Blood cell creation
The body produces millions of blood cells each day. Most develop in the bone marrow, the spongy interior of bones that contains immature stem cells.
In a healthy person, these immature stem cells first become either lymphoid stem cells or myeloid stem cells.
Lymphoid stem cells develop into white blood cells, which are immune system cells. They start by becoming immature white blood cells known as lymphoblasts, then mature into lymphocytes. The two types of lymphocytes that are usually involved in leukemia are B cells and T cells. B cells produce the antibodies responsible for attacking invading bacteria and viruses. T cells help alert other immune cells to the presence of infection or fight infection directly.
Myeloid stem cells also develop into white blood cells. The myeloid stem cells first become immature white blood cells known as myeloblasts. They then mature into monocytes and granulocytes, including neutrophils, all of which fight disease. Other myeloid stem cells develop into red blood cells, which carry oxygen throughout the body; and platelets, which help the blood clot.
Leukemia occurs when the DNA (the genetic instructions that control cell activity) of a bone marrow stem cell mutates at some point in its development. The cell becomes cancerous, begins multiplying rapidly and crowds out healthy cells in the blood and bone marrow. These diseased cells can also gather in specific parts of the body, including the liver, lymph nodes, spleen and skin.
How is leukemia classified?
The four most common types of leukemia are classified by the type of stem cell that has turned cancerous, either lymphoid or myeloid.
These diseases are also classified as either chronic or acute. Acute leukemia impacts immature cells, preventing them from developing and carrying out their function. These cells tend to multiply rapidly, making acute leukemia more aggressive. Almost all childhood leukemias are acute.
Chronic leukemia involves mature or partially mature cells. These cells multiple more slowly, making chronic leukemia less aggressive than acute leukemia. Chronic leukemia is rare in children.
About childhood ALL
ALL forms from lymphoid stem cells. These disease cells multiply rapidly and are poor at fighting infection. They also crowd out healthy cells, leaving people with ALL weak and prone to infection.
The two main subtypes of ALL are B cell, which makes up about 85% of ALL cases, and T cell, which makes up 15%. Many other subtypes depend on different chromosome abnormalities of the cancer cells and the types of molecules these cells produce. These specific subtypes can impact a patient’s treatment plan and outlook.
About 6,000 ALL cases are diagnosed in the United States each year. More than half of these are in pediatric patients. The number of pediatric cases peaks from age 2 to 3, while there is a smaller increase during the teenage years.
Fortunately, ALL is highly treatable. Among pediatric patients, the five-year survival rate is about 90% for children under 14 and 75% for people aged 15-19. The specific ALL subtype and characteristics of each cancer can impact a patient’s outlook.
Childhood ALL risk factors
A risk factor is anything that increases the chance of developing a disease. Knowing a disease’s risk factors can be an important step towards catching it early. It's important to note that not everyone with risk factors will develop the disease.
- Risk factors for childhood ALL include:
- Being exposed to X-rays before birth.
- Past treatment with chemotherapy or radiation therapy for a previous cancer. While these therapies can cause AML, their benefits as cancer treatments far outweigh their risks.
- Genetic disorders: Individuals with certain genetic disorders are at a higher risk of developing AML. These include:
- Li Fraumeni syndrome, a hereditary cancer syndrome
- Ataxia telangiectasia
- Bloom syndrome
- Down syndrome
- Fanconi anemia
Some cases of leukemia can be passed down from one generation to the next. Genetic counseling may be right for you. Learn more about the risk to you and your family on our genetic testing page.
Why choose MD Anderson for childhood ALL treatment?
Selecting a hospital is the first big choice a family makes after a cancer diagnosis. MD Anderson’s Children’s Cancer Hospital offers childhood leukemia patients the most advanced treatments from an expert team, along with support services designed to help the entire family through their cancer journey.
This journey starts with a highly detailed diagnosis of each patient’s leukemia. Through the skills of our leading pathologists, MD Anderson is able to quickly pinpoint alterations in the cancer cells. This information can be used to develop treatment plans tailored to each individual patient.
These treatment plans are created by our multidisciplinary team of physicians working together to benefit each patient. Among these physicians are leading medical oncologists who focus exclusively on treating childhood leukemia and related conditions and specialists from one of the largest stem cell transplantation services in the country. Their expertise includes caring for the newly diagnosed, as well as patients whose leukemia has relapsed or not responded to treatment.
While here, pediatric leukemia patients have access to clinical trials for children, teens and even adults. We’re also home to advanced treatments such as CAR T cell therapy, which is only available at a few hospitals in the United States.
In addition, the Children’s Cancer Hospital offers supportive care services designed to improve your child’s quality of life, such as counseling and symptom management. Patients also have access to programs like our arts in medicine activities, summer camps and support groups. We even have an accredited, in-hospital school that helps patients meet their academic goals while in treatment.
If it weren’t for MD Anderson, we never would have seen our child soar and become the outstanding young woman she is today.
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Prevention & Screening
Many cancers can be prevented with lifestyle changes and regular screening.