If you or a loved one has been diagnosed with non-Hodgkin’s lymphoma and are embarking on treatment, it’s likely you’ve heard about stem cell transplants at some point. These transplants can be an important part of treatment for some patients, but they’re not appropriate for everyone who has lymphoma. Let’s take a look at the facts you should know.
These transplants work by improving function in the bone marrow
Stem cells are blood cells in their earliest stage of development, and they’re made in the body’s bone marrow. Think of bone marrow — the spongy substance inside our bones — as the immune system’s factory, churning out additional fighters every day.
The stem cells develop into mature blood cells within the bone marrow and then go into the bloodstream, where they serve a number of functions, including carrying oxygen to cells, helping blood to clot, and fighting infection. Normally, the bone marrow makes millions of new blood cells daily, to replenish the cells that are dying off naturally. For example, red blood cells live for only about four months.
In a stem cell transplant, bone marrow that’s been damaged — for those with non-Hodgkin’s lymphoma, that trauma comes from chemo — and unable to keep producing stem cells on its own gets a fresh infusion, so the factory can get back up and running.
Stem cell transplants are usually only used for recurring lymphoma
There are many forms of lymphoma, so when and how stem cell transplants are used will depend on what type of lymphoma is present, says Robert Dean, M.D., in the Department of Hematology and Medical Oncology at Cleveland Clinic. But, that said, these transplants are primarily used only when first-line treatments aren’t working, or if lymphoma has gone into remission and then recurred.
“When that happens, it tells us that some of the cancer cells were strong enough to resist the initial chemo, or that they managed to bypass the chemo in some way,” he says. “In that case, going back to using the same chemo as we did the first time wouldn’t be the best treatment, because it’s likely those cancer cells would be resistant. So, we need to consider adding a stem cell transplant into the mix for those patients.”
Stem cell transplants are not a treatment option on their own
Although they’re sometimes called “stem cell treatments,” this form of intervention is not a treatment by itself, the way that chemotherapy or radiation would be. Instead, it’s used as a way to help the immune system recover from stronger chemotherapy, says Jack F. Jacoub, M.D., medical oncologist and medical director of California-based MemorialCare Cancer Institute at Orange Coast Medical Center.
When lymphoma patients see their cancer come back, high-intensity chemo is the best option, Dr. Jacoub adds. But the major side effect of that is significantly reduced or even destroyed capability within the bone marrow.
“When you wipe out the bone marrow, essentially you no longer have immune system function,” he says. “You may have eliminated the cancer, but you can’t operate without an immune system.”
Stem cell treatments help the body start growing blood cells normally again, so that your immune system can get back to its normal functioning. “Think of a stem cell transplant as a parachute,” Dr. Dean says. “It’s a valuable safety mechanism, but chemo is the jump out of the airplane.”
Ideally, this combination provides a powerful way to treat recurrent lymphoma, because the stronger chemotherapy potentially clears the system of cancer cells, and the stem cell treatment helps the body get back to normal immune system function more quickly.
Dr. Dean adds that for many patients, higher dose chemo without a stem cell treatment isn’t recommended, because the body may not be able to get “back online” without one. After all, he adds, who would risk skydiving without a parachute?
You may get your own stem cells or donor cells
In some cancers, like leukemia, donor cells are preferred because they tend to be better at finding and attacking leftover cancer cells, Dr. Dean notes. But for lymphoma, using a patient’s own cells can often be just as effective. If that’s the approach an oncologist chooses, some of your stem cells will be harvested and stored before the stronger-chemo rounds, and then re-introduced to the body after the chemo has cleared from the system.
There are some cases where donor cells are more commonly used, mainly with certain forms of particularly aggressive lymphoma. For example, there’s a type of non-Hodgkin’s lymphoma called mantle cell lymphoma where the body makes abnormal B-cells (the white blood cells that fight infection). Dr. Dean notes that this type of cancer tends to be treated more effectively with high-dose chemo and donor stem cells.
But no matter where your stem cells might originate, the goal is the same. “Stem cell therapy is added on to treatment with the expectation of a longer remission,” he says.
See more helpful articles:
How Do Stem Cell Transplants Work?
Infographic: The Science of Stem Cells
Stem Cells: What You Need to Know