Sunday, September 2, 2001
Steamboat Springs Leukemia is a type of cancer that starts in the bone marrow the soft inner core of bones and in most cases quickly moves into the blood, where it spreads to many other organ systems. This cancer of the white blood cells takes its name from the Greek words "leukos" meaning white and "halma" meaning blood. It was discovered in the 19th century when European doctors observed under a microscope unusually high numbers of white cells in the blood of their patients.
There are four major types of leukemia and several subtypes. Acute leukemia grows rapidly, while chronic leukemia is a slowly growing disease.
Of an estimated 31,500 newly diagnosed cases of leukemia in the United States this year, there will be an equal number of acute and chronic forms of the disease.
Ten times as many adults as children are diagnosed with leukemia.
Nevertheless, it is the most common cancer among children and adolescents.
Acute lymphocytic leukemia accounts for 80 percent of childhood cases while acute myelogenous leukemia is more common in adults. Leukemia is more common among males than females and incidence is highest among Caucasians.
The bone marrow is made up of blood-forming cells and supporting tissues. These aid in the development of immature cells that eventually become red cells, white cells and platelets. Acute leukemia causes a rapid accumulation of the immature cells. A single cell may develop abnormally, become malignant and multiply continuously, crowding out the cells that make normal blood cells. The accumulation of the abnormal cells interferes with the body's ability to protect itself against infections, anemia and bleeding.
Chronic leukemia progresses slowly and permits the growth of greater numbers of more developed cells that are not completely normal. These cells live much longer than normal cells.
The cause of leukemia is unknown. Scientists suspect that viral, genetic, environmental and/or immunologic factors may be involved.
Symptoms of acute leukemia include easy bruising or bleeding, paleness, fatigue, recurrent minor infections or poor healing of minor cuts.
Discomfort in the bones and joints may occur; lymph nodes may become enlarged. There may be headaches and vomiting. Some people with chronic leukemia may not have major symptoms. Often the disease is discovered when a routine complete blood count is performed.
Currently, the most effective treatment for leukemia is chemotherapy. Biological and radiotherapy are used on some forms of leukemia. Bone marrow transplantation was introduced 30 years ago. In more recent times, stem cell transplantation of immature cells has become an accepted treatment for cancer, using the patient's or a donor's blood.
Transplantation of cord blood (umbilical and placental) after childbirth has provided a source of stem cells for transplantation, especially for children. The Community Health Resource Center within the Yampa Valley Medical Center maintains a current directory of hospitals that perform transplants.
Leukemia treatment research is prolific and promising. A new drug called Gleevec, developed by Novartis Pharmaceuticals, has had remarkable results. Gleevec acts like a magic bullet, targeting only cancer cells and leaving most of the healthy cells alone.
To date the drug has been approved to treat chronic myeloid leukemia, which strikes about 4,700 people each year. A typical cancer-therapy drug can take from three to five years for approval from the Food and Drug Administration. Gleevec was approved in less than three months, the fastest time in FDA history.
Nancy S. Bretz is coordinator of the Community Health Resource Center at Yampa Valley Medical Center.