How Bone Marrow Transplants are Used to Treat Blood Cancers

5 min read

How Bone Marrow Transplants are Used to Treat Blood Cancers

Bone marrow transplants are a special type of treatment that is recommended for patients who have certain types of blood cancers and diseases. While not typically used as a first line of treatment, this procedure helps to stimulate the production of healthy blood cells by infusing stem cells into the bone marrow. You may also hear of a bone marrow transplant referred to as a stem cell transplant. 

How Blood Cancers Are Related to Your Bone Marrow and Stem Cell Production

Blood cancers are sometimes called “hematologic cancers,” and they usually start in the bone marrow which is the source of blood cells. When blood cells start to grow abnormally they start to crowd out the healthy cells. Sometimes this happens slowly and in other cases it’s a much quicker process. 

As more and more abnormal cells interfere with the functioning of normal blood cells, symptoms start to appear.

Some common types of blood cancers include:

  • Lymphoma. Lymphoma, which is the largest category of hematologic cancers, affects immune cells called lymphocytes, a type of white blood cell. These cells are found in the lymph nodes, spleen, thymus, and bone marrow. There are two main types of lymphomas: non-Hodgkin lymphoma and Hodgkin lymphoma. Non-Hodgkin lymphoma is the most common type of lymphoma. 
  • Leukemia. This type of cancer starts in the bone marrow and interferes with white blood cells, red blood cells, and platelets. 
  • Multiple myeloma. This type of cancer starts in the blood’s plasma cells which are a type of white blood cell. 

Most blood cancers require treatment, although if slow growing (indolent) treatment may not need to begin immediately. When treatments are necessary, there is usually a medical oncology regimen that is known to work well for many patients with that type of blood cancer. This will typically include treatments such as chemotherapy and targeted therapy. 

However, chemo and targeted therapy aren’t always effective. In that case, it’s possible to use a bone marrow transplant to “reset” the body’s ability to make healthy blood cells. 

What is a Bone Marrow Transplant?

A bone marrow transplant is also sometimes referred to as a stem cell transplant or a hematopoietic stem cell transplant. This practice involves infusing healthy bone marrow or stem cells to help stimulate the production of healthy and normal blood cells. The transplant is then performed to replace these abnormal cells with healthy ones. 

There are two main types of bone marrow transplants: autologous transplant and an allogeneic transplant. An autologous transplant uses the patient’s own stem cells. The way this works is the patient’s stem cells are removed, and those cells are filtered and then given back. 

An allogeneic transplant uses stem cells from a donor.

Preparation for Bone Marrow Transplant

Prior to the bone marrow transplant, the patient will usually receive high doses of chemotherapy.  The goal of this treatment is to kill the current “stem cells” which are the building blocks of future blood cells. During this time, patients are very vulnerable to any virus or bacterial infections because their immune system has been reduced. 

There is also the process of finding the right donor if an allogenic transplant will be needed. Some patients are able to receive stem cells from a sibling or other family member, but for others, it can be a challenging process. A stem cell donor will need to be found through international registries of people willing to give stem cells to someone who needs them. 

How Do They Collect Stem Cells for the Transplant?

Stem cells can be collected from the donor or from the patient through several different processes. One method involves collecting stem cells that are already circulating in the blood. This is called peripheral blood stem cells. This process involves being hooked up to a machine that draws blood out of the vein, separates the stem cells then puts the remaining plasma back into another vein. 

Another method involves harvesting the stem cells directly from the bone marrow. In this process, a needle is placed into the center of a bone, and bone marrow is removed. This procedure takes place in an operating room, and numbing medicine will be used so that the donor doesn’t feel any pain during the procedure. 

Once the stem cells are ready and the patient has received whatever chemotherapy or preparatory therapies they’ll need, it is time for the infusion. The stem cells are administered through the central line or catheter that is also used for giving chemotherapy. The stem cells will naturally move to the bone marrow, where they should begin to grow healthy new blood cells. 

How Do You Know If the Transplant was Successful?

The most common way to tell if the transplant is working is to monitor blood counts. Are the red blood cell, white blood cell, and platelet counts going back up to normal levels? If so, the transplanted stem cells are doing their job!

Monitoring the presence of your cancer is often the goal of a bone marrow/stem cell transplant. Some cancers, such as some types of leukemia and lymphoma can be cured with a stem cell transplant. Others may go into remissions -- showing no signs of cancer -- but could return again in the future. 

Your oncology team will ask that you come back for testing to be sure they’re seeing both improved blood counts and no signs of cancer in the blood. Be sure to stay on top of these appointments.

Side Effects of a Bone Marrow Transplant

The biggest risk for patients who have a bone marrow transplant is the development of an infection. Because your immune system is greatly reduced by the chemo treatment before the transplant, it takes a few weeks after the transplants for you to begin to have a functioning immune system again. While the biggest risk for developing an infection is in the first two weeks, you will still be at a higher risk of infections for a year or more after. 

There are other side effects, primarily from the high doses of chemotherapy that can include mouth sores, stomach issues such as nausea and vomiting, diarrhea, hair loss, and weight loss. These usually improve as time passes and the stem cells begin to regenerate.

Post-Transplant Care and Follow-Up

The success rates for bone marrow transplants depend on a number of factors, such as the type of transplant, type of cancer, and overall health. Patients will need long-term monitoring to watch out for cancer recurrence and other complications. For many patients, bone marrow transplants are a great option to help prevent cancer from progressing and to improve the odds of survival. Your oncologist will let you know if the recommended treatment for a blood cancer is a bone marrow transplant. 

If you or a loved one was diagnosed with lymphoma, leukemia, myeloma, or a non-cancerous condition such as aplastic anemia, our team of hematologic oncologists are available to provide a recommended treatment plan. They are also available for second opinions.

Find a Hematologist Near You