Acute Lymphoblastic Leukemia
Acute lymphocytic leukemia (ALL) is cancer of the lymph cells, a type of white blood cell. While ALL is known as the childhood form of leukemia, 20% of the people who develop the disease are adults.
What is going on in the body?
When the body has an infection, the number of lymph cells often rises sharply. These cells play a role in fighting off infection. When a person has ALL, the lymph cells do not mature enough to do their job. The cells become malignant, and their growth is unchecked. The abnormal cells can build up in the bone marrow, blood, and other tissues.
Generally, the abnormal cells crowd out normal blood cells and cause the following problems:
- anemia, or a low red blood cell count
- bleeding problems due to poorly working blood-clotting cells, called platelets
- loss of normal white blood cell function, which increases the risk of infection
- a need for red blood cell transfusions
Other white blood cells help in immune monitoring and healing. ALL can compromise or even stop all of these functions. The buildup of abnormal lymph cells can enlarge or infiltrate any organ in the body, including lymph nodes and the brain.
What are the causes and risks of the disease?
ALL is thought to have many causes, including:
- exposure to radiation
- exposure to toxins
- gene or chromosome abnormalities that are passed on from parent to child
- a poorly working immune system
- viruses that affect the immune system
It is known that people:
- who have AIDS are at higher risk for lymphatic cancers, including ALL.
- who have been treated for other cancers can get ALL. This is called a secondary leukemia.
- who have Down syndrome may be at higher risk for ALL.
What can be done to prevent the disease?
In most cases, ALL cannot be prevented. People can avoid exposure to toxins, such as:
- the antibiotic chloramphenicol
- arsenic compounds
Radiation from highly radioactive compounds is clearly dangerous. This does not involve household appliances. A person who has had chemotherapy or radiation is at risk for ALL. He or she should be monitored for life.
Occasionally, family clusters of acute leukemia occur. Genetic counseling may be helpful in this situation. Whether or not nutrition and generally avoiding infections are of benefit in preventing ALL is actively being researched.
How is the disease diagnosed?
Diagnosis of ALL begins with a medical history and physical exam. Samples of blood and bone marrow cells taken during a biopsy are examined for a buildup of immature cells, called lymphoblasts, and abnormal lymph cells.
Afterward, other tests are done to evaluate the extent of the disease, such as:
- blood tests
- scans of the brain and body to check for any tumor masses, bone weakness, or bleeding sites
- spinal tap
- tests to check the functions of organs such as the kidneys, liver, heart, and lungs
Long Term Effects
What are the long-term effects of the disease?
Some people live an entirely normal, healthy life after ALL has been treated and cured. However, ALL can be lethal even with good treatment. People who survive often have many chronic health problems. Any organ, including the brain, can be damaged before treatment starts. The treatments can have serious permanent side effects, too.
What are the risks to others?
It is not clear if a leukemia virus might spread ALL. It is an uncommon cancer, and any risk of it spreading from one person to another is very low. However, a person with ALL might have an unusual or aggressive infection that could possibly spread to others. This is more likely to happen when AIDS or another disorder weakens a person's immune system.
What are the treatments for the disease?
Treatment for ALL may include:
- bone marrow transplant from a matched donor
- chemotherapy for months or occasionally up to a year
- intravenous feeding for people who cannot eat, swallow, or digest food
- radiation therapy of the brain and spine to kill even tiny, hidden leukemia cells
- surgery to implant a tube into a major vein to deliver medicine or gain quick access to the bloodstream
People are treated in a hospital at first, then later as outpatients. Treatment can go on for several months to a couple of years depending on the case. The goal of treatment is a cure, or at least remission. Remission is the disappearance of symptoms and signs of ALL. If the cancer returns, a bone marrow transplant or salvage therapy may be done. Salvage therapy is chemotherapy used to try to get a second remission or to extend life.
What are the side effects of the treatments?
Side effects of treatments can include some of the same signs and symptoms as the leukemia, such as:
- allergic reactions to medicines
- bleeding problems that may require transfusions
- common or unusual infections
- diarrhea or poor food absorption
- irritation of the gastrointestinal tract
- mouth sores
- nausea and vomiting
- numbness or burning pain in the extremities
- weakness and fatigue
- weight loss
When treatment involves the brain and nervous system, the following temporary side effects may occur:
- hair loss
Infertility and impaired memory and math and motor skills can be permanent with this type of treatment.
What happens after treatment for the disease?
People often need long-term care for complications from leukemia or its treatments. Children may have more neurological or psychological problems. Developing bones can be affected, too. Adults have fewer of these complications but have a lower rate of remission and cure.
How is the disease monitored?
People who have been treated for ALL are often monitored for several years. The healthcare provider may order regular blood tests and biopsies. Sometimes spinal taps are done. The fluid is tested for signs of cancer. Genetic testing of the bone marrow may be done, too. It may find traces of residual leukemia before other tests do. Any new or worsening symptoms should be reported to the healthcare provider.