What is Acute Lymphoblastic Leukemia and Whom Does it Affect?
Leukemia is a blood cancer that affects red blood cells, white blood cells and/or platelets. One type of leukemia, acute lymphoblastic leukemia (ALL) – also called acute lymphocytic leukemia and acute lymphoid leukemia – is a blood and bone marrow cancer that can affect both children and adults. In adults with ALL, the bone marrow makes too many of a type of white blood cell called lymphocytes, while in children with ALL, the bone marrow makes too many immature lymphocytes. This type of cancer usually gets worse quickly and can be fatal within a few months if it is not treated.
The American Cancer Society estimates that about 6,600 new cases of ALL will be diagnosed this year (well under one percent of all new cancer cases). While most cases of ALL are diagnosed in patients younger than 20, most deaths from ALL occur in adults. According to the Leukemia & Lymphoma Society, the five-year relative survival rates for ALL are 72.1 percent overall, 92.5 percent for children and adolescents under 15 and 92.5 percent for children younger than five.
Childhood ALL
ALL is the most common type of cancer in children. Risk factors for the disease include past treatment for cancer and certain genetic conditions. Signs and symptoms of childhood ALL include (but are not limited to) fever, easy bruising or bleeding, weakness, pain or feeling of fullness below the ribs and loss of appetite.
Health care providers may use a number of tests to diagnose ALL and find out if the leukemia cells have spread to other parts of the body:
- Complete blood count (CBC) with differential
- Blood chemistry studies
- Bone marrow aspiration and biopsy
- Cytogenic analysis of blood cell chromosomes
- Immunophenotyping to identify cell surface markers
- Lumbar puncture to test cerebrospinal fluid
- Chest x-ray
Several factors affect the chance of recovery from childhood ALL including:
- How quickly and how low the leukemia cell count drops after the first month of treatment.
- Age at the time of diagnosis, sex, race, and ethnic background.
- The number of white blood cells in the blood at the time of diagnosis.
- Whether the leukemia cells began from B lymphocytes or T lymphocytes.
- Whether there are certain changes in the chromosomes or genes of the leukemia cells.
- Whether the child has Down syndrome.
- Whether leukemia cells are found in the cerebrospinal fluid.
- The child’s weight at the time of diagnosis and during treatment.
Treatment options for childhood ALL vary and depend upon:
- Whether the leukemia cells began from B lymphocytes or T lymphocytes.
- Whether the child has standard-risk, high-risk, or very high-risk ALL.
- The age of the child at the time of diagnosis.
- Whether there are certain changes in the chromosomes of lymphocytes.
- Whether the child was treated with steroids before the start of induction therapy.
- How quickly and how low the leukemia cell count drops during treatment.
Treatment for childhood ALL takes about two to three years and is done in three phases. In the first (most intense) phase, remission induction, the goal is to kill the leukemia cells in the blood and bone marrow, which puts the leukemia into remission. More than 95 percent of children with ALL enter remission after one month of induction treatment. The second phase, consolidation/intensification, is designed to kill any leukemia cells that remain in the body and may cause relapse. Maintenance is the third phase of treatment, in which lower treatment doses are given to kill any remaining leukemia cells that may regrow and cause a relapse.
Most children with ALL are cured of their disease after treatment. Sometimes, however, childhood ALL does not respond to treatment or comes back after treatment. For leukemia that comes back after treatment, prognosis and treatment options depend partly on the time between diagnosis and relapse and whether or not the leukemia comes back in the bone marrow or in other parts of the body.
For more information about standard and new types of treatments for childhood ALL, visit the National Cancer Institute’s Physician Data Query Summary web page for childhood ALL.
Adult ALL
Risk factors for adult ALL include but are not limited to being male, white, and older than 70; past treatment with chemotherapy or radiation therapy; being exposed to high levels of radiation in the environment; and having certain genetic disorders. Early signs and symptoms may mimic those of the flu and other common diseases, such as weakness, feeling tired, fever, easy bruising or bleeding, shortness of breath and loss of weight or appetite, among others.
Tests to diagnose adult ALL by examining the blood and bone marrow are similar to those used to diagnose childhood ALL. Once adult ALL has been diagnosed, further tests are done to find out if the cancer has spread to the central nervous system or to other parts of the body. Prognosis and treatment options vary depending on:
- The age of the patient.
- Whether the cancer has spread to the brain or spinal cord.
- Whether there are certain changes in the genes.
- Whether the cancer has been treated before or has recurred.
Unlike with childhood ALL, treatment for adult ALL is done in two phases over about two years. The first and most intense phase, remission induction therapy, has the same goal as in childhood ALL: kill the leukemia cells in the blood and bone marrow, which places the leukemia in remission. The second phase is post-remission therapy, which is designed to kill any remaining leukemia cells that may not be active but could begin to regrow and cause a relapse.
Central nervous system (CNS) prophylaxis therapy is usually given during each phase to reach leukemia cells in the CNS that may not be reached by standard doses of chemotherapy.
For more information about standard and new types of treatments for adult ALL, visit the National Cancer Institute’s Physician Data Query Summary web page for adult ALL.
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