Bone Abstracts

Overall cure rates for childhood acute lymphoblastic leukemia (ALL) have improved allowing the cure of over 85% of patients. At least 70% of survivors of childhood ALL cancers have substantial morbidities as a result of their treatment. There is evidence that survivors of ALL have increased rates of long-term skeletal muscle dysfunction and weakness. Our objective was to determine the percentage of patients with muscle dysfunctions (muscle force, power, endurance, and % of fitness impairment) and to define the clinical characteristics associated with muscle dysfunction in long-term ALL survivors. Our study, part of the PETALE project, draws its subjects from a pool of 350 French-Canadian ALL patients aged under 19 at diagnostic that have been in remission for at least 5 years post-diagnostic.

The patients for this study (n=150) were recruited as part of the PETALE project at Sainte-Justine UHC: 59% are females; the mean age at diagnostic of 5.6±4.2 years; mean age at recruitment of 22.3±6.7 years; 59% of patients were classified as high risk at diagnosis; treatment duration was on average 26±4.7 months and was finished 171.6±70.6 months ago. Study participants were assessed once by mechanography, bone mineral density (DXA) scans, 6 min walk tests, and pQCT scans. Results show a high prevalence (32%) of low muscle power (Pmax/body mass lower than −2 S.D.) compared to age- and gender-specific reference values. Significant differences were observed between patients with muscle dysfunction compared to those without for: the high-risk DFCI protocol prognosis group, exposure to radiation; BMI (P<0.001). One third of all participants are vitamin D deficient (<50 nmol/l) but without significant differences between low and normal muscle power groups.

Since this population mostly consists of young adults and adolescents, these data raise concerns on their future muscle and bone health.

The PETALE project is funded by a CIHR team grant.

Disclosure: The authors declared no competing interests.