What is Leukemia?

Leukemia is a type of cancer characterized by the production of abnormal white blood cells in the bone marrow. White blood cells normally defend the body against infection. The abnormal white blood cells produced in leukemia do not function properly increasing the likelihood of infections. The white blood cells increase in number while other blood cells (red blood cells and platelets) diminish. The lack of red blood cells results in a decreased oxygen supply to the tissues and a lack of platelets results in poor clotting function leading to bruising or bleeding.

Children are more commonly affected by certain types of leukemia while adults are affected by other types. Men are more commonly affected than women.

Types of Leukemia

Leukemia may be described by the cells in the bone marrow that are affected. There are usually two types of cells affected, lymphoid cells and myeloid cells. Lymphoid cells give rise to lymphatic tissue in the body responsible for immunity. Myeloid cells give rise to all types of blood cells. Leukemia based on cell type therefore includes:

  • Lymphocytic leukemia: The lymphoid cells are cancerous.
  • Myelogenous leukemia: The myeloid cells are cancerous.

Leukemia may also be described by the rate at which the disease progresses.

  • Acute leukemia: This condition progresses quickly and produces numerous immature blood cells. It usually occurs in young individuals and requires immediate treatment.
  • Chronic leukemia: The type is often asymptomatic and progresses slowly. It occurs in adults and the cells are more mature and function for a short while.

Based on the above descriptions, there are 4 types of leukemia:

  • Acute lymphocytic leukemia
  • Acute myelogenous leukemia
  • Chronic lymphocytic leukemia
  • Chronic myelogenous leukemia

Symptoms of Leukemia

The symptoms of leukemia include:

  • Weakness and fatigue
  • Recurrent severe infections
  • Swollen lymph nodes
  • Enlarged liver or spleen or both
  • Recurrent nosebleeds or gum bleeding
  • Bleeding through stools or urine
  • Pain and tenderness of the bones
  • Small red spots on the skin
  • Loss of weight
  • Loss of appetite
  • Sweating at night
  • Anemia

What Causes Leukemia?

The exact cause of leukemia is unknown. The cause may be genetic or environmental. It may be associated with smoking, previous chemotherapy or radiation therapy, exposure to certain chemicals (carcinogens) and a family history of leukemia.

Diagnosis of Leukemia

If you have the above symptoms or if routine blood work shows signs of leukemia, your doctor will review your medical history and perform a physical examination to look for signs such as bruising, swollen gums, enlarged liver, spleen or lymph nodes. Chronic leukemia does not usually show symptoms in the early stages.  Tests that may be ordered include:

  • Blood Tests: Specific blood tests can show the presence of abnormal cells or show increased levels of certain cell types.
  • Biopsy: A biopsy of bone marrow may be obtained to confirm the presence of cancerous cells.
  • Molecular Tests: Molecular tests of the suspected cells can determine the presence of specific cancer-causing DNA or abnormal proteins which are absent in normal cells.

How is Leukemia Treated?

The treatment depends on various factors including:

  • Type of leukemia
  • The severity of leukemia
  • Your age and current health condition

Treatments for leukemia include:

  • Chemotherapy: It involves the use of drugs to treat cancer. The drugs may be pills or intravenous injections.
  • Radiation: X-rays are used to kill or damage leukemia cells. You may receive radiation treatment for a part of your body or your entire body.
  • Surgery: Your doctor may suggest a splenectomy (removal of the spleen by surgery). An excess of cancer cells is eliminated by this procedure.
  • Targeted Cell Therapy: It involves the use of drugs which specifically target certain molecules of cancer cells to destroy them but does not damage other cells of the body.
  • Biological Therapy: A healthy immune system is necessary to fight cancerous cells. Biological therapy involves administering interleukins or interferons to naturally defend your body against cancerous cells.
  • Stem Cell Transplant: Stem cells from a donor are implanted in your bone marrow which give rise to healthy blood cells. Chemotherapy is performed before stem cell therapy to kill all the existing cancer cells.

You may require blood or platelet transfusions if your red blood cells and platelet counts are very low. Antibiotics are administered to prevent or treat an infection. Certain treatments such as chemotherapy have side effects. You will also receive medication to control them.

Prognosis

Recent advances in medicine have greatly improved survival rates, especially in children. It also depends on the type of leukemia you have, your age and level of fitness.

Preventing Leukemia

Though there are no known ways of preventing leukemia it is advised that you avoid exposure to carcinogens (cancer-causing chemicals or radiation) and pollutants, quit smoking, reduce alcohol consumption and live a healthy lifestyle.