Stem cell transplants are essential procedures that restore blood-forming stem cells in individuals whose cells have been destroyed by high doses of chemotherapy or radiation therapy used to treat certain cancers.
Types of Blood Cells
Blood-forming stem cells grow into various types of blood cells. The main types include:
- White Blood Cells: Part of the immune system, helping the body fight infections.
- Red Blood Cells: Transport oxygen throughout the body.
- Platelets: Assist in blood clotting.
These three types of blood cells are crucial for maintaining health.
Types of Stem Cell Transplants
In a stem cell transplant, blood-forming stem cells are transferred into the bloodstream. They travel to the bone marrow to replace cells destroyed by treatment. The primary types of stem cell transplants include:
- Autologous Transplants: Stem cells come from the patient.
- Syngeneic Transplants: Stem cells come from the patient’s identical twin, if available.
- Allogeneic Transplants: Stem cells come from another person, who may be a related or unrelated donor. To minimize potential side effects and improve the success rate of an allogeneic transplant, the donor’s blood-forming stem cells must be compatible with the patient’s.
How Stem Cell Transplants Work Against Cancer
Generally, stem cell transplants do not directly attack cancer. Instead, they help patients recover their ability to produce stem cells after high-dose treatments of radiation or chemotherapy. However, in multiple myeloma and certain types of leukemia, stem cell transplants can have a direct anti-cancer effect due to the graft-versus-tumor effect, which occurs when the donor’s white blood cells attack the remaining cancer cells in the patient’s body.
Candidates for Stem Cell Transplants
Stem cell transplants are frequently used to assist individuals with leukemia and lymphoma and can also be used for neuroblastoma and multiple myeloma. Ongoing clinical trials are exploring the efficacy of stem cell transplants for other types of cancer.
What to Expect During a Stem Cell Transplant
The process of a stem cell transplant can take several months. It starts with a high-dose chemotherapy and/or radiation therapy treatment lasting one to two weeks, followed by a few days of rest. Then, the patient receives the blood-forming stem cells through an intravenous catheter, similar to a blood transfusion, which takes one to five hours. Post-transplant, the patient enters the recovery phase, waiting for the new blood cells to start producing.
Impact of Stem Cell Transplants
The effects of stem cell transplants vary depending on factors such as:
- Type of transplant
- Pre-transplant treatment doses
- Patient’s reaction to high-dose treatments
- Type and stage of cancer
- Patient’s health before the transplant
Monitoring Success of Stem Cell Transplants
Doctors monitor the success of stem cell transplants through frequent blood count tests. As the newly transplanted stem cells produce new blood cells, the patient’s blood counts will rise, indicating recovery.
