Tumor cells disengage from the primary breast cancer site often travel to the bone marrow and spread from there to other areas of the body. Chemotherapy briskness up bone turnover which releases bone derived growth factors that can promote tumor growth in breast cancer patients. It is propone that zoledronic acid which reduces bone loss by slowing the activity of cells that destroy bone  can make bone marrow a less inviting place for cancer cells.

The new state two trial included 120 women undergoing chemotherapy for locally advanced breast cancer. Few of the patients received four milligrams of zoledronic acid every three weeks for one year starting with their first dose of chemotherapy while others received no zoledronic acid and the bone marrow samples were taken at the start of the study and again after three months and one year of treatment.

Between women who had no tumor cells in their bone marrow at the start of the study 87 % of those in the zoledronic acid group were free of tumor cells at three months compared with 60 percent of those who received chemotherapy alone. After  one year treatment, the rates were 40 percent and 33 percent respectively the study authors noted. Researchers also found that zoledronic acid prevented chemotherapy-related bone loss, among patients who had low bone mineral density at the start of the study 44 % of those who took zoledronic acid had normal bone density after one year and significant decreases in bone-turnover markers at three months and one year.