Bone Drug Could Help Prevent the Spread of Breast Cancer

Maintaining bone density could be a key to decreasing the spread of cancer in women with locally advanced breast cancer, according to research at Washington University School of Medicine in St. Louis.

Bones are common sites for the spread, or metastasis, of breast cancer. Scientists here found that women treated for stage II/III breast cancer who also received a bone strengthening drug were less likely to have breast tumor cells growing in their bones after three months. The bone-strengthening drug used was zoledronic acid, a drug that decreases bone turnover and reduces bone fractures in patients with osteoporosis.

“Tumor cells are continually being released from the primary tumor,” says lead author Rebecca Aft, MD, PhD, associate professor of surgery, faculty member of the Siteman Cancer Center and a Washington University breast surgeon at Barnes Jewish Hospital. “It is thought that the bone marrow harbors these cells and that these cells are likely to evolve into metastatic disease. We think that zoledronic acid changes the bone marrow so that cancer cells are unable to lodge there.”

The researchers randomly assigned 120 women being treated for clinical stage II/III breast cancer to receive 4 milligrams of zoledronic acid intravenously every three weeks for one year, starting with their first cycle of chemotherapy, or to receive no zoledronic acid. Stage II/III cancer means the primary tumor has spread into lymph nodes or other areas near the breast.

At the time of diagnosis, none of the patients had evidence of metastatic disease on computed tomography (CT) and/or positron emission tomography (PET) scans. But bone marrow samples showed that about 40 percent of the patients had detectable breast tumor cells in the bone marrow.

Relase date: May 15, 2008
Source: Washington University in Saint Louis