Stem Cells for Cancer Treatment. Stem cell transplants are used to replace the bone marrow cells that have been destroyed by cancer. They are also used to replace cells destroyed by chemotherapy and radiation therapy used to treat cancer.
There are different types of stem cell transplants.
In all of them, high doses of chemotherapy (sometimes along with radiation) are used to eliminate cancer cells. However, high doses can also eliminate all the stem cells a person has, causing the bone marrow to temporarily stop producing blood cells. In other words, the original stem cells of a person are intentionally destroyed. But since our bodies need blood cells to function, this is where stem cell transplants come in handy. Transplanted stem cells help “rescue” the bone marrow by replacing the body’s destroyed stem cells due to treatment. Therefore, transplanting healthy cells allows doctors to use much higher doses of chemotherapy in an attempt to kill all cancer cells. Transplanted stem cells can become healthy, mature blood cells that function normally and reproduce cancer-free cells.
Stem Cells for Cancer Treatment Another way a stem cell transplant can work is by using stem cells from another person (not the cancer patient). In these cases, the transplant can help treat certain types of cancer in a way that goes beyond simply replacing the stem cells. Often, donated cells can find and eliminate cancer cells more effectively than the person’s immune system cells could. This is known as the “graft-versus-cancer” or “graft-versus-leukemia” effect. The “graft” refers to the donated cells. The effect means that certain types of transplants effectively help kill cancer cells. They also aid in rescuing the bone marrow and allowing normal blood cells to develop from the stem cells.
Where do stem cells for transplantation come from?
Sources of Stem Cells for Transplants Depending on the type of transplant being performed, there are three possible sources of stem cells to use:
- Bone marrow (either from the patient or someone else)
- Peripheral blood (peripheral blood stem cells, either from the patient or someone else)
- Umbilical cord blood from newborns
Cancers Affecting Bone Marrow Some types of cancer originate in the bone marrow, while others can spread to it. Cancer in the bone marrow causes an excessive number of certain cells to be produced. These cells are unhealthy and don’t function properly, outnumbering other cells and preventing their normal development. To stop these cancers from growing, proper functioning of the bone marrow cells and the production of new healthy cells are necessary.
Stem Cells for Cancer Treatment Most cancers that affect the function of the bone marrow are leukemias, multiple myeloma, and lymphomas. All of these cancers begin in the blood cells. Other cancers can spread to the bone marrow, which can also affect the function of blood cells.
For certain types of leukemia, lymphoma, and multiple myeloma, a stem cell transplant can be an important part of treatment. The goal of the transplant is to eliminate cancer cells and damaged or unhealthy cells that are not functioning well, and provide the patient with new healthy stem cells to “start anew.”
Don’t forget to read our article on What are stem cells?