Childhood acute lymphocytic leukemia
Childhood acute lymphocytic leukemia (also called acute lymphoblastic leukemia or ALL) is a disease in which too many immature infection-fighting white blood cells, called lymphocytes, are found in children's bone marrow and blood. Acute lymphocytic leukemia is the most common form of leukemia in children, and the most common children's cancer.
Lymphocytes are made by the bone marrow as well as by other organs of the lymph system. The bone marrow is the "spongy" tissue inside the large bones of the body. The bone marrow makes red blood cells (which carry oxygen and other materials to all tissues of the body), white blood cells (which fight infection), and platelets (which help the blood to clot). Normally, the bone marrow makes immature cells (called blasts) that develop (mature) into the different types of blood cells that have specific jobs in the body.
The lymph system is made up of thin tubes that branch, like blood vessels, into all parts of the body. Lymph vessels carry lymph, a colorless, watery fluid that contains lymphocytes. Along the network of vessels are groups of small, bean-shaped organs called lymph nodes. Clusters of lymph nodes are found in the underarm, pelvis, neck, and abdomen. The spleen (an organ in the upper abdomen that makes lymphocytes and filters old blood cells from the blood), the thymus (a small organ beneath the breastbone), and the tonsils (an organ in the throat) are also part of the lymph system.
Lymphocytes fight infection by making substances called antibodies, which attack germs and other harmful bacterial in the body. In acute lymphocytic leukemia, the immature lymphocytes become too numerous. These immature lymphocytes are then found in the blood and the bone marrow. They may also collect in the lymph tissues and make them swell. Lymphocytes may crowd out other blood cells in the blood and bone marrow. If children's bone marrow cannot make enough red blood cells to carry oxygen, they will have anemia. If children's bone marrow cannot make enough platelets to make the blood clot normally, they will bleed or bruise easily. The cancerous lymphocytes can also invade other organs, the spinal cord, and the brain.
Leukemia can be acute (progressing quickly with many immature cancer cells) or chronic (progressing slowly with more mature-looking leukemia cells). Acute lymphocytic leukemia can occur in both children and adults. Children and adolescents are treated differently than adults.
Acute Lymphoblastic Leukemia patients through age 19 should be treated on Pediatric protocols for the best outcome.
Early signs of acute lymphocytic leukemia may be similar to those of the flu or other common diseases, such as fever that won't go away, feeling weak or tired all the time, aching bones or joints, or swollen lymph nodes. If your child has symptoms of leukemia, his or her doctor will order blood tests to count the number of each of the different kinds of blood cells. If the results of the blood tests are not normal, a bone marrow aspiration and biopsy will be performed. During this test, a needle is inserted into a bone in the hip and a small amount of bone marrow is removed and examined under the microscope, enabling the doctor to determine if your child has leukemia and what kind of leukemia your child has. The best treatment plan will then be discussed with you.
Your child's doctor may also do a spinal tap, in which a needle is inserted into the back to remove a sample of fluid that surrounds the brain and spine. The fluid is examined under a microscope to see if leukemia cells are present.
Children's chances of recovery (prognosis) depend upon their age at diagnosis, the number of white blood cells in the blood (the white blood cell count) at diagnosis, the biologic characteristics of the leukemia cells, and how well the leukemia cells respond to treatment. Current clinical trials are designed to look very hard at risk factors for relapse, and doctors are treating different risk groups with different therapies. This is why your doctor might not answer questions about prognosis until all the testing is complete.
Approximately 75-80% of cases of acute lymphocytic leukemia in children are cured with current treatments.
There is no staging for childhood acute lymphocytic leukemia. Treatment is according to risk group,which is related to the clinical and laboratory features of the ALL. The treatment depends upon children's ages, the results of laboratory tests and whether they have been previously treated for leukemia.
Remission means that treatment has been given and that the number of white blood cells as well as other blood cells in the blood and bone marrow are normal. The marrow report will say "less than 5% blasts." There are no signs or symptoms of leukemia.
Recurrent disease means that the leukemia has come back (recurred) after it had been in remission. Refractory disease means that, ultimately, the leukemia in children and young adults failed to go into remission following treatment.
All patients with Childhood Acute Lymphocytic Leukemia (ALL) should be treated. Nationwide clinical trials are available for children and adolescents with ALL. Adolescents have better outcomes when treated on pediatric protocols . The primary treatment for ALL is chemotherapy. Radiation therapy may be used in certain cases. Bone marrow transplantation may also be used in specific circumstances.
Chemotherapy means drugs that kill cancer cells. Chemotherapy drugs may be taken by mouth, or be put into the body by a needle stuck into a vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream and travels throughout the body. For acute lymphocytic leukemia, chemotherapy drugs are also injected into the fluid that surrounds the brain and spinal cord; this is known as intrathecal chemotherapy (or a spinal tap with chemotherapy).
Radiation therapy uses x-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation for ALL usually comes from a machine outside the body (external beam radiation therapy).
Bone marrow transplantation is a more intensive type of treatment used in very specific situations. High doses of chemotherapy with or without radiation therapy are given to destroy all of the bone marrow in the body. Healthy marrow is then taken from another person (a donor) whose tissue is the same as or almost the same as the patient's. The donor may be a twin (the best match), a brother or sister, rarely a parent, or from a person not related. The healthy marrow from the donor is given to the patient through a needle in a vein, and that marrow replaces the marrow that was destroyed. A bone marrow transplant using marrow from a relative or person not related is called an allogeneic bone marrow transplant.
There are generally four phases of treatment for acute lymphocytic leukemia. The first phase, remission induction therapy, uses chemotherapy to kill the leukemia cells and cause the cancer to go into remission. Induction therapy results in remission rates of approximately 95-98%. A second phase of treatment called central nervous system (CNS) prophylaxis is begun in the induction phase and continues during the consolidation/intensification phase of therapy. This is therapy using intrathecal and/or high dose systemic therapy to kill any leukemia cells present in the CNS as well as to prevent the spread of leukemia cells to the CNS (brain and spinal fluid). Radiation therapy to the brain and spine may also be given in specific situations for the same purpose of killing leukemia cells and preventing their spreading to the CNS.
The third phase of treatment, called consolidation or intensification chemotherapy, is given once remission is attained. Consolidation uses intermediate to high-dose chemotherapy to attempt to kill any remaining leukemia cells. The fourth phase of treatment, maintenance chemotherapy, generally continues for 2 to 3 years of continuous remission.
Treatment for acute lymphocytic leukemia in children and young adults depends on the risk group (prognostic group) assigned at diagnosis. It is based primarily on age, white blood cell count at diagnosis and results of the initial laboratory tests, including cytogenetics.
Your child may receive treatment that is considered standard based on its effectiveness in patients in past clinical trials, or your child may participate in an ongoing clinical trial.
Clinical trials are designed to test new potentially better treatments against those treatments considered standard of care, in the hope of finding better treatments for childhood cancer. Clinical trials are ongoing in most parts of the country for most risk groups of childhood ALL. The good news is that Children's Oncology Group clinical trials are closely overseen by a data monitoring committee, so that in real time, if one treatment is found to be better than another, the treating physicians are notified immediately, and your child's treatment will be changed right away if necessary.
Treatment for leukemia in children depends on previously received treatment, how soon the leukemia came back following treatment, and whether the leukemia cells are found outside the bone marrow. Your child's treatment will be systemic chemotherapy and/or bone marrow transplantation. You may want to consider entering your child into a clinical trial if available.
Here at Cleveland Clinic Children's, we specialize in the care of children and young adults with cancer. We use a team approach that cares for all members of the family, recognizing that this is a very difficult time for all of them. Our goal is to have our patients get through therapy with as normal a life as possible, and to emerge from therapy knowledgeable about how to maintain their health.
Should you have more questions about the child or young adult in your life with cancer, please contact Cleveland Clinic Children's Pediatric Oncology Team at 216.444.5517 or 800.223.2273 extension 4-5517, extension 1. Your question will be forwarded to the Chair of the Pediatric Oncology Department.
We wish you and your child well.
For other websites regarding leukemia in children:
Source: National Institutes of Health, National Cancer Institute, Children's Oncology Group.
This information is provided by the Cleveland Clinic Health System and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. Health Information Last Reviewed: 6/14/05 / Disclaimer & Privacy/ © Cleveland Clinic Health System 2005 Rev. 6/05