What Is Chronic Lymphocytic Leukemia (CLL)?

Chronic lymphocytic leukemia (CLL) is a cancer of the blood in which too many lymphocytes, a type of white blood cell, are produced by the bone marrow and by organs of the lymph system.

Normally, most lymphocytes fight infection by making antibodies that attack harmful elements. But, in CLL, the cells are immature and overabundant. They crowd out other blood cells, and may collect in the blood, bone marrow, and lymph tissue. CLL is a slowly progressing disease.

CLL is found almost exclusively in adults. It is rare in people younger than age 40 and is extremely rare in children. Most develop the disease after age 60.

Chronic lymphocytic leukemia is the most common adult leukemia. The average age at diagnosis is 70 and often individuals are without symptoms. Many do not need immediate treatment and can go for years before treatment is required. Our knowledge about risk factors for progression of disease as well as factors that predict response to treatment has advanced in recent years. Blood tests for these factors are readily available at Stanford.

Stanford expertise

Novel, oral therapies will soon be available based on clinical trials that were performed at Stanford. These drugs, and others, continue to be studied in clinical trials and offer the promise of revolutionary new therapies for CLL.

Clinical Trials

Cancer Center doctors are active in developing and testing new therapies for the treatment of CLL, including:

  • New methods for delivering radiation therapy
  • Targeted biological therapies such as monoclonal antibodies

When appropriate, patients are invited to participate in studies to investigate the newest treatments as well as large-scale clinical trials for more established treatments.

Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you may have access to the latest, advanced clinical trials.

Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.

Before beginning treatment, ask your doctor about any clinical trials you should consider. Learn more about clinical trials for cancer patients.

Clinical trial eligibility flowcharts

Eligibility flowcharts map clinical trials to specific types of cancers to determine if a participant is eligible for the particular clinical trial. View all hematology eligibility flowcharts at the Stanford Cancer Institute.

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