Stem Cell Transplant for Multiple Myeloma
In a stem cell transplant, the patient gets high-dose chemotherapy (sometimes with radiation to the whole body) to kill the cells in the bone marrow (including the myeloma cells). Then the patient receives new, healthy blood-forming stem cells. When stem cell transplants were first developed, the new stem cells came from bone marrow, and so this was known as a bone marrow transplant. Now, stem cells are more often gathered from the blood (a peripheral blood stem cell transplant).
Stem cell transplant is commonly used to treat multiple myeloma. Before the transplant, drug treatment is used to reduce the number of myeloma cells in the patient’s body. (See Chemotherapy and Other Drugs for Multiple Myeloma.)
Stem cell transplants (SCT) are autologous and allogeneic.
For an autologous stem cell transplant, the patient’s own stem cells are removed from his or her bone marrow or peripheral blood before the transplant. The cells are stored until they are needed for the transplant. Then, the person with myeloma gets treatment such as high-dose chemotherapy, sometimes with radiation, to kill the cancer cells. When this is complete, the stored stem cells are infused back into the patient’s blood.
This type of transplant is a standard treatment for patients with multiple myeloma. Still, while an autologous transplant can make the myeloma go away for a time (even years), it doesn’t cure the cancer, and eventually the myeloma returns.
Some doctors recommend that patients with multiple myeloma have 2 autologous transplants, 6 to 12 months apart. This approach is called tandem transplant. Studies show that this may help some patients more than a single transplant. The drawback is that it causes more side effects and so is riskier.
In an allogeneic stem cell transplant, the patient gets blood-forming stem cells from another person – the donor. The best treatment results occur when the donor’s cells are closely matched to the patient’s cell type and the donor is closely related to the patient, such as a brother or sister. Allogeneic transplants are much riskier than autologous transplants, but they may be better at fighting the cancer. That’s because transplanted (donor) cells may actually help destroy myeloma cells. This is called a graft vs. tumor effect. Still, in studies of multiple myeloma patients, those who got allogeneic transplants often did worse in the short term than those who got autologous transplants. At this time, allogeneic transplants are not considered a standard treatment for myeloma, but may be done as a part of a clinical trial.
The early side effects from a stem cell transplant (SCT) are similar to those from chemotherapy and radiation, only more severe. One of the most serious side effects is low blood counts, which can lead to risks of serious infections and bleeding.
The most serious side effect from allogeneic transplants is graft-versus-host disease (or GVHD). This occurs when the new immune cells (from the donor) see the patient’s tissues as foreign and so attack them. GVHD can affect any part of the body and can be life threatening.
For more information about stem cell transplants, including details about the processes and side effects, see Stem Cell Transplant for Cancer.