Leukemia

About cancer in general
The human body is made up of very small cells. Normal cells in the body grow and die in a controlled way. Sometimes cells keep dividing and growing without normal controls, causing an abnormal growth called a tumor. If a tumor does not invade nearby tissues and body parts, it is called a benign, non-cancerous tumor. Benign tumors are almost never life threatening. If the tumor invades and destroys nearby cells, it is called a malignant tumor, or cancer. Cancer can sometimes by life threatening. Cancerous cells sometimes spread to different parts of the body through blood vessels and lymph channels.

Leukemia is cancer of the body´s blood-forming tissues (blood cells), including the bone marrow and lymphatic system. The term „leukemia“ comes from Greek that means „white blood“. The disease usually starts in the white blood cells (leukocytes). Under normal circumstances, the white blood cells are potent infection fighters. These cells normally grow and divide in an orderly, controlled way, as the body needs them. But leukemia disrupts this process.

In leukemia, the bone marrow produces a large number of abnormal white blood cells, that look different from normal blood cells and do not function properly. They also crowd out other types of blood cells produced by the bone marrow, including red blood cells, which carry oxygen to tissues throughout the body, and plateles, which help form blood clots.

Doctors do not understand the exact cause of leukemia. It seems to develop from a combination of genetics and environmental factors (radiation, chemicals as benzene). However, many people with known risk factors don´t get leukemia. And many people with leukemia have none of these risk factors.
It is now known that all cancers, including leukemia, begin as a mutation in the genetic material – the DNA – within certain cells. Leukemia begins when one or more white blood cells experience DNA loss or damage. Those errors are copied and passed on to subsequent generations of cells.

Symptoms of leukemia

• fever, chills, and frequent infections
• anemia
• pale
• tiredness, weakness, persistent fatigue
• short breath during physical activity
• frequent nosebleeds, or bleed for an unusually long time after even a minor cut
• pain in the bones and joints
• swollen or bleeding gums
• swollen lymph nodes in the neck, groin, or elsewhere
• enlarged liver or spleen
• abnormally tired feeling
• loss of appetite or weight
• headaches, seizures, balance problems, abnormal vision (spread of leukemia to the brain)
• tiny red marks under the skin (petechiae)
• excessive sweating, especially at night

The first indications of leukemia often are nonspecific or vague. They may occur with other cancerous as well as noncancerous disorders. The severity of signs and symptoms depends on the number of abnormal blood cells and where they collect. Signs and symptoms vary for each type of leukemia.

Types of leukemia
There are 4 main types of leukemia with several of subtypes:

1. acute lymphocytic leukemia (ALL)
2. acute myelogenous leukemia (AML)
3. chronic lymphocytic leukemia (CLL)
4. chronic myelogenous leukemia (CML)

Diagnosing leukemia

• physical examination
  • signs of infection, pale skin from anemia, abnormal bleeding, and swollen lymph nodes
  • examination of abdomen to see if there is an enlarger liver or spleen
  • past health status, family medical history, used mediactions, allergies
• CBC (complete blood count) – measurement of white cells, red celss, and platelets
• cytogenetic analysis – test that detects changes in the chromosomes, including the presence of the Philadelphia chromosome
• microscopic examination of blood – to see an abnormal blood cells
• examination of blood chemistry
• a bone marrow biopsy and aspiration
• a lymph node biopsy
• a lumbar puncture (spinal tap)
• imaging studies – X-rays, CT, MRI, radionuclide scanning, UTS

All tests are needed to confirm the diagnosis and to determine the type of leukemia and its extent in the body (stage). Staging helps the doctor determine a treatment plan.

Treatment of leukemia
Thanks to recent medical advances, treatment of leukemia has improved dramatically in the last 10 to 20 years. This has resulted in frequent cures and long-term survival!

Certain features of a leukemia, such as age and initial white blood cell count, are used in determining the intensity of tretament needed to achieve the best chance for cure. Patients are treated with chemotherapy (chemical agents to kill leukemia cells), but the dosase and drug combinations may differ.

For most people with CML, the drug imatinib mesylate (Gleevec) is the first line of therapy. It is a type of cancer drug called a kinase inhibitor. It was specifically developed to inhibit the BCR-ABL protein, and it has proved effective in treating the early stages of CML. Several newer kinase inhibitors are in development.

Biological therapy (immunotherapy) uses substances that bolster the immune system´s response to cancer.

Radiation therapy, which use high-energy rays to shrink tumors and keep cancer cells from growing, may be used in addition to intrathecal chemotherapy for certain high-risk patients. Patient than recquire continued close monitoring by a oncologist, a specialist in cancers.
The goal of leukemia treatment is remission of the leukemia (where there is no longer evidence of cancer cells in the body).

Bone marrow transplant is the process of replacement of leukemic bone marrow with leukemia-free marrow from a compatible donor, or by autologous transplant (own bone marrow).
Stem cell transplant is similar to bone marrow transplant except the cells are collected from stem cells that circulate in the bloodstream (peripheral blood). Doctors use this procedure more frequently than bone marrow transplant because of shortened recovery times and possible decreased risk of infection.
Some people with leukemia choose to enroll in clinical trials to try out experimental treatments or new combinations of known therapies.

No matter what kind of cancer therapy is choosed, patient will likely need some supportive care (e.g. medications) to control pain and side effects of leukemia.

Leukemia in children
As a group, leukemias account for about 25% of all childhood cancers. Luckily, the chances for a cure of children are very good with leukemia. With treatment, most children with leukemia are free of the disease without it coming back.
Approximately 60% of children with leukemia have ALL, and about 38% have AML. Although slow-growing chronic myelogenous leukemia (CML) may also be seen in children, it is very rare. The ALL form of the disease most commonly occurs in younger children ages 2 to 8, with a peak incidence at age 4. But it can affect all age groups.
Children have 20%-25% chance of developing ALL or AML if they have an identical twin who was diagnosed with the illness before age 6. In general, nonidentical twins and other siblings of children with leukemia have 2-4 times the average risk of developing this illness.
Children who have inherited certain genetic problems – such as Li-Fraumeni syndrome, Down syndrome, Kleinfelter syndrome, neurofibromatosis, ataxia telangectasia, or Fanconi´s anemia – have a higher risk of developing leukemia, as do children who are receiving medical drugs to suppress their immune systems after organ transplants.
Children who have received prior radiation or chemotherapy for other types of cancer also have a higher risk for leukemia, usually within the first 8 years after treatment.
In most cases, neither parents nor children have control over the factors that trigger leukemia, although current studies are investigating the possibility that some environmental factors may predispose a child to develop the disease. Most leukemias arise from noninherited mutations in the genes of growing blood cells. Because these errors occur randomly and unpredictably, there is currently no effective way to prevent most types of leukemia.
To limit the risk of prenatal radiation exposure as a trigger for leukemia, women who are pregnant or who suspect that they might be pregnant should always inform their doctors before undergoing tests or medical procedures that involve radiation (such as X-rays).

During and after treatment of leukemia
A diagnosis of leukemia can be devastating. Remember that no matter what your concerns or prognosis, you are not alone. The road ahead may not be easy, but these strategies and resources may make it easier:

• Know what to expect – find out everything you can about the type, the stage, the treatment options and their side effects. The more you know, the more active role you can play in the process of the disease.
• Be proactive – although you may feel tired and discouraged, do not let others make important decisions for you, take an active role in the treatment.
• Maintain a strong support system – having a support system (support group, family, friends) and a positive attitude can help you cope with the issues, pain and anxieties that might occur. Although support groups aren´t for everyone, they can be a good source for practical information.
• Set reasonable goals – having goals helps you feel in control and can give you a sense of purpose. But don´t choose goals you can´t possibly reach.
• Take time for yourself – eating well, relaxing and getting enough rest can help combat the stress and fatigue of cancer. Also, plan ahead for the downtimes when you may need to rest more or limit what you do.
• Stay acitve – having cancer doesn´t mean you have to stop doing the things you enjoy or normally do. If you feel well enough to do something, go ahead and do it.
• Nutrition – patients need to eat well during cancer therapy. They need enough calories to maintain a good weight and protein to keep up strength. Good nutrition often helps people with cancer feel better and have more energy.
• Followup care – regular checkups after treatment for leukemia are an important part of the overall treatment plan.