Answers to Common Questions About Stem Cell Transplants

Stem cell transplantation can be a life-saving treatment option for patients with blood cancers or disorders. The procedure, sometimes called bone marrow transplantation, replaces bone marrow that doesn’t work correctly or has been damaged by disease.

Joseph Antin, MD, explains a procedure to a patient.
Joseph Antin, MD, explains a procedure to a patient.

We spoke with Joseph Antin, MD, chief of the Stem Cell Transplantation Program at Dana-Farber/Brigham and Women’s Cancer Center, to learn more about this procedure:

Why might I need a stem cell transplant?

You might need a stem cell transplant if your bone marrow can’t make enough blood cells or if it produces abnormal blood cells, usually because it is damaged by disease. For example, acute myeloid leukemia (AML) is a cancer of the bone marrow. Typically there are too many white blood cells and those cells fail to mature and function properly.  Conversely, patients with aplastic anemia can’t make enough blood cells. Depending on the source of the stem cells, this procedure may be called a peripheral blood stem cell transplant, a bone marrow transplant, or a cord blood transplant. All of these are stem cell transplants; the stem cells are collected differently in each of the three procedures.

 

What does a stem cell transplant do?

Stem cell transplantation refers to a procedure where healthy stem cells are taken from one individual and given to another (called an allogeneic transplant), or using an individual’s own stem cells (called an autologous transplant). Your physician will decide what type of transplant should be used for your treatment and the source of the transplanted stem cells.

An allogeneic transplantation replaces damaged bone marrow with blood-forming stem cells that develop into healthy bone marrow. This helps the body make enough blood cells and it lowers risk of anemia, bleeding, and infections. In autologous transplantation, collecting the stem cells before treatment and preserving them allows a much higher (and hopefully curative) dose of chemotherapy to be administered. The stem cells allow blood counts to recover after the high dose therapy.

Hematopoietic stem cells can grow into any of the cells found within the bloodstream. They make blood cells and the components that your immune system needs to function. During a transplant, your body is infused with healthy stem cells that then grow and produce all of the different parts of the blood that both your body and your immune system need.

 

Why would doctors choose a stem cell transplant?

Stem cell transplantation allows doctors to use much higher doses of chemotherapy and/or radiation than might otherwise be possible. These are more effective in destroying cancer cells, but they can also damage bone marrow. In allogeneic transplantation, the donor’s immune cells can also contribute to the anti-cancer effect of the procedure.

 

What’s the link between bone marrow and stem cells?

Bone marrow is the spongy tissue inside large bones such as hip and thigh bones. It contains immature cells called hematopoietic, or blood-forming, stem cells that develop into three types of blood cells: red blood cells that carry oxygen through the body; white blood cells that are responsible for fighting infection; and platelets that help the blood clot.  It is the stem cells that allow us to make trillions of blood cells over our lifetimes.  Those stem cells can be collected directly from the pelvic bone (bone marrow harvest), or they can be released into circulation and collected by a procedure called apheresis (peripheral blood stem cell harvest). There are advantages and disadvantages to each approach that would be explained by the transplant physician.

Blood-forming stem cells are not the same as embryonic stem cells studied in cloning and other types of research.

 

What conditions are treated by stem cell transplantation?

Stem cell transplantations are a common treatment option for cancers such as multiple myeloma, certain types of lymphoma, and leukemia. They are also used to treat several types of blood disorders and immune system diseases, including: aplastic anemia, sickle cell anemia, disorders of immunity, myelodysplastic syndrome, Waldenström’s macroglobulinemia, and myeloproliferative disorders.

Do you have a question that is not answered here? You can ask the bone marrow expert or visit the website for the Stem Cell Transplantation Program at Dana-Farber/Brigham and Women’s Cancer Center