Leukemia is derived from the Greek words “leukos” and “aima” which mean white and blood. It is cancer of the blood or bone marrow, which produces blood cells. When a person suffers from leukemia, there is an abnormal production of blood cells, generally white blood cells. There are different types of leukemia, categorized based on how fast the disease gets worse and the kind of white blood cells it affects.
The causes of leukemia are not well known. However, it is known that people exposed to certain risk factors are more prone to developing this disease. The following risk factors increase the chances of a person developing leukemia, and hence can be termed as the causes.
Causes of Leukemia
High levels of Radiation
This is one of the most common reasons cited by doctors for a patient to develop leukemia. People exposed to very high levels of radiation are more prone to getting leukemia. A good example would be the atomic blasts in Japan in World War 2. Radiation used in the treatment of certain diseases can also be a cause. However, diagnostic radiation (example: X-Rays and CT Scans) have lower levels of radiation and are not causes of leukemia. Artificial ionizing radiation also results in leukemia.
High Exposure to Certain Chemicals
Long-term exposure to harmful chemicals like benzene or formaldehyde can be risk factors for leukemia. This is mainly found in unleaded gasoline and chemical production facilities. Long term exposure could be due to occupational hazards, where the work demands exposure to such harmful chemicals (such as in the chemical industry).
Previous Chemotherapy Treatments
A chemotherapy or radiation therapy to treat previous cancers can result in leukemia later in life.
The radiation treatment could add to the risk of leukemia which is linked with some chemotherapy drugs. Drugs known as alkylating drugs and topoisomerase inhibitors which are used in cancer treatment are known to cause leukemia many years later.
Genetic reasons are another high risk-factor for leukemia. Having a close relative (parent, sibling or child) who suffers from chronic leukemia increases a person’s risk of developing the disease by as much as four times that of a person who doesn’t have such a relative. A family history is thus a very important reason for being affected by leukemia. A genetic abnormality, like an abnormality on Chromosome 22 (Philadelphia chromosome) can cause leukemia. Single or multiple genes can cause this problem.
Anyone affected by Down syndrome has a significantly higher risk of being affected by leukemia as compared to people who are not affected by Down syndrome. Thus, a chromosomal abnormality can pose a higher risk.
Certain viruses like Human T-cell leukemia virus 1 (HTLV-1) and Human Immunodeficiency Virus (HIV) can develop leukemia.
Maternal Fetal Transmission
Though the occurrence of leukemia by this method is rare, there are stray cases of this being a risk factor.
This is an unusual type of blood disease which is characterized by abnormal blood cell development. Patients suffering from this are at an increased risk of leukemia.
Smoking is a risk factor for all cancers in general. Similarly, it is a risk factor for leukemia as well. However, many people who develop leukemia have never smoked, and the vice-versa is also true.
Though the above are the most probable causes of leukemia, they are risk factors at best. The direct cause of leukemia is still not very clear to the medical world. Some people who have leukemia have never been exposed to the above risk factors, while some people who have been exposed to one or more of the above risk factors do not have leukemia.