Treating chronic myeloid leukaemia

Unlike acute lymphoblastic leukaemia and acute myeloid leukaemia, childhood chronic myeloid leukaemia (CML) cannot be cured by any type of chemotherapy at present.

Chronic myeloid leukaemia is a form of leukaemia that progresses slowly during its initial phase. This chronic phase can last six years or more before undergoing a transformation to a second ‘accelerated’ stage, which lasts three to nine months.

In the third and final ‘blast’ stage, the disease resembles acute leukaemia and is usually fatal within three to six months.

No form of chemotherapy is currently thought to cure CML, although a new drug called Imatinib can eliminate easily detectable signs of leukaemia from the blood. This prolongs the chronic phase of the disease and delaying transformation to the accelerated stage.

The only treatment that can cure childhood CML is a stem cell transplant.

Stem cell transplantation

A stem cell transplant involves having high dose chemotherapy and, in some cases, whole body radiation. This destroys the leukaemic cells but it also kills the bone marrow cells.

The bone marrow cells are then replaced with stem cells from a donor. These stem cells replenish the bone marrow and start to make healthy new blood cells.

Stem cell transplantation is the term now used in place of what used to be called bone marrow transplantation. The new terminology reflects a different way of collecting the cells for transplantation.

Read more: Stem cell transplantation

Treatment complications

Stem cell transplant is an inherently risky procedure.

The child’s own bone marrow is destroyed before the transplant takes place - this effectively destroys their immune system. With no immune system, exposure to even a common infection could prove deadly.

To minimise the risks, the child will have to remain in isolation until the graft has ‘taken’ – this usually takes several weeks. They are likely to have to stay off school for several months until their immune system is stronger.

The transplant itself can cause all sorts of complications including the risk of graft rejection and graft versus host disease.

Sadly. one of the most common long-term side effects is infertility because of the high-dose chemotherapy and radiotherapy used to destroy the child’s bone marrow before the graft.

Long-term follow up

Children will have regular follow-ups to check for any recurrence of leukaemia and for any problems which may arise as a result of the treatment they were given.

A small number of children may develop long-term problems because of the treatment they received for leukaemia. There are risks associated with both chemotherapy and radiotherapy.

The main risk of long-term effects is in children who receive cranial and spinal irradiation to prevent central nervous system (CNS) relapse. Cranial and spinal irradiation is associated with impairment of growth and educational achievement and with premature onset of puberty. In order to minimise the risk, only a minority of children now receive cranial irradiation routinely and those that do receive the absolute minimum dose of radiotherapy necessary to prevent CNS relapse.

Other documented problems include cardiac problems, fertility problems and a small elevated risk of second cancers.

Read more: Long-term and late effects of treatment

Hear from families affected by childhood cancer

Coping with the diagnosis of cancer and the subsequent treatment and uncertainties is extremely difficult for children and their families.

A number of families have kindly offered to share their experiences to help others understand what it’s like to live with childhood leukaemia.

Read more: Patient stories