In the first post we talked about cancers generally and what it means for you and also about blood elements and what they are supposed to do and how they malfunction leading to cancer,this time we talk more about leukemia basics and i will do my best to make it very simple for you.
What are the types of leukemia?
The types of leukemia are grouped by how quickly the disease develops and gets worse. Leukemia is either chronic (gets worse slowly) or acute (gets worse quickly):
- Chronic leukemia—Early in the disease, the abnormal blood cells can still do their work, and people with chronic leukemia may not have any symptoms. Slowly, chronic leukemia gets worse. It causes symptoms as the number of leukemia cells in the blood rises.
- Acute leukemia—The blood cells are very abnormal. They cannot carry out their normal work. The number of abnormal cells increases rapidly. Acute leukemia worsens quickly.
The types of leukemia are also grouped by the type of white blood cell that is affected. Leukemia can arise in lymphoid cells or myeloid cells. Leukemia that affects lymphoid cells is called lymphocytic leukemia. Leukemia that affects myeloid cells is called myeloid leukemia or myelogenous leukemia.
There are four common types of leukemia:
- Chronic lymphocytic leukemia (chronic lymphoblastic leukemia, CLL) accounts for about 7,000 new cases of leukemia each year. Most often, people diagnosed with the disease are over age 55. It almost never affects children.
- Chronic myeloid leukemia (chronic myelogenous leukemia, CML) accounts for about 4,400 new cases of leukemia each year. It affects mainly adults.
- Acute lymphocytic leukemia (acute lymphoblastic leukemia, ALL) accounts for about 3,800 new cases of leukemia each year. It is the most common type of leukemia in young children. It also affects adults.
- Acute myeloid leukemia (acute myelogenous leukemia, AML) accounts for about 10,600 new cases of leukemia each year. It occurs in both adults and children.
Hairy cell leukemia is a rare type of chronic leukemia. This booklet does not deal with hairy cell leukemia or other rare types of leukemia. Together, these rare leukemias account for about 5,200 new cases of leukemia each year. The Cancer Information Service (1-800-4-CANCER) can provide information about these types of leukemia.
Who is at risk for leukemia?
No one knows the exact causes of leukemia. Doctors can seldom explain why one person gets this disease and another does not. However, research has shown that people with certain risk factors are more likely than others to develop leukemia. A risk factor is anything that increases a person's chance of developing a disease.
Studies have found the following risk factors for leukemia:
- Very high levels of radiation —People exposed to very high levels of radiation are much more likely than others to develop leukemia. Very high levels of radiation have been caused by atomic bomb explosions (such as those in Japan during World War II) and nuclear power plant accidents (such as the Chernobyl [also called Chornobyl] accident in 1986).
Medical treatment that uses radiation can be another source of high-level exposure. Radiation used for diagnosis, however, exposes people to much lower levels of radiation and is not linked to leukemia.
- Working with certain chemicals—Exposure to high levels of benzene in the workplace can cause leukemia. Benzene is used widely in the chemical industry. Formaldehyde is also used by the chemical industry. Workers exposed to formaldehyde also may be at greater risk of leukemia.
- Chemotherapy—Cancer patients treated with certain cancer-fighting drugs sometimes later develop leukemia. For example, drugs known as alkylating agents are associated with the development of leukemia many years later.
- Down syndrome and certain other genetic diseases—Some diseases caused by abnormal chromosomes may increase the risk of leukemia.
- Human T-cell leukemia virus-I (HTLV-I)—This virus causes a rare type of chronic lymphocytic leukemia known as human T-cell leukemia. However, leukemia does not appear to be contagious.
- Myelodysplastic syndrome—People with this blood disease are at increased risk of developing acute myeloid leukemia.
