ASCO recommends the following for the use of bone-modifying drugs for breast cancer:
- Bone-modifying drugs are recommended for people with breast cancer who have evidence of bone metastases on an x-ray. They are also recommended for people with evidence of bone metastases on a bone scan and a computed tomography (CT) scan or magnetic resonance imaging (MRI), even if an x-ray shows no evidence. Results of a bone scan alone should not be used to recommend treatment.
- If you are taking one of these drugs, talk with your doctor about how long you should take the drug since doctors often recommend that patients keep taking the drug because the risk of having bone problems continues.
- If you have breast cancer that has spread to the bone, you should talk with your doctor about choosing a bone-modifying drug. The choice of drugs depends on your overall health, your individual risk of side effects, the cost, and the amount of time needed for each dose. For example, pamidronate is given intravenously (IV; through a vein) every three to four weeks for at least two hours. Zoledronic acid is given by IV every three to four weeks for at least 15 minutes. Denosumab is given as an injection under the skin (called a subcutaneous injection) every four weeks.
- If you are taking pamidronate or zoledronic acid, you should have a blood test for creatinine levels each time the drugs are given. Creatinine is a type of protein in the blood that shows how well the kidneys are working. High levels of creatinine may indicate kidney damage and that the medications you are taking may need to be changed. Calcium, electrolytes, phosphate, magnesium, and hematocrit/hemoglobin should also be monitored regularly. If you are receiving denosumab, you should be tested for creatinine levels before the first dose and monitored for hypocalcemia. Talk with your doctor about when and how often these should be monitored.
- Before taking bone-modifying drugs, you should have a thorough dental examination, and any invasive procedures to the jaw bone or treatments for mouth infections should be done before starting these drugs. While receiving bone-modifying drugs, you should take good care of your teeth, mouth, and gums and avoid having any unnecessary invasive dental work done, such as dental surgery. Following these recommendations may help lower the risk of osteonecrosis of the jaw.
- Although bone-modifying drugs may help reduce or lessen pain over the long term, they should not replace other treatments to reduce pain. Patients who experience bone pain should receive other medications and/or radiation therapy and/or surgery that are commonly used to manage the pain .
Research on bone-modifying drugs is ongoing. At this time, people with breast cancer in the situations listed below should take bone-modifying drugs only as part of a clinical trial:
- Patients with breast cancer who have evidence of bone metastases only on a bone scan, but not on x-ray, CT scan, or MRI
- Patients who have breast cancer that has spread to other parts of the body but have no evidence of bone metastases