Simply said, bone marrow transplantation is the transfusion of bone marrow from one individual to another or, in some cases, to the same person. That’s the easy part. It’s what happens before and after the actual infusion that gets tricky.
Why is Bone Marrow Transplant necessary?
You may be facing a bone marrow transplant for one of two reasons:
- Your medical team believes this treatment is the best way to prevent a relapse in certain cancers that are more likely to come back again.OR
- Your cancer has not responded well to previous therapy and you have either relapsed or never gained remission.
The types of teen cancers most often treated with BMT are:
- Leukemia (ALL, AML)
- Lymphoma (Hodgkin’s, Non-Hodgkin’s)
- Sarcomas (Rhabdo or Ewing’s)
- Myelodysplasia (rare in teens)
A little bit about your bone marrow…
Bone marrow is the spongy material found in the cavities of your bones, where all your blood cells are produced (the process, in case you are interested, is called hematopoiesis). Each type of blood cell – red (carries oxygen), white (fights infection), and platelet (helps stop bleeding) – develops from a stem cell made in your marrow. These cells divide and produce all the different cells that mature and become fully functional in your body. As old cells wear out and die, stem cells divide and produce new ones. Most stem cells are found in the bone marrow, but some stem cells called peripheral blood stem cells (PBSC’s) can be found in the bloodstream. Umbilical cord blood from newborn babies also contains stem cells.
But when you have cancer…
Chemotherapy and radiation are often used to treat cancer. As you know, both of these therapies not only destroy cancer cells but normal ones as well. Doses have to be carefully monitored to reduce the risk of damaging your bone marrow beyond repair, yet still kill the cancer. When you have a bone marrow transplant, very high doses of chemotherapy and radiation are administered which essentially destroy your own marrow, but also, you hope, all the cancer. The new marrow which is transfused from a donor, or in some cases, yourself, “rescues” the old marrow which has been destroyed by the intensive treatment. If all goes well, new cells will be normal and the cancer will be cured.
Types of BMT’s
There are different types of transplants depending on how and from whom the new marrow is donated:
The person donating the bone marrow or stem cells is an identical twin.
The person giving the bone marrow or stem cells is a genetically matched family member (usually a brother or sister). If you don’t have a sibling to be a donor, you may have a type of allogeneic transplant called a matched unrelated transplant or MUD. The donor is unrelated to you but has matching marrow.
Depending on your specific situation, you may be your own donor. If you have a type of cancer that does not affect your marrow or if you are in remission after another form of treatment, your own marrow can be harvested and frozen for future use.
Peripheral blood stem cell transplant:
With this type of transplant, the donor’s cells are collected from his or her circulating blood instead of from bone marrow. Essentially, it’s the same as a bone marrow transplant except that the stem cells were collected in a different way.
Umbilical Cord Blood Transplant:
This is usually unrelated, and may be available if an adequate match is not found from the bone marrow registry. Frozen stem cells from a newborn’s umbilical cord are available from a cord blood registry.
So, what exactly will happen?
The timeline will look something like this:
- A decision will be made between you and your medical team to proceed with bone marrow transplant. This may either be a first step or a next step, if earlier treatments were unsuccessful.
- The search for a suitable donor will begin. If you have an identical twin, he or she may be the first choice. If not, other siblings will be tested to see if their marrow is genetically matched to yours. This is called HLA (human leukocyte antigen) typing, done through blood tests to make sure their marrow is compatible with you.
- If you have no siblings or none that match, your medical team may recommend looking for an unrelated donor in a national registry of people who have volunteered to be donors. The transplant coordinator in your hospital will help you with this.
- Once a donor has been identified, a plan will be created that will include several steps for both you and your donor.
- The donor will go through a series of tests to be absolutely certain that a good match has been found. The potential donor also is carefully screened to be sure that he or she is totally committed to going forward. Once your treatment starts, it is critical that the donor continue with the process.
- You will begin what’s called conditioning treatment. This sometimes includes total body radiation (TBI) for a number of sessions over a few days plus high dose chemotherapy. This conditioning treatment is designed to kill all cancer cells in your body, but it also destroys your marrow in the process.
- At this point, you are very susceptible to life-threatening infection and must take strict precautions. Visitors must be sure to wash their hands very well before coming into your room. You must not be exposed to anyone who is sick, even with a little cold. You might be instructed to wear a sterile mask when around other people. These precautions must be followed until your new marrow is working.
- Everything will be timed perfectly, so that your donor’s marrow is harvested (or removed) the day before you receive it. The donor goes to a hospital in whatever city he or she lives for the harvest. In a procedure much like a bone marrow biopsy but longer, marrow is taken from your donor. The donor is usually able to go home that same day.If your donor lives in another city, the marrow will be flown to your hospital where you will be waiting.
- After all the planning and preparation, some teens find the actual transplant to be a bit anticlimactic. Unlike other organ transplants, there is no surgery for you on the day of the procedure. The new marrow is simply given to you intravenously through your central line (Broviac or Hickman).It looks much like a blood transfusion (of which you have had many, by now). But the stem cells you are getting have a very special function. They miraculously find their way directly into your bone marrow where they will hopefully begin producing new blood cells.
- It usually takes a couple of weeks for your new marrow to engraft – or begin making new blood after a bone marrow transplant. With a peripheral stem cell transplant, engraftment usually begins a little earlier.Once the new marrow engrafts, your counts will continue to climb. If there are no complications, you should be able to go home in 4-6 weeks.
There are several things that your medical team will be closely monitoring following your transplant:
Failure to engraft:
Sometimes (very rarely) the new marrow will not “take” or engraft. Your medical team will guide you to making the best decision about what to do in this case.
This poses one of your greatest dangers. If you develop a high fever (100.5 F. or 38 C), you will likely be treated with antibiotics.
Graft vs. Host Disease (GVH or GVHD):
When your new marrow “takes”, you develop the immune system of your donor. In some cases, your new immune system sees the rest of you as foreign – it doesn’t recognize you – and begins to attack. In other words, the new marrow (graft) is fighting you (host). This is called graft vs. host disease.
The most common symptoms are skin rash, diarrhea and jaundice. If you develop any of these symptoms, there is medication to treat them. Uncontrolled GVH can be very serious and potentially life threatening.
What happens after my BMT?
After you are discharged from the hospital, you will be closely monitored for signs of graft vs. host disease as well as possible infections. You may need to take many medications while your immune system is still recovering and also have injections of a growth factor called G-CSF (growth colony stimulating factor) to boost your white blood cells. Make sure the EMLA cream is handy – the G-CSF stings if it goes in too fast! Periodic bone marrow biopsies will also be done to ensure that you are disease free. Bone marrow transplant is a very rough ordeal. If you stay focused on the goal of getting better and take one step at a time, you’ll get through this.