Zoledronic Acid May Have Anti-Tumor Properties
December 11, 2008
SAN ANTONIO - Early evaluations of zoledronic acid suggest a possible direct anti-tumor effect when combined with neoadjuvant chemotherapy in breast cancer treatment, according to data presented at the CTRC-AACR San Antonio Breast Cancer Symposium.
"Zoledronic acid is primarily targeted to bone and metastasis within the bone marrow microenvironment, but it may also be enhancing the response in the primary breast tumor," said Robert Coleman, M.D., FRCP, professor of medical oncology at the University of Sheffield in the United Kingdom.
Coleman is the lead researcher on the AZURE (Adjuvant Zoledronic Acid to Reduce Recurrence) trial, which is evaluating the effect of zoledronic acid on breast cancer. Although the larger AZURE trial is still being evaluated, if the findings in this smaller study are confirmed, the effect could be "practice changing," Coleman said.
The AZURE trial enrolled 3,360 women with stage II/III breast cancer to determine whether treatment with zoledronic acid in addition to adjuvant or neoadjuvant chemotherapy would improve disease outcomes.
Coleman and colleagues performed a retrospective pathology analysis on 205 patients who received neoadjuvant chemotherapy to determine zoledronic acid's impact on the primary tumor.
Zoledronic acid appeared to reduce tumor size from 30 mm in the chemotherapy alone group to 20.5 mm in the combination group. After adjusting for variables like estrogen receptor status and treatment duration, the difference remained at 42.4 mm in the chemotherapy group and 28.2 mm in the combination group.
The pathological complete response rate was 5.8 percent in the chemotherapy arm and 10.9 percent in the zoledronic acid group.
The number of patients requiring mastectomy was 77.9 percent in the chemotherapy group and 65.3 percent in the combination group.
"Zoledronic acid is currently approved for the treatment of bone metastasis and osteoporosis. If the AZURE trial remains positive, then we'll file for an additional indication," said Coleman.
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The mission of the CTRC-AACR San Antonio Breast Cancer Symposium is to produce a unique and comprehensive scientific meeting that encompasses the full spectrum of breast cancer research, facilitating the rapid translation of new knowledge into better care for breast cancer patients. The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio, the American Association for Cancer Research (AACR), and Baylor College of Medicine are joint sponsors of the San Antonio Breast Cancer Symposium. This collaboration utilizes the clinical strengths of the CTRC and Baylor, and the AACR's scientific prestige in basic, translational and clinical cancer research to expedite the delivery of the latest scientific advances into the clinic. The 31st Annual Symposium is expected to draw more than 8,500 participants from more than 80 countries.
In San Antonio Dec. 10-15: