Long-Term Prognosis and Survival Rates for Childhood Leukemia
Before beginning any discussion of prognosis and long-term survival for anyone with childhood cancer, including leukemia, it is important to understand that oncologists rarely use the term “cure”. Instead, oncologists focus on short-term outlook in terms of remission, minimal residual disease, and relapse. For discussion of longer-term outlook, oncologists look at the 5-year survival rate, or how many children remain cancer-free 5 years after the end of treatment. In general, children who are still cancer-free after five years are considered “cured” of the disease.
- Remission: A child is said to have achieved remission if, after the first phase of chemotherapy (induction), the bone marrow contains less than 5% of leukemia cells, blood cell counts are normal, and no symptoms are present
- Minimal residual disease (MRD): The cancer did not respond as expected to the initial round of chemotherapy, and cancer cells remain in the bone marrow when measured with the most sensitive testing tools (beyond a simple microscope scan)
- Relapse: Growth of new cancer cells after treatment is complete. MRD usually involves a higher risk of relapse. Both MRD and relapse usually require a more intensive chemotherapy regime.
Once treatment is complete and deemed successful (remission), oncologists can begin to discuss the 5-year survival rate. Thanks to advances in treatment methodologies, the 5-year survival rate for childhood leukemia has greatly improved over the past several decades. The 5-year survival rate for Acute lymphocytic leukemia (ALL) is now greater than 85%. The 5-year survival rate for Acute myelogenous leukemia (AML) remains lower than for ALL, at 60-70%, but has still improved. Moreover, the rates for AML vary greatly spending on subtype and other factors.
These numbers do not, however, provide a specific prognosis for any given child. They are only averages compiled from treated cases of childhood leukemia from across the country. Your child’s prognosis and long-term outlook after treatment will be heavily dependent on your child’s diagnosis, response to treatment, and general health.
Prognosis Factors for Childhood Leukemia
Prognosis factors are a series of measurements that your child’s oncology team may use to potentially the degree of risk posed by the cancer, as well as to optimize a treatment plan with the greatest possible chance of success. There are several key prognosis factors that oncologists use when dealing with a leukemia diagnosis. In general, these prognosis factors are the same for ALL and AML, but they do not seem to play as great a role in either guiding treatment or predicting outcomes for AML.
- Risk group: standard-risk, high-risk, or very high risk. These groupings help determine the intensity of treatment and may impact long-term prognosis; however, it is important to note that even children in the very high-risk group still have an excellent chance of achieving remission.
- Age at diagnosis: Children between the ages of 1 and 9 seem to have a more positive prognosis than children under the age of 1 or over the age of 10. (This factor applies only to B-cell ALL; age does not appear to be a prognosis factor in T-cell ALL.)
- Initial white blood cell count: Very high WBC counts at diagnosis is generally considered high-risk or very high-risk.
- Subtype of ALL: Children diagnosed with pre-B, common, or early pre-B-cell ALL seem to have a more positive prognosis than children with mature B-cell leukemia; this is also true of B-cell ALL if treated with intensive chemotherapy.
- Gender: In general, girls seem to have a slighter better prognosis than boys; this gap has shrunk in recent years thanks to today’s advanced treatment options.
- Race/ethnicity: African-American and Hispanic children may have a slighter worse prognosis than other ethnicities.
- Spread to other organs: If the leukemia has spread into the fluid around the brain and spinal cord, and the testicles in boys, it is usually classified as high-risk or very high-risk.
- Number of chromosomes and chromosome translocations: Some studies have begun to link longer-term prognosis with the number of chromosomes within the leukemia cells, as well as with translocations between specific chromosomes.
- Response to treatment: The initial reduction of leukemia cells in the bone marrow during the first 1 to 2 weeks of chemotherapy may help determine long-term prognosis; however, if the leukemia does not respond as expected in this time frame, most oncologists will move to a more intensive treatment protocol.
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.