While leukemia is one of the most common childhood malignancies, the vast majority of those who develop this blood cancer each year are adults.
More than 43,000 adults and 3,300 children are expected to be diagnosed with leukemia in 2010, according to the Leukemia and Lymphoma Society (LLS). Thanks to treatment advancements that use targeted therapies to prevent abnormal cells from multiplying, more patients than ever before can hope for long-term survival.
Leukemia is divided into four major types based on the specific bone marrow cells in which it develops. Regardless of the type, however, diseased cells eventually outnumber and crowd out normal blood cells, which carry oxygen throughout the body and fight infection.
According to the Mayo Clinic, the first classification is based on how quickly the leukemia progresses:
- Acute leukemia worsens rapidly and requires quick, potent treatment. Abnormal cells are immature blood cells called blasts, which cannot function correctly.
- Chronic leukemia progresses slowly and may not produce any initial symptoms. Abnormal cells are mature blood cells that can function normally for a period of time.
The second classification is based on the kind of white blood cells affected:
- Myelogenous leukemia begins in the myeloid cells deep in the bone marrow. Myeloid cells normally produce red and white blood cells as well as platelets, which help clot blood.
- Lymphocytic leukemia affects lymphoid cells, which form the immune system's lymph tissue throughout the body.
Different types of leukemia affect different types of patients. For example, both chronic myelogenous leukemia (CML) and chronic lymphocytic leukemia (CLL) affect mostly adults, according to the National Cancer Institute. Acute lymphocytic leukemia (ALL) is the most common type in young children, and acute myelogenous leukemia (AML) occurs in both adults and children.
Initial symptoms of leukemia mimic those of several other conditions, including the flu, and can be easy to overlook. According to the LLS, common symptoms include:
- Chills, fever or night sweats
- Persistent weakness and fatigue
- Shortness of breath upon exertion
- Pale skin
- Pinhead-sized red dots under the skin
- Unexplained bruises
- Slow-healing cuts and excess bleeding
- Joint or bone aches
- Swollen lymph nodes
Diagnosis & Tests
Because chronic leukemia is often symptomless at first, many cases are discovered during a routine blood test, according to the Mayo Clinic. Those with clear symptoms will undergo a physical exam, where doctors look for visible leukemia signs such as pale skin or swollen glands.
If leukemia is suspected, a blood test will be taken to search for abnormal levels of red and white blood cells and platelets. A diagnosis is confirmed with a bone marrow aspiration test, in which a needle is inserted into the hipbone to extract bone marrow cells. The type of leukemia is identified by examining these cells.
Treatments & Medications
A treatment regimen is based on a patient's age, overall health and type of leukemia, according to the LLS. A variety of treatments may be employed, including:
- Chemotherapy, which is the main form of leukemia treatment, according to the Mayo Clinic. This systemic treatment uses potent chemicals to kill leukemic cells and may come in pill or intravenous form. Commonly used chemotherapy drugs include vincristine and methotrexate.
- Biologic drugs such as interferon, which prompt the immune system to recognize and destroy leukemic cells.
- Targeted drugs, which help control the disease for long periods by inhibiting abnormal cells' ability to multiply. These drugs include imatinib (known as the brand name Gleevec), dasatinib (Sprycel) and nilotinib (Tasigna).
- Radiation, which uses x-rays or high-energy beams to damage leukemic cells.
- Stem cell or bone marrow transplant, which replaces diseased bone marrow with healthy marrow created from blood-forming cells from a donor or the patient.