Recovery kinetics of heart rate and oxygen uptake in long-term survivors of acute leukemia in childhood

Skeletal, neuromuscular and fitness impairments among children with newly diagnosed acute lymphoblastic leukemia

This study describes skeletal, neuromuscular and fitness impairments among 109 children (median age 10 [range 4-18] years, 65.1% male, 63.3% white) with acute lymphoblastic leukemia (ALL). Outcomes were measured 7-10 days after diagnosis and compared to age- and sex-specific expected values. Associations between function and health-related quality of life (HRQL) were evaluated with logistic regression. Children with ALL had sub-optimal bone mineral density (BMD) Z-score/height (mean ± standard error: - 0.53 ± 0.16 vs. 0.00 ± 0.14, p < 0.01), body mass index percentile (57.6 ± 3.15 vs. 50.0 ± 3.27%, p = 0.02), quadriceps strength (201.9 ± 8.3 vs. 236.1 ± 5.4 N, p < 0.01), 6 min walk distance (385.0 ± 13.1 vs. 628.2 ± 7.1 m, p < 0.001) and Bruininks-Oseretsky Test of Motor Proficiency scores (23 ± 2.5 vs. 50 ± 3.4%, p < 0.01). Quadriceps weakness was associated with a 20.9-fold (95% confidence interval 2.5-173.3) increase in poor physical HRQL. Children with newly diagnosed ALL have weakness and poor endurance and may benefit from early rehabilitation that includes strengthening and aerobic conditioning.

Reduced cardiorespiratory fitness in adult survivors of childhood acute lymphoblastic leukemia

BACKGROUND

Adult survivors of childhood acute lymphoblastic leukemia (ALL) are at increased cardiovascular risk. Studies of factors including treatment exposures that may modify risk of low cardiorespiratory fitness in this population have been limited.

PROCEDURE

To assess cardiorespiratory fitness, maximal oxygen uptake (VO2 max) was measured in 115 ALL survivors (median age, 23.5 years; range 18-37). We compared VO2 max measurements for ALL survivors to those estimated from submaximal testing in a frequency-matched (age, gender, race/ethnicity) 2003-2004 National Health and Nutritional Examination Survey (NHANES) cohort. Multivariable linear regression models were constructed to evaluate the association between therapeutic exposures and outcomes of interest.

RESULTS

Compared to NHANES participants, ALL survivors had a substantially lower VO2 max (mean 30.7 vs. 39.9 ml/kg/min; adjusted P < 0.0001). For any given percent total body fat, ALL survivors had an 8.9 ml/kg/min lower VO2 max than NHANES participants. For key treatment exposure groups (cranial radiotherapy [CRT], anthracycline chemotherapy, or neither), ALL survivors had substantially lower VO2 max compared with NHANES participants (all comparisons, P < 0.001). Almost two-thirds (66.7%) of ALL survivors were classified as low cardiorespiratory fitness compared with 26.3% of NHANES participants (adjusted P < 0.0001). In multivariable models including only ALL survivors, treatment exposures were modestly associated with VO2 max. Among females, CRT was associated with low VO2 max (P = 0.02), but anthracycline exposure was not (P = 0.58). In contrast, among males, anthracycline exposure ≥ 100 mg/m(2) was associated with low VO2 max (P = 0.03), but CRT was not (P = 0.54).

CONCLUSION

Adult survivors of childhood ALL have substantially lower levels of cardiorespiratory fitness compared with a similarly aged non-cancer population.

Motor performance and functional exercise capacity in survivors of pediatric acute lymphoblastic leukemia

BACKGROUND

Impaired motor performance and reduced maximum exercise capacity during and after treatment of acute lymphoblastic leukemia (ALL) has been shown. However, no longitudinal study monitoring motor performance after cessation of treatment has been published. Whether sub-maximal exercise capacity is reduced is unknown.

PROCEDURE

Motor performance of pediatric ALL survivors, treated with Dutch Childhood Oncology Group ALL-9 protocol was measured with the movement-ABC at stop treatment and ≥5 years later. At follow-up functional exercise capacity was also investigated using the 6-minute walk test (6MWT). Heart rate and oxygen saturation were measured with a portable pulse oximeter before and after the 6MWT.

RESULTS

Nineteen boys and 15 girls, median age 12.3 years (range: 9.0-18.7), median time since completion of chemotherapy 5.2 years (5.0-7.1), participated. Mean height/age and weight/age were within the norm, whereas mean BMI/age was significantly increased (mean SDS 0.38, SEM 0.17, P = 0.04). Motor performance had improved significantly (P = 0.001). In contrast, functional exercise capacity at follow-up was significantly impaired (mean SDS -2.05, SEM 0.13, P < 0.001).

CONCLUSIONS

At ≥5 years after completion of ALL treatment motor performance had improved significantly, but functional exercise capacity was significantly impaired. The exact underlying cause of this late effect needs further study.