Zometa (chemical name: zoledronic acid) is used to strengthen bones and lower the risk of fractures or other bone problems in women diagnosed with metastatic breast cancer that has spread to the bones. Zometa is a bisphosphonate. Earlier studies suggested that Zometa also might help stop breast cancer from spreading to the bones by making it harder for breast cancer cells to grow in bones. So doctors are studying whether Zometa can lower the risk of cancer coming back (recurrence) in women diagnosed with early-stage breast cancer.
The latest results from the Adjuvant Zoledronic Acid to Reduce Recurrence (AZURE) trial suggest that Zometa after surgery may reduce the risk of recurrence and improve overall survival in postmenopausal women diagnosed with early-stage breast cancer. The results were presented at the September 2011 European Multidisciplinary Cancer Conference (ECCO-ESMO).
In the AZURE trial, 3,360 women diagnosed with stage II or stage III breast cancer had surgery and then hormonal therapy and/or chemotherapy to reduce the risk of recurrence. Half the women also got Zometa; the other half didn't.
About 5 years after surgery, the women who got Zometa and the women who didn't get Zometa had the same risk of recurrence. So Zometa didn't seem to affect disease-free survival (living without the cancer coming back).
But when the researchers compared the recurrence risk of premenopausal and postmenopausal women (more than 1,000 women were 5 or more years into menopause) who did and didn't get Zometa, Zometa seemed to have an effect. Compared to postmenopausal women who didn't get Zometa, postmenopausal women who got Zometa:
- had 25% better disease-free survival
- were 26% more likely to be alive with or without a cancer recurrence (overall survival)
Zometa made no difference in disease-free survival in premenopausal women.
Earlier studies suggested that Zometa might help reduce the risk of breast cancer recurring specifically in the bones. But the AZURE trial suggests that Zometa also lowers the risk of the cancer coming back in the breast area and in areas away from the breast other than bone in postmenopausal women.
Other research hasn't shown that Zometa convincingly reduces the risk of recurrence or improves survival for women diagnosed with early-stage breast cancer. So Zometa isn't routinely used in that way at this time.
Still, Zometa and other bisphosphonates may make sense for postmenopausal women to strengthen bones that may be weakened by some breast cancer treatments.
Bisphosphonates used to prevent or treat osteoporosis include:
- Actonel (chemical name: risedronate)
- Boniva (chemical name: ibandronate)
- Fosamax (chemical name: alendronate)
- Reclast (chemical name: zoledronic acid -- the same active ingredient as Zometa but a different formulation)
Reclast is given intravenously once a year. The others are pills taken by mouth.
If you've been diagnosed with early-stage breast cancer, you may want to ask your doctor if a bisphosphonate makes sense for you. If you're postmenopausal, your doctor may recommend a bisphosphonate to strengthen your bones or treat osteoporosis. Whether Zometa also can lower your risk of recurrence is still not entirely clear, though the AZURE study suggests that it might. If you're prescribed a bisphosphonate, know that some of them need to be taken in a specific way and all may cause serious side effects; make sure you and your doctor talk about how to take the medicine.