Guidelines on Bone-Modifying Agents in Metastatic Breast Cancer Updated
NEW YORK (Reuters Health) - The American Society of Clinical Oncology (ASCO) and Cancer Care Ontario (CCO) have updated their joint recommendations on bone-modifying agents (BMAs) for women with metastatic breast cancer, with an emphasis on dosing intervals and management of bone pain.
Senior author Dr. Beverly Moy of Massachusetts General Hospital, Boston, told Reuters Health by email, "The updated recommendations provide evidence that it is reasonable to administer intravenous zoledronic acid every three months, rather than monthly, for patients with metastatic breast cancer to bone."
"This," she added, "will reduce the overall treatment burden for our patients, reduce exposure to a drug and its potential side effects, and reduce overall treatment costs."
For their October 16 online report in the Journal of Clinical Oncology, Dr. Moy and colleagues on the ASCO-CCO committee reviewed three trials of BMA dosing intervals, a review and meta-analysis on de-escalation of BMAs, and two randomized trials of BMAs for controlling pain secondary to bone metastases.
In keeping with the 2011 guidelines, the committee recommends that patients with breast cancer who have evidence of bone metastases be treated with BMAs. In addition to IV zoledronic acid (4 mg every 12 weeks or every 3 to 4 weeks), they list the options of subcutaneous denosumab (120 mg every 4 weeks) and IV pamidronate (90 mg every 3 to 4 weeks). However, they say, "one BMA is not recommended over another."
Regarding pain control, the authors point to the “modest” analgesic effects of BMAs. “They should not be used alone for bone pain," they write. Again, evidence was insufficient to support one agent over another pending further research.
The committee notes that standard supportive care and pain management may include analgesia, adjunct therapies, radiotherapy, surgery, and systemic anticancer therapy.
Although they found no relevant cost-effectiveness analyses, the authors highlight that BMA prices vary markedly, with annual costs ranging from close to US$400 for pamidronate; from roughly $200 to $700 for zoledronic acid, depending on the dose; and nearly $26,000 for denosumab.
"Clinicians should exercise judgment and, whenever it is practical and feasible, discuss with patients the use of less expensive alternatives when considering two or more treatment options that are comparable in terms of benefits and harms," the authors write.
They add that since 2000, "ASCO guidelines have recommended the use of BMAs indefinitely. There are no new data to alter the 2000 duration of therapy recommendation."
They conclude that this is also true of information "outlining the risk/benefit ratio of stopping and potentially restarting BMA therapy during long-term care. Data on the long-term dosing and long-term effects of BMAs are needed."
J Clin Oncol 2017.