Leukemias are cancers of white blood cells that occur in the blood and bone marrow. When leukemia develops, the bone marrow makes too many abnormal white blood cells, crowding out any existing healthy blood cells. Leukemias are categorized into two groups: acute (faster growing) and chronic (slower growing).
There are two major types of acute leukemia:
Acute Myeloid Leukemia (AML): is the most common type of acute leukemia, usually occurring in older adults, and is very aggressive. About 19,000 cases of AML are diagnosed each year and is slightly more common in men than in women.
Acute Lymphocytic Leukemia (ALL): is the most common type of leukemia in children, but it can also affect adults. While most cases of ALL occur in children, most deaths from ALL occur in adults. Children may do better because of differences in childhood and adult ALL in the disease itself or because children’s bodies can often handle aggressive treatment better than adult’s.
There are two major types of chronic leukemia:
Chronic Myeloid Leukemia (CML): is uncommon and accounts for only 10% of leukemia cases. This disease is almost always caused by the development of an abnormal chromosome, called the Philadelphia chromosome. With treatment, most patients achieve remission.
Chronic Lymphocytic Leukemia (CLL): is the most common type of leukemia, accounting for one-third of all leukemia cases, and is typically found in older adults. It is very slow to progress and can often be observed for an extended period without requiring treatment.
Leukemia symptoms vary depending on the type of leukemia, but common symptoms include fever or chills; persistent fatigue or weakness; frequent or severe infections; unexplained weight loss; swollen lymph nodes or enlarged liver or spleen; easy bleeding or bruising; recurrent nosebleeds; tiny red spots on the skin; excessive sweating especially at night; bone pain or tenderness.
Leukemia is usually found in routine blood tests, however physical exams or bone marrow biopsies may be needed for an accurate diagnosis. Treatment for leukemia can be complex and depend on many factors, such as the type of leukemia, and whether it has spread to other parts of the body like the central nervous system.
Common treatments used to fight leukemia include:
Chemotherapy: major form of treatment for most leukemias.
Biological Therapy or Immunotherapy: uses treatments that help the body’s own immune system recognize and attack leukemia cells.
Targeted Drug Therapy: uses drugs that attack specific vulnerabilities or malfunctions within the cancer cells.
Radiation Therapy: may be given to one specific area of the body where there is a collection of leukemia cells or may be given all over the body; used to prepare for a stem cell transplant.
Stem Cell (or Bone Marrow) Transplant: a procedure to replace diseased bone marrow with healthy bone marrow. Before a stem cell transplant, high doses of chemotherapy or radiation therapy will be given to destroy diseased bone marrow. Then an infusion of blood-forming stem cells is given to help rebuild healthy bone marrow. Stem cells may be from a donor or in some cases the patient’s own stem cells.
Scientists don’t understand the exact causes of leukemia. It seems to develop from a combination of genetic and environmental factors. However, there are a few known risk factors: previous chemotherapy or radiation therapy treatments, genetic disorders such as Down syndrome, exposure to certain chemical such as benzene, family history of leukemia and smoking.