New Cancer Cases
An estimated 25,700 new cases in 1995, approximately evenly divided into acute leukemia and chronic leukemia. Although often thought of as a primarily childhood disease, leukemia will strike many more adults (23,100 this year) than children (2,600 this year). Acute lymphoblastic leukemia accounts for approximately 2,000 of the cases of leukemia among children. In adults, the most common types are acute granulocytic (approximately 7,000 cases) and chronic lymphoblastic (approximately 7,800 cases).
An estimated 20,400 deaths in 1995.
Signs and Symptoms
Fatigue, paleness, weight loss, repeated infections, bruising easily, and nosebleed or other hemorrhages. In children, these signs can appear suddenly. Chronic leukemia can progress slowly and with few symptoms.
Leukemia strikes both sexes and all ages. Causes of most cases are unknown. Persons with Down syndrome and other genetic abnormalities have higher than normal incidence of leukemia. It has also been linked to excessive exposure to ionizing radiation and to certain chemicals such as benzene, a commercially used toxic liquid that is also present in lead-free gasoline. Certain forms of leukemia and lymphoma are caused by a retrovirus, HTLV-I (human T-cell leukemia/lymphoma virus-I).
Because symptoms often resemble those of other, less serious conditions, leukemia can be difficult to diagnose early. When a physician does suspect leukemia, diagnosis can be made using blood tests and biopsy of the bone marrow.
Chemotherapy is the most effective method of treating leukemia. Various anticancer drugs are used, either in combination or as single agents. Transfusions of blood components and antibiotics are used as supportive treatments. To illuminate hidden cells, therapy of the central nervous system has become standard treatment, especially in acute lymphoblastic leukemia Under appropriate conditions, bone marrow transplantation may be useful in the treatment of certain leukemias.
The 5-year survival rate for patients with leukemia is 38%, due partly to very poor survival of patients with some types of leukemia such as acute granulocytic. Over the last 30 years, however, there has been a dramatic improvement in survival of patients with acute lymphocytic leukemia; from a 5-year survival rate of 4% for people diagnosed in the early 1960s to 28% in the early 1970s to 52% in the mid-1980s. In children, the improvement has been from 4% to 73%.