Zoledronic acid may have anti-tumor effect with neoadjuvant chemotherapy

San Antonio Breast Cancer Symposium

SAN ANTONIO — Researchers in Sheffield and Leeds in the United Kingdom found that women with advanced hormone-receptor–positive breast cancer assigned to zoledronic acid plus chemotherapy had a reduced tumor size compared with women assigned to chemotherapy alone.

Robert Coleman, MD, a professor of medical oncology at the University of Sheffield, presented the results of a subset of women with stage II/III disease participating in the AZURE trial (n=3,360). He acknowledged the results were hypothesis-generating and not practice-changing, but said the results suggest new evidence of a possible anti-tumor effect of zoledronic acid (Zometa, Novartis).

“What this data suggests is that perhaps zoledronic acid is doing something more than just affecting bone density,” he said during a press conference at the San Antonio Breast Cancer Symposium. “It is the first patient-related evidence that this class of drugs may have direct anti-tumor activity.”

Investigators performed a retrospective pathology analysis on 101 women assigned to chemotherapy plus zoledronic acid and 104 women assigned to chemotherapy alone.

They found that the median size of tumors in patients assigned to zoledronic acid was 20.55 mm, compared with 30 mm in those assigned to chemotherapy alone. The adjusted mean residual invasive tumor size for patients receiving zoledronic acid was 28.2 mm compared with 42.4 mm for patients assigned to chemotherapy alone (95% CI, 5.4 mm-22.9 mm).

Patients in the zoledronic acid group had complete response rate of 10.9% compared with 5.8% in the chemotherapy group. More than three-quarters of patients assigned to chemotherapy alone required mastectomy (77.9%) compared with 65.3% in the zoledronic acid group. – by Jason Harris

For more information:

Winter MC. #5101. Presented at the 31st Annual CTRC-AACR San Antonio Breast Cancer Symposium; Dec. 10-14, 2008; San Antonio.