Overview

Chronic lymphocytic leukemia (CLL) is a type of cancer of the blood and bone marrow — the spongy tissue inside bones where blood cells are made.

The term "chronic" in chronic lymphocytic leukemia comes from the fact that it typically progresses more slowly than other types of leukemia. The term "lymphocytic" in chronic lymphocytic leukemia comes from the cells affected by the disease — a group of white blood cells called lymphocytes, which help your body fight infection.

Chronic lymphocytic leukemia most commonly affects older adults. There are treatments to help control the disease.

Chronic lymphocytic leukemia care at JPeei Clinic

Symptoms

Many people with chronic lymphocytic leukemia have no early symptoms. Those who do develop signs and symptoms may experience:

  • Enlarged, but painless, lymph nodes
  • Fatigue
  • Fever
  • Pain in the upper left portion of the abdomen, which may be caused by an enlarged spleen
  • Night sweats
  • Weight loss
  • Frequent infections

When to see a doctor

Make an appointment with your doctor if you have any persistent signs and symptoms that worry you.

Causes

Doctors aren't certain what starts the process that causes chronic lymphocytic leukemia. What's known is that something happens to cause a genetic mutation in the DNA of blood-producing cells. This mutation causes the blood cells to produce abnormal, ineffective lymphocytes.

Beyond being ineffective, these abnormal lymphocytes continue to live and multiply, when normal lymphocytes would die. The abnormal lymphocytes accumulate in the blood and certain organs, where they cause complications. They may crowd healthy cells out of the bone marrow and interfere with normal blood cell production.

Doctors and researchers are working to understand the exact mechanism that causes chronic lymphocytic leukemia.

Risk factors

Factors that may increase the risk of chronic lymphocytic leukemia include:

  • Your age. This disease occurs most often in older adults. On average, people diagnosed with chronic lymphocytic leukemia are in their 70s.
  • Your race. Whites are more likely to develop chronic lymphocytic leukemia than are people of other races.
  • Family history of blood and bone marrow cancers. A family history of chronic lymphocytic leukemia or other blood and bone marrow cancers may increase your risk.
  • Exposure to chemicals. Certain herbicides and insecticides, including Agent Orange used during the Vietnam War, have been linked to an increased risk of chronic lymphocytic leukemia.

Complications

Chronic lymphocytic leukemia may cause complications such as:

  • Frequent infections. People with chronic lymphocytic leukemia may experience frequent infections. In most cases, these infections are common infections of the upper and lower respiratory tract. But sometimes more-serious infections can develop.
  • A switch to a more aggressive form of cancer. A small number of people with chronic lymphocytic leukemia may develop a more aggressive form of cancer called diffuse large B-cell lymphoma. Doctors sometimes refer to this as Richter's syndrome.
  • Increased risk of other cancers. People with chronic lymphocytic leukemia have an increased risk of other types of cancer, including skin cancer, such as melanoma, and cancers of the lung and the digestive tract.
  • Immune system problems. A small number of people with chronic lymphocytic leukemia may develop an immune system problem that causes the disease-fighting cells of the immune system to mistakenly attack the red blood cells or the platelets.

Overview

Chronic myelogenous leukemia (CML) is an uncommon type of cancer of the bone marrow — the spongy tissue inside bones where blood cells are made. CML causes an increased number of white blood cells in the blood.

The term "chronic" in chronic myelogenous leukemia indicates that this cancer tends to progress more slowly than acute forms of leukemia. The term "myelogenous" (my-uh-LOHJ-uh-nus) in chronic myelogenous leukemia refers to the type of cells affected by this cancer.

Chronic myelogenous leukemia can also be called chronic myeloid leukemia and chronic granulocytic leukemia. It typically affects older adults and rarely occurs in children, though it can occur at any age.

Advances in treatment have contributed to a greatly improved prognosis for people with chronic myelogenous leukemia. Most people will achieve remission and live for many years after diagnosis.

Symptoms

Chronic myelogenous leukemia often doesn't cause signs and symptoms. It might be detected during a blood test.

When they occur, signs and symptoms may include:

  • Bone pain
  • Easy bleeding
  • Feeling full after eating a small amount of food
  • Feeling run-down or tired
  • Fever
  • Weight loss without trying
  • Loss of appetite
  • Pain or fullness below the ribs on the left side
  • Excessive sweating during sleep (night sweats)

When to see a doctor

Make an appointment with your doctor if you have any persistent signs or symptoms that worry you.

Causes

Chronic myelogenous leukemia occurs when something goes awry in the genes of your bone marrow cells. It's not clear what initially sets off this process, but doctors have discovered how it progresses into chronic myelogenous leukemia.

An abnormal chromosome develops

Human cells normally contain 23 pairs of chromosomes. These chromosomes hold the DNA that contains the instructions (genes) that control the cells in your body. In people with chronic myelogenous leukemia, the chromosomes in the blood cells swap sections with each other. A section of chromosome 9 switches places with a section of chromosome 22, creating an extra-short chromosome 22 and an extra-long chromosome 9.

The extra-short chromosome 22 is called the Philadelphia chromosome, named for the city where it was discovered. The Philadelphia chromosome is present in the blood cells of 90 percent of people with chronic myelogenous leukemia.

The abnormal chromosome creates a new gene

The Philadelphia chromosome creates a new gene. Genes from chromosome 9 combine with genes from chromosome 22 to create a new gene called BCR-ABL. The BCR-ABL gene contains instructions that tell the abnormal blood cell to produce too much of a protein called tyrosine kinase. Tyrosine kinase promotes cancer by allowing certain blood cells to grow out of control.

The new gene allows too many diseased blood cells

Your blood cells originate in the bone marrow, a spongy material inside your bones. When your bone marrow functions normally, it produces immature cells (blood stem cells) in a controlled way. These cells then mature and specialize into the various types of blood cells that circulate in your body — red cells, white cells and platelets.

In chronic myelogenous leukemia, this process doesn't work properly. The tyrosine kinase caused by the BCR-ABL gene allows too many white blood cells to grow. Most or all of these cells contain the abnormal Philadelphia chromosome. The diseased white blood cells don't grow and die like normal cells. The diseased white blood cells build up in huge numbers, crowding out healthy blood cells and damaging the bone marrow.

Risk factors

Factors that increase the risk of chronic myelogenous leukemia:

  • Older age
  • Being male
  • Radiation exposure, such as radiation therapy for certain types of cancer

Family history is not a risk factor

The mutation that leads to chronic myelogenous leukemia isn't passed from parents to children. This mutation is believed to be acquired, meaning it develops after birth.


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