What is a stem cell transplant?
Most stem cells are in your bone marrow. You also have some in your blood that circulate from your bone marrow. Bone marrow stem cells turn into red blood cells, white blood cells, or platelets to help your body stay healthy. If your bone marrow is attacked by a disease such as multiple myeloma, it can no longer make normal blood cells. In a stem cell transplant, healthy stem cells are placed in your body through an IV to help your bone marrow start to work right.
When the stem cells come from your own blood or bone marrow, it is called an autologous transplant.
When is a stem cell transplant needed?
Stem cell transplants are used to:
- Treat diseases that damage or destroy the bone marrow. Such diseases include non-Hodgkin's lymphoma and Hodgkin's lymphoma, multiple myeloma, and aplastic anemia.
- Restore bone marrow that has been damaged by total body radiation and high doses of chemotherapy used for cancer treatment.
How do you know if you are a good candidate for a stem cell transplant?
Your doctor will consider your overall health and your age. People who are good candidates usually are younger than 70, do not have other diseases such as heart disease or diabetes, and have a normal kidney and liver. Your doctor will also consider how much your disease has grown and how aggressive your cancer is. People with aggressive cancer that has spread to many areas of the body are not usually thought to be good candidates. Your doctor may also consider whether you have cancer that has come back, such as relapsed non-Hodgkin's lymphoma.
How are stem cells collected?
Autologous stem cell transplants are done using peripheral blood stem cell transplantation (PBSCT). With PBSCT, the stem cells are taken from blood. The growth factor G-CSF may be used to stimulate the growth of new stem cells so they spill over into the blood. G-CSF is a protein that is produced naturally in the body. The blood is removed from a vein and passed through a machine that separates the stem cells. The machine then returns the remaining blood through a needle in the person's arm or through a central venous catheter. This way of collecting stem cells is called apheresis.
In adults, most autologous transplants use stem cells from blood. In a child, the decision whether to use cells from the bone marrow or the blood depends on the size of the child.
Why are chemotherapy and radiation therapy used before a transplant?
Before you have chemotherapy and radiation, you have blood taken and stored (banked) for later. Then you have chemotherapy and radiation to destroy the diseased cells in your bone marrow and the rest of your body. This gets rid of the cancer cells in your bone marrow. Later, when you get your stored blood cells back, those new stem cells will be able to take over the job of making new blood cells.
How are stem cells transplanted?
A central venous catheter is inserted in your chest. The stem cells travel from the blood bag through the catheter into your blood, and to your bone marrow, where they will begin to produce new cells in 1 to 3 weeks. During this time:
- You may be in isolation and given antibiotics to prevent or to treat infection. Destroying your bone marrow cells with chemotherapy leaves your body unable to fight infection.
- Your blood will be tested often to check the levels of red blood cells, white blood cells, and platelets in your body.
- You may need to receive several transfusions of blood cells and platelets until your body begins to produce its own.
- You may need more antibiotics or other medicines if you get an infection.
Transplants from your own marrow
Using your own stem cells in a transplant is safer than using someone else's, because your body will not reject your own stem cells. But stem cells from your own marrow or blood may still contain some cancer cells. So the stem cells may be treated to get rid of any cancer cells before being put back into your body.
What To Expect After Treatment
Some people are able to receive part or even all of their treatment in an outpatient clinic. Even if you need to be in a hospital, you will not usually have to stay longer than 3 weeks.
Severe, often life-threatening infection can develop after a stem cell transplant. You will need to take antibiotics for several months to prevent infection.
Your immune system may take 1 to 2 years or longer to recover after a transplant. Bone marrow aspiration or biopsy is used to check your bone marrow. You will need to have many immunizations updated. Check with your doctor to find out which immunizations you will need.
Why It Is Done
Autologous stem cell transplant is used:
- After high doses of chemotherapy for killing cancer cells. The chemotherapy also destroys your bone marrow. The stem cell transplant gives you back your normal bone marrow.
- To treat diseases that damage the bone marrow, such as multiple myeloma.
- Experimentally (and rarely) to treat solid tumours, such as breast cancer or testicular cancer. It is also used to treat tumours that develop from cells producing eggs or sperm (germ cell tumours), such as dysgerminomas and teratomas.
- Experimentally for gene therapy and the treatment of other diseases, such as diabetes.
How Well It Works
The success of a transplant depends on the type and stage of the disease and your age and general health.
The original disease may come back after the transplant. If relapse occurs after autologous transplant, chemotherapy or other treatments may be used.
Early complications usually occur within 5 to 10 days and include:
- Nausea and vomiting.
- Mouth sores.
- Hair loss.
- Bleeding because of severe reduction in red blood cells, white blood cells, and platelets.
- Infection, such as pneumonia, shingles, or herpes simplex.
Other possible complications include:
What To Think About
Not every hospital is able to perform transplants. You may have to travel to a hospital that has special equipment and specially trained doctors and nurses.