Acute lymphoblastic leukemia, or acute lymphocytic leukemia, is a type of blood cancer that can affect both children and adults.
Acute lymphoblastic leukemia (ALL) is most common among children under 5 years of age, according to the American Cancer Society (ACS). The risk reduces until a person is in their 20s and then rises again after a person reaches 50 years. Around 60% of diagnoses are in children.
The ACS predict that around 5,930 people will receive a diagnosis of ALL in 2019, and about 1,500 people will die of ALL. It is more likely to be fatal in adults than in children.
Leukemia happens when the body produces too many immature white blood cells, or blast cells. In the case of ALL, it produces too many lymphoblasts or lymphocytes. These become leukemia cells.
As the concentration of these blast cells increases in the bone marrow and the blood, they crowd out the healthy cells that enable the body to function. As the person’s blood count changes, symptoms start to appear.
They usually start slowly but grow increasingly more severe as the concentration of blast cells rises in the blood.
Signs and symptoms may include:
- excessive sweating
- a fever
- easy bruising or frequent bleeding, such as nosebleeds
- difficulty breathing
- painful joints, bones, or both
- frequent infections
- swollen lymph nodes
- pale skin
- poor appetite and weight loss
As ALL progresses, it can affect other organs.
If it reaches the liver and spleen, a person may experience abdominal swelling and discomfort.
If ALL starts to affect the brain and spinal cord, the person may have headaches, dizziness, weakness, and other symptoms.
Leukemia can be chronic or acute.
Chronic leukemia develops slowly. As it grows, it allows the body to produce more mature, useful cells.
Acute leukemia develops rapidly. It quickly crowds out the good cells, leaving less room for healthy cells. As immature, useless blast cells accumulate in the marrow and blood, the body finds it harder to function properly.
Doctors do not know exactly why ALL happens, but there are some common risk factors.
Age: Children and those over 50 years of age have a higher risk.
Genetic factors: Some genetic features or conditions make ALL more likely. These include Down syndrome, Fanconi anemia, Klinefelter syndrome, and others.
Exposure to radiation: Exposure during a nuclear accident or treatment for previous cancer may increase the risk.
Exposure to chemicals: Exposure to benzene, which is present in cigarette smoke and petroleum products, may increase the risk.
Viruses: People who have the Epstein-Barr virus or the human T-cell leukemia virus may have a higher risk.
A 2018 study suggests there may be a “small and imprecise” risk between proximity to overhead power cables and childhood leukemia. The researchers called for more studies.
The National Cancer Institute cites studies suggesting that there may be a link between mobile phone use and head and neck cancers among some groups of people.
However, there does not appear to be any evidence that it increases the risk of leukemia. A 2010 study concluded that mobile phone use did not increase the risk of leukemia.
If a person has symptoms that could indicate ALL, the doctor will take a medical history, do a physical examination, and carry out some tests.
These may include:
- blood tests
- bone marrow tests
- genetic tests
- a lumbar puncture
- a lymph node biopsy
- imaging tests
A biopsy can confirm if cancer is present and, if so, which type it is. Imaging tests can show if it has spread to other parts of the body.
Treatment options will depend on the type of ALL, as well as the individual’s age and overall health.
There are several treatment options.
Chemotherapy is a type of medicine that kills cancer cells. It is an effective treatment for cancer, but it can also kill healthy cells. This means there is a high risk of adverse effects. These usually pass after treatment finishes.
Radiation therapy targets affected areas with a radioactive beam. A doctor may recommend it if ALL has spread to the central nervous system, including the brain.
What happens during radiation therapy? Find out here.
A bone marrow or stem cell transplant can support chemotherapy. Because chemotherapy can kill both healthy bone marrow cells and cancer cells, a transplant can help boost the renewal of these cells and the body’s ability to recover from chemotherapy.
Targeted therapy is a relatively new strategy. Treatment targets specific proteins, genes, or other factors that encourage cancer to grow. Blocking these factors can delay or prevent the growth of cancer. As the treatment has a specific target, it should have fewer side effects than chemotherapy, but adverse effects are still possible.
Immunotherapy is another new treatment option. Medications aim to help the body defeat cancer by boosting the action of the immune system.
Treatment aims to achieve remission. When this happens, tests will show there is no more evidence of ALL.
In some cases, treatment can remove all evidence of ALL, and it does not come back. In others, however, cancer returns or does not go away completely.
In these cases, the person may live for many years with chronic leukemia. They will continue to attend medical checks, have tests, and undergo treatment to assess the progress of their condition.
Treatment for children
The main treatment for children with leukemia is chemotherapy.
Initial treatment is intense, and the child will usually need to spend time in the hospital. However, over 95% of children enter remission after 1 month of initial treatment, according to the ACS.
The Dana-Farber Foundation note that 15–20% of children experience a relapse after treatment.
However, the Foundation also note that over 90% of people with ALL will be cured.
ALL can be life-threatening, but it is also highly treatable, especially in children.
According to the ACS, a child with ALL has around a 90% chance of surviving at least another 5 years after diagnosis.
The overall survival rate for ALL in 2009–2015 was 68.6%, according to the Surveillance, Epidemiology, and End Results Program (SEER). Various factors affect the outlook, including a person’s age, overall health, the type of ALL, and individual genetic factors.
The outlook for different types of cancer has improved dramatically in recent years. In 1975, only 33% of people survived 5 years or longer with leukemia.
As scientists make progress in the diagnosis and treatment of leukemia and other cncers, the chance of surviving continues to increase.
My son had ALL when he was very young. Now he is 22, and he has been clear for 18 years. Is there a risk that it might come back again?
As with most cancers, there is a risk that the cancer will come back after treatment. As noted in the article, the Dana-Farber Cancer and Blood Disorders program states that between 15–20% of children who receive successful treatment (achieve initial complete remission) for ALL will get the disease again.
Yamini Ranchod, PhD, MS Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.