What Is Hairy Cell Leukemia? Treatment, Symptoms, and Causes

Hairy cell leukemia is considered a chronic condition, meaning it is incurable.

But the good news is that it is highly treatable. People can go into long, sustained remissions, with levels of hairy cells in the blood and marrow that are so low, they are undetectable even using the most advanced technologies. With proper medical attention, many patients do well for years or even decades and have a near-normal life expectancy.

Finding a doctor who has specialized knowledge of this leukemia can make a significant difference in outcome. For the highest quality of care, the Leukemia & Lymphoma Society recommends that patients seek out physicians with experience in hairy cell leukemia (usually a hematologist oncologist) or a doctor who works closely with a specialist. (8)

Treatment for hairy cell leukemia can take a number of forms. These include:

Watch and Wait About 10 percent of patients with this slow-growing form of leukemia don’t take any medication or receive any other form of therapy at all. Instead, doctors monitor the condition with regular physical exams and blood tests. This approach allows patients to avoid medication and the potential side effects for as long as possible.

Chemotherapy This is one of the front-line treatment for hairy cell leukemia. Chemo drugs are toxic: They damage or kill hairy cells. But they may also harm healthy cells in the process, causing side effects.

Patients typically receive a type of chemo drug called a purine analog — usually cladribine (Leustatin), administered intravenously every day for up to a week. Around 85 percent of patients treated with cladribine go into complete remission (meaning there is no evidence of disease), while 10 percent or so have a partial response.

Doctors may also use a purine analog called pentostatin (Nipent). It causes remission rates similar to cladribine but is administered according to a different schedule. Patients may receive this medication every other week for three to six months. (5)

What Happens if Treatment for Hairy Cell Leukemia Doesn’t Work?

Some patients will still have detectable levels of hairy cells in their body after treatment, a condition called refractory hairy cell leukemia. Or the hairy cell leukemia may relapse — that is, it may return after a period of remission.

Doctors use a number of drugs to treat refractory or relapsed hairy cell leukemia. Among the newest are targeted therapies that attack cancer cells without harming normal cells.

• Cladribine or Pentostatin Physicians may go back to these first-line chemotherapy drugs.
• Rituximab (Rituxan) This drug is a monoclonal antibody — a laboratory-made version of an immune-system protein that is genetically engineered to find and attach to specific targets on hairy cells. Rituximab targets and binds to CD20, a protein on the surface of hairy cells, triggering the body’s immune system to attack.
• Moxetumomab Pasudotox (Lumoxiti) This monoclonal antibody targets the CD22 protein on the surface of hairy cells, then delivers a deadly bacterial toxin right to the cells.
• Roferon-A or Intron A (Interferon-Alfa) This type of drug is called an immunomodulator. Interferon is a hormone naturally produced by the body to mount an immune response to infection.

Occasionally, patients with enlarged spleens may need to have the organ removed surgically in a procedure called a splenectomy. This won’t cure hairy cell leukemia, but it can rid the body of the accumulated hairy cells in the spleen, helping normalize blood cell levels. (8)

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