Bone Abstracts

Objectives: To evaluate the skeletal profile of paediatric patients with cancer at diagnosis.

Methods: Children diagnosed with cancer in our Oncology Centre were recruited during a fifteen-month period and underwent metabolic bone profile and dual-energy X-ray absorptiometry (DXA) at the time of diagnosis. Subsequently, they were divided in two subgroups, according to diagnosis; haematological malignancy vs solid tumour. For comparison, a group of 38 sex and age-matched controls was used.

Results: Sixty-nine children were recruited (41 boys, 50 prepubertal), aged 7.6±4.6 years. Of those, 39 were diagnosed with haematologic malignancies and 30 with solid tumours. Eighteen out 69 patients had bone pain, fourteen had a limp and one sustained a femoral fracture. 45% of the patients were vitamin D insufficient (25–OH-D: 12–20 ng/ml) and 7.2% were deficient (<12 ng/ml). There was no difference compared to controls or between the subgroups. Hyperparathyroidism was present in 10% and hypercalciuria in 28% of all patients. Bone turnover was also affected, particularly bone formation, because the patients had lower levels of osteocalcin (OC, P<0.001) and procollagen type I propeptide (PICP, P=0.003), compared to controls. Within-group analysis revealed lower bone formation markers in the haematological subgroup i.e. OC and PICP (P=0.003 and 0.01, respectively), whereas the solid tumour subgroup had higher bone resorption markers, ie tartrate-resistant acid phosphatase (P=0.02) and urine deoxypyridinoline/urine creatinine (P=0.005). Finally, a DXA scan was performed in 38 patients; 20% of them had low-normal bone mineral density (BMD) of the lumbar spine (LS Z-score between −1 and −2) and only one patient had low BMD Z-score <−2 at the same site. Total body less head scans (TBLH) were normal. Patients with haematological malignancy had lower BMD, with a more pronounced reduction at the lumbar spine (P=0.03), compared to those with solid tumour.

Conclusion: Skeletal health is already adversely affected at the time of diagnosis of paediatric cancer. Low vitamin D is common. Bone turnover is disturbed and follows different patterns, depending on the type of the tumour. Finally, BMD reduction is more pronounced in haematological malignancies. These observations support bone health surveillance and intervention at the time of cancer diagnosis.

Disclosure: The authors declared no competing interests.