Leukemia

Leukemia is a group of cancers that usually begins in the bone marrow and results in high numbers of white blood cells. These white blood cells are not fully developed and are called blasts or leukemia cells. White blood cells are a vital part of your immune system. They protect your body from invasion by bacteria, viruses, and fungi. WBCs (white blood cells) also protect your body from abnormal cells and other foreign substances. In leukemia, the white blood cells have mutated. These mutant white blood cells may divide too quickly and eventually crowd out normal cells. Often, they do not function as normal WBCs.

Acute Leukemia

Acute leukemia is characterized by a rapid increase in the number of immature blood cells. Crowding due to such cells makes the bone marrow unable to produce healthy blood cells. Immediate treatment is required in acute leukemia due to the rapid progression and accumulation of the malignant cells, which then spill over into the bloodstream and spread to other organs of the body. Acute forms of leukemia are the most common forms of leukemia in children.

Chronic Leukemia

Chronic leukemia is characterized by the excessive build up of relatively mature, but still abnormal, white blood cells. Typically taking months or years to progress, the cells are produced at a much higher rate than normal, resulting in many abnormal white blood cells. Whereas acute leukemia must be treated immediately , chronic forms are sometimes monitored for some time before treatment to ensure maximum effectiveness of therapy. Chronic leukemia mostly occurs in older people, but can theoretically occur in any age group.

Risk Factors

People who have been exposed to high levels of radiation, such as long-term survivors of atomic bombs, may be more likely to develop leukemia. Exposure to electromagnetic fields or high-voltage electric lines has not been proven to increase a person's risk of leukemia. Also people with down syndrome have a higher risk of developing leukemia than the general population.

 

Survival Rates and Deaths Globally

The average five-year survival rate of leukemia is 57% in the United States. In children under 15, the five-year survival is greater than 60% to 85%, depending on the type of leukemia. In people with acute leukemia who are cancer-free after five-years, the cancer is unlikely to return. In 2012, leukemia developed in 352,000 people globally and caused 265,000 deaths. It is the most common type of cancer in children, with three quarters of leukemia cases in children. However, about 90% of all leukemia's are diagnosed in adults.

Most Often Found

Leukemia often is considered a disease of children, yet it actually affects far more adults. In fact, the frequency of the disease increases with age. Leukemia is more common in men than in women, and more common in Caucasians than in African-Americans. Almost 30,000 cases are diagnosed in the United States each year. White people are somewhat more likely than black people to develop leukemia. Children younger than 15 and adults older than 50 are more likely to develop leukemia. In Canada it is estimated that in 2014:
- 5,900 Canadians will be diagnosed with leukemia.
- 2,700 Canadians will die from leukemia.
- 3,400 men will be diagnosed with leukemia and 1,550 will die from it.  
- 2,600 women will be diagnosed with leukemia and 1,100 will die from it.
It is estimated that around 600,000 people worldwide, will be diagnosed with leukemia in 2015.

 

Causes

Experts say that different leukemias have different causes. The following are either known causes, or strongly suspected causes:
- Artifical ionizing radiation
- Viruses
- Chemotherapy agents used in previous cancer treatments
- Maternal fetal transmission (rare)
- Hair dyes
- Genetic Predispostion- some studies researching family history and looking at twins have    
  indicated that some people have a higher risk of developing leukemia because of a single 
  gene or multiple genes.
- Electromagnetic energy- studies indicate there is not enough evidence to show that ELF 
  magnetic (not electric) fields that exist currently might cause leukemia. The IARC (International Agency for Research on Cancer) says that studies which indicate there is risk tend to be biased and unreliable.