What do we know about acute myeloid leukemia in children?
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AML represents about 15% of all childhood leukemias
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Each year, about 500 children are diagnosed with AML in the U.S.
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There are 8 different types of AML: M0, M1, M2, M3, M4, M5, M6, and M7. The types differ in the kind of blood cells that the cancer cells develop from.
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Boys and girls are equally likely to develop AML.
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U.S. children of all races and ethnicities are thought to have the same chance of developing AML.
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Some risk factors (things that make it more likely for children to get AML) have been discovered through epidemiology studies
Only a few risk factors for AML are known for sure.
Genetic conditions
Children with some genetic syndromes are more likely to develop AML than other children. These are Down syndrome, Fanconi anemia, neurofibromatosis type 1, Bloom syndrome, Schwachman syndrome, familial monosomy 7 and Kostmann granulocytopenia. Children with these genetic conditions are more at risk for AML, but most children with AML do not have one of these conditions. These syndromes usually require medical care, so you would know if your child had one of them.
Ionizing radiation (x-rays)
Early studies showed there was an increased risk when the baby was x-rayed while in its mother's womb. Today, however, researchers believe that x-rays during pregnancy cause few if any cases of AML because pregnant women are not x-rayed often and the amount of radiation used in x-rays is much, much lower than it was years ago. Children who receive x-rays to diagnose a medical condition, such as a broken bone or tooth decay are NOT at increased risk.
Chemotherapy for a previous cancer
Treatment with certain chemotherapy medications increases the risk of AML, although the overall risk is low.
What characteristics and exposures are possible risk factors for AML?
Researchers have been looking for causes of AML for some years. Some studies identified what seemed like clues at the time, but they were not confirmed in later studies. Even though one or even several studies may find a link between something and risk of AML, there are scientific criteria that must be met before it can be concluded that the something really causes AML.
If my child has AML, will we be asked to participate in research studies?
Researchers in the Children’s Oncology Group (COG) design studies about the causes of childhood AML. The National Cancer Institute, which is part of the federal government, must also approve such studies. If there is a research study “open” in COG, and your child is “eligible” you may be asked to participate. It is possible that you may be asked to participate in more than one study.
Whether an individual is eligible for a particular study may depend on age, type of AML, year of diagnosis, and other information. Researchers usually must limit their study to some of these characteristics to have a scientifically valid study. For example, a study might be restricted to patients diagnosed within certain years so the researchers can locate nearly all eligible families and avoid asking parents to recall events too far in the past. Researchers must follow exactly the same restrictions throughout the study.
Researchers investigating the causes of childhood AML usually will interview one or both parents by telephone. During the interview, parents are asked questions about their experiences and those of their child. The purpose of the interview is to gather information on things that may or may not influence the risk of cancer. The researchers don’t know whether these things influence risk. They are asking the questions to find out more. Sometimes, the researcher will ask for a small biological sample from you and your child, usually cheek cells, blood or hair. Researchers may also ask for samples of dust or water from your home. The researchers use the information from the interviews and the samples to study whether genes or exposures such as medications, radon, and chemicals alone or together make some people more likely to develop cancer.
Will I find out the results of research that my child and/or I participate in?
The type of information you will receive about the results will be explained to you when you are asked to participate in the study. The overall results of the research study will be published to inform the public and other researchers. No study will publish any information that identifies an individual.
What epidemiology studies regarding childhood AML are currently being done in COG?
AE23: Epidemiology of Down Syndrome-Leukemia and Down Syndrome.
No more families are being asked to participate. The researchers are analyzing the information they collected.
AE24: Epidemiology of Infant Leukemia. Eligible families with children diagnosed with leukemia before the age of 12 months are being recruited.
Researchers in COG are actively pursuing clues from previous studies. We currently DO NOT know what causes AML.
Acknowledgment: The development of this epidemiology update was supported in part by a gift from the Aidan O'Neil Foundation.