Bone Abstracts

Improvements in diagnosis, multi-modal therapy and supportive care over the past several decades have resulted in substantial reductions in mortality rates for childhood cancer. Approximately 80% of children diagnosed with cancer are now expected to survive for at least 5 years after initial diagnosis. Nevertheless, improvements in survival rates have not come without cost, with survivors at risk of skeletal morbidities as a result of disturbances in normal bone metabolism during childhood or adolescence. Deficits in bone mineral density (BMD) are among the most commonly reported skeletal morbidity among long-term survivors of childhood cancer. Reductions in BMD may develop as a consequence of the side effects of childhood cancer, such as nutritional deficiencies and reduced physical activity levels, or as a result of the anti-cancer therapies, such as methotrexate and corticosteroids, received in childhood. Among survivors, BMD deficits may also occur as a result of gonadal failure following exposure to pelvic radiation or alkylating agents, or as a consequence of hypothalamic pituitary endocrinopathies following radiation to the CNS. In the general population, reductions in BMD can significantly increase the risk of fracture, which may result in acute or chronic pain, impaired mobility and physical function, as well as an increased risk of mortality. Failure to accrue sufficient bone mass during childhood may place childhood cancer survivors at an increased risk for fracture and skeletal morbidity later in life. This presentation will review the literature and findings from two large cohort studies, the Childhood Cancer Survivor Study and the St Jude Lifetime Cohort Study, regarding the current state of knowledge of fractures and associated risk factors among childhood cancer survivors. A brief discussion of the methodological challenges encountered when conducting research among cancer survivors will also be included. This presentation will conclude with a short discussion of several innovative approaches and interventions being explored in an effort to ameliorate or reverse bone loss among individuals treated for childhood cancer.