Late mortality from other diseases following childhood cancer in Australia and the impact of intensity of treatment.

BACKGROUND: People who receive treatment for cancer during childhood often experience subsequent complications of therapy, known as late effects, which can lead to an increased risk of death. PROCEDURE: Using deidentified population-based data from the Australian Childhood Cancer Registry for children aged 0-14 diagnosed with cancer during the period 1983-2011 and who survived for a minimum of 5 years, we examined disease-related deaths (other than cancer recurrence or second primary cancers) that occurred up to 31 December 2016. Risk of death relative to the general population was approximated using standardised mortality ratios (SMRs). Treatment received was stratified according to the intensity of treatment rating, version 3 (ITR-3). RESULTS: During the study period, 82 noncancer disease-related deaths were recorded among 13 432 childhood cancer survivors, four times higher than expected (SMR = 4.43, 95% CI = 3.57-5.50). A clear link to treatment intensity was observed, with the relative risk of noncancer disease-related mortality being twice as high for children who underwent 'most intensive' treatment (SMR = 5.94, 95% CI = 3.69-9.55) compared to the 'least intensive' treatment group (SMR = 2.98, 95% CI = 1.42-6.24; Ptrend  = .01). Thirty-year cumulative mortality from noncancer disease-related deaths was estimated at 1.4% (95% CI = 1.1-1.9) after adjusting for competing causes of death such as cancer, accidents, or injuries. CONCLUSIONS: Although childhood cancer survivors are at increased relative risk of death from noncancer diseases, particularly those who undergo more intensive treatment, the cumulative mortality within 30 years of diagnosis remains small. Knowledge of late effects can guide surveillance of survivors and treatment modification, without wanting to compromise the high rates of survival.

Cardiovascular Testing Detects Underlying Dysfunction in Childhood Leukemia Survivors.

PURPOSE: Childhood leukemia survivors commonly develop late-onset cardiovascular disease after treatment with anthracyclines. Resting echocardiogram is the standard procedure for monitoring cardiac health but this method may not be sensitive enough to detect subclinical injury. Exercise echocardiography may provide a viable alternative. METHODS: Nineteen (9 males; age, 19 ± 3 yr) anthracycline-treated survivors of childhood leukemia and 17 (8 males) healthy individuals of similar age (22 ± 2 yr) were recruited. All survivors had normal resting echocardiography upon recruitment. Exercise echocardiography was performed using contemporary imaging techniques. Flow-mediated dilation (FMD), body composition, and cardiorespiratory fitness (V˙O2peak) were assessed to determine predisposition to additional disease. RESULTS: Mitral valve peak flow velocity in late diastole (interaction, P = 0.007) increased from rest in survivors (P = 0.023) and controls (P = 0.020) immediately postexercise but did not recover again in the survivors (exercise-recovery, P = 0.784) after recuperation. Consequently, E/A ratio (interaction, P < 0.001) was lower in the survivors at recovery (P < 0.001). Survivors had reduced FMD (7.88 ± 1.70 vs 9.65 ± 2.83; P = 0.030), maximal and recovery HR (P = 0.001; P < 0.001), minute ventilation (P < 0.001), and V˙O2peak (absolute, 2.64 ± 0.62 vs 3.14 ± 0.74 L·min, P = 0.034; relative, 36.78 ± 11.49 vs 45.14 ± 6.80 mL·kg·min; P = 0.013) compared with controls. They also had higher total body fat (percentage, P = 0.034; mass, P = 0.024) and fat mass in the central (P = 0.050), peripheral (P = 0.039) and visceral (P < 0.001) regions. Survivors matched controls with regard to height (173.0 ± 7.8 cm vs 173.8 ± 9.1 cm; P = 0.796), body mass (76.16 ± 19.05 kg vs 70.07 ± 13.96 kg; P = 0.287) and body mass index (25.2 ± 5.1 vs 22.9 ± 2.7; P = 0.109). CONCLUSIONS: Exercise echocardiography unmasked subclinical diastolic dysfunction that may indicate late anthracycline toxicity in apparently healthy survivors of childhood leukemia. Presence of secondary risk factors indicates increased predisposition to comorbidities and highlights the importance of assessing cardiovascular health during follow-up.

Early markers of cardiovascular injury in childhood leukaemia survivors treated with anthracycline chemotherapy.

BACKGROUND: Cardiovascular disease (CVD) is the leading non-malignant cause of death in childhood cancer survivors. Heightened risk of CVD is often attributable to treatment with anthracycline chemotherapy. Anthracycline-mediated cardiac injury may lie latent for years following cessation of treatment and is therefore often not detected until disease is advanced and aggressive therapy is required. Symptomatic CVD may be preceded by subclinical cardiac and vascular dysfunction. This study aimed to determine whether such dysfunction could be detected in healthy, anthracycline-treated survivors of childhood leukaemia. METHODS: Cardiac magnetic resonance imaging (cMRI) with late gadolinium enhancement and endothelial function were used to characterise pre-clinical stages of CVD. Twenty-two long-term (>5 years survival; age 21 ± 3 years) childhood leukaemia survivors were assessed. All survivors were asymptomatic and had normal resting echocardiography. To exclude potential confounding effects of radiotherapy, no survivors had received this treatment. Twenty-two similarly aged (25 ± 3 years) gender-matched controls were recruited for comparison. RESULTS: Left ventricular ejection fraction was lower in the survivors (55.0 ± 4.6%) compared to the controls (59.4 ± 6.2%; p = 0.010). Further, five survivors (23%) had clinically reduced (<50%) left ventricular ejection fraction. Normalised left ventricular end systolic volume was augmented in survivors (40.0 ± 9.1 mL·m2 vs. 34.5 ± 7.5 mL·m2; p = 0.038). Cardiac MRI did not show any late gadolinium enhancement. High resolution, ultrasound-derived flow mediated dilation was impaired in survivors (6.7 ± 2.1% vs. 8.60 ± 1.91%, p = 0.005). CONCLUSIONS: We detected subclinical changes in cardiovascular structure and function indicative of early disease in anthracycline-treated childhood leukaemia survivors with normal echocardiography. Early detection and characterisation of underlying disease allows for timely intervention and improved outcomes in this at-risk population.

Exercise training improves vascular function and secondary health measures in survivors of pediatric oncology related cerebral insult.

Adolescent and young adult (AYA) survivors of pediatric oncology related cerebral insult are vulnerable to numerous treatment-induced deficits that significantly enhance cardiovascular disease risk. Regular exercise improves endothelial function, fitness, body composition and musculoskeletal function which may reduce predisposition for cardiovascular disease. Here we assessed the feasibility and effectiveness of a 24-week exercise intervention on cardiovascular, physical and metabolic outcomes in this population. Thirteen survivors (6 male, 7 female; median age 19 y (range 16-23 y) were recruited to participate in a 48-week study consisting of a 24-week control period (regular care) followed by a 24-week exercise intervention. Outcome measures were collected at entry (week 0) and following regular care (24-week) and exercise (48-week). Assessed variables included endothelial function (flow mediated dilation, FMD), blood pressure, heart rate (HR), aerobic capacity, anthropometry, body composition, muscular strength (3 repetition maximum testing), muscular endurance (repetitions/min) and physical activity levels (accelerometry). Compared to baseline, delta diameter (p = 0.008) and FMD (p = 0.029) of the brachial artery increased following exercise. Bicep-curl strength also increased following exercise compared to baseline (p = 0.019), while submaximal (6 min mark) measures of ventilation (p = 0.012), rating of perceived exertion (p = 0.012), HR (p = 0.001), absolute (p = 0.000) and relative (p = 0.000) aerobic capacity decreased. Breaks in sedentary time increased (p = 0.043) following exercise compared to regular care. Although the sample was small and heterogeneous, this study demonstrates that exercise is achievable and has positive effects on vascular function, submaximal fitness, local strength and physical activity in a population of AYA survivors of pediatric oncology related cerebral insult.