A B C D E F G H I J K L M N O P R S T U V W

CHRONIC MYELOID LEUKAEMIA

What is Chronic Myeloid Leukaemia ?

Chronic myeloid leukaemia (CML) is a type of leukaemia or cancer of the white blood cells. Chronic myeloid leukaemia differs from acute leukaemia in that the white blood cells are more mature, and therefore the disease progresses more slowly. CML can occur at any age, but is commonest between the ages of 20 and 50.

How does Chronic Myeloid Leukaemia occur ?

The bone marrow normally produces three types of cells. Red cells carry oxygen, white cells fight infection, and platelets help blood clotting. In CML the bone marrow produces too many white blood cells. These fill up the bone marrow and the marrow may be less able to produce enough red cells and platelets. The white cells overflow into the blood and the number of white blood cells is increased. Chronic myeloid leukaemia is a slowly progressive disease. It is therefore often picked up by chance on a routine blood test without the patient having any symptoms. As the disease advances, anaemia can develop and cause tiredness and shortness of breath. Patients may notice a feeling of fullness in the abdomen or feel a lump on the left side. This is due to enlargement of the spleen which is itself full of white blood cells. Some patients may feel generally unwell, lose their appetite, or have fevers at night. Problems with the platelets may cause abnormal bruising or bleeding.

Why does Chronic Myeloid Leukaemia occur ?

Like other leukaemias, CML can occur as a result of exposure to excessive doses of radiation (x-ray or radioactivity). However, the cause in most patients is unknown. There is a particular change in the chromosomes of the bone marrow cells in CML called the Philadelphia chromosome, but we do not know what causes this change in the chromosomes.

Treatment Involved for Chronic Myeloid Leukaemia

The behaviour of the disease varies from person to person. In almost all cases, the white cell count and the symptoms can be controlled quite easily with anti-cancer drugs or a drug called interferon. After a number of years the disease tends to undergo alteration or transformation and becomes difficult to control with chemotherapy.

CHEMOTHERAPY

There are a variety of drugs which are effective in lowering the white cell count. As the count falls the spleen usually shrinks and symptoms improve. These drugs are given in tablet form, daily or less often, depending on the the particular drug. The dose will be adjusted according to the blood count and spleen size. In the transformation phase stronger chemotherapy is usually needed.

INTERFERON

This is a substance normally produced by the body in response to virus infections. It has been found to reduce the growth of several types of cancer, including CML. In CML it will lower the white cell count. In some people the abnormal chromosome even disappears from the bone marrow cells. It is injected under the skin, usually three times a week. These injections may be given by a practice nurse or district nurse but many patients learn to give their own injections.

BONE MARROW TRANSPLANTATION

Although drugs will control the blood count during the chronic phase, this does not prevent transformation. In other words, the disease is controlled but not cured. Bone marrow transplantation is a way of trying to get rid of the leukaemia cells completely. This is done by first giving high dose chemotherapy with or without radiotherapy. Then the marrow is replaced by healthy marrow from a donor with the same tissue type (bone marrow transplantation). You may also be given back certain of your own marrow cells, called stem cells. These have the ability to develop into more mature bone marrow cells..The results are encouraging but this treatment may not be suitable for you.

NEW TREATMENTS A drug which blocks an important enzyme in leukaemic cells is under study. Blocking the action of this enzyme (called tyrosine kinase) may stop or slow down the growth of leukaemic cells.

During Treatment for Chronic Myeloid Leukaemia

During oral chemotherapy, symptoms should improve as the white cell count comes under control. The drugs used do not usually cause nausea or hair loss, and most patients have no side-effects at all. In women of child-bearing age the periods can disappear. Fertility may be reduced in both men and women. It is anyway inadvisable to conceive or father a child during chemotherapy or within 3 months of stopping treatment. Interferon may cause headaches and flu-like symptoms especially in the early stages of treatment. This can usually be prevented by taking paracetamol an hour or two before the injection. Usually these symptoms disappear after 2 to 3 weeks. In rare cases, other side-effects can occur so any unusual symptoms should be reported to the doctor.

After Treatment for Chronic Myeloid Leukaemia

There may be times when one can stop treatment because the white cell count has come down to normal. However, the disease is still there so the blood count needs to be checked regularly and the doctor needs to be told if any new symptoms develop. This may mean that treatment needs to be restarted. As explained above, bone marrow transplantation is currently the only way of permanently curing this type of leukaemia.

Effects on Family of Chronic Myeloid Leukaemia

Family and friends will see your improvement when the disease is treated. All normal activities can be continued while on treatment. CML is not inherited or infectious and it cannot be passed on to family or friends.