By Rebecca Jenkins
Children who have survived cancer are at increased risk of fracture and need long-term follow up to monitor their bone health, an international review has concluded.
All cancer therapies can decrease bone mineral density (BMD) through long-term endocrine alterations, such as gonadal dysfunction, growth hormone deficiency and altered body composition, and can also directly affect bone cells, a team of experts wrote in the Annals of Oncology.
‘Furthermore, modifiable factors, such as nutritional deficiency and less physical activity, can modify bone mass and quality,’ they said.
After reviewing the available literature and guidelines, and considering their clinical experience, the authors, on behalf of the International Osteoporosis Foundation Cancer and Bone Working Group, recommended a baseline bone health assessment two years after a patient finished cancer therapy. This should include a BMD evaluation, followed by laboratory examinations to assess bone metabolism, renal function and factors inducing secondary osteoporosis.
The review also recommended patients ensure adequate vitamin D and calcium intake, whether through diet or supplementation, and focus on physical activity to build and maintain BMD.
Clinicians should consider national guidelines as well as the patient’s latitude of residence, age, body weight and dietary and cultural habits when deciding on appropriate supplement dosages.
Long-term studies were needed, however, to quantify the effects of vitamin D, calcium and physical activity on future fracture morbidity in this patient group, the review concluded.
Professor John Eisman, Head of the Osteoporosis and Translational Research Laboratory at the Garvan Institute of Medical Research and an endocrinologist at Sydney’s St Vincent’s Hospital, said the paper was a high-level review of the serious issue of the potential long-term sequelae of childhood cancer treatment.
He supported the key recommendations to check BMD and advise on healthy lifestyle, adding that in some cases specific bone active therapy, such as a bisphosphonate, might be indicated.
‘If specific bone active therapy seems to be required that’s when specialist care is needed,’ he told Endocrinology Today, urging GPs to refer if they were concerned about a childhood cancer survivor’s bone health.
When ordering BMD assessments, Professor Eisman said any good quality Australian BMD service should be able to provide an age-appropriate interpretation for a paediatric patient.
‘My view would be that BMD be repeated in two years or one year if a new bone specific therapy was started. If the BMD seemed okay, the repeat interval could be extended to, say, five years,’ he said.
Ann Oncol 2019; 30: 908-920.