Although it is possible to use very high doses of chemotherapy or radiation to kill cancer cells, such treatments also kill the blood-making stem cells in the bone marrow. Damage to these cells lowers a person's white blood cell count, which can lead to severe infections that could be fatal. It also makes people bleed easily. This, too, can be fatal.

One way to get around this is to remove some of the patient's stem cells from either the peripheral (circulating) blood or bone marrow, give the high-dose treatment, and then return the stem cells into the body through a blood transfusion. The stem cells are able to find their way back into the bone marrow, where they soon re-establish themselves and restore the body's ability to make new blood cells.

At one time it was thought that this would be a good way to treat women with advanced breast cancer. However, several studies have found that women who receive high-dose chemotherapy do not live any longer than women who receive standard chemotherapy without a stem cell transplant. High-dose chemotherapy with stem cell transplant also causes more serious side effects than standard dose chemotherapy.

Research is still being done in this area. Although newer studies may show a benefit, it is likely to be small, and the toxicity from this treatment is very high. At this time, most experts recommend that women with breast cancer not receive high-dose chemotherapy, except as part of a clinical trial.

Last Medical Review: 09/04/2008
Last Revised: 09/04/2008