Stem cell or bone marrow transplants are complex treatments that carry a significant risk of serious complications.
It's important that you're aware of both the risks and possible benefits before treatment begins. You may wish to discuss them with your treatment team and your family.
Generally speaking, younger people who don't have any other serious conditions or those who receive transplants from a closely matched sibling are less likely to experience serious problems. People receiving transplants of their own stem cells (autologous transplants) are also less likely to experience serious side effects.
The main risks associated with a stem cell transplant are outlined below.
Graft versus host disease
In some cases, the transplanted cells recognise the recipient's cells as "foreign" and attack them. This is known as graft versus host disease (GvHD).
GvHD can occur within a few months of the transplant or develop several months or occasionally a year or two later. The condition is usually mild, but can sometimes be life-threatening.
Symptoms of GvHD can include:
Tell your treatment team if you develop these symptoms. GvHD can be treated with medications that suppress your immune system and stop the transplanted stem cells attacking the rest of your body.
Reduced number of blood cells
In preparation for a stem cell transplant, you'll need to have chemotherapy to destroy the damaged or diseased blood cells. These will eventually be replaced by the transplanted stem cells, although this process can take several weeks or more.
Until your body starts being able to produce healthy blood cells again, you may be at risk of:
- anaemia – a lack of red blood cells that can make you feel tired and short of breath; this may be treated with regular blood transfusions
- excessive bleeding or bruising caused by a lack of clotting cells called platelets; you may need transfusions of platelets if this is a problem
- infections – a lack of white blood cells and any immunosuppressant medication you're taking will mean your body isn't able to fight off infections
You'll need to stay in a special germ-free hospital room during the first few weeks after the transplant. After going home, you'll need to be careful about coming into contact with people with infections and take steps to prevent food poisoning.
You may also be given antibiotics to prevent or treat any bacterial infections.
Chemotherapy side effects
Common side effects of chemotherapy include:
These side effects are usually temporary and only last a few weeks. Hair usually grows back within a few months.
However, high-dose chemotherapy can also have some long-lasting effects, including permanent infertility, which affects most people who have the treatment.
Your treatment team will tell you about this before treatment starts if it's a risk and they can discuss possible ways of having children in the future. In some people this may include procedures to collect and freeze eggs or sperm, although this isn't always possible. Read more about cancer and fertility.