Identification of genetic association between cardiorespiratory fitness and the trainability genes in childhood acute lymphoblastic leukemia survivors

Predictors of low and very low bone mineral density in long-term childhood acute lymphoblastic leukemia survivors: Toward personalized risk prediction

BACKGROUND

Cohorts of childhood acute lymphoblastic leukemia (cALL) survivors reaching adulthood are increasing. Approximately 30% of survivors meet criteria for low bone mineral density (BMD) 10 years after diagnosis. We investigated risk factors for low BMD in long-term cALL survivors.

METHODS

We recruited 245 cALL survivors from the PETALE (Prévenir les effets tardifs des traitements de la leucémie aiguë lymphoblastique chez l'enfant) cohort, who were treated with the Dana Farber Cancer Institute protocols, did not experience disease relapse or hematopoietic stem cell transplants, and presented with more than 5 years of event-free survival. Median time since diagnosis was 15.1 years.

RESULTS

Prevalence of low DXA-derived BMD (Z-score ≤-1) ranged between 21.9% and 25.3%, depending on site (lumbar spine (LS-BMD), femoral neck (FN-BMD), and total body (TB-BMD), and between 3.7% and 5.8% for very low BMD (Z-score ≤-2). Males had a higher prevalence of low BMD than females for all three outcomes (26%-32% vs. 18%-21%), and male sex acted as a significant risk factor for low BMD in all models. Treatment-related factors such as cumulative glucocorticoid (GC) doses and cranial radiation therapy (CRT) were associated with lower BMDs in the full cohort and in females at the FN-BMD site.

CONCLUSION

Low and very low BMD is more prevalent in male cALL survivors. Male sex, high cumulative GC doses, CRT, risk group, and low body mass index (BMI) were identified as risk factors for low BMD. A longer follow-up of BMD through time in these survivors is needed to establish if low BMD will translate into a higher risk for fragility fractures through adulthood.

Echocardiographic Parameters Associated With Cardiorespiratory Fitness and Physical Activity in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

Children's exposure to chemotherapeutic agents causes several long-term adverse effects but physical activity has been evidenced to be an effective strategy to improve cardiac function. This cross-sectional study aimed to explore the association between physical activity levels, cardiorespiratory fitness, and cardiac parameters measured by echocardiography.

METHODS

Participants were 216n childhood acute lymphoblastic leukemia survivors who underwent a maximal cardiopulmonary exercise test and self-reported their daily minutes of moderate to vigorous physical activity. They underwent a complete transthoracic echocardiographic assessment. Systolic and diastolic function analysis and strain images analysis were performed. The associations were studied through the preventive fraction (examined with univariate crude and adjusted logistic regression models) of regular physical activity (≥150 min·wk-1) and adequate cardiorespiratory fitness levels (above the median ≥ 32.0 mL·kg-1·min-1) on cardiac parameters.

RESULTS

Crude analysis shows that regular physical activity was associated with a significant preventive fraction in mitral E/A ratio (56%; P = .013), while adjusted analyses highlighted a nonsignificant reduction of 74% to 37% in the prevalence of cardiac parameters associated with physical activity. Similar associations of adequate cardiorespiratory fitness on cardiac parameters were observed. Adjusted analyses revealed a nonsignificant reduction of 7% to 86% in the prevalence of cardiac parameters associated with cardiorespiratory fitness.

CONCLUSION

This study reports that regular physical activity and adequate cardiorespiratory fitness were associated with a higher preventive fraction. Thus, engaging in physical activity prevents childhood acute lymphoblastic leukemia survivors' cardiac dysfunctions. These findings are novel and clinically relevant in pediatric cardiooncology and provide additional evidence to strengthen the benefits of exercise as long-term care in childhood cancer survivors.

Cardiorespiratory Fitness and Cardiac Magnetic Resonance Imaging in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

Childhood acute lymphoblastic leukemia survivors' anthracycline-induced cardiotoxicity could be prevented with good cardiorespiratory fitness levels and regular physical activity. This cross-sectional study aimed to assess the association between cardiorespiratory fitness and physical activity with cardiac magnetic resonance parameters.

METHODS

A total of 96 childhood acute lymphoblastic leukemia survivors underwent a maximal cardiopulmonary exercise test and answered physical activity questionnaires. We calculated the odds ratio of the preventive fraction of regular physical activity (≥150 min/wk) and adequate cardiorespiratory fitness levels (above the median ≥31.4 mL·kg-1·min-1) on cardiac magnetic resonance parameters (left ventricular [LV] and right ventricular [RV] morphological and functional parameters).

RESULTS

An adequate cardiorespiratory fitness was associated with a significant preventive fraction for LV (up to 84% for LV end-diastolic volume) and RV volumes (up to 88% for RV end-systolic volume). The adjusted analyses highlighted a preventive fraction of 36% to 91% between an adequate cardiorespiratory fitness and LV and RV parameters, late gadolinium enhancement fibrosis, and cardiac magnetic resonance relaxation times. No associations were reported with regular physical activity.

CONCLUSIONS

This study provides additional evidence regarding the benefits of an adequate cardiorespiratory fitness level for childhood cancer survivors' cardiac health.

Genomic heterogeneity contributed to different prognosis between adult and pediatric acute lymphoblastic

The prognosis of acute lymphoblastic leukemia (ALL) in adults is inferior to that in children. Hence, ALL remains challenging to cure in the adult population. Aberrant genetic alterations have been observed in ALL, although the patterns of differential gene alterations in adult and pediatric ALL have not been comprehensively determined on a genome-wide scale. We investigated the biologic differences in genomic profiles between adults (n = 64) and children (n = 54) with ALL and relationship between genomic heterogeneity and prognosis. The 2 populations showed similar common mutation types but an increased prevalence of genetic alterations in adult ALL. The median numbers of gene mutations were 17 (range: 1-53) and 4.5 (range: 1-19) per sample in adult and pediatric ALL, respectively (p < 0.001). An increased number of gene mutations and age were significantly correlated (R²  = 0.5853, p < 0.001). We identified 122 and 53 driver genes in adult and pediatric ALL samples, respectively. IKZF1, IDH1, and TTN mutations were significantly enriched in adult patients with ALL. KRAS, ARID1A, and CREBBP mutations were significantly enriched in pediatric patients with ALL (p < 0.05). The incidence of relapse was 40.0% and 9.6% in adult and pediatric patients with ALL, respectively (p = 0.003). The overall survival and relapse-free survival of adult patients with ALL were poorer than those of pediatric patients with ALL (p = 0.002 and p < 0.001, respectively). This genomic landscape enhances the understanding of the biologic differences in ALL between the 2 populations and provides insight for developing therapeutic approaches.

Genetic factors in treatment-related cardiovascular complications in survivors of childhood acute lymphoblastic leukemia

Aim: Cardiovascular disease represents one of the main causes of secondary morbidity and mortality in patients with childhood cancer. Patients & methods: To further address this issue, we analyzed cardiovascular complications in relation to common and rare genetic variants derived through whole-exome sequencing from childhood acute lymphoblastic leukemia survivors (PETALE cohort). Results: Significant associations were detected among common variants in the TTN gene, left ventricular ejection fraction (p ≤ 0.0005), and fractional shortening (p ≤ 0.001). Rare variants enrichment in the NOS1, ABCG2 and NOD2 was observed in relation to left ventricular ejection fraction, and in NOD2 and ZNF267 genes in relation to fractional shortening. Following stratification according to risk groups, the modulatory effect of rare variants was additionally found in the CBR1, ABCC5 and AKR1C3 genes. None of the associations was replicated in St-Jude Lifetime Cohort Study. Conclusion: Further studies are needed to confirm whether the described genetic markers may be useful in identifying patients at increased risk of these complications.

Heart rate response and chronotropic incompetence during cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors

Cardiopulmonary exercise tests (CPET) focusing on analyses of heart rate (HR) responses and chronotropic incompetence (CI) could provide early information about treatment's negative cardiac effects. We examined childhood acute lymphoblastic leukemia (ALL) survivors' HR response during maximal CPET and identified survivors with CI. A total of 250 childhood ALL survivors underwent a CPET on ergocycle to assess their HR response. We used a multiparametric structure of three methods to assess survivors' CI, as follows: 1) age-predicted HR_max (APMHR): failure to achieve 85% of the APMHR at the peak of CPET; 2) HR reserve (HRR): failure to achieve 80% of the HRR at the peak of CPET; and 3) metabolic chronotropic relationship (MCR): failure to reach an MCR slope ratio >0.8 at each stage of the CPET. Among 250 childhood ALL survivors, 216 survivors performed a maximum CPET. We observed that 73 males and 74 females did not achieve their predicted HR_max. We found that 6 survivors did not achieve 85% of their APMHR (80.9 ± 3.9%) and had an MCR below 80% (53.9 ± 13.8%). In addition, 16 survivors did not achieve 80% of their HRR (71.0 ± 7.4%) and among them, 15 survivors had an MCR below 80% (61.0 ± 12.1%). Survivors with CI had a significantly lower cardiorespiratory fitness than those without CI. This study shows that survivors are at risk of developing altered HR responses and CI many years after the end of their cancer treatments. These findings highlight the importance of early detection of cardiac damage due to cancer treatments.

Predictors of Vertebral Deformity in Long-Term Survivors of Childhood Acute Lymphoblastic Leukemia: The PETALE Study

BACKGROUND

The prevalence of vertebral deformities in long-term survivors of childhood acute lymphoblastic leukemia (ALL) is unknown. Our objectives were to identify the prevalence of vertebral deformities and their risk factors among long-term childhood ALL survivors.

METHODS/RESULTS

We recruited 245 (49% male) long-term childhood ALL survivors from the Preventing Late Adverse Effects of Leukemia Cohort (French-Canadian ALL survivors treated between the years 1987 and 2010 with the Dana Farber Cancer Institute clinical trials protocols, who did not experience disease relapse and/or receive hematopoietic stem cell transplant). Median age at recruitment was 21.7 years (range, 8.5-41) and median time since diagnosis was 15.1 years (range, 5.4-28.2). All participants underwent spine radiograph and dual-energy X-ray absorptiometry scans. The prevalence of vertebral deformity was 23% with 88% classified as grade 1 according to the Genant method. The majority of vertebral deformities were clinically silent. Regression analysis confirmed male sex (risk ratio [RR] = 1.94; 95% confidence interval [CI], 1.16-3.24; P = 0.011), higher glucocorticoid cumulative dose (RR = 1.05; 95% CI, 1.00-1.10; P = 0.032), and back pain (RR = 2.44; 95% CI, 1.56-3.84; P < 0.001) as predictors of prevalent vertebral deformity. Sex differences in vertebral deformity predictors emerged.

CONCLUSIONS

We report a significant prevalence of vertebral deformities in this young cohort. Male sex, cumulative glucocorticoid dose, and back pain were identified as predictors of prevalent vertebral deformity. Back pain emerging as a strong predictor of vertebral deformity underscores the importance of ongoing bone health surveillance in survivors with persistent vertebral deformities treated with these earlier protocols.

The effect of cardiorespiratory fitness and physical activity levels on cognitive functions in survivors of childhood acute lymphoblastic leukemia

Introduction. Most childhood acute lymphoblastic leukemia (ALL) survivors develop chronic treatment-related adverse effects several years after the end of the treatment. Regular physical activity and a good cardiorespiratory fitness can decrease the risks of neurological disturbances and increase cognitive function scores. The aim of this study was to examine the effect of good cardiorespiratory fitness and physical activity levels on cognitive functions.Methods. We enrolled 219 survivors of childhood ALL. The participants underwent a cardiopulmonary exercise test, neuropsychological tests of executive functions (i.e. verbal fluency, cognitive flexibility, working memory, processing speed) and completed a physical activity questionnaire. We calculated the odds ratio to obtain the preventive fraction of physical activity and cardiorespiratory fitness levels on cognitive functions.Results. The cohort is 52% male and 48% female. A total of 182 survivors (83%) have a cardiorespiratory fitness below their predicted (<100%). Our analyses show that there is an association between good cardiorespiratory fitness and processing speed (preventive fraction of 70% for dominant hand (p < 0.01) and 65% for non-dominant hand (p < 0.01)) and with cognitive flexibility identified as the category switching measure of the D-KEFS verbal fluency (preventive fraction of 61%; p < 0.05).Conclusion. Good cardiorespiratory fitness and good levels of physical activity were associated to a preventive fraction for most cognitive function parameters measured. Good cardiorespiratory fitness levels were significantly associated with a lower prevalence of deficits in processing speed (i.e., dominant hand and non-dominant hand) and in cognitive flexibility (i.e., category switching) in childhood acute lymphoblastic leukemia survivors.

Maximal cardiopulmonary exercise testing in childhood acute lymphoblastic leukemia survivors exposed to chemotherapy

PURPOSE

The purpose of this study was to demonstrate if childhood acute lymphoblastic leukemia (ALL) survivors exposed to chemotherapy (i.e., doxorubicin) are able to achieve a safe maximal cardiopulmonary exercise test (CPET).

METHODS

A total of 250 childhood ALL survivors were eligible to undergo a CPET on ergocycle. Analyses were performed in 216 survivors and stratified in regard to their prognostic risk groups: 99 survivors (55 males and 44 females) at standard risk and 117 survivors (56 males and 61 females) at high risk.

RESULTS

Results showed that 100% (n = 216) of survivors completed a maximal CPET confirmed by the achievement of two out of three of the following criteria: 197 survivors (91.2%) reached a peak RER value of ≥ 1.15, 197 survivors (91.2%) reached a RPE score > 7, and 210 survivors (97.2%) reached a maximal heart rate ≥ 85% of the predicted value. Linear regression analysis showed a significant association between the survivors' cumulative dose of doxorubicin and their VO₂ peak measured. Two non-fatal adverse events were observed and reported at the end of the maximal CPET, while non-fatal adverse events were reported in 5 survivors during the recovery period. None of these events resulted in a long-term complication.

CONCLUSION

Childhood ALL survivors with prior exposure to chemotherapy can achieve a safe maximal CPET. They were able of achieving a maximal exercise test without being limited by symptoms, potential overprotection, or musculoskeletal issues. Thus, it should be the norm to realize a CPET prior a physical activity program to propose an optimal prescription. This study provides important information regarding the maximal physiological parameters that childhood ALL survivors are able to reach and have important clinical implications in the exercise and oncology field for this population of survivors.