<qa>  What is hyaluronic acid?This research trial studies the role of a substance called hyaluronic acid in causing the growth of cancer stem cells in the bones of patients with breast cancer. Cancer stem cells are a type of cancer cells that may cause the cancer to spread to other parts of the body. Studying samples of blood and bone marrow from patients and animal models in the laboratory may help doctors learn more about whether hyaluronic acid affects the growth of cancer in the bones. 