglobinopathies informs our approach in other diseases, it is clear that factors not present in hemoglobinopathies may be operative in patients with malignancy undergoing intense chemotherapy that lead to high levels of free iron and rapid loading of the heart and endocrine organs.

Deferasirox in a refractory anemia after other treatment options: case report and literature review

Deferasirox, represents an effective iron chelator drug in lower risk myelodysplastic syndromes. Reduction in oxidative stress is responsible of the hematologic improvement but further explanation may impact on its benefit. Biological and clinical studies are necessary to better define mechanisms of action, assess toxicities, and predicting factors of response.

Iron toxicity and its possible association with treatment of Cancer: lessons from hemoglobinopathies and rare, transfusion-dependent anemias

Exposure to elevated levels of iron causes tissue damage and organ failure, and increases the risk of cancer. The toxicity of iron is mediated through generation of oxidants. There is also solid evidence indicating that oxidant stress plays a significant role in a variety of human disease states, including malignant transformation. Iron toxicity is the main focus when managing thalassemia. However, the short- and long-term toxicities of iron have not been extensively considered in children and adults treated for malignancy, and only recently have begun to draw oncologists' attention. The treatment of malignancy can markedly increase exposure of patients to elevated toxic iron species without the need for excess iron input from transfusion. This under-recognized exposure likely enhances organ toxicity and may contribute to long-term development of secondary malignancy and organ failure. This review discusses the current understanding of iron metabolism, the mechanisms of production of toxic free iron species in humans, and the relation of the clinical marker, transferrin saturation (TS), to the presence of toxic free iron. We will present epidemiological data showing that high TS is associated with poor outcomes and development of cancer, and that lowering free iron may improve outcomes. Finally, we will discuss the possible relation between some late complications seen in survivors of cancer and those due to iron toxicity.