Chronic Lymphocytic Leukemia (CLL): Stem Cell Transplant
What is stem cell transplant?
Stem cells are immature cells. These are the starter cells for all types of body tissues. A stem cell transplant uses stem cells to replace bone marrow that contains cancer. These stem cells will grow and become new and healthy bone marrow that makes healthy blood cells. The bone marrow with cancer is first destroyed with high-dose chemotherapy. Or, this may be done with radiation to the whole body. Healthy stem cells are then put in your body.
When might a stem cell transplant be used for CLL?
Researchers are working to find out how helpful stem cell transplants are for chronic lymphocytic leukemia (CLL). Stem cell transplants are not often used for CLL. If a stem cell transplant is used, it’s usually part of a clinical trial. But your healthcare provider may suggest it in cases like these:
Your leukemia is no longer responding to standard treatment.
Your leukemia responds to treatment, but returns quickly.
Your leukemia has certain factors that mean it will likely get worse more quickly.
You are younger and healthy enough to tolerate it.
Types of stem cell transplants
There are 2 kinds of stem cell transplants:
Allogeneic transplant. This means the stem cells come from another person. This may be a brother or sister.
Autologous transplant. This means the stem cells are collected from your own body and preserved. This is done before you get chemotherapy.
For CLL, stem cells from a matched donor are preferred over using your own stem cells. In many cases this may be a family member. But stem cells may also come from a matched, unrelated donor if no family member has the same tissue type as you.
How stem cells are collected
Stem cells may be collected in one of two ways.
From the blood
This is the most common source of stem cells for a transplant. You or your donor may get an injection of a growth factor medicine for several days. This medicine helps stimulate stem-cell production. The process for collecting stem cells from the blood is called apheresis. It’s a lot like giving blood, but it takes longer. A thin, flexible tube (catheter) is used to get blood from your vein or from a donor. The blood goes to a device to remove the stem cells. The stem cells are then frozen until needed later. Then the extra blood is returned to you or the donor. This process may need to be done more than once to collect the right amount of cells.
From the bone marrow
Stem cells may also be taken from the bone marrow of you or the donor. This process is done while you or your donor is asleep with general anesthesia. A healthcare provider makes several punctures in the pelvic or hip bone to remove marrow. These stem cells are filtered and frozen until they are needed.
Having the transplant
You may be admitted to the hospital the day before your transplant.
You will be given chemotherapy or radiation therapy to treat the leukemia.
After the chemotherapy or radiation therapy is finished, you will get the stored stem cells through a thin needle that is put into your arm and attached to a tube. This is similar to a blood transfusion.
You will then have to wait for your stem cells to start multiplying. You may have to stay in isolation away from people to avoid getting an infection. Once the part of your white blood cell count (absolute neutrophil count) reaches a safe level, you can come out of isolation and then eventually go home. This may happen within several weeks, or it may take longer. Sometimes you can have this done as an outpatient.
You will need to have your blood drawn often to check your blood cell count for the next several weeks. This can be done on an outpatient basis.
What is a mini-transplant?
A mini-transplant is a type of allogeneic transplant that's sometimes used for a person with high-risk CLL who can’t tolerate a standard stem cell transplant. It’s also called a nonmyeloablative transplant. Or it may be called a reduced intensity allogeneic transplant
The treatment is done with a lower dose of chemotherapy or radiation. This doesn't fully destroy the cells in the bone marrow. But it’s enough to suppress the immune system. Then you get donor stem cells. These stem cells later develop an immune reaction to the leukemia cells and kill them. Because this treatment uses lower doses of chemotherapy or radiation, it often has less severe side effects. Older adults or people with other health problems can often tolerate this treatment better.
Possible short-term side effects
Most of the short-term side effects of a stem cell transplant are from the high doses of chemotherapy or radiation. These should go away as you recover from the transplant. Common side effects can include:
Low blood cell counts
Low blood pressure
Shortness of breath
Chest pain or tightness
Fever or chills
Loss of appetite
Possible long-term side effects
Some side effects of a stem cell transplant may be long-lasting or appear years later, such as:
Growth of another cancer
Damage to other organs, such as the heart, kidneys, or liver
Lack of menstrual periods. This may mean damage to the ovary causing infertility
Vision problems caused by damage to the lens of the eye
Weight gain, which may be a sign of thyroid gland damage
Another possible long-term side effect is graft-versus-host disease. This can only occur with an allogeneic transplant. The immune system cells in the donor's stem cells attack your body. The cells can attack your skin, liver, gastrointestinal tract, mouth, or other organs. This can cause symptoms such as:
Talking with your healthcare provider
It's important to discuss the procedure with your healthcare provider to make sure you understand the possible risks and benefits.
Stem cell transplant is a complex procedure. It’s only done by healthcare providers with special training. If you decide to have one, go to a hospital that specializes in stem cell transplants, such as a major cancer center. The procedure is also expensive. Make sure to check with your insurance provider to see how much of it will be covered.