Stem cell transplants (SCTs) are sometimes used for hard-to-treat Hodgkin disease, such as disease that doesn’t go away completely after chemotherapy (chemo) and/or radiation or that comes back after treatment.
The doses of chemo drugs given to patients normally are limited by the side effects these drugs cause. Higher doses can’t be used, even if they might kill more cancer cells, because they would severely damage the bone marrow, where new blood cells are made.
A stem cell transplant lets doctors give higher doses of chemo (sometimes along with radiation therapy). This is because after getting high-dose chemo treatment, the patient receives a transplant of blood-forming stem cells to restore the bone marrow.
The blood-forming stem cells used for a transplant come either from the blood (for a peripheral blood stem cell transplant, or PBSCT) or from the bone marrow (for a bone marrow transplant, or BMT). Peripheral blood stem cells are obtained from a procedure similar to a blood donation, while bone marrow donation is usually done in an operating room with the marrow donor under general anesthesia (in a deep sleep). Bone marrow transplants were more common in the past, but they have largely been replaced by PBSCTs.
Types of transplants
There are 2 main types of stem cell transplants. They use different sources of blood-forming stem cells.
Autologous stem cell transplant
In this type of transplant, a patient’s own blood stem cells are removed from his or her bone marrow or peripheral blood. They are collected several times in the weeks before treatment. The cells are frozen and stored while the person gets treatment (high-dose chemo and/or radiation) and then are given back to the patient’s bloodstream by IV. This is the more common type of transplant for Hodgkin disease.
Allogeneic stem cell transplant
In this type of transplant, the blood stem cells come from someone else. The donor’s tissue type (also known as the HLA type) needs to match the patient’s tissue type as closely as possible to help prevent major problems with the transplant.
Usually the donor is a brother or sister if they have the same tissue type as the patient. If there are no siblings who are a good match, the cells may come from an HLA-matched, unrelated donor — a stranger who has volunteered to donate their cells.
Sometimes umbilical cord blood stem cells are used. These cells come from blood drained from the umbilical cord and placenta after a baby is born, which is rich in blood stem cells. These are more often a source of blood stem cells for transplants in children.
Regardless of the source, the stem cells are then frozen and stored until they are needed for the transplant.
Allogeneic transplants may be more likely to rid the body of lymphoma cells, but they are also more likely to cause serious complications that could be life-threatening. In treating Hodgkin disease, an allogeneic transplant is generally used only if an autologous transplant has already been tried without success.
Non-myeloablative transplant: This special type of allogeneic transplant may be an option for some patients who wouldn’t be able to get a regular allogeneic transplant because it would be too toxic. This type of transplant uses less chemo and radiation, so it is also known as a mini-transplant or reduced-intensity transplant.
The lower doses of chemo and radiation do not completely destroy the cells in the bone marrow. After treatment, the patient gets the allogeneic (donor) stem cells. These cells establish a new immune system in the body, which sees the lymphoma cells as foreign and attacks them (called the graft-versus-lymphoma effect).
Even though it uses small doses of certain chemo drugs and low doses of total body radiation, this type of transplant can still sometimes work and have less serious side effects. In fact, some patients can receive a non-myeloablative transplant as an outpatient.
Doctors aren’t yet sure exactly how effective these types of transplants are for patients with Hodgkin disease, but studies are now being done to find out.
The transplant procedure
The patient may be admitted to the stem cell transplant unit of the hospital or get treatment as an outpatient, depending on a number of factors.
If the treatment is to be given in the hospital, the person is usually admitted the day before the high-dose chemo is to begin. He or she will usually stay in the hospital until the stem cells have started to make new blood cells again, which often takes several weeks.
If the transplant is done as an outpatient procedure, patients and families must be able to spot complications requiring their doctor’s attention. Unless they live close to the transplant center, they will be asked to stay someplace nearby.
Treatment starts with high-dose chemo and may include high-dose total body irradiation. The chemo and radiation treatments are meant to destroy the cancer cells, but they also kill the normal cells of the bone marrow and the immune system. Once treatment is complete, the new stem cells (autologous or allogeneic) are given through a vein, just like a blood transfusion. The stem cells then travel to the bone marrow. Usually within a couple of weeks after they have been infused, the stem cells begin making new white blood cells. This is later followed by new platelet and red blood cell production.
In the meantime, the person is at high risk for serious infections because of a low white blood cell count, as well as bleeding because of a low platelet count. During this time, blood and platelet transfusions and treatment with strong antibiotics are often used to help prevent or treat infections or bleeding problems.
In an allogeneic SCT, the person getting the transplant may also be given drugs to keep the new immune system from attacking the body (known as graft-versus-host disease or GVHD, which is described below).
Because of the high risk of serious infections right after treatment, patients usually stay in a special hospital room in protective isolation (where exposure to germs is kept to a minimum) until a measure of their white blood cells, the absolute neutrophil count (ANC), rises above a certain level.
Patients then typically make regular visits to the outpatient transplant clinic for about 6 months, after which their care may be shared with their regular doctors. At this point, they may only come back to the clinic for their regular exams or if they have symptoms that need to be checked.
A stem cell transplant is a complex treatment that can cause life-threatening side effects. If the doctors think a person might benefit from a transplant, it should be done at a cancer center where the staff has experience with the procedure and with managing the recovery phase.
SCTs often require a long hospital stay and can be very expensive (costing well over $100,000). Because some insurance companies might view it as an experimental treatment, they may not pay for it. Even if the transplant is covered by your insurance, your co-pays or other costs could easily amount to many thousands of dollars. Find out what your insurer will cover before the transplant so you will have an idea of what you might have to pay.
Possible side effects
The possible side effects from a stem cell transplant are generally divided into early (short-term) and late (long-term) effects.
Early or short-term effects: The early complications and side effects are basically the same as those caused by any other type of high-dose chemotherapy (see “Chemotherapy for Hodgkin disease”), and can be severe. They can include:
- Low blood cell counts (with fatigue and increased risks of infection and bleeding)
- Nausea and vomiting
- Loss of appetite
- Mouth sores
- Hair loss
One of the most common and serious short-term effects is the increased risk of serious infections. Antibiotics are often given to try to prevent this. Other side effects, like low red blood cell and platelet counts, might require blood product transfusions or other treatments.
Late and long-term side effects: Some complications and side effects can last for a long time or occur many years after the transplant. These can include:
- Graft-versus-host disease, which occurs only in allogeneic transplants (see next paragraph)
- Menstrual changes, early menopause, and loss of fertility in female patients (caused by damage to the ovaries)
- Loss of fertility in male patients
- Damage to the thyroid gland, causing problems with metabolism
- Cataracts (damage to the lens of the eye that can affect vision)
- Damage to the lungs, causing shortness of breath
- Bone damage called aseptic necrosis (if damage is severe, the patient might need to have part of the affected bone and the joint replaced)
- Development of another cancer (such as leukemia) years later
Graft-versus-host disease (GVHD): This is one of the most serious complications of allogeneic (donor) stem cell transplants. It occurs because the immune system of the patient is replaced by the donor’s immune system. The donor immune system then may attack the patient’s own body tissues.
Symptoms of GVHD can include severe skin rashes, itching, mouth sores (which can affect eating), nausea, and severe diarrhea. Liver damage may cause yellowing of the skin and eyes (jaundice). The lungs may also be damaged. The patient may also tire easily and have muscle aches.
Sometimes GVHD can become disabling, and if it is severe enough, it can be life-threatening. Usually, immune-suppressing drugs can be used to help control GVHD, although they can have their own side effects.
On the positive side, the GVHD also leads to graft-versus-lymphoma activity. Lymphoma cells remaining after the chemo and radiation therapy are often killed by donor immune cells since the lymphoma cells are also seen as foreign by the donor’s immune system. Mild GVHD can be a good thing.
For more on stem cell transplants, see Stem Cell Transplant (Peripheral Blood, Bone Marrow, and Cord Blood Transplants).
Last Revised: 02/09/2016