Researchers have been studying breast cancer for many years to learn how best to treat this disease. They have given special attention to ways to prevent breast cancer from recurring (returning) after primary treatment.
Scientists once thought that breast cancer metastasizes (spreads) first to nearby tissue and underarm lymph nodes before spreading to other parts of the body. They now believe that cancer cells may break away from the primary tumor in the breast and begin to metastasize even when the disease is in an early stage.
Adjuvant therapy is treatment given in addition to the primary therapy to kill any cancer cells that may have spread, even if the spread cannot be detected by radiologic or laboratory tests. Studies have shown that adjuvant therapy for breast cancer may increase the chance of long-term survival by preventing a recurrence.