Medical researchers are continuously working on the quest for a drug that can cure breast cancer. The last significant breakthrough was three decades ago when tamoxifen was found to reduce the risk of recurrence of breast cancer. At the CTRC-AACR San Antonio Breast Cancer Symposium in Texas this year, several drugs that show promise for curing this deadly disease have been presented.
Among these drugs, zoledronic acid (Zometa) was found to be the most promising one. Zoledronic acid is a drug used for treating osteoporosis. Recent studies, however, showed that this drug may potentially have direct anti-tumor properties and can also shrink breast tumors in patients who are undergoing chemotherapy. Zoledronic acid is already an approved drug for treating breast cancer that has spread to the bone. Aside from osteoporosis, however, they discovered that it can also lower the risk of breast cancer recurrence in pre-menopausal women with early estrogen- or progesterone-positive tumors. This was based on the study involving more than 200 women with breast cancer. Those patients who were treated with zoledronic acid in addition to chemotherapy have better results compared to those who were treated with chemotherapy alone. The “chemotherapy-alone” group had an average tumor size of 42.4 millimeters. This is significantly bigger compared to those patients with the zoledronic acid – chemotherapy combination where the average tumor size was only 28.2 millimeters.
Zoledronic acid is currently being evaluated against breast cancer in the clinical trial AZURE (Adjuvant Zoledronic Acid to Reduce Recurrence).
“This data suggests that zoledronic acid is doing something more than protecting bone,” said study senior author Dr. Robert Coleman, a professor of medical oncology at the University of Sheffield in England. “It’s not practice-changing. It’s hypothesis-generating, which will lead to the design of new trials to look at this in detail. But this is the first patient-related evidence.”
The other promising drugs presented in the symposium include the following:
- Aromatase inhibitor exemestane (Aromasin) reduced cancer by 15% and reduced the risk of distant metastasis by 19% in postmenopausal women with breast cancer.
- Herceptin (trastuzumab) which is a drug used to treat HER2-positive breast cancer plus chemotherapy before surgery resulted in 70% of women surviving for 3 years without cancer recurrence.
- Lapatinib (Tykerb) which is another HER2 inhibitor if combined with another aromatase inhibitor can extend progression-free survival by 5 months on patients with HER2-positive metastatic breast cancer.
- Aromatase inhibitors show promise as potential replacement of tamoxifen as standard treatment to prevent recurrence of breast cancer in women who have already undergone conventional therapy.