Adjuvant Bisphosphonates for Breast Cancer
Name of the Trial
Phase III Randomized Study of Adjuvant Zoledronate Versus Clodronate Versus Ibandronate in Women With Resected Primary Stage I-III Adenocarcinoma of the Breast (SWOG-S0307). See the protocol summary.
Dr. Julie Gralow and Dr. Robert Livingston, SWOG; Dr. James Ingle, NCCTG; Dr. Carla Falkson, ECOG; Dr. Alexander Paterson, NSABP; Dr. Elizabeth Dees, CALGB; and Dr. Mark Clemons, NCIC Clinical Trials Group.
Why This Trial Is Important
When breast cancer spreads (metastasizes), it often spreads first to the bones. Bone metastases can lead to complications such as pain, fractures, spinal cord compression, bone marrow suppression, and hypercalcemia (abnormally high blood calcium).
Drugs called bisphosphonates have been shown to slow the progression of bone metastases and reduce skeletal complications in women with metastatic breast cancer. Bisphosphonates may also prevent the development of bone metastases in newly diagnosed patients with no evidence of metastasis.
"Breast cancer cells stimulate bone cells called osteoclasts, and these osteoclasts in turn stimulate the growth of breast cancer cells," said Dr. Gralow. "A bisphosphonate called clodronate has been shown to interrupt the relationship between osteoclasts and breast cancer cells in early stage breast cancer. With this trial, we're comparing clodronate with two newer, more-potent bisphosphonates—zoledronate and ibandronate.
"If we can eliminate bone as a safe harbor for breast cancer cells in women who would have experienced bone metastases as the first site of metastasis, we may be able to prevent the spread of breast cancer in these women altogether and save lives. Additionally, we hope to determine which types of breast cancer preferentially metastasize to bone," Dr. Gralow added.
This study is no longer accepting new patients. To locate other clinical trials for breast cancer, search the NCI's list of clinical trials or call the NCI's Cancer Information Service toll free at 1-800-4-CANCER (1-800-422-6237). The call is confidential.