Stem cell transplant for acute lymphoblastic leukemia

Stem cells are basic cells that develop into different types of cells that have different jobs. For example, all our blood cells develop from blood stem cells. Stem cells are made in the bone marrow.

A stem cell transplant replaces stem cells when stem cells or the bone marrow are damaged. It uses chemotherapy at very high doses to kill all of the cells in the bone marrow. This includes both healthy cells and cancer cells. Sometimes radiation therapy to the entire body (called total body irradiation, or TBI) is also used. Healthy stem cells are then given to replace the ones in the bone marrow that were killed.

This complex treatment has many risks, and it must be done in a special transplant centre or hospital.

Some people with acute lymphoblastic leukemia (ALL) will have a stem cell transplant. You may be offered a stem cell transplant to treat ALL:

• during the first complete remission, depending on prognosis and risk of ALL returning (called relapsed ALL)
• after the leukemia relapses if another complete, or sometimes partial, remission is reached
• if the leukemia did not fully respond to treatment (called refractory ALL) and only a partial remission was ever reached

Standard doses of chemotherapy don't always bring about a remission. Higher doses of chemotherapy and radiation can be used to destroy the leukemia cells that are still in your body, but they can damage or destroy your bone marrow in the process. To counter this, a stem cell transplant will infuse (transplant) stems cells from your donor into your body. The goal of the transplant is to help repair the damage done to your bone marrow and replace the blood cells that were destroyed by the higher doses of chemotherapy or radiation.

But a stem cell transplant is not the right choice for everyone with ALL. Your age and other health conditions may make a stem cell transplant too dangerous. Your healthcare team can help you consider the risks and benefits of this treatment and recommend if a transplant is right for you. Other treatments are often considered before transplant.

The following types of stem cell transplant may be used with ALL.

In an allogeneic stem cell transplant, the stem cells are taken from one person (the donor) and are given to another person (the recipient). The donor may be a relative or may be unrelated to the recipient. The donor and recipient are matched through a process called human leukocyte antigen (HLA) typing.

An allogeneic transplant is the preferred type of stem cell transplant used to treat ALL. But not everyone can have an allogeneic transplant because they need to have a donor.

The side effects of the high doses of chemotherapy used before a stem cell transplant may be too severe for people older than 55. People in this age group may also have other health conditions that mean they can’t have an allogeneic transplant. They may be offered a reduced-intensity transplant, which uses lower-dose conditioning treatment.

In an autologous stem cell transplant, the stem cells are taken from your own bone marrow or blood. An autologous transplant is used rarely, but the healthcare team might consider it when there is no available donor.

Side effects of a stem cell transplant will depend mainly on the type of chemotherapy or drug combination given, if radiation therapy was given, the type of transplant and your overall health. Tell your healthcare team if you have side effects that you think are from a stem cell transplant. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

Side effects of a stem cell transplant include:

• low blood cell counts, which can cause infection, bleeding and anemia
• graft-versus-host disease (GVHD)
• veno-occlusive disease (VOD)
• digestive system problems, including sore mouth and throat, loss of appetite and diarrhea
• skin problems
• pain
• organ problems, such as kidney, lung or heart problems
• fertility problems
• graft failure or graft rejection
• osteoporosis
• second cancers

Find out more about side effects of a stem cell transplant.

Find out more about a stem cell transplant and side effects of a stem cell transplant. To make the decisions that are right for you, ask your healthcare team questions about a stem cell transplant.