Prevalence and risk factors of iron overload after hematopoietic stem cell transplantation for childhood acute leukemia: a LEA study

How I treat long-term survivors of childhood acute leukemia

ABSTRACT

The population of survivors of childhood leukemia who reach adulthood is growing due to improved therapy. However, survivors are at risk of long-term complications. Comprehensive follow-up programs play a key role in childhood leukemia survivor care. The major determinant of long-term complications is the therapeutic burden accumulated over time. Relapse chemotherapy, central nervous system irradiation, hematopoietic stem cell transplantation, and total body irradiation are associated with greater risk of long-term complications. Other parameters include clinical characteristics such as age and sex as well as environmental, genetic, and socioeconomic factors, which can help stratify the risk of long-term complications and organize follow-up program. Early diagnosis improves the management of several late complications such as anthracycline-related cardiomyopathy, secondary cancers, metabolic syndrome, development defects, and infertility. Total body irradiation is the treatment associated with worse long-term toxicity profile with a wide range of complications. Patients treated with chemotherapy alone are at a lower risk of long-term complications, although the optimal long-term follow-up remains unclear. Novel immunotherapies and targeted therapy are generally associated with a better short-term safety profile but still require careful long-term toxicity monitoring. Advances in understanding genetic susceptibility to long-term complications could enable tailored therapeutic strategies for leukemia treatment and optimized follow-up programs.

Iron Overload Following Hematopoietic Stem Cell Transplantation: Prevalence, Severity, and Management in Children and Adolescents with Malignant and Nonmalignant Diseases

Iron overload (IOL) is a frequently reported complication following hematopoietic stem cell transplantation (HSCT) that has been investigated extensively in the field of hemoglobinopathies but has not been thoroughly characterized after HSCT in pediatric malignancies. Our aim was to assess prevalence, severity, risk factors, and management of IOL, as defined using biochemical (serum ferritin) and radiologic tools (T2*-weighted magnetic resonance imaging [MRI]), in a cohort of pediatric patients who underwent HSCT for either malignant or benign diseases. This monocentric, retrospective, observational study included all the 163 patients alive and in continuous remission at 24 months post-HSCT out of the 219 consecutive children and adolescents who underwent HSCT at our institution between 2012 and 2018, were included in the study. IOL was classified into 4 categories: absent, mild, moderate, and severe. Among the 163 patients, 73% had some degree of IOL (mild in 37%, moderate in 29%, and severe in 7%). Moderate/severe IOL was more frequent among patients diagnosed with a malignant disease versus those with a benign disease (43% versus 19%; P = .0065). Trend lines for serum ferritin showed a "bell-shaped" distribution, with the highest levels recorded during the first 6 months post-HSCT, followed by a spontaneous reduction. Both pre-HSCT (1659 ng/mL versus 617 ng/mL; P < .001) and maximum post-HSCT (2473 ng/mL versus 1591 ng/mL; P < .001) median ferritin levels were statistically higher in the patients with malignancies. Radiologic assessment of IOL confirmed a more severe degree in patients with malignant disorders compared to those with benign disorders (median T2*-MRI, 4.20 msec [interquartile range (IQR), 3.0 to 6.40 msec] versus 7.40 msec [IQR, 4.90 to 11.00 msec]; P = .008). T2* levels were associated with the number of transfusions performed (P = .0006), with a steeper drop in T2* values for the first 20 transfusions and a milder slope for subsequent transfusions. T2* and ferritin values showed a statistically significant negative exponential relationship (P < .0001), although a ferritin level ≥1000 ng/mL showed poor specificity (48%) and low positive predictive value (53%) for discriminating moderate-to-severe IOL from absent-mild IOL as assessed by T2*-MRI, but with high sensitivity (92%) and negative predictive value (91%). In a multivariable model, >20 transfusions (odds ratio [OR], 4.07; 95% confidence interval [CI], 1.61 to 10.68; P = .003) and higher pre-HSCT ferritin level (P < .001) were associated with the risk of developing moderate-to-severe IOL. Use of a sibling donor (OR, .29; 95% CI, .10 to .77; P = .015) and a nonmalignancy (OR, .27; 95% CI, .08 to .82; P = .026) were protective factors. Phlebotomy (66%), low-dose oral chelators (9%), or a combined approach (25%) were started at a median of 12 months after HSCT in 78% of the patients with IOL. Six percent of the patients treated exclusively with phlebotomy (median, 14, significantly higher in patients >40 kg) discontinued phlebotomy owing to poor venous access, lack of compliance, or hypotension, whereas 39% of patients treated with chelators developed mild renal or hepatic side effects that resolved after tapering or discontinuation. Patients with malignancies showed statistically higher pre-HSCT and post-HSCT ferritin levels and lower T2* values. High ferritin level recorded on T2*-MRI showed unsatisfactory diagnostic accuracy in predicting IOL; thus, T2*-MRI should be considered a key tool for confirming IOL after HSCT in patients with an elevated serum ferritin level. IOL treatment is feasible after HSCT.

Estimation of iron overload with T2*MRI in children treated for hematological malignancies

Iron overload may contribute to long-term complications in childhood cancer survivors. There are limited reports of assessment of tissue iron overload in childhood leukemia by magnetic resonance imaging (MRI). A cross-sectional, observational study in children treated for hematological malignancy was undertaken. Patients ≥6 months from the end of therapy who had received ≥5 red-cell transfusions were included. Iron overload was estimated by serum ferritin (SF) and T2*MRI. Forty-five survivors were enrolled among 431 treated for hematological malignancies. The median age at diagnosis was 7-years. A median of 8 red-cell units was transfused. The median duration from the end of treatment was 15 months. An elevated SF (>1,000 ng/ml), elevated liver iron concentration (LIC) and myocardial iron concentration (MIC) were observed in 5 (11.1%), 20 (45.4%), and 2 (4.5%) patients, respectively. All survivors with SF >1,000 ng/ml had elevated LIC. The LIC correlated with SF (p < 0.001). MIC lacked correlation with SF or LIC. Factors including the number of red-cell units transfused and duration from the last transfusion were associated with elevated SF (p = 0.001, 0.002) and elevated LIC (p = 0.012, 0.005) in multiple linear regression. SF >595 ng/ml predicted elevated LIC with a sensitivity of 85% and specificity of 91.6% (AUC 91.2%). A cutoff >9 units of red cell transfusions had poor sensitivity and specificity of 70% and 75% (AUC 76.6%) to predict abnormal LIC. SF >600 ng/ml is a robust tool to predict iron overload, and T2*MRI should be considered in childhood cancer survivors with SF exceeding 600 ng/ml.

Irradiation Causes Alterations of Polyamine, Purine, and Sulfur Metabolism in Red Blood Cells and Multiple Organs

Investigating the metabolic effects of radiation is critical to understand the impact of radiotherapy, space travel, and exposure to environmental radiation. In patients undergoing hemopoietic stem cell transplantation, iron overload is a common risk factor for poor outcomes. However, no studies have interrogated the multiorgan effects of these treatments concurrently. Herein, we use a model that recapitulates transfusional iron overload, a condition often observed in chronically transfused patients. We applied an omics approach to investigate the impact of both the iron load and irradiation on the host metabolome. The results revealed dose-dependent effects of irradiation in the red blood cells, plasma, spleen, and liver energy and redox metabolism. Increases in polyamines and purine salvage metabolites were observed in organs with high oxygen consumption including the heart, kidneys, and brain. Irradiation also impacted the metabolism of the duodenum, colon, and stool, suggesting a potential effect on the microbiome. Iron infusion affected the response to radiation in the organs and blood, especially in erythrocyte polyamines and spleen antioxidant metabolism, and affected glucose, methionine, and glutathione systems and tryptophan metabolism in the liver, stool, and the brain. Together, the results suggest that radiation impacts metabolism on a multiorgan level with a significant interaction of the host iron status.

Late hepatic toxicity surveillance for survivors of childhood, adolescent and young adult cancer: Recommendations from the international late effects of childhood cancer guideline harmonization group

BACKGROUND

Survivors of childhood, adolescent and young adult (CAYA) cancer may develop treatment-induced chronic liver disease. Surveillance guidelines can improve survivors' health outcomes. However, current recommendations vary, leading to uncertainty about optimal screening. The International Late Effects of Childhood Cancer Guideline Harmonization Group has developed recommendations for the surveillance of late hepatotoxicity after CAYA cancer.

METHODS

Evidence-based methods based on the GRADE framework were used in guideline development. A multidisciplinary guideline panel performed systematic literature reviews, developed evidence summaries, appraised the evidence, and formulated recommendations on the basis of evidence, clinical judgement, and consideration of benefits versus the harms of the surveillance while allowing for flexibility in implementation across different health care systems.

RESULTS

The guideline strongly recommends a physical examination and measurement of serum liver enzyme concentrations (ALT, AST, gGT, ALP) once at entry into long-term follow-up for survivors treated with radiotherapy potentially exposing the liver (moderate- to high-quality evidence). For survivors treated with busulfan, thioguanine, mercaptopurine, methotrexate, dactinomycin, hematopoietic stem cell transplantation (HSCT), or hepatic surgery, or with a history of chronic viral hepatitis or sinusoidal obstruction syndrome, similar surveillance for late hepatotoxicity once at entry into LTFU is reasonable (low-quality evidence/expert opinion, moderate recommendation). For survivors who have undergone HSCT and/or received multiple red blood cell transfusions, surveillance for iron overload with serum ferritin is strongly recommended once at long-term follow-up entry.

CONCLUSIONS

These evidence-based, internationally-harmonized recommendations for the surveillance of late hepatic toxicity in cancer survivors can inform clinical care and guide future research of health outcomes for CAYA cancer survivors.

PROGNOSIS OF ACUTE LEUKEMIA DEPENDING ON THE IRON METABOLISM PARAMETERS IN CHILDREN AFTER CHORNOBYL NUCLEAR POWER PLANT ACCIDENT

OBJECTIVE

To determine the influence of iron metabolism on the prognosis of acute lymphoblastic (ALL) and (AML)myeloblastic leukemia at the different phases of chemotherapy in children after Chоrnobyl accident.

MATERIALS AND METHODS

333 children (295 - ALL, 38 - AML) were examined at the stages of chemotherapy. Thecomparison group included 93 children without leukemia. Acute leukemia variants, patients survival, relapses, thenature of disease (live child or died), iron methabolism (morphometric parameters of erythrocytes, SI, SF, STf, TS),manifestations of dyserythropoiesis, bone marrow sideroblast and patients radiation dose were taken into account.

RESULTS

In 295 patients with ALL the following variants of leukemia were established: pro-B-ALL in 23, «common»type of ALL in 224, pre-B-ALL in 29, T-ALL in 19. Thirty eight patients were diagnosed with AML (11 - M1, 19 - M2,8 - M4). Doses of radiation in patients with AL were (2.78 ± 0.10) mSv and they did not correlate with clinical andhematological parameters, disease variant. Relapse rates and shorter survival were in patients with T-ALL, pro-B-ALLand AML with SF levels > 500 ng/ml (p < 0.05). The amount of children with normochromic-normocytic anemias andmanifestations of dysplasia of erythroid lineage elements was greater in the AML than in ALL. SF content in patientswas elevated during chemotherapy and was lower than the initial one only in the remission period. Transferrin wasreliably overloaded with iron: TS (70.2 ± 2.3) % compared with the control group (32.7 ± 2.1) %. Correlationbetween TS and survival of patients was detected (rs = -0.45). Direct correlation between the number of iron granules in erythrocariocytes and SF level (rs = 0.43) was established, indicating the phenomena of ineffective erythropoiesis.

CONCLUSIONS

The negative influence of iron excess in the patients body on the hemopoiesis function, manifestations of ineffective erythropoiesis and the course of acute leukemia in children have been established. Changes inferrokinetic processes in children can be the basis of leukemоgenesis development.

Iron overload after allogeneic stem cell transplantation in children with acute lymphoblastic leukemia

Red blood cell transfusions are an essential part of supporting care in leukemia treatment. We examined the prevalence of iron overload and its effects on organ function and childhood growth in pediatric patients after allogeneic HSCT for acute lymphoblastic leukemia. Twenty-three patients were included (median age 12.6, range 7.5-21.4 years). Body iron load was determined using laboratory tests, hepatic and cardiac MRI, and by calculating iron received from transfusions. We performed multivariate analysis to determine association of body iron load with liver enzymes, cardiac function, insulin resistance, and growth. Median plasma ferritin was 344 (range 40-3235) ng/mL and exceeded 1000 ng/mL in three patients (13%). In MRI, 11 patients (48%) had hepatic iron overload and 1 patient (4%) myocardial iron overload. In cardiac MRI, 8 patients (35%) had significant but subclinical decrease in ejection fraction (median z-score -1.7, range -3.1-0.14), but cardiac function did not associate with iron status. Alanine transaminase associated with transfused iron per time unit (P = .001) after the median follow-up of 4.5 years. No correlation was found between iron load and growth or insulin resistance. Iron overload is common in children transplanted for ALL, but iron overload associated organ dysfunction is not present at early age. We recommend evaluation of iron load for all patients at least once during follow-up after transplantation.

Long-term Follow-up of Hematopoietic Stem Cell Transplant Survivors: A Focus on Screening, Monitoring, and Therapeutics

Annually, ~50,000 patients undergo hematopoietic stem cell transplantation (HCT) worldwide with almost 22,000 of these patients receiving HCT in the United States. HCT is a curative option for a wide range of hematologic malignancies, and advances in transplantation medicine have resulted in an increase in HCT survivors. It is anticipated that the number of HCT survivors will more than double from 242,000 in 2020 to ~500,000 in 2030. Survivors of HCT are at an increased risk of developing late complications due to exposure to chemotherapy and/or radiation in the pre-, peri-, and post-HCT phases and these cumulative exposures have the potential to damage normal tissue. This tissue damage leads to the early onset of chronic health conditions resulting in premature mortality in HCT survivors, who have a 15-year cumulative incidence of severe or life-threatening chronic health conditions exceeding 40%. Due to the significant burden of morbidity in HCT survivors and the delay in the development of long-term complications, this delicate patient population requires life-long monitoring due to the risk for neuropsychological, cardiac, pulmonary, renal, hepatic, ocular, skeletal, cardiac, endocrine, fertility, and sexual health complications, as well as secondary neoplasms. This review will focus on recent advances in screening, monitoring, and therapeutics for late-occurring or long-term complications in HCT survivors.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately, the improved prognosis has been accompanied by the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors, the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies, it is important to know the risk of, and associated risk factors for, hepatic late adverse effects. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate all the existing evidence on the association between antineoplastic treatment (that is, chemotherapy, radiotherapy involving the liver, surgery involving the liver and BMT) for childhood cancer and hepatic late adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2018, Issue 1), MEDLINE (1966 to January 2018) and Embase (1980 to January 2018). In addition, we searched reference lists of relevant articles and scanned the conference proceedings of the International Society of Paediatric Oncology (SIOP) (from 2005 to 2017) and American Society of Pediatric Hematology/Oncology (ASPHO) (from 2013 to 2018) electronically.

SELECTION CRITERIA

All studies, except case reports, case series, and studies including fewer than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection and 'risk of bias' assessment. The 'risk of bias' assessment was based on earlier checklists for observational studies. For the original version of the review, two review authors independently performed data extraction. For the update of the review, the data extraction was performed by one reviewer and checked by another reviewer.

MAIN RESULTS

Thirteen new studies were identified for the update of this review. In total, we included 33 cohort studies including 7876 participants investigating hepatic late adverse effects after antineoplastic treatment (especially chemotherapy and radiotherapy) for different types of childhood cancer, both haematological and solid malignancies. All studies had methodological limitations. The prevalence of hepatic late adverse effects, all defined in a biochemical way, varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well-defined as alanine aminotransferase (ALT) above the upper limit of normal, indicating cellular liver injury, resulted in eight studies. In this subgroup, the prevalence of hepatic late adverse effects ranged from 5.8% to 52.8%, with median follow-up durations varying from three to 23 years since cancer diagnosis in studies that reported the median follow-up duration. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal, resulted in five studies, with a prevalence ranging from 0.9% to 44.8%. One study investigated biliary tract injury, defined as gamma-glutamyltransferase (γGT) above the upper limit of normal and above twice the upper limit of normal and reported a prevalence of 5.3% and 0.9%, respectively. Three studies investigated disturbance in biliary function, defined as bilirubin above the upper limit of normal and reported prevalences ranging from 0% to 8.7%. Two studies showed that treatment with radiotherapy involving the liver (especially after a high percentage of the liver irradiated), higher BMI, and longer follow-up time or older age at evaluation increased the risk of cellular liver injury in multivariable analyses. In addition, there was some suggestion that busulfan, thioguanine, hepatic surgery, chronic viral hepatitis C, metabolic syndrome, use of statins, non-Hispanic white ethnicity, and higher alcohol intake (> 14 units per week) increase the risk of cellular liver injury in multivariable analyses. Chronic viral hepatitis was shown to increase the risk of cellular liver injury in six univariable analyses as well. Moreover, one study showed that treatment with radiotherapy involving the liver, higher BMI, higher alcohol intake (> 14 units per week), longer follow-up time, and older age at cancer diagnosis increased the risk of biliary tract injury in a multivariable analysis.

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects among studies with an adequate outcome definition varied considerably from 1% to 53%. Evidence suggests that radiotherapy involving the liver, higher BMI, chronic viral hepatitis and longer follow-up time or older age at follow-up increase the risk of hepatic late adverse effects. In addition, there may be a suggestion that busulfan, thioguanine, hepatic surgery, higher alcohol intake (>14 units per week), metabolic syndrome, use of statins, non-Hispanic white ethnicity, and older age at cancer diagnosis increase the risk of hepatic late adverse effects. High-quality studies are needed to evaluate the effects of different therapy doses, time trends, and associated risk factors after antineoplastic treatment for childhood cancer.

The impact of severe late-effects after 12 Gy fractionated total body irradiation and allogeneic stem cell transplantation for childhood leukemia (1988-2010)

This study consists of a retrospective study including 71 childhood leukemia survivors (36 females) treated with allo-HSCT 12 Gy fractionated total body irradiation (fTBI) conditioning, with a median age of 25.0 y at time of follow-up and a median delay of 14.8 y since the graft. The recovery ratio was 90%. The number of severe late-effects was specified for each patient: 21 with growth deficiency (final height <162.5 cm for 12/35 men and <152.0 cm for 9/36 women - Growth deficiency was correlated to young age at the time of the allograft); 5 with sclerodermic chronic graft vs. host disease; 9 with osteonecrosis; risk of impaired fertility for 25 women and 28 men (only 2 women had a child); 8 with diabetes; 5 with pulmonary late-effects including 1 death; 5 with chronic renal insufficiency including 1 death; 2 with cardiac late-effects; 2 with arterial high blood pressure; 11 (8 women) declared 14 subsequent cancers (7 with thyroid carcinomas, 3 with multiple squamous cell carcinomas, 2 with epidermoïdis carcinomas of the tongue or the lip, 1 with bone sarcoma, and 1 with carcinoma of the breast); 6 with chelating treatments of hemochromatosis; 14 with important educational underachievement; 11 with depression at adult age; 1 with hepatitis B virus infection; 4 with other severe late-effects, including 2 with blindness. The average number of severe late-effects was 2.3 with a positive correlation according to delay from fTBI (p < 0.0002). Two-thirds had at least 2 late-effects. These results emphasize the urgent abandonment of conditioning by TBI in children.

Adolescence and Socioeconomic Factors: Key Factors in the Long-Term Impact of Leukemia on Scholastic Performance-A LEA Study

OBJECTIVE

To evaluate the association between medical and social environmental factors and the risk of repeating a grade in childhood leukemia survivors.

STUDY DESIGN

A cross-sectional study of childhood leukemia survivors, recruited through the LEA cohort (Leucémie de l'Enfant et de l'Adolescent [French Childhood Cancer Survivor Study for Leukemia]) in 2014. An adjusted logistic regression model was used to identify variables linked to repeating a grade after the diagnosis among the survivors, and the rates of repeating a grade were compared between the survivors and their siblings using a multilevel logistic regression model.

RESULTS

The mean age at inclusion of the 855 participants was 16.2 ± 7.0 years, and the mean duration of follow-up from diagnosis to evaluation was 10.2 ± 6.2 years. After disease onset, 244 patients (28.5%) repeated a grade, with a median interval of 4 years (IQR, 2-8 years). Independent factors associated with repeating a grade were male sex (OR, 1.78; 95% CI, 1.21-2.60), adolescence (OR, 2.70; 95% CI, 1.63-4.48), educational support during the treatment period (OR, 3.79; 95% CI, 2.45-5.88), low parental education level (OR, 2.493; 95% CI, 1.657-3.750), and household financial difficulties (OR, 2.62; 95% CI, 1.607-4.28). Compared with siblings, survivors were at greater risk of repeating a grade (OR, 1.87; 95% CI, 1.48-2.35).

CONCLUSIONS

The most vulnerable patients seemed to be adolescents and those with parents of low socioeconomic status. Improving the schooling career of leukemia survivors will require that the medical community more carefully consider the social status of patients.

Long-term follow-up after childhood cancer in France supported by the SFCE-force and weakness-current state, results of a questionnaire and perspectives

OBJECTIVE

The survival rate of children treated for cancer is currently about 80% at 5 years and we estimate that about 50,000 adults in France have survived childhood cancer. In 2011, there was a call for projects relating to long-term follow-up (LTFU), which led to several studies being conducted. Five years later, we sent a questionnaire to present LTFU in France and describe its strengths and weaknesses and to establish appropriate steps that should be taken.

METHODS

A questionnaire was sent by email to all the members of the French Society of Childhood Cancers in spring 2016. The study involved 44 centres/hospitals with a Paediatric Oncology Department.

RESULTS

54 answers were analysed, provided by 31/44 (70%) centres working together with the French Society of Childhood Cancers. Screening is the main objective of LTFU care (90%). The main difficulties that arose were: lack of sufficient time to devote to this activity (57%), difficulties contacting adult childhood cancer survivors (aCCSs) (26%), aCCSs who ultimately did not show up to the consultation (19%), cost (15%), and lack of organization (13%). Seven LTFU programmes were identified: two regional organizations (Rhône Alpes and Grand Ouest), four centre-size organizations, and one national study (involving 15 Haematology Centres) relating to Child and Adolescent Leukaemia.

CONCLUSION

LTFU is a major concern for French centres specialized in paediatric oncology. Organization is not well defined and difficulties still arise (Who are the best care providers? What frequency of care is most appropriate? etc.). Advances in knowledge: LTFU focused on health problems (physical, psychological, social, economic issues) that affect CCSs is needed to ensure that these patients regain the most optimal physical and emotional health possible. Practitioners suggest different ways to improve LTFU, such as national co-operation with Epidemiology Registers to promote homogenous LTFU care.

Genetic hemochromatosis: Pathophysiology, diagnostic and therapeutic management

The term hemochromatosis (HC) corresponds to several diseases characterized by systemic iron overload of genetic origin and affecting both the quality of life and life expectancy. Major improvement in the knowledge of iron metabolism permits to divide these diseases into two main pathophysiological categories. For most HC forms (types 1, 2, 3 and 4B HC) iron overload is related to cellular hepcidin deprivation which causes an increase of plasma iron concentration and the appearance of plasma non-transferrin bound iron. In contrast, iron excess in type 4A ferroportin disease is related to decreased cellular iron export. Whatever the HC type, the diagnosis rests on a non-invasive strategy, combining clinical, biological and imaging data. The mainstay of the treatment remains venesection therapy with the perspective of hepcidin supplementation for hepcidin deprivation-related HC. Prevention of HC is critical at the family level and, for type 1 HC, remains a major goal, although still debated, at the population level.