Children & Cancer
Children’s cancers are rare – only about 1 in every 600 children under 15 years will develop cancer. These are different from cancers affecting adults and often occur in different parts of the body. They look different under the microscope and respond differently to treatment. In the UK there are around 1700 new cases of children’s cancer.
The cause of cancer is unknown although there are many different theories. Many parents worry that their child has developed cancer because of something they have done wrong. However this isn’t the case and parents should not feel guilty if their child develops cancer.
Over the past 40 years the prospects for a child with cancer has improved dramatically because of advances in treatment. Seven out of 10 children with cancer are cured.
Leukaemia
One third of childhood cancers are leukaemia and around 400 new cases occur each year in the UK. 75% of these cases are Acute Lymphoblastic Leukaemia (ALL). ALL is most common in children aged 1-4 although it can occur at any age.
ALL is a cancer of the white blood cells. Blood cells are produced in the bone marrow. Bone marrow contains red blood cells (which carry oxygen around the body), white blood cells (which fight infection) and platelets (which help the blood to clot and control bleeding).
The 2 types of white blood cells are lymphocytes and myeloid cells. Normally white blood cells reproduce in an orderly and controlled manner. In leukaemia the process gets out of control and the cells continue to divide but do not mature. These immature cells fill up the bone marrow and prevent it from making healthy blood cells.
Leukaemic cells are immature so they cannot work properly leading to an increased risk of infection. Since the bone marrow cannot make enough health red blood cells and platelets, symptoms like anaemia and bruising occur.
There are 4 different types of leukaemia
- • Acute Lymphoblastic (ALL)
- • Acute myeloid (AML)
- • Chronic Lymphocytic (CLL)
- • Chronic Myeloid (CML)
Chronic leukaemias are rare in children and usually affect adults.
Causes of ALL
The exact cause in unknown. However children with certain genetic disorders such as Down’s syndrome have a higher risk of developing leukaemic. Brothers and sisters of a child with ALL have a slightly increased risk of developing ALL themselves. Research is being conducted to see if there is a link between nuclear power plants and children nearby developing leukaemia but currently there is no evidence of this.
Leumaemia is not infectious.
Signs and symptoms
Because the leukaemia cells develop in the bone marrow, the production of normal blood cells in reduced. This results in children becoming tired and lethargic due to anaemia which is caused by a reduction in red blood cells. They bruise more easily and bleeding may take longer to stop since they have less platelets in their blood. They may also be more prone to infections due to the low number of white blood cells. The child also may have aches and pains in the limbs and have swollen lymph glands.
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Diagnosis
A blood test will show low numbers of normal white blood cells and the presence of abnormal leukaemic cells. A sample of bone marrow is taken to confirm the diagnosis. A lumbar puncture will detect if the spinal fluid contains any leukaemia cells. A chest x-ray will also be done to see if there are any enlarged glands in the chest.
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Treatment
Chemotherapy is the main treatment. It is given in several phases:
Induction – involved intensive treatment aimed at destroying as many leukaemia cells as possible. This phase lasts 4-6 weeks. A bone marrow test is taken at the end of induction to determine whether the child still has leukaemia.
Consolidation and Central Nervous System (CNS) Treatment – this aims to maintain remission and prevent the spread of leukaemia cells into the brain and spinal cord. This treatment involved injecting a drug, typically methotrexate, into the spinal fluid during a lumbar puncture. Sometimes radiotherapy to the brain is required.
Further doses of chemotherapy are given to kill off any remaining leukaemia cells.
Maintenance Treatment – this lasts for up to 2 years for girls and 3 years for boys. The child is given daily tablets and monthly injections of chemotherapy.
Bone-marrow transplantation – this is given to children with ALL that is likely to come back following chemotherapy or for children whose leukaemia has recurred following treatment.
Testicular radiotherapy – boys may need radiotherapy on their testicles because leukaemia cells can survive in the testicles despite chemotherapy.
Central Nervous System (CNS) radiotherapy – children with leukaemia cells in their CNS may need radiotherapy to their brain.
Side effects of treatment:
- • hair loss
- • less blood cells produced by the bone marrow which can lead to anaemia, increased bruising, bleeding and infection
- • loss of weight and appetite
- • nausea and vomiting
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The future
Most children with ALL are cured and grow up normally. If the leukaemia comes back it is normally within the first three years after treatment and further treatment can then be given.