Very high doses of chemo drugs might work better to kill cancer cells, but the damage to the bone marrow (where new blood cells are made) could be fatal. A stem cell transplant (SCT) is a way for doctors to use high doses of chemo. The drugs destroy the patient’s bone marrow, but the transplanted stem cells restore it.
Stem cells for a transplant can come from either from the blood or from the bone marrow. Sometimes stem cells from a baby’s umbilical cord blood are used.
The 2 main types of stem cell transplants differ based on whom the blood-forming stem cells come from.
- An allogeneic transplant is the most common form of SCT used to treat acute myeloid leukemia (AML). For this, the stem cells come from a donor whose tissue matches the patient’s – often a close relative, like a brother or sister. Sometimes umbilical cord stem cells are used.
- In an autologous transplant, a patient’s own stem cells are removed from the blood or bone marrow. They are frozen and stored while the person gets strong chemo and perhaps radiation. The stem cells are then given back to the patient after treatment.
There is a good reason to use stem cells from someone else for the transplant. These cells seem to help fight any remaining leukemia cells through an immune reaction. This is called a graft-versus-leukemia reaction. Also, the patient’s own stem cells may contain some leukemia cells, even if they are collected when the leukemia is in remission.
Most older patients can’t have a regular allogeneic SCT that uses high doses of chemo. Some may be able to have what is called a mini-transplant (also called a non-myeloablative transplant or reduced-intensity transplant), where they get lower doses of chemo and radiation that do not destroy the all cells in their bone marrow. They then are given the donor stem cells. These cells enter the body and form a new immune system, which sees the leukemia cells as foreign and attacks them (a graft-versus-leukemia effect). This is not the standard type of transplant used for AML, and some doctors still think of this approach as experimental in this disease.
Some things to keep in mind
A stem cell transplant (SCT) is a complex treatment that can sometimes cause life-threatening side effects. If the doctors think you might be helped by this treatment, it is important that it be done at a hospital where the staff has experience.
SCT can cost more than $100,000 and might mean a long hospital stay. Because certain types of SCT may be seen as experimental by insurance companies, they might not pay for it. You should find out what your insurance will cover and what you might have to pay before deciding on a transplant.
Side effects of stem cell transplant
Common side effects are from the high doses of chemo and can be severe. These include nausea and vomiting, mouth sores, hair loss, and very low blood counts. One of the most common and serious short-term effects is the greater risk of infection caused by low white blood cell counts. Antibiotics are often given to try to prevent this. You might need to stay in a special hospital room to lower your exposure to germs until your immune system has recovered. Other side effects, like low red blood cell and platelet counts, might mean you will need transfusions.
Graft-versus-host-disease (GVHD): This is one of the most serious side effects from allogeneic SCTs. It happens when the patient’s immune system is taken over by that of the donor. The donor immune system then attacks the patient’s other tissues and organs.
Symptoms can include bad skin rashes with itching, mouth sores, nausea, and severe diarrhea. The liver and lungs may also be damaged. The patient may also be very tired and have aching muscles. If bad enough, GVHD can be fatal.
Drugs that weaken the immune system may be given to try to control it.
Long-term side effects: Stem cell transplants can also have some long-term side effects, including:
- Loss of fertility
- Damage to the lungs, causing shortness of breath
- Damage to the thyroid gland
- Cataracts (damage to the lens of the eye that can affect vision)
- Bone damage from poor blood supply. If damage is severe, the patient might need to have part of the bone and the joint replaced.
- Developing another cancer years later
To learn more about stem cell transplants, see Stem Cell Transplant (Peripheral Blood, Bone Marrow, and Cord Blood Transplants).
Last Revised: 02/22/2016