Leukemia at a glance
- Leukemia is a form of cancer (the uncontrolled growth of cells) that develops in blood cells within bone marrow.
- Sometimes called blood cancer, leukemia is broadly categorized into types by where it develops and whether it is spread acutely or more slowly.
- Symptoms include fatigue, bone pain, bruising and frequent infections.
- No precise cause of leukemia has been determined, however, both genetic and environmental risk factors may increase the chances of getting it.
- Some forms of the disease mostly affect children and other forms only affect adults.
- Treatment options depend on which type of leukemia is present, as well as the age and health of the patient, and include chemotherapy, targeted therapy and stem cell transplants.
What is leukemia?
Leukemia is a rare type of cancer that develops in the white blood cells, which are crucial in fighting off infections in the body, controlling bleeding and transporting oxygen. Around 54,000 Americans are diagnosed with leukemia each year, and it accounts for around 3 percent of all new cancer diagnoses.
Bone marrow, which is found in the inner layers of bones, produces blood cells. In the case of leukemia, the blood cells produce abnormally, as all cancer cells do, and overpower the healthy cells. This abnormality causes dysfunctions in the body’s systems that vary but can include fatigue, bruising and reduced immunity.
Leukemia can arise in different scenarios. It is categorized into types, depending on how rapid the cell mutations begin and which type of blood cells are affected. Acute leukemia comes on suddenly and requires a fast response to treatment, while chronic leukemia cells grow more slowly and are consequently harder to cure completely. Some forms of leukemia almost exclusively affect children while others only occur in adults.
Primary forms of leukemia
- Acute lymphocytic leukemia (ALL). Also known as acute lymphoblastic leukemia, this is the most common form in children, although it can present in adults. Symptoms include enlarged lymph nodes, pain in the bones and infections.
- Acute myeloid leukemia (AML). This form occurs in both children and adults, and occurs when the myeloid cells grow out of control. AML comes on and progresses rapidly. Symptoms might include recurring infections and fatigue.
- Chronic lymphocytic leukemia (CLL). This is a slow growing cancer that typically occurs in adults over the age of 55 and rarely occurs in children. CLL symptoms don’t present for years in some cases and may include swollen lymph nodes and susceptibility to bruising.
- Chronic myeloid leukemia (CML). A slow growing myeloid cell mutation that primarily affects adults, its symptoms don’t arise until in the later stages and might include weight loss, pale skin and extreme fatigue.
The precise cause of of this form of cancer is unknown. All cancer involves mutated cells. Research and data suggest a combination of environmental and genetic factors contribute to the disease’s development.
One type of mutation that commonly presents is called chromosome translocation. This occurs when part of a chromosome breaks and attaches itself to another chromosome. Leukemia cells almost always include an exchange between the 9th and 22nd chromosome.
Risk factors that increase the chances of leukemia cells developing include exposure to radiation, exposure to the chemical benzene (present in coal and tar), as well as tobacco use. Genetic disorders such as Down syndrome as well as previous cancer treatments (chemotherapy or radiation) have a higher risk of developing leukemia. Keep in mind that risk factors are not causative, and those with this cancer may not have exhibited any of the suggestive risk factors.
Symptoms will depend on the type diagnosed. The chronic, slow growing forms may not present any symptoms early on. Noticeable symptoms result from the blood cells’ inability or struggle to function properly. These symptoms might include fatigue, bone or joint pain, night sweats and fevers, or frequent recurring infections.
A physician diagnoses the cancer by performing a physical exam as well as ordering a blood sample to be examined. A sample of bone marrow may also be required in order to confirm cancerous cells.
Treatment options vary from case to case and largely depend on the type of leukemia as well as the age and health of the patient. Those with chronic forms may practice “watchful waiting” and postpone treatment until symptoms develop, since the cells are so slow growing that treatment side effects might be worse than the symptoms of the actual cancer. Acute leukemia should be treated as soon as it is diagnosed.
The primary method of treating leukemia is with chemotherapy medicine. The patient may receive the medicine orally, intravenously or directly into the cerebrospinal fluid (found in the spine and brain).
This therapy uses high-energy radiation to kill or target cancer cells in the blood. Usually, radiation therapy is reserved for when leukemia has moved to large organs in he body such as the spleen or brain.
Targeted and biological therapy
Biological therapy involves using living organisms or substances from organisms that can assist the immune system to recognize and fight the cancer cells. Targeted therapy consists of medicine that attacks a specific function or property of the cancer cell instead of the entire cell (which is how chemotherapy and biological therapy work). Targeted therapy is typically used to treat acute forms of leukemia and may, for example, only treat the damaged chromosomes, not the entire cell. Targeted therapy usually results in less severe side effects.
Stem cell transplants
A stem cell is a type of cell that can regenerate and stimulate into many different types of cells. In the case of Leukemia treatment, the stem cells are transplanted into bone marrow so that healthy, noncancerous blood cells can regenerate.
Prior to the treatment, chemotherapy or radiation are administered to kill leukemia cells. Transplant stem cells are then delivered with an IV infusion. Stem cells may be the patient’s own or come from a donor.
Stem cell transplantation requires a patient to stay in the hospital for several weeks following the infusion because there is a risk the procedure increases infections as a result of the large depletion of normal blood cells from the body.
Following any treatment for leukemia, supportive measures may be necessary because of the increased risk of bleeding and susceptibility to infection. Types of supportive treatments may include regular pneumonia or flu vaccines, anti-nausea medicine and antibiotics to prevent infections.