Your doctor may recommend a stem cell transplantation to treat your acute myeloid leukemia (AML). While treatment with chemotherapy alone is appropriate for some patients, others may benefit from stem cell transplantation.
First the patient receives intensive chemotherapy, with or without radiation, to kill the remaining leukemic cells in the patient's body. This also destroys the normal stem cells in the patient's bone marrow. After the chemotherapy, the patient receives an infusion of stem cells to replace the stem cells destroyed by the intensive therapy. These new stem cells restore healthy stem cells in the bone marrow that can form new red blood cells, white blood cells and platelets.
The two main types of stem cell transplantation are
- Allogeneic stem cell transplantation, using stem cells from a healthy donor
- Autologous stem cell transplantation, using stem cells from the patient.
The question of which patients are likely to benefit from transplantation after their first complete remission is under study in clinical trials. The decision to do a stem cell transplant depends on whether the patient’s AML is favorable risk, intermediate risk or high risk. The doctor also considers
- The patient’s overall health
- The chances that chemotherapy alone will cure the AML
- The type of abnormal changes to the chromosomes and cells
- The availability of a matched donor, if necessary
- The patient’s understanding of the benefits and risks of transplant.
The age limit for transplantation vaies by treatment center. Many centers do not offer stem cell transplantion for patients older than 60 or 65 years of age. A reduced-intesity allogeneic stem cell transplantion may be an option for older patients.
Allogeneic Stem Cell Transplantation
This is the most common type of stem cell transplantation used to treat AML. Allogeneic transplantation uses healthy blood-forming cells from an HLA-matched family member, an unrelated donor, or from umbilical cord blood. The donated stem cells restore the bone marrow’s ability to form new blood cells. Ideally, an allogeneic stem cell transplant will generate a new immune system or the patient. The immune system helps the body fight infections and other diseases. The new immune system also has the potential to recognize and attack any remaining cancer cells. The transplanted immune cells (the graft) perceive the leukemia cells in the body as foreign and destroy them. This is called the “graft-versus-leukemia (GVL)” effect.
Allogeneic stem cell transplantation, compared to other treatment approaches, is associated with a higher rate of side effects and mortality in patients. However, it may be considered for patients with higher-risk AML, based on cytogenetic and molecular test results and currently available therapies.
Reduced-Intensity Allogeneic Stem Cell Transplantation
Reduced-intensity allogeneic stem cell transplantation may be a treatment option for patients who are too old or who may have other medical conditions that prevent them from having a standard allogeneic stem cell transplant. The conditioning therapy used for a reduced-intensity transplant is of lower intensity than that for a standard stem cell transplant. It does not completely inactivate the patient’s immune system or treat the AML as intensively. Thus, if a suitable donor is available, patients up to age 75 may benefit from this form of treatment.
Graft Versus Host Disease
A serious risk of allogeneic and reduced-intensity allogenic stem cell transplantation is graft versus host disease (GVHD), which develops if the donor's immune cells attack your normal tissue. GVHD's effects can range from minor to life threatening.
Autologous Stem Cell Transplantation
This is a procedure in which bone marrow is removed from a patient after achieving a remission during induction therapy, and then frozen and stored. The cells are returned to the patient’s body after receiving intensive chemotherapy. Before the stem cells are infused back into the patient’s body, they undergo a process called “purging” to try to eliminate any leukemic cells. Even after purging, there is the risk of returning some leukemia cells back to the patient. The procedure is only appropriate for certain patients.
Autologous transplantation is sometimes used for patients who do not have an HLA-matched donor. Autologous transplants are usually easier for patients to tolerate than allogeneic transplants. This is because patients receive their own stem cells, so the risk of some complications, such as graft-versus-host disease, is lower.
Autologous transplants are used less frequently than allogeneic transplants for AML patients mainly because of the lack of a graft-versus-leukemia effect and the risk of returning some leukemia cells back to the patient.
Related Links
- Stem Cell Transplantation
- Managing Side Effects
- Integrative Medicine and Complementary and Alternative Therapies
- Food and Nutrition
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