Trends in transfusion burden among long-term survivors of childhood hematological malignancies

Transfusional hemosiderosis in childhood cancer patients and survivors

BACKGROUND

Children treated for cancer are at risk for adverse effects of iron due to transfusions administered during prolonged marrow suppression, which may increase exposure to toxic forms of iron, extrahepatic iron accumulation, and long-term organ damage.

OBJECTIVE

This study aimed to characterize the severity and organ distribution of clinically significant, multisystem iron overload (IO) in an at-risk cohort of pediatric cancer patients.

METHODS

This was a retrospective, cross-sectional study of childhood cancer patients who underwent a magnetic resonance imaging (MRI) due to clinical concern for IO. Data regarding cancer type and treatment, transfusion history, MRI and laboratory results, and treatment for IO were collected. Severity of IO was analyzed by non-parametric tests with respect to clinical characteristics.

RESULTS

Of the 103 patients, 98% of whom had a Cancer Intensity Treatment Rating (ITR-3) of 3 or higher, 53% (54/102) had moderate or greater hepatic siderosis, 80% (77/96) had pancreatic siderosis, 4% (3/80) had cardiac siderosis, and 45% (13/29) had pituitary siderosis and/or volume loss. Pancreatic iron was associated with both cardiac (p = .0043) and pituitary iron (p = .0101). In the 73 off-therapy patients, ferritin levels were lower (p = .0008) with higher correlation with liver iron concentration (LIC) (p = .0016) than on-therapy patients. Fifty-eight subjects were treated for IO.

CONCLUSION

In this heavily treated cohort of pediatric cancer patients, more than 80% had extrahepatic iron loading, which occurs with significant exposure to toxic forms of iron related to decreased marrow activity in setting of transfusions. Further studies should examine the effects of exposure to reactive iron on long-term outcomes and potential strategies for management.

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 in Children with Acute Lymphoblastic and Acute Myeloblastic Leukemia-Experience of One Center

Transfusions of packed red blood cells (PRBCs), given due to an oncological disease and its acute complications, are an indispensable part of anticancer therapy. However, they can lead to post-transfusion iron overload. The study aim was to evaluate the role of ferritin as a nonspecific marker of leukemic growth and marker of transfusion-related iron overload. We performed a longitudinal study of PRBC transfusions and changes in ferritin concentrations during the oncological treatment of 135 patients with childhood acute lymphoblastic and acute myeloblastic leukemia (ALL and AML, median age 5.62 years). At the diagnosis, 41% of patients had a ferritin level over 500 ng/mL, and 14% of patients had a ferritin level over 1000 ng/mL. At the cessation of the treatment, 80% of the children had serum ferritin (SF) over 500 ng/mL, and 31% had SF over 1000 ng/mL. There was no significant difference between SF at the beginning of the treatment between ALL and AML patients, but children with AML finished treatment with statistically higher SF. AML patients had also statistically higher number of transfusions. We found statistically significant positive correlations between ferritin and age, and weight and units of transfused blood. Serum ferritin at the moment of diagnosis can be a useful marker of leukemic growth, but high levels of SF are connected with iron overload in both AML and ALL.

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.

Hepatic Iron Quantification Using a Free-Breathing 3D Radial Gradient Echo Technique and Validation With a 2D Biopsy-Calibrated R2* Relaxometry Method

BACKGROUND

Hepatic iron content (HIC) is an important parameter for the management of iron overload. Non-invasive HIC assessment is often performed using biopsy-calibrated two-dimensional breath-hold Cartesian gradient echo (2D BH GRE) R2* -MRI. However, breath-holding is not possible in most pediatric patients or those with respiratory problems, and three-dimensional free-breathing radial GRE (3D FB rGRE) has emerged as a viable alternative.

PURPOSE

To evaluate the performance of a 3D FB rGRE and validate its R2* and fat fraction (FF) quantification with 3D breath-hold Cartesian GRE (3D BH cGRE) and biopsy-calibrated 2D BH GRE across a wide range of HICs.

STUDY TYPE

Retrospective.

SUBJECTS

Twenty-nine patients with hepatic iron overload (22 females, median age: 15 [5-25] years).

FIELD STRENGTH/SEQUENCE

Three-dimensional radial and 2D and 3D Cartesian multi-echo GRE at 1.5 T.

ASSESSMENT

R2* and FF maps were computed for 3D GREs using a multi-spectral fat model and 2D GRE R2* maps were calculated using a mono-exponential model. Mean R2* and FF values were calculated via whole-liver contouring and T2* -thresholding by three operators.

STATISTICAL TESTS

Inter- and intra-observer reproducibility was assessed using Bland-Altman and intraclass correlation coefficient (ICC). Linear regression and Bland-Altman analysis were performed to compare R2* and FF values among the three acquisitions. One-way repeated-measures ANOVA and Wilcoxon signed-rank tests, respectively, were used to test for significant differences between R2* and FF values obtained with different acquisitions. Statistical significance was assumed at P < 0.05.

RESULTS

The mean biases and ICC for inter- and intra-observer reproducibility were close to 0% and >0.99, respectively for both R2* and FF. The 3D FB rGRE R2* and FF values were not significantly different (P > 0.44) and highly correlated (R2  ≥ 0.98) with breath-hold Cartesian GREs, with mean biases ≤ ±2.5% and slopes 0.90-1.12. In non-breath-holding patients, Cartesian GREs showed motion artifacts, whereas 3D FB rGRE exhibited only minimal streaking artifacts.

DATA CONCLUSION

Free-breathing 3D radial GRE is a viable alternative in non-breath-hold patients for accurate HIC estimation.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Blood product administration during high risk neuroblastoma therapy

The increasing intensity of high-risk neuroblastoma (HR NB) treatment over the last decades has resulted in improved survival at the expense of prolonging therapy and exposure to additional potentially toxic agents. Anemia and thrombocytopenia requiring transfusion are common during therapy for HR NB. Risks of cumulative red blood cell and platelet transfusions are incompletely defined in pediatric oncology patients, however, risks of transfusional iron overload are well described in other populations. This study aimed to determine the number of packed red blood cell (pRBC) and platelet transfusions throughout treatment for HR NB and how these numbers have changed with modern therapy. We performed a retrospective review of 92 patients with HR NB from June 2002 until September 2017. Patients received a median of 20 pRBC and 32 platelet transfusions. Our results demonstrated large numbers of transfusions with significantly increased blood product exposures among patients who received intensified therapy, either with additional induction chemotherapy, tandem autologous stem cell transplants, or dinutuximab plus cytokines with isotretinoin. Similar volumes of pRBC transfusions have been associated with iron overload in other populations and warrant further discussion of guidelines for long-term follow up of HR NB patients.

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.

Serum Alanine Aminotransferase Elevations in Survivors of Childhood Cancer: A Report From the St. Jude Lifetime Cohort Study

The purpose of this study was to define the prevalence of and risk factors for elevated serum alanine aminotransferase (ALT) level among adult childhood cancer survivors (CCS). The study cohort comprised 2,751 CCS from the St. Jude Lifetime Cohort Study (>10 years postdiagnosis, age ≥18 years). Serum ALT level was graded using the Common Terminology Criteria for Adverse Events v. 4.03. Modified Poisson regression models were used to estimate relative risks and 95% confidence intervals for the association between demographic and clinical factors and grades 1-4 ALT on the selected models. A total of 1,339 (48.7%) CCS were female; 2,271 (82.6%) were non-Hispanic white. Median age at evaluation was 31.4 years (interquartile range [IQR] = 25.8-37.8); median elapsed time from diagnosis to evaluation was 23.2 years (IQR = 17.6-29.7). A total of 1,137 (41.3%) CSS had ALT > upper limit of normal (Common Terminology Criteria for Adverse Events v. 4.03 grade 1-1,058 (38.5%); grade 2-56 (2.0%); grade 3-23 (0.8%); grade 4-none). Multivariable models demonstrated non-Hispanic white race/ethnicity, age at evaluation in years, being overweight or obese, presence of the metabolic syndrome, current treatment with atorvastatin or rosuvastatin or simvastatin, hepatitis C virus infection, prior treatment with busulfan or thioguanine, history of hepatic surgery, and the percentage of liver treated with ≥10 Gray, ≥15 Gray, or ≥20 Gray were associated with elevated ALT. Conclusion: Grade 3 or 4 hepatic injury is infrequent in CCS. Mild hepatic injury in this group may be amenable to lifestyle modifications.

Assessment of MR-based R2* and quantitative susceptibility mapping for the quantification of liver iron concentration in a mouse model at 7T

PURPOSE

To assess the feasibility of quantifying liver iron concentration (LIC) using R2* and quantitative susceptibility mapping (QSM) at a high field strength of 7 Tesla (T).

METHODS

Five different concentrations of Fe-dextran were injected into 12 mice to produce various degrees of liver iron overload. After mice were sacrificed, blood and liver samples were harvested. Ferritin enzyme-linked immunosorbent assay (ELISA) and inductively coupled plasma mass spectrometry were performed to quantify serum ferritin concentration and LIC. Multiecho gradient echo MRI was conducted to estimate R2* and the magnetic susceptibility of each liver sample through complex nonlinear least squares fitting and a morphology enabled dipole inversion method, respectively.

RESULTS

Average estimates of serum ferritin concentration, LIC, R2*, and susceptibility all show good linear correlations with injected Fe-dextran concentration; however, the standard deviations in the estimates of R2* and susceptibility increase with injected Fe-dextran concentration. Both R2* and susceptibility measurements also show good linear correlations with LIC (R2  = 0.78 and R2  = 0.91, respectively), and a susceptibility-to-LIC conversion factor of 0.829 ppm/(mg/g wet) is derived.

CONCLUSION

The feasibility of quantifying LIC using MR-based  R2* and QSM at a high field strength of 7T is demonstrated. Susceptibility quantification, which is an intrinsic property of tissues and benefits from being field-strength independent, is more robust than R2* quantification in this ex vivo study. A susceptibility-to-LIC conversion factor is presented that agrees relatively well with previously published QSM derived results obtained at 1.5T and 3T.

Ultrashort echo time imaging for quantification of hepatic iron overload: Comparison of acquisition and fitting methods via simulations, phantoms, and in vivo data

BACKGROUND

Current R2*-MRI techniques for measuring hepatic iron content (HIC) use various acquisition types and fitting models.

PURPOSE

To evaluate the accuracy and precision of R2*-HIC acquisition and fitting methods.

STUDY TYPE

Signal simulations, phantom study, and prospective in vivo cohort.

POPULATION

In all, 132 patients (58/74 male/female, mean age 17.7 years).

FIELD STRENGTH/SEQUENCE

2D-multiecho gradient-echo (GRE) and ultrashort echo time (UTE) acquisitions at 1.5T.

ASSESSMENT

Synthetic MR signals were created to mimic published GRE and UTE methods, using different R2* values (25-2000 s^-1 ) and signal-to-noise ratios (SNR). Phantoms with varying iron concentrations were scanned at 1.5T. In vivo data were analyzed from 132 patients acquired at 1.5T. R2* was estimated by fitting using three signal models. Accuracy and precision of R2* measurements for UTE acquisition parameters (SNR, echo spacing [ΔTE], maximum echo time [TE_max ]) and fitting methods were compared for simulated, phantom, and in vivo datasets.

STATISTICAL TESTS

R2* accuracy was determined from the relative error and by linear regression analysis. Precision was evaluated using coefficient of variation (CoV) analysis.

RESULTS

In simulations, all models had high R2* accuracy (error <5%) and precision (CoV <10%) for all SNRs, shorter ΔTE (≤0.5 msec), and longer TE_max (≥10.1 msec); except the constant offset model overestimated R2* at the lowest SNR. In phantoms and in vivo, all models produced similar R2* values for different SNRs and shorter ΔTEs (slopes: 0.99-1.06, R² > 0.99, P < 0.001). In all experiments, R2* results degraded for high R2* values with longer ΔTE (≥1 msec). In vivo, shorter and longer TE_max gave similar R2* results (slopes: 1.02-1.06, R² > 0.99, P < 0.001) for the noise subtraction model for 25≤R2*≤2000 s^-1 . However, both quadratic and constant offset models, using shorter TE_max (≤4.7 msec) overestimated R2* and yielded high CoVs up to ∼170% for low R2* (<250 s^-1 ).

DATA CONCLUSION

UTE with TE_max ≥ 10.1 msec and ΔTE ≤ 0.5 msec yields accurate R2* estimates over the entire clinical HIC range. Monoexponential fitting with noise subtraction is the most robust signal model to changes in UTE parameters and achieves the highest R2* accuracy and precision.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1475-1488.

Automated vessel exclusion technique for quantitative assessment of hepatic iron overload by R2*-MRI

BACKGROUND

Extraction of liver parenchyma is an important step in the evaluation of R2*-based hepatic iron content (HIC). Traditionally, this is performed by radiologists via whole-liver contouring and T2*-thresholding to exclude hepatic vessels. However, the vessel exclusion process is iterative, time-consuming, and susceptible to interreviewer variability.

PURPOSE

To implement and evaluate an automatic hepatic vessel exclusion and parenchyma extraction technique for accurate assessment of R2*-based HIC.

STUDY TYPE

Retrospective analysis of clinical data.

SUBJECTS

Data from 511 MRI exams performed on 257 patients were analyzed.

FIELD STRENGTH/SEQUENCE

All patients were scanned on a 1.5T scanner using a multiecho gradient echo sequence for clinical monitoring of HIC.

ASSESSMENT

An automated method based on a multiscale vessel enhancement filter was investigated for three input data types-contrast-optimized composite image, T2* map, and R2* map-to segment blood vessels and extract liver tissue for R2*-based HIC assessment. Segmentation and R2* results obtained using this automated technique were compared with those from a reference T2*-thresholding technique performed by a radiologist.

STATISTICAL TESTS

The Dice similarity coefficient was used to compare the segmentation results between the extracted parenchymas, and linear regression and Bland-Altman analyses were performed to compare the R2* results, obtained with the automated and reference techniques.

RESULTS

Mean liver R2* values estimated from all three filter-based methods showed excellent agreement with the reference method (slopes 1.04-1.05, R² > 0.99, P < 0.001). Parenchyma areas extracted using the reference and automated methods had an average overlap area of 87-88%. The T2*-thresholding technique included small vessels and pixels at the vessel/tissue boundaries as parenchymal area, potentially causing a small bias (<5%) in R2* values compared to the automated method.

DATA CONCLUSION

The excellent agreement between reference and automated hepatic vessel segmentation methods confirms the accuracy and robustness of the proposed method. This automated approach might improve the radiologist's workflow by reducing the interpretation time and operator dependence for assessing HIC, an important clinical parameter that guides iron overload management.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1542-1551.

Radial Ultrashort TE Imaging Removes the Need for Breath-Holding in Hepatic Iron Overload Quantification by R2* MRI

OBJECTIVE

The objective of this study is to evaluate radial free-breathing (FB) multiecho ultrashort TE (UTE) imaging as an alternative to Cartesian FB multiecho gradient-recalled echo (GRE) imaging for quantitative assessment of hepatic iron content (HIC) in sedated patients and subjects unable to perform breath-hold (BH) maneuvers.

MATERIALS AND METHODS

FB multiecho GRE imaging and FB multiecho UTE imaging were conducted for 46 test group patients with iron overload who could not complete BH maneuvers (38 patients were sedated, and eight were not sedated) and 16 control patients who could complete BH maneuvers. Control patients also underwent standard BH multiecho GRE imaging. Quantitative R2* maps were calculated, and mean liver R2* values and coefficients of variation (CVs) for different acquisitions and patient groups were compared using statistical analysis.

RESULTS

FB multiecho GRE images displayed motion artifacts and significantly lower R2* values, compared with standard BH multiecho GRE images and FB multiecho UTE images in the control cohort and FB multiecho UTE images in the test cohort. In contrast, FB multiecho UTE images produced artifact-free R2* maps, and mean R2* values were not significantly different from those measured by BH multiecho GRE imaging. Motion artifacts on FB multiecho GRE images resulted in an R2* CV that was approximately twofold higher than the R2* CV from BH multiecho GRE imaging and FB multiecho UTE imaging. The R2* CV was relatively constant over the range of R2* values for FB multiecho UTE, but it increased with increases in R2* for FB multiecho GRE imaging, reflecting that motion artifacts had a stronger impact on R2* estimation with increasing iron burden.

CONCLUSION

FB multiecho UTE imaging was less motion sensitive because of radial sampling, produced excellent image quality, and yielded accurate R2* estimates within the same acquisition time used for multiaveraged FB multiecho GRE imaging. Thus, FB multiecho UTE imaging is a viable alternative for accurate HIC assessment in sedated children and patients who cannot complete BH maneuvers.

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

Data on post-transplant iron overload (IO) are scarce in pediatrics. We conducted a prospective multicenter cohort study (Leucémie de l'Enfant et de l'Adolescent cohort) to determine the prevalence and risk factors of IO in 384 acute leukemia survivors transplanted during childhood. Prevalence of IO (ferritin level ⩾350 ng/mL) was 42.2% (95%CI 37.2-47.2%). Factors significantly associated with IO were: 1) in univariate analysis: older age at transplant (P<0.001), allogeneic versus autologous transplantation (P<0.001), radiation-based preparative regimen (P=0.035) and recent period of transplantation (P<0.001); 2) in multivariate analysis: older age at transplant in quartiles (Odds Ratio (OR)=7.64, 95% CI: 3.73-15.64 for age >12.7 years and OR=5.36, 95% CI: 2.63-10.95 for age from 8.2 to 12.7 years compared to age < 4.7 years), acute myeloid leukemia (OR=3.23, 95% CI: 1.47-7.13), allogeneic graft (OR=4.34, 95% CI: 2.07-9.12 for alternative donors and OR=2.53, 95% CI: 1.2-5.33 for siblings, compared to autologous graft) and radiation-based conditioning regimen (OR=2.45, 95% CI: 1.09-5.53). Graft-versus-host disease was an additional risk factor for allogeneic graft recipients. In conclusion, IO is a frequent complication in pediatric long-term survivors after transplantation for acute leukemia, more frequently observed in older children, those transplanted from alternative donors or with graft-versus-host disease.

An assessment of iron overload in children treated for cancer and nonmalignant hematologic disorders

Our goal was to assess the natural fate of iron overload (IO) following transfusions of packed red blood cells (PRBCs) in children treated for cancer and nonmalignant disorders according to the intensity level of their treatment. Sixty-six children were followed up from February 2010 to March 2013. The transfusion burden was compared between three treatment intensity groups assigned according to the Intensity of Treatment Rating Scale 3.0 (ITR-3). IO was assessed by serial measurements of serum ferritin (SF) (n= 66) and quantification of tissue iron by magnetic resonance imaging (MRI) (n=12). Of the children studied, 36 % (24/66) received moderately intensive treatment (level 2), 21 % (14/ 66) received very intensive treatment (level 3), and 42 % (28/ 66) received the most intensive treatment (level 4). The number of PRBC (p=0.016), the total transfused volume (p= 0.026), and transfused volume adjusted to body weight (p= 0.004) were significantly higher in the level 4 group. By the median follow-up time of 35.5 months (range 8–133), 21– 29 % of patients (including level 2 and level 3 children) had SF >1,000 μg/l 1 year after cessation of transfusions. The slowest decrease of SF was observed in the level 4 group. Initial MRI examination demonstrated either mild or moderate IO in the liver and spleen. Repetitive MRI showed significant improvement in relaxation time between the initial and follow-up MRI performances in the liver (5.9 vs. 8.6 ms, p= 0.03) and the spleen (4.3 vs. 8.8 ms, p=0.03).

CONCLUSION

IO diminished over time, but in the level 4 patients, it was detectable for years after cessation of transfusions.

Characterization of transfusion-derived iron deposition in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) receiving packed red blood cell (PRBC) transfusions may have increased risk for vital organ iron deposition causing serious late effects.

METHODS

This cross-sectional cohort study of a CCS cohort quantified organ iron content by magnetic resonance imaging. Iron status by serum markers and hemochromatosis gene mutation status were assessed.

RESULTS

Seventy-five patients who had received a range (0-392 mL/kg) of cumulative PRBC transfusion volumes were enrolled (median age 14 years, range 8-25.6 years at evaluation). Median follow-up time was 4.4 years, and median time since last transfusion was 4.9 years. Cancer diagnoses included acute lymphoblastic or myelogenous leukemia (ALL/AML; n = 33) and solid tumors (n = 42). Liver and pancreatic iron concentrations were elevated in 36 of 73 (49.3%) and 19 of 72 (26.4%) subjects, respectively. Cardiac iron concentration was not increased in this cohort. In multivariate analysis, cumulative PRBC volume (P < 0.0001) and older age at diagnosis (P < 0.0001) predicted elevated liver iron concentration.

CONCLUSIONS

Iron overload (IO) may occur in children and adolescents/young adults treated for cancer and is associated with cumulative PRBC transfusion volume and age at diagnosis.

IMPACT

These findings have implications for development of monitoring and management guidelines for cancer patients and survivors at risk for IO, exploration of the additive risk of liver/pancreatic damage from chemotherapeutic exposures, and health education to minimize further liver/pancreatic damage from exposures such as excessive alcohol intake and hepatotoxic medications.