What is Bone Marrow Transplantation?
Bone marrow transplant or stem cell transplant is a cancer treatment during which the diseased or damaged cancerous bone tissues are replaced with new bone marrow cells either from the individual’s body or from a donor.
Stem cells are specialised cells in the body with the potential to form different kinds of cells, depending on the body’s needs. These cells can be found in different parts of the body like the bone marrow, umbilical cord and even milk teeth in children. The stem cells in the bone marrow are constantly dividing to form the different kinds of blood cells – red blood cells (RBCs), white blood cells (WBCs) and platelets.
A bone marrow transplant can be used to treat different cancers, hereditary blood disorders and autoimmune diseases.
A bone marrow transplant procedure is complex and requires a team of specialists. Your healthcare team will usually include:
- Specialists from oncology, haematology, immunology and experts in bone marrow transplant
- Nurse coordinators
- Physical therapists
- Other support staff
What are The Types of Bone Marrow Transplants?
Different types of bone marrow transplants are performed depending upon the donor:
- Autologous bone marrow transplant
In some cancers, stem cells are collected from the patient’s body through apheresis or bone marrow harvest, frozen and transplanted back into the patient. Since the patient is the donor, this procedure is called an autologous bone marrow transplant.
- Allogenic bone marrow transplant
When the bone marrow cells are taken from an individual who shares the same genetic type as the patient, usually a sibling, it is called an allogeneic bone marrow transplant. Apart from siblings, parents and other unrelated individuals (found through bone marrow registries) can be donors.
Umbilical Cord transplant
The umbilical cord contains stem cells. When a baby is born, these stem cells are collected and stored in stem cell banks for later use. The stem cells are usually tested, counted, typed, frozen and stored until the need for a transplant arises.
When is a Bone Marrow Transplant Needed?
A bone marrow transplant is needed in cases where high doses of chemotherapy, targeted drug therapy or radiotherapy have been used to kill the cancer cells but have permanently damaged the bone marrow stem cells or if a disease has destroyed the tissues.
Bone marrow transplant is helpful to:
- Replace dead or improperly working marrow cells with healthy cells to restore normal bone marrow functioning in leukaemia, aplastic, and sickle cell anaemias.
- Regenerate and re-establish the immune system that develops the strength to fight residual cancer cells that haven’t been destroyed by chemotherapy or radiation used before the transplant.
- Replace damaged bone marrow and restore its normal health and function after high chemotherapy doses or radiation therapy (this process is called rescue).
- Replace damaged or diseased bone marrow with a healthy, functioning marrow and prevent further damage in conditions like Hurler’s syndrome.
The team of doctors will evaluate the benefits vs risks of using a bone marrow transplant to treat your cancer.
Which Cancers Can Be Treated by a Bone Marrow Transplant?
Cancers that benefit from a bone marrow transplant are:
- Severe aplastic anaemia
- Multiple myeloma
- Solid tumours (in rare cases)
Bone marrow transplants are also effective in treating immunodeficiency disorders.
Since everyone’s cancer experience and the journey is different, a bone marrow transplant is not recommended for everyone with a particular cancer type. Your doctor will assess all your diagnostic test results and determine if a bone marrow transplant is helpful in your case.
What Happens During a Bone Marrow Transplant Procedure?
A bone marrow transplant procedure is an extensive one and involves multiple stages:
- Evaluation and preparation for a transplant
The first step is a comprehensive evaluation to determine if you are a candidate for a bone marrow transplant. This procedure is not just complex clinically but can be challenging emotionally, physically and psychologically. You will require a series of diagnostic tests and evaluations to assess your suitability for a bone marrow transplant.
- Hospital admission or outpatient treatment
After assessing your reports and creating your treatment plan, your healthcare team will decide if you require hospital admission for your transplant procedure or if it can be done in an outpatient centre. They will instruct you accordingly and give you a list of instructions to prepare for the next steps in your treatment.
- Conditioning treatments
Before a bone marrow transplant, you will require conditioning or pre-transplant treatments. These treatments, also called bone marrow preparation or myeloablation, use with high-dose of chemotherapy or radiation therapy for the following reasons:
· To suppress the body’s immune system and lessen the risk of bone marrow transplant rejection
· To accommodate the transplanted stem cells
· To destroy remaining cancer cells before re-establishing a strong immune system
The conditioning treatment varies with every transplant and is planned based on your cancer type, stage, type of transplant and history of other cancer treatments you have undergone.
- Infusion of stem cells
After conditioning, your body will need a few days to rest and recover before the transplant procedure. The stem cells are infused using a catheter after being thawed and processed if required. You might need some drugs to prevent allergic reactions to preservatives used when freezing the stem cells.
Though rare and mild, you may experience some infusion side effects such as:
· Chest tightness
· Reduced urine output
Your recovery phase begins after the transplant procedure, during which the transplanted cells settle into your marrow and start producing new blood cells. Depending on the type of transplant, it may take anything between two to six weeks for your blood counts to return to normalcy. It is natural to experience some side effects. Your doctor and healthcare team will support you through this phase.
After a Bone Marrow Transplant: What to Expect?
After your bone marrow transplant procedure, you will require a hospital stay for a few weeks to allow your transplant marrow cells to settle in your bone marrow and begin producing new blood cells.
During this period, you can expect:
- To stay in a germ-free room with protective clothing to prevent any infections until you develop sufficient white blood cells
- To feel weak or tired
- Nausea, diarrhoea, vomiting and loss of appetite
- To be fed by mouth or through a tube to ensure you are getting all the required nutrients
- To have regular blood transfusions to improve your red blood cell count (in people who develop anaemia)
- To have regular platelet transfusions if you develop a low platelet count before the transplant procedure
Most people are fit enough to leave the hospital one to three months after their transplant procedure. Once home, you will still need to take precautions to avoid infections, at least for the next one or two years, as your immune system takes some time to re-establish itself. Your doctor and healthcare team will monitor your progress closely. You must continue to take your prescribed medications and follow your doctor’s instructions during your recovery phase.
What Are the Risks of a Bone Marrow Transplant?
Bone marrow transplant is a complex procedure and involves risks and chances of complications. Before your treatment, your doctor and healthcare team will discuss all the possible benefits, side effects, and risks.
Take time to understand and discuss the same with your family. It may be good to seek a second opinion to get another specialist’s view on your condition and available treatment options.
Major risks associated with a Bone Marrow Transplant are either due to high chemotherapy dose or the choice of targeted drugs. These include:
- Graft Vs Host Disease: A condition when the grafted or transplant bone marrow cells identify the recipient’s cells as foreign and attack them. Some symptoms of this condition include itchy rash, diarrhoea, nausea, dry eyes and flaky skin, shortness of breath, joint pain, and yellowing of skin and eyes (jaundice).
- Reduced blood cells: To undergo a bone marrow transplant, you will need to undergo chemotherapy to destroy cancer cells and affected blood cells. This results in a reduced number of all types of blood cells, increasing your risk for anaemia (reduced number of red blood cells causing shortness of breath), excessive bleeding and bruising (due to reduced platelet count), and infections (due to a decrease in the number of white blood cells)
Side effects that you may experience during or after your bone marrow transplant are:
- Sore mouth and ulcers
- Reduced appetite
- Feeling tired and worn out
Seeking a Second Opinion
It is natural to have questions about undergoing a bone marrow transplant. Discuss any concerns and queries regarding this treatment with your healthcare team. It is also recommended to seek a second opinion to understand how this treatment will help treat your cancer.