Acute lymphoblastic leukemia is a type of cancer affecting the white blood cells that grows quickly. Lymphocytes are white blood cells responsible for fighting infections in the body. With this type of leukemia, the bone marrow produces many blasts (unformed cells) that would become lymphocytes in normal causes, however, these blasts are abnormal. They are not able to fight infections and do not develop. The number of these abnormal cells, also referred to as leukemia cells, grow quickly. They crowd out the white blood cells, red blood cells, and platelets that the body needs. This leukemia may also be referred to as acute lymphoid leukemia or acute lymphocytic leukemia.
In the United States, approximately 4,000 new cases of this cancer are diagnosed every year. Children under the age of ten are most often affected and this leukemia is the most common leukemia in children. However, adults can also be affected and about one-third of all cases are adults.
Causes and Risk Factors
When a bone marrow cell’s DNA develops an error, this cancer occurs. The errors direct the cell to keep growing and dividing, instead of dying like a healthy cell would do. When this occurs, the production of blood cells goes awry. What causes the mutations in the DNA is not clear, but it has been found that most cases of this cancer are not inherited. There are certain risk factors that put a patient at a higher risk for developing this cancer:
- Previous cancer treatment
- Genetic disorder (such as Down syndrome)
- Exposure to radiation
- Having a sibling with this cancer
Signs and Symptoms
The signs and symptoms of this leukemia may include:
- Bleeding from the gums
- Frequent infections
- Swollen lymph nodes causing lumps
- Shortness of breath
- Frequent or severe nosebleeds
- Pale skin
- Fatigue, weakness, or general low energy
Diagnosis and Evaluation
Blood tests are commonly performed because they can tell the doctor if the patient’s platelets and red blood cells are low, and if their white blood cells are high. These tests can also reveal whether or not blast cells are present.
Bone marrow testing involves using a needle and removing a bone marrow sample from the patient’s hip joint. Once the sample is in the laboratory, it will be evaluated to classify blood cells into particular types based on the shape, size, and other features.
Spinal fluid may be obtained through a lumbar puncture in which a doctor inserts a needle into the spine to collect a fluid sample. This test may be done to determine if any cancer cells have spread to the patient’s spinal fluid.
Imaging test can be done to determine if this cancer has spread to the spinal cord, brain, or other parts of the body, such as computerized tomography and a chest x-ray.
The treatments for acute lymphoblastic leukemia fall into different phases. During induction therapy, which is the first phase, the focus is killing the leukemia cells present in the bone marrow and blood. During the second phase known as consolidation therapy or post-remission therapy, the focus is killing any leukemia cells that are remaining in the spinal cord or brain. Maintenance therapy, the third phase, focuses on preventing leukemia cells from regrowing. The final phase is preventative treatment to the spinal cord. This involves injecting chemotherapy drugs directly into the fluid surrounding the spinal cord.
Commonly used treatments include:
- Chemotherapy involves using cancer cell-killing drugs
- Radiation therapy involves using high-powered beams to destroy cancer cells
- Targeted drug therapy involves using drugs to attack particular cancer cell abnormalities to prevent these cells from growing and thriving. Imatinib and dasatinib are commonly used to fight this type of leukemia
- A stem cell transplant may be done during the second phase of treatment for patients who are at a high risk for relapsing or to treat a relapse and allows a leukemia patient to re-establish healthy stem cells through replacing bone marrow affected by leukemia with bone marrow free of leukemia
National Marrow Donor Program. (2010). Acute Lymphoblastic Leukemia. Retrieved on October 8, 2010 from the National Marrow Donor Program: https://www.marrow.org/PATIENT/Undrstnd_Disease_Treat/Lrn_about_Disease/ALL/index.html
MayoClinic.com. (2010). Acute Lymphocytic Leukemia. Retrieved on October 8, 2010 from MayoClinic.com: https://www.mayoclinic.com/health/acute-lymphocytic-leukemia/DS00558