Could the long-term persistence of low serum calcium levels and high serum parathyroid hormone levels during bisphosphonate treatment predispose metastatic breast cancer patients to undergo osteonecrosis of the jaw?

摘要

In the randomised registrative study of zoledronic acid in bone metastatic breast cancer patients , increased PTH was observed in the first treatment months, showing a progressive decrease in the subsequent months. This pattern has been confirmed in our control patients, since, after 12 months of zoledronate treatment, serum calcium was normal and serum PTH was only slightly elevated. Patients developing ONJ showed a clear persistence of a condition of relative hypocalcaemia and secondary hyperparathyroidism in the time period preceding this adverse event. These results suggest that persistent hyperparathyroidism may be involved in the complex pathogenesis of ONJ associated with bisphosphonate treatment. Tailoring calcium and vitamin D consumption to each patient, on the basis of serum calcium and serum PTH, could potentially limit the onset of ONJ.