Leukaemias: a review

Leukaemia is the most common cancer in children. Leukaemia results from clonal proliferation of stem cells and leads to bone marrow failure. Symptoms at presentation include bruising, bleeding, pallor due to anaemia and infection. The incidence is approximately 5 in 100 000 children. The cause is largely unknown although there is a predisposition in certain congenital conditions such as Fanconi's Anaemia and Down's syndrome and there is some understanding of how genetic mutations may cause leukaemia, but this is not thought to be a single event. The treatment of acute lymphoblastic leukaemia in children older than 1 year is extremely successful and continues to improve. Treatment is tailored according to response (minimal residual disease directed). Multi-agent immunosuppressive chemotherapy, with central nervous system prophylaxis is given over 2–3 years. Acute myeloid leukaemia is five times less common than acute lymphoblastic leukaemia and is treated intensively for 4–5 months and cure rates have remained at 60–70% for two to three decades. Survival has improved due to better supportive care. Chronic myeloid leukaemia is rare and treated with tyrosine kinase inhibitors and as in preleukemic conditions (myelodyplasia) may require allogenic bone marrow transplant.