A Common Treatment for Blood and Immune System Cancers
By Sherry Christiansen
Medically reviewed by Scott Sundick, MD
Stem cell transplants are used to treat some types of cancer, particularly those of the blood or immune system such as leukemia, multiple myeloma, or lymphoma. The stem cells can be taken from a donor (allogeneic stem cell transplant) or they may be harvested from the person who is receiving the stem cell transplant (autologous stem cell transplant). The procedure involves harvesting (taking) healthy stem cells from bone marrow, blood, or cord blood (from a newborn).
During cancer treatment, bone marrow is damaged, either by cancer itself or by the chemotherapy or radiation treatment. Stem cell therapy is a way to replenish the bone marrow with healthy stem cells.
Tim Boyle / Getty Images
What Are Stem Cells?
To fully understand how stem cell transplants work, one must be aware of some basic anatomy involving blood cells. There are several types of blood cells; stem cells are those that are in the beginning stages of growth, found mostly in the bone marrow and, to a lesser extent, in the blood.
All stem cells begin life in the same way. Then, they mature into different types of blood cells. These young, immature stem cells are also called hematopoietic (blood-forming) stem cells.
In the bone marrow (the spongy center of some bones), the stem cells divide and form new cells for the body. During the process of blood cell maturity, the cells eventually form into white or red blood cells.
The mature cells travel into the blood to perform the function they are meant to do in the body, but a small number of the immature stem cells (called peripheral stem cells) are also released into the blood.
Reasons for a Stem Cell Transplant
A stem cell transplant may be performed for different reasons,1 including:
To replace damaged bone marrow with new stem cells
To replenish the body with healthy stem cells after cancer treatment
Bone marrow transplant (stem cell therapy) may help to treat many different conditions, including:
Aplastic anemia: Failure of bone marrow development resulting in a deficiency of all types of blood cells
Leukemia
Hodgkin’s and non-Hodgkin’s Lymphoma
Bone marrow failure syndrome: A rare disease involving the inability to make enough blood cells
Immune deficiencies
Multiple myeloma: A type of cancer of the blood
Neuroblastoma: A type of neurological cancer
Who Is Not a Good Candidate for a Stem Cell Transplant?
The American Cancer Society reports that those who are good candidates for treatment have better results. The criteria include those who:
Are younger
Have NOT had a lot of previous treatments
Are in the earlier stages of the disease
“Some transplant centers set age limits. For instance, they may not allow regular allogeneic [donor] transplants for people over 50 or autologous [self] transplants for people over 65,” says the American Cancer Society.
Other factors that may disqualify a person from having a transplant include serious health conditions (such as heart, lung, liver or kidney problems).2
The evaluation process may take a few days and involve various tests and assessments, including:3
A medical history
A physical exam
Blood tests
Chest X-ray
CT scans
Tests to evaluate heart, lung, and liver function
Bone marrow biopsy (removing a very small piece of bone marrow to exam its condition and functional ability)
A psychological evaluation
Other tests or assessments
Types of Stem Cell Transplants
There are primarily two different types of stem cell transplant procedures.
Autologous stem cell transplants involve using a patient's own stem cells, taken from their blood, that are then given back after cancer treatment.
Allogeneic stem cell transplants involve harvesting stem cells from a donor, then giving the cells to the recipient via an IV transfusion. The donor can be a family member or a non-related person from donor organizations such as the National Marrow Donor Program.
Sub-Types
The specific sub-type of stem cell therapy depends on where the cells are harvested.
The bone marrow: A bone marrow transplant
The blood: Peripheral blood stem cell transplant
Cord blood: Cord blood transplant
Note: Another name for a stem cell transplant is hematopoietic stem cell transplant.
Donor Recipient Selection Process
A successful stem cell transplant procedure provides a person with healthy bone marrow. When a donor is involved (an allogeneic procedure), a new immune system is provided. The donor’s stem cells may provide the recipient with protection against underlying cancer.4
Matching the best donor to the patient who is receiving a stem cell transplant procedure is the goal of successful treatment for those receiving an allogeneic transplant. To find the best (and safest) donor, there must be a match in the antigens of the cells.
The body can replace bone marrow that is lost during a transplant in approximately two weeks.5
What Are Antigens?
Human cells have what is called surface antigens that function to recognize and kill “invaders,” such as viruses, bacteria, or even cancer cells. These antigens are called HLAs, an acronym for human leukocyte antigens. The white blood cells (leukocytes) are those that are responsible for protecting the body against infection and other diseases such as cancer.
There are four sets of antigens that have been scientifically identified. When a donor is matched, preferably all four of the HLA antigen sites match up.
Types of Donors
There are two types of donors: those who are family and those who are unrelated to the recipient.
Family Donors
Originally, only family members (exclusively siblings) with identical HLA genes on chromosome 6 were identified as eligible donors for stem cell transplants. This instance represents an identical match of the HLA antigens.
But, today, in some instances, a parent or a child may be matched as a donor as well. Blood tests must be performed to evaluate whether the immediate family member is a match.
Unrelated Donors
Unrelated donors can be considered. This is done using a computerized system through the National Marrow Donor Program (NMDP), an organization sponsored by the National Institutes of Health. The transplant center performing the procedure will oversee the search.
A registry of all potential NMDP donors can offer vital information, free of charge, about the number of potential donors available for a person in need of a stem cell transplant. This can help alleviate some of the stress associated with not knowing if, or when, a donor is available.
Before the Procedure
To prepare for the stem cell transplant procedure, many transplant centers provide consultations with supportive staff, who answer questions and help patients with the pre-procedure phase. This may involve some tests, and treatments (such as treating infections) to help lower any risk of complications and improve the outcome of the procedure.
Knowing what to expect during and after the procedure can help reduce emotional stress. Not only is stress reduction beneficial to overall health and wellness, it can also help improve outcomes.
Those who are scheduled for stem cell therapy can expect pre-procedure interventions,3 which may include:
A dental exam to check for any signs of infection
Dietary changes may be suggested before the procedure to help meet nutritional needs (such as weight loss or weight gain) on an individual basis
A physical exam to diagnose and treat any infections
Fertility planning, involving a sperm bank or harvesting eggs before treatment, since chemotherapy and radiation can cause infertility
Other tests to establish normal organ function and get an overall baseline of a person’s health status to evaluate any changes that occur after the procedure
Questions to Ask
Before the procedure, it’s important to ask questions.1 Getting answers to the many questions you may have before the procedure will result in a better outcome by reducing stress related to the fear of the unknown.
Questions to ask your healthcare provider may include:
Which transplant procedure is best for me and why?
What is the overall goal of the stem cell transplant procedure?
What is the overall success rate of the transplants done at this specific center?
How many stem cell transplants are completed each year (by the healthcare provider and by the transplant center)?
Are there any current clinical research trials that I should investigate?
What other treatment options are available?
How many donors are there in the system that are a good match?
What are the risks?
What types of complications are common after stem cell therapy?
Is there clinical research that shows the transplant has a high success rate for my specific condition?
What is the cost?
Is the expense fully or partially covered by my insurance?
What type of pre-treatment will I require?
Are there any activity restrictions after the procedure?
When can I go back to work?
What is the backup plan if the treatment fails?
Transplant Process
The specific steps in a stem cell therapy procedure depend on many factors, such as:
The type of stem cell therapy (bone marrow transplant, peripheral blood stem cell transplant, or cord blood transplant)
Whether the procedure involves a donor, or it is an autologous procedure
The type of cancer being treated
There are usually two phases involved in the stem cell transplant procedure.
Conditioning treatment (chemotherapy or radiation therapy) is used to kill the cancer cells and to make room in the bone marrow for the new stem cells. Conditioning treatment also helps to suppress the immune system to lower the chance of complications from rejecting the new donor cells.
Harvesting involves collecting the new stem cells from the recipient for autologous transplants or from the donor in allogeneic transplant procedures. This could involve collecting blood, a bone marrow aspiration (to collect bone marrow after anesthesia to numb the area), or the collection of cells from an umbilical cord.
Blood stem cell harvesting involves a needle placed in the vein of the donor. The blood goes into a machine that removes the white blood cells; the rest of the blood is replaced back into the donor’s bloodstream. Harvesting may occur the same day as the transplant if the stem cells are coming from a donor.
During an autologous stem cell transplant, the cells are collected and then stored until after the conditioning treatment is complete.
Receiving the Stem Cell Transplant
During the procedure, the new stem cells are infused into the body through a central IV line. The procedure itself is painless. The blood stem cells (or bone marrow stem cells) which were previously frozen and then thawed have a preservative to protect the cells.
Before the procedure, medication is given to lower the risk of side effects. IV fluids are also given for hydration and to help flush out the preservative.
The transplanted stem cells travel to the patient's bone marrow and begin making new blood cells. The transplant recipient remains awake during the entire procedure and can usually go home after it is complete.
When a stem cell transplant is implemented, higher doses of chemo can be used—resulting in more effective cancer-killing properties.6
Complications
Complications from stem cell transplants could result from high-dose cancer (chemo) treatment, or they could also arise from the transplant process itself and involve the body’s attempt to reject the donor stem cells.
Complications may include mild symptoms such as fatigue and weakness, flu-like symptoms such as nausea, diarrhea, or a change in taste perception, serious complications, or even death. Therefore, it's vital to weigh all the options before having the procedure.
Asking questions and considering the pros and cons of treatment is important. It may also be wise to get a second opinion to be sure that the stem cell transplant is the best treatment option.
Some insurance companies will pay for a second opinion when it comes to cancer treatment (such as stem cell transplants).6
What Is GvHD?
A common complication from stem cell therapy is called graft-versus-host disease (or GvHD). This occurs when the donor’s stem cells end up attacking the recipient’s blood cells (identifying them as foreign invaders). The percentage of those who experience GvHD can be as high as 70%.7
The symptoms of GvHD may range from mild to severe and, in extreme cases, they can be life-threatening.
Mild symptoms may include:
A rash and itchy skin
Nausea, vomiting, diarrhea
Abdominal cramps
Hair loss
Severe symptoms may include liver damage (exhibited by jaundice) and damage to the organs (such as the lungs or esophagus).
Life-threatening symptoms include sepsis, a severe type of infection in the blood. It is often the cause when death occurs after a stem cell transplant procedure.
It’s important to note that in many instances GvHD becomes a long-term condition. In fact, according to Kiadis Pharma (an integrated biopharmaceutical company involved in clinical research trials on therapies for late-stage blood cancers) in Amsterdam, the Netherlands, “Graft-versus-host disease (GvHD) can lead to permanent impairment of quality of life, and in many cases even to death. Patients with GvHD often require prolonged immunosuppressive treatment, which increases the risks for infections, organ damage, secondary malignancies [cancers] and other complications associated with these medications.”
The risk of getting GvHD is much higher when the donor is not properly matched or a person has had extensive cancer treatment (such as chemotherapy or radiation) before the transplant procedure.8
Risk Prevention
There are medications that can minimize the risk of a person getting GvHD. These include:
Antibacterial drugs
Antiviral drugs
Steroids
Drugs that suppress the immune system (such as cyclosporine)
Other Complications
Other complications that may occur after a stem cell transplant procedure include:
Stem cell (graft) failure
Organ damage
Infections
Cataracts
Infertility
New cancers
After the Procedure
Once the new stem cells are in the body, they begin to travel to the bone marrow, making new, healthy blood cells. This process is called engraftment. According to the Mayo Clinic, the engraftment process— the process of returning the blood cell count back to normal— usually takes several weeks after a stem cell transplant procedure, but it can sometimes take longer.1
After the procedure, follow-up appointments are vital to check blood count levels and to see if the new blood cells are proliferating as expected. Healthcare providers will also want to monitor the overall condition of a transplant recipient.
Mild symptoms such as diarrhea and nausea may occur. Your healthcare provider can prescribe medication to help with these symptoms.
Close medical supervision is required after a stem cell transplant to screen for serious complications such as infections or signs of GvHD. Transplant recipients should stay within close proximity to a local hospital for several weeks9 and visit their healthcare provider regularly as instructed during their discharge plan.
Note: Many transplant recipients require blood transfusions while waiting for the bone marrow to begin making enough new cells on its own.1
Keep in mind that people who receive stem cell transplants are at higher risk of infections for several months (and up to years) after the procedure. Monitor and report any signs of infection including:
Fever and chills
Nausea, vomiting, and diarrhea
Rapid breathing and pulse
High temperature (particularly if followed by a very low body temperature, which is a sign of sepsis)
Scanty urination
Prognosis
The good news about having a bone marrow transplant is that, depending on the specific cancer type, it may raise the one-year cancer survival rate from very low (nearly zero) to as high as 85%, according to the Seattle Cancer Care Alliance.10
Support and Coping
Having any type of transplant, including a stem cell transplant, can be an emotionally stressful experience. There are long hospital stays, severe symptoms, and a high risk of long-term complications (many of which continue for years after the procedure).
Staying in touch with others who have had transplant procedures, such as through local support groups, can help a person cope with the emotional toll of having such a serious procedure. Support groups may be found through your local hospital, through the transplant center, or online.
Sources
Mayo Clinic. Bone Marrow Transplant.
American Cancer Society. What’s It Like to Get a Stem Cell Transplant?
Medstar Georgetown University Hospital. Stem Cell Transplant and Cellular Immunotherapy. (n.d.)
Texas Oncology. Donor Selection.
American Cancer Society. Why Are Stem Cell Transplants Used as Cancer Treatment?
American Cancer Society. Why are Stem Cell Transplants used as Cancer Treatments?
Kiadis Pharma. Graft-Versus-Host Disease.
Cleveland Clinic. Graft vs Host Disease: An Overview in Bone Marrow Transplant.
Mayo Clinic. Bone Marrow Transplant.
Seattle Cancer Care Alliance. How Bone Marrow Transplants Save Lives.
Additional Reading
Memorial Sloan Kettering Cancer Center. Types of Stem Cell Transplants.
By Sherry Christiansen
Sherry Christiansen is a medical writer with a healthcare background. She has worked in the hospital setting and collaborated on Alzheimer's research.
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