A stem cell transplant uses young blood cells, called stem cells, to replace bone marrow that has been destroyed by cancer treatment. These stem cells will grow and become new and healthy bone marrow. The bone marrow is first destroyed with high-dose chemotherapy. Or this may be done from radiation treatment to your whole body. Then healthy stem cells are put back in your body.
A stem cell transplant is a complex treatment. It can cause serious side effects. Because of this, it is most often used only when lymphoma is no longer affected by other treatments, or has come back after treatment. A stem cell transplant may also be part of the first treatment for some hard-to-treat types of lymphoma.
There are 2 kinds of stem cell transplants:
Allogeneic transplant. This means the stem cells come from another person, called a donor, whose cell type is almost exactly like yours. This may be a close relative such as a brother or sister.
Autologous transplant. This means the stem cells are collected from your own body and saved. This is done before you get chemotherapy.
Autologous transplants are usually preferred over allogeneic transplants. This is because of the lower risk of serious side effects. But autologous transplants can have some possible problems. For example, they may be a little less likely to fully destroy the lymphoma. An allogeneic transplant is often done if an autologous transplant didn’t work. Discuss the risks and benefits of each with your doctor.
Stem cells may be collected in one of these 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 method 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, called a catheter, is used to get blood from your vein or from a donor. The blood goes to a cell separation device to remove the stem cells. Then the extra blood is returned to you or the donor. You may have a strange taste in your mouth during this process. This is from the substance or preservative used to freeze the stem cells. 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 your bone marrow. Or they may be taken from your donor’s bone marrow. This is done while you or your donor are in a deep sleep with general anesthesia. A doctor makes a few small holes or punctures in the pelvic or hip bone to remove marrow. The hip bone may be sore for a few days. These stem cells are filtered and frozen until they are needed.
From umbilical cord blood. Stem cells may also be collected from umbilical cord blood. After a baby is born, the blood from the placenta and umbilical cord is collected. This blood has many stem cells. The blood is frozen and stored until it is needed by someone with a matching tissue type.
You will be admitted to the hospital the day before your transplant. Your doctor or nurse will go over the procedure with you. They will also talk about ways to lower your risk for infections.
The next morning, you will begin several days of high-dose chemotherapy or radiation.
After this therapy is done, you will get the stored stem cells through an IV or intravenous line that’s attached to a tube. This is like a blood transfusion. The stem cells will go to the bone marrow. In the bone marrow, they begin to multiply and make new blood cells.
You will then have to wait for your stem cells to start multiplying. This is called engraftment. You may have to be away from other people, or be isolated, during this time. This is to help prevent getting an infection. Engraftment may take 3 to 4 weeks.
In some cases, the cancer comes back (relapses) after the transplant. If you had an allogeneic transplant, you may be eligible for a treatment after the stem cell transplant. This treatment is called DLI, or donor lymphocyte infusion. DLI is done by removing a type of white blood cell called lymphocytes from the stem cell donor’s blood and freezing them. The lymphocytes are later thawed. They are given to you in 1 or more infusions. The donor’s lymphocytes will see any lymphoma cells that are left as not belonging to your body. They will attack the lymphoma cells.
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
Upset stomach, or nausea
Loss of appetite
Fever or chills
Shortness of breath
Tightness or pain in the chest
Low blood pressure
Some side effects of a stem cell transplant may be long-lasting or appear years later, such as:
Shortness of breath, often caused by radiation damage to the lungs
Lack of menstrual periods, which may mean ovary damage and cause infertility
Infertility in men
Vision problems such as blurriness or cloudiness, caused by damage to the lens of the eye
Bone pain, caused from damage due to lack of blood supply (aseptic necrosis)
Problems with metabolism, caused by damage to the thyroid gland
Growth of another cancer, such as leukemia, years later
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:
Skin rashes with itching
Extreme tiredness, or fatigue
Yellow-colored skin, called jaundice