Details about the disease that killed CBS newsman Ed Bradley--the type of leukemia from which he suffered and when he was first diagnosed with the condition--were not immediately made public with the news of the esteemed 65-year-old journalist's death in New York Thursday.

What is known is that leukemia is a mysterious cancer that begins in the blood cells and affects people of all ages. Its exact cause is unknown.

What Is Leukemia?

There are four common types of the disease:

Acute myeloid leukemia: About 11,930 new cases expected this year in the U.S.; affects adults and children.

Chronic myeloid leukemia: About 4,600 new cases estimated for this year; mainly affects adults.

Acute lymphocytic leukemia: About 3,900 new cases expected this year; mainly in young children, but can affect adults.

Chronic lymphocytic leukemia: About 9,700 cases expected this year; usually seen in people over 55.

What Are the Symptoms of Leukemia?

Common leukemia symptoms include:

--Fevers or night sweats

--Frequent infections

--Feeling weak or tired


--Easy bleeding and bruising

--Pain in bones or joints

--Swelling or discomfort in abdomen (from enlarged spleen)

--Swollen lymph nodes, especially in the neck or armpit

--Weight loss

Such symptoms aren’t sure signs of leukemia. Only a doctor can diagnose the disease.

Leukemia symptoms may be acute, meaning they start suddenly and worsen quickly. Or they can be chronic, starting mildly and worsening gradually.

Treatment depends on the type and extent of the disease and can include chemotherapy, biological therapy, radiation therapy, and bone marrow transplantation.

How is Leukemia Detected and Treated?

Doctors often can’t say why one person gets cancer and another doesn’t. But several risk factors have been tied to leukemia, including:

--Exposure to very high levels of radiation

--Working with certain chemicals, such as benzene and formaldehyde


--Down syndrome and certain other genetic diseases

--Human T-cell leukemia virus (HTLV-1), which causes a rare type of chronic leukemia

--Myelodysplastic syndrome, a blood disease that makes acute myeloid leukemia more likely.

--Smoking and tobacco use

Most people who get leukemia do not have any risk factors. Leukemia does not usually run in families. But in very rare cases this can happen with chronic myeloid leukemia.

Ed Bradley worked for CBS for 35 years and was a reporter on the CBS newsmagazine, 60 Minutes, for 26 of those years.

Leukemia Vaccine Looks Promising

By Miranda Hitti, reviewed By Louise Chang, MD

SOURCES: CBS News: “60 Minutes’ Ed Bradley Dead at 65.” WebMD Medical Reference from MedicineNet.com: “Leukemia.” American Cancer Society web site: "What are the key statistics about acute myeloid leukemia?", " What are the key statistics about acute lymphocytic leukemia?", " What are the key statistics about chronic myeloid leukemia?", "What are the key statistics about chronic lymphocytic leukemia?" WebMD Medical Reference from Healthwise: "Leukemia."