Stem Cell Transplantation
Stem cell transplants are used for cancer patients whose bone marrow isn’t working or has been destroyed by disease, chemotherapy or radiation therapy. Damaged or diseased stem cells can make too few blood cells, too few immune cells, or too many abnormal cells. Any of these problems can cause the body to not have enough normal red blood cells, white blood cells, or platelets. We need the right balance of all three of these cells to live. A stem cell transplant may help correct these problems.
In some cancers, such as certain leukemias, multiple myeloma, and some lymphomas, a stem cell transplant can be an important part of treatment.
How it works
High doses of chemotherapy, which is sometimes given with radiation, work better than standard doses to kill cancer cells. But high doses can also cause the bone marrow to completely stop making blood cells, which we need to live. The patients is given stem cells from a donor. This transplant lets doctors use much higher doses of chemo to try to kill all of the cancer cells.
Where do stem cells come from?
The main job of bone marrow, the spongy tissue in the center of some bones, is to make blood cells that circulate in your body, which includes immune cells that recognize invaders and fight infection. Bone marrow has a rich supply of stem cells.
Umbilical cord blood
A large number of stem cells are normally found in the blood of newborn babies. After birth, the blood that is left behind in the placenta and umbilical cord (known as cord blood) can be taken and stored for later use in a stem cell transplant. The cord blood is frozen until needed. A cord blood transplant uses blood that normally is thrown out after a baby is born. About one of every three umbilical cord blood transplants are done between two people who aren’t related, but their blood type matches.
Normally, a lot of stem cells aren’t found in the blood. But a hormone-like substances called growth factors can be given to stem cell donors a few days before the harvest. The growth factors cause their stem cells to grow faster and move from the bone marrow into the blood.
For a peripheral blood stem cell transplant, the stem cells are taken from blood. A special thin flexible tube (called a catheter) is put into a large vein in the donor and attached to tubing that carries the blood to a special machine. The machine separates the stem cells from the rest of the blood, which is given back to the donor during the same procedure. This takes several hours, and may need to be repeated for a few days to get enough stem cells. The stem cells are filtered, stored in bags, and frozen until the patient is ready for them.
The patient’s stem cell transplant specialist will guide him or her through the best treatment options.