Advanced breast cancer develops when cells from the original breast tumor travel to other parts of the body such as the bones, liver and lungs. Although at this stage, which is sometimes known as stage four breast cancer, or metastatic breast cancer, the disease can not be cured, cancer treatments are available which can control symptoms, improve a person's quality of life and prolong survival. Advanced breast cancer treatment may involve chemotherapy, where drugs destroy cancer cells; radiotherapy, in which radiation is used to shrink tumors; and occasionally surgery to cut out a tumor. Types of medication known as hormonal therapies, biological therapies and biphosphonates may be used to treat some tumors.
Early breast cancer, where the tumor cells have not spread farther than the breast and nearby lymph nodes, has a possibility of a cure, with the odds depending on how far the disease has progressed. Compared with advanced cancer treatment, the management of early stage disease may be more aggressive to give the best chance of providing that cure. With advanced breast cancer treatments, the focus is more on giving the best quality of life available in the time remaining, although trying to prolong survival time is also important.
Chemotherapy may be the first method of advanced breast cancer treatment given in cases where cancer is growing rapidly, or where it has spread to the lungs or liver. The drugs used in chemotherapy may be given singly or in combination with others, and are normally administered by infusion into a vein. Chemotherapy may be given every week or every few weeks for several months, forming what is known as a treatment cycle. Side effects from chemotherapy may include tiredness, a reduced resistance to infection, anemia, nausea and hair loss, but medications are available to treat some of these problems.
Advanced breast cancer treatment may sometimes involve the use of radiotherapy, particularly when tumors have spread to bone. Radiation targeted at the tumor sites can reduce pain as well as strengthen the bone. Drugs known as biphosphonates may be given as well, as they also help to build up bone. Radiotherapy is also used to shrink tumors in the brain and lungs. Sessions are usually given daily for a number of days, and side effects of tiredness, nausea and hair loss may develop.
Some tumor cells carry proteins known as estrogen receptors, to which the hormone estrogen attaches, stimulating tumor growth. Hormonal therapies which block the estrogen receptors, or which lower the levels of estrogen in the body, can inhibit cancer progression. Some stage four breast cancer cells carry HER2 proteins, to which growth factors bind, causing the cells to grow. Biological therapies target these HER2 proteins and block them so the growth factors can not attach to them. Hormonal therapies used in advanced breast cancer treatment may cause menopause-like side effects, and biological therapies can cause flu-like symptoms.