Leukemia

Written by Verneda Lights and Elizabeth Boskey, PhD | Published on 16 August 2012
Medically Reviewed by George Krucik, MD

What Is Leukemia?

Leukemia is a cancer of the blood cells. There are several types of blood cells, including red blood cells (RBCs), white blood cells (WBCs), and platelets. Generally, leukemia refers to cancers of the WBCs. Two types of WBCs often involved in leukemia are granulocytes and lymphocytes.

White blood cells are a vital part of your immune system. They protect your body from invasion by bacteria, viruses, and fungi. WBCs also protect your body from abnormal cells and other foreign substances. In leukemia, the white blood cells have mutated. These mutant white blood cells may divide too quickly and eventually crowd out normal cells. Often, they do not function as normal WBCs.

Blood cells are made in the bone marrow. When WBCs leave the marrow, they are found in the lymph nodes and spleen. They also circulate throughout the blood and lymphatic systems.

Help Friends and Family with Their Medical Costs: Raise Money Now »

The Types of Leukemia

The onset of leukemia can be acute (sudden onset) or chronic (slow onset). In chronic leukemia, cancer cells increase slowly. Early symptoms can be very mild. Acute leukemia develops quickly. Cancer cells increase rapidly and symptoms occur early.

Acute and chronic leukemia are also classified according to the cell type. Leukemia involving myeloid cells is called myelogenous leukemia. These cells are immature blood cells that would normally become granulocytes or monocytes. Leukemia involving lymphocytes is called lymphocytic leukemia. There are four main types of leukemia.

Acute Myelogenous Leukemia (AML) has a rapid onset. It can occur in children and adults. About 13,000 new cases of AML are diagnosed annually.

Chronic Myelogenous Leukemia (CML) has a slow onset and affects mostly adults. About 5,000 new cases of CML are diagnosed annually.

Acute Lymphocytic Leukemia (ALL) has a rapid onset and occurs mostly in children. 5,000 new cases of ALL are diagnosed annually.

Chronic Lymphocytic Leukemia (CLL) is slow in onset. It is most likely to affect people over the age of 55. It is very rarely seen in children. There are about 15,000 new cases of CLL diagnosed every year.

Hairy cell leukemia is another type of leukemia. It is very rare.

Risk Factors for Leukemia

The causes of leukemia are not known. However, several factors have been identified which may increase your risk. These include:

  • family history of leukemia
  • smoking (AML)
  • genetic disorders such as Down syndrome
  • blood disorders - myelodysplastic syndromes are sometimes known as pre-leukemia
  • prior treatment for cancer with chemotherapy or radiation
  • exposure to high levels of radiation
  • chemical exposures, such as to benzene

What Are the Symptoms of Leukemia?

The symptoms of leukemia include:

  • excessive sweating, especially at night
  • fatigue and weakness that do not go away with rest
  • unintentional weight loss
  • bone pain and tenderness
  • painless, swollen lymph nodes (especially in the neck and armpits)
  • enlargement of the liver or spleen
  • red spots on the skin (petechiae)
  • bleeding and bruising easily
  • fever or chills
  • frequent infections

Leukemia can also cause symptoms in organs that have been infiltrated or affected by the cancer cells. For example, central nervous system involvement can cause:

  • headaches
  • nausea and vomiting
  • confusion
  • loss of muscle control
  • seizures

Leukemia can also involve the lungs, gastrointestinal tract, heart, kidneys, and testes.

Diagnosing Leukemia

Leukemia may be suspected if you have certain risk factors or symptoms. Then diagnosis begins with a complete history and physical examination. The physical exam looks for pale skin, tender bones, enlarged lymph nodes, and enlargement of the liver and spleen. Leukemia can not be fully diagnosed by physical exam. Instead, doctors will use blood tests, biopsies, and imaging studies to see if you have this cancer.

There are a number of different tests that can be used to diagnose leukemia:

Complete Blood Counts determine the numbers of RBCs, WBCs, and platelets in the blood. Looking at your blood under a microscope can also determine if the cells have an abnormal appearance.

Tissue biopsies can be taken from the bone marrow or lymph nodes to look for evidence of leukemia. These small samples can identify the type of leukemia and its growth rate. Biopsies of other organs such as the liver and spleen can show if the cancer has spread.

Flow Cytometry examines the DNA of the cancer cells and determines their growth rate.

Liver Function Tests show whether leukemia cells are affecting or invading the liver. These tests look for elevated liver enzymes and bilirubin levels. Bilirubin is a substance made by the liver from the breakdown of RBCs.

Lumbar puncture is performed by inserting a thin needle between the vertebrae of your lower back. This allows your doctor to collect spinal fluid and determine if cancer has spread to the central nervous system.

Imaging studies help doctors look for damage leukemia has caused in other organs. These may include:

  • X-rays
  • Ultrasound
  • CT scan
  • PET scan
  • 2D echocardiogram
  • pulmonary function tests

Once your leukemia is diagnosed, it will be staged. Staging helps your doctor determine your prognosis. AML and ALL are staged based on how cancer cells look under the microscope and the type of cell involved. ALL and CLL are staged based on the WBC count at the time of diagnosis. The presence of immature cells white blood cells (myeloblasts) in the blood and bone marrow is also used to stage AML and CML.

Treating Leukemia

Leukemia is usually treated by a hematologist-oncologist. These are doctors who specialize in blood disorders and cancer. Treatment depends upon the type and stage of the cancer. Some slow growing forms of leukemia do not need immediate treatment. This is called “watchful waiting.” However, treatment of leukemia usually involves chemotherapy, radiation therapy, and possibly stem cell transplantation.

The cells in your bone marrow which make new blood are known as stem cells. Stem cell transplantation replaces your stem cells with cells from a healthy donor. This can keep your body from making more cancerous cells. The diseased bone marrow has to be destroyed before a stem cell transplant can be performed. Doctors do this with chemotherapy and radiation. Radiation therapy can be directed to a specific part of the body or applied to the entire body. This is known as whole body radiation.

Biological therapy can also be used to treat leukemia. It uses medications to boost your immune system. Targeted therapy uses drugs that take advantage of specific vulnerabilities in cancer cells. Imatinib (Gleevec) is a targeted drug that acts against a protein found in CML cells.

Long-Term Outlook

The long-term outlook for leukemia patients depends on the type of the cancer and the stage at diagnosis. The sooner the disease is diagnosed and the faster it is treated, the better the chance of recovery.

The following factors can negatively affect the prognosis of leukemia:

  • older age
  • high WBC or low platelet count
  • past history of blood disorders
  • enlargement of the liver or spleen
  • presence of bone damage
  • chromosome mutations
Was this article helpful? Yes No

Thank you.

Your message has been sent.

We're sorry, an error occurred.

We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later.

Article Sources:

Recommended for You

Leukemia vs. Lymphoma: Origins, Types, and Treatments
Leukemia vs. Lymphoma: Origins, Types, and Treatments
Both leukemia and lymphoma cancers involve white blood cells. In leukemia, bone marrow produces too many cells, while lymphoma begins with lymph nodes.
Symptoms of Leukemia in Pictures: Rashes and Bruises
Symptoms of Leukemia in Pictures: Rashes and Bruises
Leukemia is a type of blood cancer that develops in bone marrow—where blood cells are made. The disease can cause many symptoms, including rashes and bruises.
Chronic Lymphocytic Leukemia: Survival Rate and Prognosis
Chronic Lymphocytic Leukemia: Survival Rate and Prognosis
Chronic lymphocytic leukemia is the result of an overproduction of abnormal lymphocytes, a type of white blood cell. Learn about prognosis and survival rates.
7 Important Symptoms of Leukemia in Children
7 Important Symptoms of Leukemia in Children
Leukemia is the most common cancer in children. Though symptoms can vary or indicate a different problem, these are seven important symptoms of the disease.
Survival Rates and Prognosis for Acute Myeloid Leukemia
Survival Rates and Prognosis for Acute Myeloid Leukemia
Acute myeloid leukemia (AML) attacks the bone marrow and blood. No two patients are the same. Outcomes may differ. Learn more about prognosis and survival rate.
Advertisement
Advertisement
Advertisement