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We evaluated the feasibility of existing risk assessment tools for chronic myeloid leukemia (CML) in children. Fifty-five patients with newly diagnosed CML between 1996 and 2019 were included. Forty-nine patients presented in chronic phase, thirty-six of whom were treated with upfront tyrosine kinase inhibitor (CP-TKI group); one presented in accelerated phase and four in blastic phase. Treatment, survival, responses, and tolerance were evaluated. All patients in the CP-TKI group received imatinib as their first TKI treatment. The 10-year overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) of TKI-treated group was 97%, 91.4%, and 72.3%, respectively. At 60 months, the rates of major molecular response were 81.2% and deep molecular response was 67.5%. The EUTOS long-term survival (ELTS) risk grouping did not predict OS, PFS, or EFS. The IMAFAIL risk groups were correlated with the risk of imatinib failure. Further studies are required to modify the existing risk assessment tools for children.

Background: Pulmonary dysfunction has been reported in patients with β-thalassaemia major but data are conflicting and the association with iron overload remains unclear. Objectives: To determine the pattern of pulmonary dysfunction in patients with β-thalassaemia major and their associations with iron overload. Methods: Subjects with β-thalassaemia major were recruited for lung function assessment. Serum ferritin and magnetic resonance imaging (MRI) measurements of iron status of the myocardium and the liver were used as surrogate indexes of body iron content. A subgroup of this cohort provided data on the longitudinal progress of their lung function. Results: One hundred and one patients were recruited with a mean age of 25.1 years (SD 7.9 years). Thirty-eight (38%) and five (5%) had restrictive and obstructive lung function deficits, respectively. There was a significant correlation between MRI myocardial T2* relaxation time and forced vital capacity (r=0.291, p=0.048). Higher MRI cardiac T2* relaxation time was associated with lower risk of having restrictive lung function deficit (Odds ratio (OR): 0.94; 95% CI: 0.89-0.99; p=0.023) after adjusting for age, gender and BMI. Twenty-three subjects underwent lung function reassessment with a mean follow-up duration of 13 years. Overall, they did not demonstrate significant changes in pulmonary function over time, 3 patients who had normal lung function at baseline developed restrictive abnormality at follow-up. Conclusions: Restrictive lung disease is prevalent in patients with β-thalassaemia major, and the severity correlates with myocardial iron overload. Monitoring of lung function in this group of patients is important, particularly for those with iron overload.

Background Paediatric palliative care (PPC) focuses on the enhancement of quality of life for children with life-limiting diseases and support to their families. This study reviewed the paediatric palliative care program in Hong Kong (HK). Objectives Reviewed the characteristics and service need of children receiving PPC in a regional hospital in HK. Methods This is a retrospective chart review. All children aged less than 18 years old receiving PPC at a regional hospital in HK from 2015 to 2020 were included. Results Fifty-eight children received PPC service in the study period. Eight cases were referred for bereavement support after death and were excluded. A total of 50 children (M : F = 24 : 26) were enrolled. Median age of referral to PPC service was 8 years 9 months. Average duration of follow up was 1 year 4 months (median 9 months). Underlying diseases included neurological diseases n=20 (40%), congenital malformations and chromosomal anomalies n=10 (20%), neoplasms n=10 (20%), endocrine and metabolic conditions n=7 (14%), perinatal conditions n=2 (4%) and external causes of morbidity n=1 (2%). Sources of referral included intensivists (32%), general paediatricians (30%), oncologists (14%), neonatologists (12%), neurologists (8%), endocrinologists (2%) and respirologists (2%). Thirty-nine patients (78%) resided in the community (home 48%, residential schools 30%). Majority of children (60.8%) had high medical needs during their daily care, including wheelchair-bound n=34 (66.7%), gastrostomy feeding n=17 (33.3%), nasogastric tube-feeding n=8 (15.7%), non-invasive ventilatory support n=13 (25.5%) and tracheostomy with ventilatory support n=5 (9.8%). Advanced care plan (ACP) was discussed with 25 (50%) families. Among the 18 cases who died while receiving PPC, Do-Not Attempt Cardiopulmonary Resuscitation (DNACPR) was discussed with 15 (83.3%) of them. DNACPR had been discussed with 37.5% of the surviving cases. Median time from referral to death varied with the diseases: neoplasms (19 days), neurological conditions (54 days), congenital malformations and chromosomal anomalies (65 days), endocrine and metabolic conditions (174 days), external causes of morbidity (424 days). Forty-five percent of children passed away in the general paediatric wards (38.9%), Accident and Emergency Department (5.6%) while the remaining children passed away in the Intensive Care Units (44.4% in Paediatric ICU, 11.1% in Neonatal ICU). No patient died at home. Pain control medications were given during end-of-life period in 30.8% of cases. Conclusions This review showed majority of children on palliative care stayed at home or residential schools and had high medical needs. Community support to these families was important. The time from referral to death was short. Advanced Care Plan was discussed with only half of the families. Less than one-third of patients received pain control at end-of-life. Paediatric palliative care service is under-developed and has to be largely promoted in Hong Kong.

As a prototype of genomics-guided precision medicine, individualized thiopurine dosing based on pharmacogenetics is a highly effective way to mitigate hematopoietic toxicity of this class of drugs. Recently, NUDT15 deficiency was identified as a genetic cause of thiopurine toxicity, and NUDT15-informed preemptive dose reduction was quickly adopted in clinical settings. To exhaustively identify pharmacogenetic variants in this gene, we developed massively parallel NUDT15 function assays to determine the variants’ effect on protein abundance and thiopurine cytotoxicity. Of the 3,097 possible missense variants, we characterized the abundance of 2,922 variants and found 54 hotspot residues at which variants resulted in complete loss of protein stability. Analyzing 2,935 variants in the thiopurine cytotoxicity-based assay, we identified 17 additional residues where variants altered NUDT15 activity without affecting protein stability. We identified structural elements key to NUDT15 stability and/or catalytical activity with single amino acid resolution. Functional effects for NUDT15 variants accurately predicted toxicity risk alleles in patients treated with thiopurines with far superior sensitivity and specificity compared to bioinformatic prediction algorithms. In conclusion, our massively parallel variant function assays identified 1,152 deleterious NUDT15 variants, providing a comprehensive reference of variant function and vastly improving the ability to implement pharmacogenetics-guided thiopurine treatment individualization.

Background Children with Down syndrome (DS) are at higher risk of developing acute leukemia. Treatment continues to evolve as we accumulate better understanding of the distinctive clinical and biological features of acute leukemia in DS patients. Procedure A retrospective review of the clinical features, treatment outcomes, and survival of DS children with acute leukemia in Hong Kong from 1993 to 2013 was conducted. Patients were identified from the registry of the Hong Kong Pediatric Hematology and Oncology study group. Results This cohort included a total of 29 patients with DS. Ten were diagnosed with acute lymphoblastic leukemia and 19 had acute myeloid leukemia (AML). The mean follow-up duration was 8.3 years (range, 0.6 mo to 18.1 y). The 5-year overall survival and event-free survival for DS-acute lymphoblastic leukemia and DS-AML were 65.6%, 54.9%, 89.5%, and 89.5%, respectively. Conclusions The clinical characteristics and treatment outcomes of DS patients with acute leukemia in Hong Kong were comparable with results from other international study groups. Patients with DS-AML had a better prognosis.

Introduction Haemoglobin Bart's hydrops fetalis syndrome was once considered a fatal condition. However, advances over the past two decades have enabled survival of affected patients. Data relating to their morbidities and outcomes will help medical specialists formulate a management plan and parental counselling. Methods All babies with the syndrome who survived beyond the neonatal period and were subsequently managed long-term in eight public hospitals in Hong Kong from 1 January 1996 to 31 December 2015 were included. Patient and parent characteristics, antenatal care, reasons for continuation of pregnancy, intrauterine interventions, perinatal course, presence of congenital malformations, stem-cell transplantation details, and long-term neurodevelopmental outcomes were reviewed. Results A total of nine patients were identified, of whom five were female and four male. The median follow-up duration was 7 years. All were Chinese and were homozygous for the Southeast Asian α-thalassaemia deletion. Five of the nine mothers received antenatal care at a public hospital and opted to continue the pregnancy after antenatal diagnosis and counselling. Despite intrauterine transfusions, all babies were born with respiratory depression and required intubation and mechanical ventilation during the neonatal period. Hypospadias was identified in all four male infants. Growth retardation, global developmental delay, and residual neurological deficits were noted in two-thirds of the patients. Haematopoietic stem-cell transplantation was performed in two patients, who became transfusion-independent. Conclusions Survival of patients with Bart's hydrops fetalis syndrome is possible but not without short- and long-term complications; local epidemiology is comparable to that documented for an international registry. Detailed antenatal counselling of parents with a non-judgemental attitude and cautious optimism are imperative.

Objective The aim of this study was to review clinical outcomes and prognosis of paediatric patients with acute lymphoblastic leukaemia (ALL) with TCF3-PBX1 rearrangement. Patients All children in Hong Kong diagnosed with ALL with TCF3-PBX1 rearrangement over the past two decades were included. Methods Six hundred and twenty-four newly diagnosed patients with ALL from four consecutive studies were enrolled from 1997 to 2016. Patients carrying TCF3-PBX1 rearrangement and patients at intermediate risk without the gene expression were compared for clinical characteristics, overall survival and event-free survival (EFS). Results The TCF3-PBX1 rearrangement was detected in 30 of 624 patients (4.8%). Results were consistent across the consecutive clinical trials employed in the past two decades. Compared with 239 intermediate risk patients without TCF3-PBX1 rearrangement, the 5-year overall survival and EFS for patients with TCF3-PBX1 rearrangement was superior, with both at 100% (P = 0.12 and P = 0.029). Conclusion This population-based study over the past 20 years demonstrated that patients with TCF3-PBX1 rearrangement had favourable EFS compared with other intermediate risk patients treated with a similar chemotherapy backbone.

Background We sought to assess myocardial iron load and fibrosis, which may potentially affect cardiac function, in adult survivors of childhood leukemias and their relationships with left (LV) and right ventricular (RV) function. Procedure Fifty-eight (33 males) adult survivors, aged 24.5 ± 4.4, underwent cardiac magnetic resonance (CMR) at 16.6 ± 5.8 years after completion of treatment. Myocardial iron load and fibrosis were quantified using respectively T2* scan and late gadolinium enhancement. Right and left ventricular ejection fraction (EF) was measured by CMR, while myocardial function was assessed using tissue Doppler imaging. Results None of the survivors had significant myocardial iron overload (T2* 0.05). Conclusion Ventricular fibrosis may occur in long term survivors of childhood leukemias and is related to diastolic function in the absence of significant myocardial iron overload. Pediatr Blood Cancer 2015;62:698–703. © 2015 Wiley Periodicals, Inc.

This study sought to characterize the range of oral symptoms and affect upon quality of life reported by pediatric and adolescent patients in relation to the severity of oral mucositis and symptom burden during chemotherapy. A multicenter study included 140 patients between 6 and 18 years of age who had been treated with chemotherapy. Participants completed the self-report Mouth and Throat Soreness-related Questions of the Oral Mucositis Daily Questionnaire (OMDQ) for 14 days and the Oral Mucositis-specific Quality of Life Measure (OMQoL) at baseline, day 7, and day 14. The incidences of non-severe and severe mucositis were 23% (n = 32) and 18% (n = 25), respectively. The symptoms reported by the patients with oral mucositis were related to eating (82.4%), swallowing (78.9%), drinking (75.4%), sleeping (71.9%), and talking (43.9%). Approximately 39% (22 out of 57) of patients with mucositis reported at least two simultaneous symptoms resulting from oral mucositis. About a quarter of them (25%, 14 out of 57) reported having all five symptoms concurrently. The mean area under curve (AUC) scores for symptom severity were significantly higher in the severe mucositis group (mean 0.95 to 1.21; 95% CI 0.76 to 1.34) compared with the non-severe (mean 0.50 to 1.06; 95% CI 0.35 to 1.30) and the without mucositis (mean 0 to 0.09; 95% CI 0 to 0.12) groups (p

There is a dearth of studies with respect to oral mucositis (OM) in the paediatric and adolescent populations. The purpose of this prospective cohort study was to examine the incidence and risk factors associated with OM in paediatric and adolescent patients receiving chemotherapy. OM assessments were made daily until 14 days after chemotherapy using the self-report Mouth and Throat Soreness-Related Questions of the Oral Mucositis Daily Questionnaire (OMDQ MTS). Potential risk factors included age, gender, prior OM, anxiety level, cancer diagnosis, nausea/vomiting, use of growth factor, neutrophil count, liver enzymes, and creatinine value. Multiple logistic, Cox proportional hazards, and ordinal regression analyses were used to determine risk factors for the incidence and time to onset of MTS scores of ⩾2, and MTS scores across 14 days by AUC categories, respectively, after adjusting for chemotherapy. A total of 140 patients who were 6–18 years of age were evaluated. Forty-one percent (95% CI, 32.6–48.8%) developed OM; of these, 23% and 18% reported a maximum MTS score of 2 and 3–4 as the worst OM, respectively. The mean time to onset of OM was 4.7 ± 2.7 days with a mean duration of 6.3 ± 4 days. Prior OM (RR 1.90–3.94), a higher level of anxiety (RR 1.27–1.46), WHO grade 1–2 (RR 1.86–4.59) and 3–4 (RR 3.08–9.19) neutropenia were significantly associated with a higher probability of the incidence, earlier onset, and greater severity of OM, after controlling for chemotherapy (p < 0.01). OM was associated with indirect cytotoxicity, prior OM, and anxiety level after controlling for chemotherapy where neutropenia was found to be the most important factor.

Aims We tested the hypothesis that myocardial stiffness as assessed by diastolic wall strain (DWS) is altered in adult survivors of childhood leukaemias with preserved left ventricular (LV) ejection fraction and explored its association with myocardial fibrosis and diastolic deformation. Methods and results Ninety-four (53 males) adult survivors of childhood leukaemias aged 22.2 ± 5.5 years and 66 (36 males) healthy controls were studied retrospectively. Diastolic wall strain and calibrated integrated backscatter (cIB) were measured as indices of myocardial stiffness and fibrosis, respectively. Left and right ventricular (RV) diastolic and torsional mechanics were interrogated using speckle tracking echocardiography. Patients had significantly lower LV DWS, and hence stiffer LV myocardium, and greater myocardial cIB in patients than controls (all P < 0.001). Left ventricular longitudinal, radial, and circumferential early diastolic strain rates, circumferential late diastolic strain rate, and peak twisting and untwisting velocities, tricuspid annular early diastolic velocity, and RV-free wall longitudinal early diastolic strain rate were significantly lower in patients than controls (all P < 0.05). Diastolic wall strain correlated inversely with myocardial cIB, and positively with LV longitudinal, radial, and circumferential early diastolic strain rates (all P < 0.05), while myocardial cIB correlated inversely with LV radial and circumferential early diastolic strain rates, circumferential late diastolic strain rate, peak twisting and untwisting velocities, and tricuspid annular e velocity (all P < 0.05). Conclusion In adult survivors of childhood leukaemias, despite the preservation of LV ejection fraction, increased stiffness of the LV myocardium is evident and is associated with myocardial fibrosis and impaired ventricular diastolic function.

This report demonstrates pulmonary haemorrhage as a differential cause of anaemia. Idiopathic pulmonary hemosiderosis is a rare disease in children; it is classically described as a triad of haemoptysis, pulmonary infiltrates on chest radiograph, and iron-deficiency anaemia. However, anaemia may be the only presenting feature of idiopathic pulmonary hemosiderosis in children due to occult pulmonary haemorrhage. In addition, the serum ferritin is falsely high in idiopathic pulmonary hemosiderosis which increases the diagnostic difficulty. We recommend that pulmonary haemorrhage be suspected in any child presenting with iron-deficiency anaemia and persistent bilateral pulmonary infiltrates.

It has been well recognized that intra-thoracic surgery is a major cause of chylothorax in the newborn period; however, catheter-related thrombosis could also be a cause. We report a preterm baby who presented with right chylothorax secondary to venous thrombosis postinadvertent right internal jugular vein catheterization. The complication resolved with drainage, catheter removal and low molecular weight heparin. The literature on neonatal chylothorax and thrombosis and case reports reporting thrombosis-related chylothorax that have been successfully treated with anticoagulation are reviewed.

We sought to assess myocardial iron load and fibrosis, which may potentially affect cardiac function, in adult survivors of childhood leukemias and their relationships with left (LV) and right ventricular (RV) function.Fifty-eight (33 males) adult survivors, aged 24.5 ± 4.4, underwent cardiac magnetic resonance (CMR) at 16.6 ± 5.8 years after completion of treatment. Myocardial iron load and fibrosis were quantified using respectively T2* scan and late gadolinium enhancement. Right and left ventricular ejection fraction (EF) was measured by CMR, while myocardial function was assessed using tissue Doppler imaging.None of the survivors had significant myocardial iron overload (T2*20 msec). The prevalence of LV and RV fibrosis was 9% (5/58) and 38% (22/58), respectively. Left ventricular EF was subnormal (EF 45-55%) in 9% (5/58), while RV EF was abnormal (EF45%) in 12% (7/58) and subnormal in 34% (20/58) of survivors. Patients with LV fibrosis had significantly lower mitral annular early diastolic velocity (P = 0.01) and smaller LV end-systolic volume (P = 0.02), while those with RV fibrosis had significantly lower tricuspid late diastolic annular velocity (P = 0.02) and early to late diastolic annular velocity ratio (P = 0.02) compared to those without. Cumulative anthracycline dose correlated with early diastolic mitral (r = -0.28, P = 0.038) and tricuspid (r = -0.40, P = 0.002) annular velocities, but not LV and RV EF or fibrosis (all P 0.05).Ventricular fibrosis may occur in long term survivors of childhood leukemias and is related to diastolic function in the absence of significant myocardial iron overload.

BACKGROUND Renal tumors are one of the most common tumors in children. We aim at evaluating the characteristics and the outcome of Wilms tumor and other malignant kidney tumors in Hong Kong. PROCEDURE Between January 1990 to December 2010, 68 patients under the age of 18 with malignant renal tumors were diagnosed and received treatment in Hong Kong. Clinical records were updated regularly. Prognostic factors and survival rate were evaluated. RESULTS Fifty-four patients were diagnosed with Wilms tumor. The annual incidence was estimated to be 2.29 per million. The mean age was 38 months. Median follow-up was 9.2 years. The event-free survival and overall survival rate at 10 years were 85.2% and 92.6%, respectively. A pair of siblings with familial extrarenal Wilms tumor was included. Pulmonary metastasis did exhibit a significant difference in survival rate. Eight cases of clear cell sarcoma of the kidneys were reported and the survival rate was 100%. CONCLUSIONS The clinical characteristics and outcome of the patients diagnosed Wilms tumor were comparable with other developed countries. Relatively high proportion and excellent outcome were found in clear cell sarcoma of the kidneys.

1. Oral mucositis (OM) is common among paediatric patients receiving chemotherapy.2. Paediatric patients who are neutropaenic, with high levels of anxiety, or with a history of OM have a greater risk and an earlier onset of OM.3. OM has negative effects on clinical outcomes and the patient’s life, including on oral function and quality of life.

Several trials incorporating adjuvant focal RT for treatment of young children with ependymoma have demonstrated improved survival with acceptable adverse effects. The optimal timing of RT administration is, however, unknown.A retrospective review of territory-wide database was performed to identify pediatric patients with ependymoma diagnosed between 1995 and 2011. OS and EFS were compared between patients receiving upfront RT (150 days of diagnosis), delayed RT (≥150 days of diagnosis), or no RT.Thirty-one patients with intracranial ependymoma were identified. Median age was 3.5 years and 14 (45%) were male. Primary tumor was supratentorial in 10 (32%) and infratentorial in 21 (68%). All patients underwent initial surgery, with gross-total resection (GTR) in 27 (87%). Twelve (39%) received upfront RT, 10 (32%) had delayed RT and 9 (29%) had no RT. During the study period, there were 11 relapses (35%) and 10 deaths (32%). Five-year OS was 69.9% and 5yr-EFS was 49.3%. In univariate analysis, GTR led to improved OS (P 0.001) and EFS (P = 0.004); superior OS and EFS was observed in patients who received RT when compared with those without (P = 0.018 and 0.011, respectively). Upfront RT also resulted in better OS and EFS than delayed RT (P = 0.049 and 0.014, respectively). No significant effect on survival was observed with age, sex, tumor location, RT dosage, and protocol used. In multivariate analysis, GTR significantly improved OS (P = 0.002) and EFS (P = 0.004).Our results support the early initiation of adjuvant RT in the multi-modal management of pediatric ependymomas.

The purpose of this study is to determine the burden of the peak severity of oral mucositis and severity over time on selected clinical outcomes in paediatric and adolescent patients receiving chemotherapy.A multicentre study enrolled 140 patients between the ages of 6 and 18 years, who had been treated with chemotherapy and completed the self-report Mouth and Throat Soreness-related questions of the Oral Mucositis Daily Questionnaire for 14 days. Clinical data were collected from patients' medical records during the first 14 days after starting chemotherapy.Forty-one percent developed oral mucositis. Multiple linear regression analysis revealed that oral mucositis was significantly associated with an increased loss of baseline body weight, after controlling for nausea/vomiting (β = 0.34, p = 0.002). Multiple logistic regression analysis showed that severe mucositis was significantly associated with a higher probability of fluid replacement, after controlling for nausea/vomiting (adjusted OR = 12.8; 95 % CI = 2.7-61.0; p = 0.001). In addition, severe mucositis was significantly associated with a higher probability of fever, after controlling for neutropoenia (adjusted OR = 5.4; 95 % CI = 1.8-15.4; p = 0.002). No difference was observed for oral or systemic infections among the subgroups. About 5 % of the patients with oral mucositis had delays in chemotherapy (≤ 7 days). None of the patients had dose modification or unplanned hospitalization due to oral mucositis. The associations of peak severity and overall oral mucositis with adverse clinical outcomes in paediatric and adolescent patients were equivalent.Oral mucositis is associated with negative effects on clinical outcomes.

A Chinese adolescent girl presented with secondary amenorrhea. During follow-up, she gradually developed Cushingoid features and virilization. After a series of endocrine investigations, including urinary steroid profiling, a diagnosis of adrenocortical carcinoma was made. The treatment and prognosis of the disease are discussed.

Fetal hemoglobin (HbF) is regulated as a multigenic trait. By genome-wide association study, we confirmed that HBS1L-MYB intergenic polymorphisms (HMIP) and BCL11A polymorphisms are highly associated with HbF in Chinese β-thalassemia heterozygotes. In this population, the variance in HbF resulting from the HMIP is 13.5%; that resulting from the BCL11A polymorphism is 6.4%. To identify the functional variant in HMIP, we used 1000 Genomes Project data, single nucleotide polymorphism imputation, comparisons of association results across populations, potential transcription factor binding sites, and analysis of phylogenetic conservation. Based on these studies, a hitherto unreported association between HbF expression and a 3-bp deletion, between 135 460 326 and 135 460 328 bp on chromosome 6q23 was found. This 3-bp deletion is in complete linkage disequilibrium with rs9399137, which is the single nucleotide polymorphism in HMIP most significantly associated with HbF among Chinese, Europeans, and Africans. Chromatin immunoprecipitation assays confirmed erythropoiesis-related transcription factors binding to this region in K562 cells. Based on transient expression of a luciferase reporter plasmid, the DNA fragment encompassing the 3-bp deletion polymorphism has enhancer-like activity that is further augmented by the introduction of the 3-bp deletion. This 3-bp deletion polymorphism is probably the most significant functional motif accounting for HMIP modulation of HbF in all 3 populations. © 2011 by The American Society of Hematology., link_to_subscribed_fulltext

OBJECTIVE: To report the experience of using rasburicase as a single-dose treatment for childhood leukemia presenting with hyperuricemia. CASE SUMMARIES: Three children with acute lymphoblastic leukemia presenting with hyperuricemia received rasburicase as a single intravenous dose just prior to the start of chemotherapy. This was followed by rapid reduction of serum uric acid levels within 24 hours, which remained low throughout induction therapy while allopurinol and hydration therapy without urinary alkalinization ensued. Subclinical tumor lysis was evidenced by the appearance of hyperphosphatemia and hypocalcemia in all cases and hyperkalemia in 1 patient. These abnormalities were transient, and each patient's renal function gradually improved from pretreatment baseline without requiring dialysis. DISCUSSION: Our experience suggests that hyperuricemia in children at risk for tumor lysis can be managed with a briefer regimen of rasburicase than the recommended 5- to 7-day course. CONCLUSIONS: A shorter course of rasburicase treatment, including single-dose injection, is feasible and will improve the cost-effectiveness profile of the otherwise expensive compound.

Background We sought to quantify plasma high sensitivity cardiac troponin (hs-cTnT) levels, their determinants, and their associations with left ventricular (LV) myocardial deformation in adult survivors of childhood acute leukaemias. Methods and Results One hundred adult survivors (57 males) of childhood acute leukaemias, aged 24.1±4.2 years, and 42 age-matched controls (26 males) were studied. Plasma cTnT was determined using a highly sensitive assay. Genotyping of NAD(P)H oxidase and multidrug resistance protein polymorphisms was performed. Left ventricular function was assessed by conventional, three-dimensional, and speckle tracking echocardiography. The medians (interquartile range) of hs-cTnT in male and female survivors were 4.9 (4.2 to 7.2) ng/L and 1.0 (1.0 to 3.5) ng/L, respectively. Nineteen survivors (13 males, 6 females) (19%) had elevated hs-cTnT (>95th centile of controls). Compared to those without elevated hs-TnT levels, these subjects had received larger cumulative anthracycline dose and were more likely to have leukaemic relapse, stem cell transplant, and cardiac irradiation. Their LV systolic and early diastolic myocardial velocities, isovolumic acceleration, and systolic longitudinal strain rate were significantly lower. Survivors having CT/TT at CYBA rs4673 had higher hs-cTnT levels than those with CC genotype. Functionally, increased hs-cTnT levels were associated with worse LV longitudinal systolic strain and systolic and diastolic strain rates. Conclusions Increased hs-cTnT levels occur in a significant proportion of adult survivors of childhood acute leukaemias and are associated with larger cumulative anthracycline dose received, history of leukaemic relapse, stem cell transplant, and cardiac irradiation, genetic variants in free radical metabolism, and worse LV myocardial deformation.