What Causes Childhood Leukemia?
Both major types of childhood leukemia—Acute lymphocytic (lymphoblastic) leukemia (ALL) and Acute myelogenous leukemia (AML)—begin in the bone marrow, the soft inner part of the bone where new blood cells are created. As the leukemia cells accumulate inside the bone marrow, they overwhelm the healthy cells, eventually spreading into the blood stream. Thus, leukemia is a blood-based cancer, and must not be confused with other types of childhood cancers that start in other parts of the body and eventually spread into the bone marrow.
Why do some blood cells in children grow into abnormal leukemia cells? In other words, what causes childhood leukemia? Unfortunately, we cannot yet answer that question. We do know that childhood leukemia, like most other childhood cancers, is not caused by environmental or lifestyle factors. Absent these factors, scientists and researchers do not know what causes certain cells within a child’s bone marrow to begin growing and functioning abnormally.
Increasingly, scientists are beginning to believe that many childhood cancers, including leukemia, are linked to mutations—or random, uncontrolled alterations—to the DNA found within normal bone marrow cells. Leukemia may be connected to a specific type of DNA mutation controlling the genes responsible for ensuring that cells divide, grow, replicate, and die properly. Another potential cause of childhood leukemia may be a form of genetic mutation called chromosome translocation, where DNA from one chromosome breaks off and becomes attached to a different chromosome. Again, if this mutation affects oncogenes and/or tumor suppressor genes, it may lead to the development of childhood leukemia or other types of childhood cancer.
What are the risk factors for childhood leukemia?
If it is true that genetic mutations are responsible for most cases of childhood leukemia, it is important to note that these genetic mutations are usually the result of random and unpredictable changes and are not linked to any known or inherited risk. However, there are a few inherited conditions which may result in a higher risk factor for some rare cases of childhood leukemia, such as:
- Inherited syndromes such as Down syndrome (trisomy 21) and Li-Fraumeni syndrome
- Inherited immune system problems such as Ataxia-telangiectasia, Wiskott-Aldrich syndrome, Bloom syndrome, and Schwachman-Diamond syndrome
- Having a sibling with leukemia, especially if the sibling is an identical twin
The one environmental factor that may pose an increased risk of childhood leukemia is exposure to extremely high levels of radiation (such as Japanese survivors of the 1945 atomic bombings). However, scientists are exploring any potential links between childhood leukemia and smaller dosages of radiation (like routine x-rays), as well as chemotherapy and exposure to toxic chemicals.
Can Childhood Leukemia Be Prevented?
Although we don’t yet know definitively what causes childhood cancer, we can say definitely that there is no way to prevent it, or as of right now, screen for it the way we can with many adult cancers. We can hope that as our understanding of the causes of leukemia and other childhood cancers improves, that knowledge brings with it a better understanding of how to detect the disease before it becomes the terrible threat that it poses today.
About American Childhood Cancer Organization
American Childhood Cancer Organization (ACCO) is a non-profit charity dedicated to helping kids with cancer and their families navigate the difficult journey from cancer diagnosis through survivorship. Internationally, ACCO is the sole U.S. member of Childhood Cancer International (CCI), the largest patient-support organization for childhood cancer in the world. Here in the United States, ACCO promotes the critical importance of ensuring continued funding into new and better treatment protocols for childhood cancer. And most importantly, ACCO is focused on the children: developing and providing educational tools for children fighting cancer and their families, empowering them in their understanding of childhood cancer and the medical decisions they must make during this difficult journey. All of ACCO’s resources are available free of charge for families coping with childhood cancer.