From the Guidelines
Bisphosphonate therapy after chemotherapy typically involves zoledronic acid (4mg IV every 12 weeks) to prevent cancer treatment-induced bone loss, as recommended by the most recent guidelines 1.
Key Considerations
- The use of bisphosphonates in metastatic disease is a palliative care measure, with no impact on overall survival, but it reduces skeletal-related events and pathologic fractures 1.
- Zoledronic acid and pamidronate may be given on a 3- to 4-week schedule or every 12 weeks in conjunction with antineoplastic therapy 1.
- Patients should also take calcium (1200-1500mg daily) and vitamin D (400-800 IU daily) supplements during treatment 1.
- Dental examinations are recommended before starting therapy, and good oral hygiene should be maintained throughout treatment to minimize the risk of osteonecrosis of the jaw 1.
Treatment Details
- The recommended agents for use in the United States are pamidronate 90 mg intravenously over 2 hours or zoledronic acid 4 mg intravenously over 15 minutes 1.
- The risk of renal toxicity necessitates serum creatinine monitoring before each dose is administered and dose reduction or discontinuation if renal function is reduced 1.
- Current clinical trial results support bisphosphonate use for up to 2 years, but longer durations of bisphosphonate therapy may provide additional benefit 1.
Patient Monitoring
- Baseline bone mineral density testing is recommended before starting treatment, with follow-up scans every 1-2 years to monitor effectiveness.
- Patients should be monitored for potential side effects, including flu-like symptoms after infusions, gastrointestinal issues with oral formulations, and rarely, osteonecrosis of the jaw.
- The use of bisphosphonates should be accompanied by calcium and vitamin D supplementation to optimize bone health 1.
From the Research
Recommended Treatment with Bisphosphonates after Chemotherapy
The use of bisphosphonates after chemotherapy is a common practice to prevent bone loss and reduce the risk of skeletal-related events in patients with bone metastases from breast cancer 2, 3, 4.
- Bisphosphonates are potent inhibitors of tumor-induced osteoclast-mediated bone resorption and are used to treat and prevent bone loss and decrease the risk of skeletal-related events 4, 5.
- Intravenous bisphosphonates such as zoledronic acid and pamidronate disodium are approved by the US Food and Drug Administration for the treatment of bone pain and hypercalcemia of malignancy and the prevention of painful bone fractures in patients with metastatic bone cancer 5.
- The ASCO guidelines recommend that patients with osteolytic bone metastases be treated with concurrent bisphosphonate and systemic therapy, rather than bisphosphonate monotherapy 3.
- Long-term (≥24 months) intravenous bisphosphonate use in metastatic breast cancer is well tolerated, with low incidences of osteonecrosis of the jaw (ONJ) and renal impairment 2.
Potential Side Effects of Bisphosphonates
While bisphosphonates are generally safe, there are potential side effects to consider, including:
- Osteonecrosis of the jaw (ONJ), a rare but painful complication of treatment characterized by infection, exposed bone, and poor wound healing 2, 5.
- Renal impairment, which can occur after administration of intravenous zoledronic acid, especially in patients with preexisting kidney impairment or a history of nephrotoxic treatment 6.
- Acute kidney impairment, which can require dialysis in some cases, even in patients without a history of cancer or preexisting kidney impairment 6.
Monitoring and Prevention
To minimize the risk of side effects, it is essential to:
- Monitor kidney function in all patients receiving bisphosphonate treatment 6.
- Identify patients at high risk of ONJ and renal impairment, such as those with a history of dental problems or kidney disease 2, 5.
- Follow established guidelines for the use of bisphosphonates in patients with bone metastases from breast cancer 3, 4.