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WHAT  IS  LEUKAEMIA?

 

Leukemia is a form of cancer in which the number of white cells in the body are permanently increased.

 

• There are four main types of leukaemia, of which two are acute (of sudden onset) and two are chronic (slow and progressive). 
• The chronic types are rarely seen in a person aged under 20, but the acute types affect children and adults. 
• Acute lymphoblastic leukaemia (All), is responsible for around 85 per cent of childhood leukaemia, while acute myeloid leukaemia (AML), also known as acute non-lymphocytic leukaemia (ANLL), accounts for the vast majority of other cases. 

The most common form of childhood leukaemia is acute lymphoblastic leukaemia (ALL). This condition is usually contracted in children between the ages of two and five years.

 

What causes leukaemia?

 

Although the causes of leukaemia are still unclear, there are several theories.

 

• Possible causes include a reaction to an infectious agent, exposure to radiation, chemicals or electromagnetic fields, such as power lines, and genetic factors. 
• 'Clusters' of leukaemia cases have occurred in Britain and are being investigated. So far, little is known, other than that radiation may only account for less than 1 ° per cent of cases. 
• These 'clusters' seem to occur in areas in which one population, often urban, has moved into a rural setting. One theory, which has considerable support, is that the presence of urban incomers affects the susceptibility of the local people.  
• Certain viruses are known to cause leukaemia in domestic and laboratory animals. It is thought that a virus or viruses may be responsible for leukaemia in children who have a genetic susceptibility.  
• In the early 1990s, it was reported that vitamin K injections, given to most babies at birth, caused an increased risk of leukaemia. However, in 1997, after a series of further studies, the Department of Health decided that there was no increased risk. 

The incidence of childhood leukaemia has increased over the last 20 - 30 years. Factors thought to be responsible include exposure to chemicals and radiation.

 

Symptoms

 

Without treatment, leukaemia is fatal, and the earlier treatment starts the better the chances of remission or a cure. Symptoms include:

 

• Excessive and persistent tiredness
• Unusually severe bruising
• Breathlessness
• Pain in the bones and arm and leg joint
• Recurrent and persistent infections
• Abdominal swelling 

Diagnosing leukaemia

 

If leukaemia is suspected, your child will need to have hospital tests.

• A blood test is taken to determine the levels of red and white cells and platelets, and to detect any abnormal cells.
• The diagnosis is confirmed by a bone marrow biopsy. The precise type of leukaemia involved is identified by examination of the leukaemic cells' chromosomes and by tests to establish which type of antibodies they would normally produce. 

How does leukaemia develop?

 

ALL and AML both drastically increase the number of white blood cells, but each condition affects different types of white cells. The picture is complicated by the fact that there are different subtypes of both conditions.

 

• ALL increases the number of white cells called lymphocytes, produced in the lymph tissues and glands. Between 30 and 60 times more of them may be found in the blood than is usual. 
• AML increases the number of white cells called granulocytes, produced in the myeloid tissue of bone marrow. 
• Normally, white blood cells cannot reproduce. However, in both types of leukaemia, they do reproduce, further increasing their number, but they do not mature sufficiently to fulfill their vital role - the immune response that defends the body against infection. 
• In both cases, the numbers of red blood cells and platelets are much reduced. The result is tiredness and a tendency to bruising and bleeding.

Treating Leukaemia

 

The object of treatment is to bring about remission and then to maintain it. Different techniques are used depending on the type of leukaemia involved.

 

• Most anti-leukaemia drugs work by killing cells that are dividing. Unfortunately, they may also kill beneficial cells that are dividing, such as red blood cells. 
• A child with ALL is treated with a combination of drugs. Once the child is in remission, there will be a period of consolidation therapy, to suppress the production of the abnormal cells. Later, drugs will be given for a two-year period to maintain the remission (maintenance therapy).
• Children with AML are treated more intensively than those with ALL. Consolidation therapy is more intensive, too, but maintenance therapy may not be given. 
•  After treatment, normal life can be resumed, although with some follow-up care and testing. 
• The drugs used to treat leukaemia have a number of side-effects. Depending on the drug, these may include pins and needles, tiredness, susceptibility to infection, constipation, weight gain, bone weakening, high blood pressure, diabetes, hair loss, nausea and vomiting.  
• Whether a leukaemia sufferer relapses or comes out of remission depends to a certain extent on the individual child. However, those whose white blood cell counts were very high at the time of diagnosis and who had AML are more likely to relapse. In such cases, a bone marrow transplant may be given, depending on the availability of donor tissue that is immunologically matched to that of the child. 

Most children with ALL can be treated effectively and around 75 per cent are cured. Drugs used to send childhood leukaemia into remission can cause side effects, such as hair loss and weight gain.

 

For  More  Information:  Please  consult  your  physician  on  your  next  visit.