Leukemia is the most common cancer in children and teens, accounting for about 30% of all pediatric cancer cases. Most cases of childhood leukemias are acute lymphocytic leukemia (ALL), with most remaining cases being acute myeloid leukemia (AML).

Leukemias are cancers of the bone marrow and blood. Leukemia takes over white blood cell production, creating abnormal leukemia cells. White blood cells are typically responsible for fighting infection, however defective leukemia-infected white blood cells do not function normally and instead crowd the bone marrow, suppressing the development of normal cells. As leukemia progresses, this cancer can interfere with other bodily functions, causing problems such as anemia and increased risk of infection and other diseases. There are several different types of leukemia based on how quickly the disease progresses and on what cells it involves.

What are the Symptoms of Leukemia?

Leukemia symptoms vary, depending on the type of leukemia.

Common leukemia signs and symptoms include:

  • Fevers or chills
  • Persistent fatigue, weakness
  • Frequent or severe infections
  • Weight loss
  • Swollen lymph nodes, enlarged liver or spleen
  • Easy bleeding or bruising
  • Recurrent nosebleeds
  • Tiny red spots in your skin (petechiae)
  • Excessive sweating, especially at night
  • Bone pain or tenderness

What Causes Leukemia?

The exact cause of childhood leukemia is still unknown, and most children with leukemia do not have any identifiable risk factors.

However, we do know how certain changes in the DNA of normal bone cells can cause their transformation into leukemia cells. Cancer can be caused by DNA mutations that turn on oncogenes (genes that tell cells to grow and divide) or turn off tumor suppressor genes (genes that tell cells to die). These irregular genes can be passed down parent, or they may just happen randomly during a person’s lifetime.

What are the Different Types of Leukemia?

The first classification of leukemia is by how fast it progresses:

  • Acute leukemia
  • Chronic leukemia

The second type of classification is based on the type of affected white blood cell:

  • Lymphocytic leukemia
  • Myelogenous leukemia

The major types of leukemia are:

  • Acute lymphocytic leukemia (ALL) – This is the most common type of leukemia in young children. ALL can also occur in adults.
  • Acute myelogenous leukemia (AML) – AML is a common type of leukemia. It occurs in children and adults. AML is the most common type of acute leukemia in adults.
  • Chronic lymphocytic leukemia (CLL) – With CLL, the most common chronic adult leukemia, you may feel well for years without needing treatment.
  • Chronic myelogenous leukemia (CML) – This type of leukemia mainly affects adults. A person with CML may have few or no symptoms for months or years before entering a phase in which the leukemia cells grow more quickly.
  • Other, rarer types of leukemia exist, including hairy cell leukemia, myelodysplastic syndromes and myeloproliferative disorders.

How Is Leukemia Diagnosed?

There are currently no widely recommended blood tests or other screening tests for most children to look for leukemia before symptoms show. Childhood leukemia is often found because of symptoms that prompt a visit to the doctor. The doctor then orders blood tests, which come back and show the diagnosis. The best way to find leukemia early is to be aware of the potential signs and symptoms of the disease.

For children having a known risk factor of leukemia, such as an inherited syndrome such as Down syndrome or Li-Fraumeni, an immune system deficiency, or previous treatment with chemotherapy or radiation, doctors recommend regular medical checkups. The chance of leukemia occurring in these children is higher than the general population (although the risk is still small).

What is the Survival Rate for Leukemia?

When discussing cancer survival statistics, the term 5-year survival rate is often used. This refers to the percentage of patients that live at least 5 years after their cancer is diagnosed. With acute leukemia, patients that are free of the disease after 5 years are very likely to have been cured as the chances of cancer returning after that length of time are very low.

Survival rates are based on previous reports from large populations of patients who have had the disease, but cannot predict what happens in any individual case. In recent years, survival rates have been rising, although it is hard to pinpoint for rarer forms of the disease.

Acute lymphocytic leukemia (ALL) – more than 85%

Acute myelogenous leukemia (AML) – 60%-70%

Juvenile myelomonocytic leukemia (JMML) – 50%

For chronic leukemias, 5-year survival rates are less helpful as It’s likely the patient can live for a very long time without the disease being cured. In the past, 5-year survival rates for chronic myelogenous leukemia (CML) were reported to be in the range of 60% to 80%.