What is Leukemia
A malignant, or cancerous, disease that affects the blood-forming cells found in the bone marrow and the lymphatic system. Leukemia results in an abnormally high number of abnormal white blood cells (blasts). The blasts are cells that would develop into white blood cells but stop short in their development. High concentrations of blasts in the bone marrow, lymph nodes, and bloodstream can also impair the function of these tissues. Some types of leukemia may also affect the liver, spleen, or brain. In addition, overproduction of the blasts can crowd out normal cells in the bone marrow and decrease the number of red blood cells, platelets, and normal white blood cells formed by the bone marrow. This can lead to fatigue, weakness, increased bleeding and bruising from slow blood clotting, and a decreased ability to fight infection. Leukemia worsens over time and may result in death if left untreated.
In the United States, most types of leukemia are more common in men than in women and are found in more whites than in blacks. The risk of leukemia increases with age; more than five of ten cases occur in people older than 60. Although leukemia strikes ten times as many adults as children, it is the leading type of cancer among children. Leukemia causes more deaths in children younger than 15 than any other disease.
LEUKEMIA CELLS: Normal white blood cells (lymphocytes) are large and round. In a person with leukemia, the white blood cells are far more numerous and long-lived than normal, but they are underdeveloped. The person is less able to fight off infection, production of red blood cells is hindered, and blood clotting is affected.
Leukemia is classified according to two key characteristics. The first is the speed with which symptoms develop. In acute leukemia, symptoms begin very rapidly. Blast cells, which are immature and undeveloped, increase in number rapidly. People with acute leukemia almost always seek medical attention be-cause they feel ill and become sicker over time. Almost all childhood leukemias are acute. In chronic leukemia, the number of blasts (immature cells) is lower and increases slowly. As a result, symptoms develop gradually. In the early stages, many people with chronic leukemia may not realize they are ill. Often the disease is discovered by a physician during a routine physical examination or blood test. Chronic leukemia usually has a slowly progressive course and is largely an adult disease.
The second way of classifying leukemia pertains to the type of blast. The abnormality can arise in either of the two main types of white blood cells: lymphoid or myeloid. If the leukemia affects the lymphoid cells, it is known as lymphocytic or lymphoblastic. If it affects the myeloid cells, it is known as myeloid or myelogenous.
There are four principal types of leukemia. Acute lymphoblastic leukemia is the most common type of leukemia in children, but can also affect adults, especially those older than 65. Acute myelogenous leukemia is found in both children and adults, although it occurs most commonly in people who are middle-aged. Chronic lymphocytic leukemia is primarily a disease of people older than 65, occurring much less commonly in younger adults and almost never in children. Chronic myeloid leukemia is also primarily an adult disease that rarely afflicts children. Other less common leukemias include hairy cell leukemia.
Leukemia’s symptoms vary somewhat between the different forms of the disease. Common symptoms include fever and chills; fatigue and weakness; frequent infections and poor wound healing; unusual bruising or bleeding; loss of appetite or weight; swelling or tenderness in the spleen (upper left abdomen), liver (upper right abdomen), or lymph nodes (such as in the neck, armpits, or groin); tiny red spots under the skin (called petechiae and caused by pinpoint hemorrhages); swollen or bleeding gums; sweating, especially at night; and pain in the bones or joints. Leukemia cells may invade the nervous system, producing headache, vomiting, lack of coordination or muscle control, blurred vision, and seizures. Leukemia cells can also gather in the testicles and cause painful swelling. In some cases, the lungs, digestive tract, and other organs are affected by the spread of the cancerous cells.
In most cases, the cause of leukemia is not known. As a result, little can currently be done to prevent the disease. One exception is smoking, which seems to have a causative role in one of five cases of acute myelogenous leukemia in adults.
Exposure to large amounts of radiation is involved in a small number of cases of acute leukemia. There is no evidence that the small doses of X rays used in medical or dental care raise the risk of leukemia. Chemicals can also have a role. Exposure to benzene in particular has been shown to increase the risk of leukemia. The treatment for other types of cancer with radiation or chemotherapy increases the risk of leukemia later in life.
Genetics may also be a factor, since some families have more than the expected number of cases of the disease. Children with an inherited gene mutation known as Li-Fraumeni syndrome are at increased risk for leukemia.
Leukemia Diagnosis And Treatment
Since the symptoms of leukemia can arise as the result of other diseases as well, a number of tests are needed to make the diagnosis. A blood test called a complete blood cell count is performed to determine the number of the different types blood cells. A blood smear can be examined under a microscope and may identify abnormal cells. If these tests point toward leukemia, a small sample (biopsy) of bone marrow and bone is taken and examined for leukemic cells. In some cases, a sample of the cerebrospinal fluid (the fluid that surrounds the spine and flows through the brain) is obtained with a needle to see whether the cerebrospinal fluid contains leukemic cells. Imaging studies, such as X rays, ultrasound scans, CT SCANNING (computed tomography scanning), and MRI (magnetic resonance imaging), may be used to see whether the leukemia is affecting the lymph nodes and internal organs.
Once the extent and type of the disease have been determined, treatment can begin. Treatment varies with the type of leukemia. In general, most leukemias are treated with chemotherapy, which involves the use of cancer-killing drugs. In some types of leukemia, particularly for leukemias that have not responded well to chemotherapy, bone marrow transplant is also used.
How to Control Leukemia
There are no specific changes in your lifestyle to control leukemia. However, the following tips can help you manage the side effects of leukemia treatment:
- Balance rest and activities.
- Avoid exposure to bacteria and viruses. This could include restricting travel during times of colds and flu and, in some cases, avoiding exposure to pets that can carry viruses or other infections that can be transmitted to humans.
- Maintain good dental hygiene.
- Eat a healthy diet as tolerated.
- Avoid overly vigorous physical activities such as contact sports. During the course of leukemia and as a result of treatment, blood clotting may be compromised and the risk of bleeding and injury due to trauma is increasing.
The support of family and friends is also very important at this time. Some patients find it helpful to discuss their concerns with people who face similar challenges. The American Cancer Society can refer you to a support group in your area.
Review for Leukemia
The purpose of the review is the timely diagnosis and treatment. Screening tests are usually administered to people without symptoms present, but who may be at high risk for certain diseases or conditions.
There are no tests or indications to review for leukemia. However, your doctor may order a blood count during a routine physical examination. An examination of the blood, either for the presence of anemia or for changes in white blood cells, is the basic diagnostic test for leukemia. Occasionally, these tests, done routinely, will result in an opportune diagnosis of leukemia, especially of chronic varieties.
Reducing Your Risk of Leukemia
Avoid Exposure to Benzene and High Radiation Dose
Exposure to chemical benzene or high doses of radiation increases the risk of leukemia. Environmental exposures to radiation are usually in low doses and may increase your risk of developing leukemia. High doses of radiation are something that only cancer patients are usually exposed to, and this exposure is necessary to cure a cancer present. The risk of the cancer coming back without radiation therapy is much greater than the risk of developing leukemia due to radiation, and you should not avoid radiation because of this tiny risk of leukemia. There are certain types of chemotherapy drugs that also increase your risk of developing leukemia, such as melphalan, mechlorethamine, and other medications called alkylating agents.
If You Smoke, Leave it
Smokers over 60 years of age are twice as likely as non-smokers to develop acute myeloid leukemia.
Talking to Your Doctor About Leukemia
General Tips for Gathering Information
Here are some tips that will make it easier for you to talk to your doctor:
- Take someone else with you. It is helpful to have another person listening to what is being said and thinking about what to ask.
- Write your questions in advance, this way you will not forget them.
- Write down the answers you get, and make sure you understand what you are listening to. Ask for clarification, if this is necessary.
- Do not be afraid to ask questions or find out where you can find more information about what you are discussing. You have the right to know.
Specific Questions to Ask Your Doctor
- What type of leukemia do I have?
- Do you know why I have leukemia? Is it possible that other members of my family are at risk of developing it?
About Your Risk of Developing Leukemia
- Based on my medical history, lifestyle and family history, am I at risk for leukemia?
- Is there anything I can do to reduce my risk to get Leukemia?
About Treatment Options
- What is the best treatment option for leukemia?
- What are the other options?
- What are the risks and benefits associated with this treatment plan?
- How long will the treatment go on for?
- What side effects can I expect?
- What will I need to change in my daily routine?
- How will I feel during the treatment? What can I do to help myself feel better during the treatment? What can the doctor do to minimize the side effects I may experience?
- What will I need to do to take care of myself during the treatment period?
- What will we do if the treatment is not successful?
About Changes in Lifestyle
- What do I have to do to protect myself as much as possible from infections?
- Will I need to change my diet or other daily habits?
- Can I do exercise? If so, how much can I exercise?
About Your Panorama
- Is it likely that my treatments will kill the cancer cells?
- How do I know that my treatment program is effective?
- How will I know if the leukemia has returned and what will we do if it is so?
- Should I consider participating in a clinical trial? If one is appropriate for me, what is the cost in relation to the cost of a conventional treatment?
- Do you know of a support group I could join?