The majority of the blood cells that circulate through the body are grown in the bone marrow, the soft tissue that lies inside bones. Since blood cells live for only a few days to 3 months, the marrow generates billions of blood cells every day. But when the bone marrow produces cancerous white blood cells that don’t function properly, the condition is called leukemia. Since these cells don’t die when they normally should, they crowd out healthy blood cells and prevent them from fighting infection throughout the body.

Every year, some 40,000 Americans develop this cancer of the bone marrow and blood, and it takes the lives of 21,000. How dangerous the disease is depends on whether it’s the chronic type, which spreads slowly, or the acute variety, which worsens rapidly. The categories of leukemia are further divided by which types of cells they affect: Lymphocytic (or lymphoid) leukemias involve cells that grow into B or T cells, while myeloid leukemias alter the cells that develop into red blood cells, platelets, or several types of white blood cells. Acute myeloid (or myelogenous) leukemia is the most common form that affects both children and adults, while the acute lymphocytic type accounts for 75 percent of childhood leukemias. People with chronic lymphocytic and myeloid forms can have the disease for years before they experience symptoms.

Symptoms of leukemia include fever, chills, fatigue, swollen lymph nodes, weight loss, and bone pain, among others. Physicians screen for leukemia by testing the blood cells and bone marrow for cancerous cells. Treatments for the disease include chemotherapy, radiation therapy, and bone marrow or stem cell transplants. Because of scientific advances, 5-year survival rates for the disease have quadrupled over the past 5 decades. In the early 1960s, a person had a 14 percent chance of living 5 years after a diagnosis; today, the odds are about 51 percent.

ADDITIONAL FACTS

  1. Being exposed to radiation or certain toxic chemicals, smoking cigarettes, or having a family history of the disease raises the risk of leukemia.
  2. The ancient Chinese, Greeks, and Romans all treated leukemia with arsenic. Researchers today believe that the poison may actually have some benefit against the disease by inducing the death of the cancerous cells.