WHAT IS CHRONIC LYMPHOCYTIC LEUKAEMIA?
EACH year in Australia about 1000 people are diagnosed with chronic lymphocytic leukaemia (CLL), making it the most common type of leukaemia. Generally, CLL is a rare disease, accounting for 0.8 per cent of all cancers diagnosed. The risk of developing CLL increases with age and almost 80 per cent of all new cases are diagnosed in people aged 60 years and older. CLL is rare in people under 40 and occurs more frequently in men than in women. Chronic CLL is a type of slow growing leukaemia that affects developing B-lymphocytes (also known as B-cells). These cells are specialised white blood cells. Under normal conditions they produce immunoglobulins (also called antibodies) that help protect our bodies against infection and disease. In people with CLL, lymphocytes undergo a malignant (cancerous) change and become leukaemic cells. For many people, CLL remains stable for many months and years and has little, if any, impact on their lifestyle or general health. About 30 per cent of people diagnosed with CLL never require any treatment for their disease and can survive for many years despite their diagnosis. For others, the leukaemic cells multiply in an uncontrolled way. These cells are abnormal and as such they are unable to function properly. They live longer than they should and accumulate in the bone marrow, blood stream, lymph nodes (glands), spleen, liver and other parts of the body. Over time, an excess number of lymphocytes crowd the bone marrow, and interfere with normal blood cell production. The bone marrow produces inadequate numbers of red cells, normal white blood cells and platelets. This leads to some people with CLL being more susceptible to anaemia, recurrent infections and bruising and bleeding easily. Circulating red blood cells and platelets can also be damaged by abnormal proteins made by the leukaemic cells.