A stem cell
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The standard of care for multiple myeloma patients at Huntsman Cancer Institute typically involves treatment with tandem autologous stem cell transplants.
What is an autologous stem cell transplant?
The goal of chemotherapy treatment is to destroy the myeloma cells. Unfortunately, in addition to destroying cancerous cells, chemotherapy also destroys healthy cells in the body.
An autologous stem cell transplant involves collecting a patient’s own healthy bone marrow stem cells prior to giving the high-dose chemotherapy and then giving them back after the treatment. This way, the healthy stem cells are not damaged by the high-dose chemotherapy.
Patients are vulnerable to infection and bleeding after chemotherapy, and giving a patient back his or her unharmed stem cells significantly reduces this period of vulnerability. The stem cells help the body more quickly rebuild the blood and immune system. This is especially important for myeloma patients, who are often times older and already more vulnerable.
If the chemotherapy treatment would be given without stem cell support, it would take six to eight weeks for a person’s blood counts to return to normal levels that prevent infection and bleeding. With stem cell support, this period of vulnerability is reduced to approximately one week.
Most autologous transplants can be done safely on an outpatient basis with careful monitoring.
What is a tandem autologous stem cell transplant?
A tandem autologous transplant means that two autologous transplants are done within a period of no more than six months. This is also known as a double autologous transplant. Studies have shown improved response and survival rates with tandem transplants compared to a single transplant. Not only will patients who have received tandem transplants live longer, their quality of life will be better.
The period of time between the first transplant and second transplant is typically about two and a half to three months.
Data show that with autologous transplants, half of myeloma patients will survive more than ten years after the start of treatment. This is good news when compared to the median survival rate of myeloma patients who receive conventional chemotherapy, which is two and a half to three years, with only five percent of patients living ten years or more.
What are the steps in an autologous stem cell transplant?
First, bone marrow stem cells are collected. In the past, this was done by going into the bone marrow to get the stem cells. Now, we use a method called mobilization, which involves giving some chemotherapy combined with growth factors in order to trick the stem cells to leave the bone marrow and come out into the peripheral blood, where they can be collected more easily.
The stem cells are collected using an intravenous line, or central line, that is inserted into the chest. Blood is withdrawn and circulated through an apheresis machine, which is a device that separates white blood cells from the rest of the blood’s components. The white blood cells are the cells that need to be collected because they contain the stem cells. The white blood cells constitute less than one percent of our blood.
When the white cells are collected, the rest of the blood (the other 99%) is returned through the machine to the patient.
The stem cells are frozen until it is time to give them back to the patient.
Next, chemotherapy is given. Anti-cancer drugs like Thalidomide, Dexamethasone, Velcade, and Melphalan are administered to fight the myeloma. These chemotherapy drugs will have certain side effects and, as a result, other medications may be given to combat these side effects.
Then, some of the healthy stem cells are given back to the patient. Some of the stem cells that were collected are thawed and given back, or infused, through the central line in the chest. Remaining stem cells will stay frozen and be stored for use during the second transplant.
When the stem cells are infused, they migrate from the blood back to the bone marrow. The infused cells now have the important job of rebuilding the blood and immune system.
The patient is monitored to see if engraftment occurs. Engraftment is the point at which the body starts to reproduce the white blood cells and platelets it needs and can once again fight infection. Engraftment usually occurs twelve to fifteen days after the stem cells have been given back.
We ask patients to stay in the Salt Lake City area for about three weeks during their transplant. While the transplant will likely be done on an outpatient basis with no need for patients to spend the night at the hospital, patients will need to return to the hospital frequently for monitoring.
Importance of Maintenance Therapy After Transplant
Myeloma cells are not easily destroyed and some will survive, even after high-dose chemotherapy. The chemotherapy only targets myeloma cells that are actively dividing and not the ones that are "sleeping," or out-of-cycle. Therefore, after the transplant, we generally prescribe two years of maintenance therapy to fight those myeloma cells still lingering in the body.
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