Hairy Cell Leukemia
Introduction
Hairy cell leukemia is a rare, slow-growing cancer of the blood in which your bone marrow makes too many B cells (lymphocytes), a type of white blood cell that fights infection. These abnormal cells look "hairy" under a microscope because of fine projections (villi) from their surface. As the number of leukemia cells increases, fewer healthy white blood cells, red blood cells and platelets are produced.
About 600 people are diagnosed with hairy cell leukemia each year in the United States. Hairy cell leukemia affects more men than women, and it occurs most commonly in middle-age or older adults. Children and teenagers don't get hairy cell leukemia.
Doctors aren't sure what causes hairy cell leukemia. Although there is no cure, new treatments offer an excellent chance of living cancer-free for at least 10 years. Doctors consider hairy cell leukemia a chronic form of cancer because treatments can lead to a remission for years, though hairy cell leukemia may never completely disappear.
Signs and symptoms
Some people show no signs or symptoms of hairy cell leukemia, but a blood test for another disease or condition may inadvertently reveal hairy cell leukemia in their blood.
Other times people with hairy cell leukemia experience signs and symptoms common to a number of diseases and conditions, such as:
- A feeling of fullness in your abdomen that may make it uncomfortable to eat more than a little at a time
- Fatigue
- Easy bruising
- Recurring infections
- Weakness
- Weight loss
Cancers are caused by a defect in your DNA. In the case of hairy cell leukemia, mutations in the DNA cause your bone marrow stem cells to create too many white blood cells that don't work properly. It isn't clear what causes the DNA mutations that lead to hairy cell leukemia.
Treatment
Treatment isn't always necessary for people with hairy cell leukemia. Because this cancer progresses very slowly and sometimes doesn't progress at all, some people prefer to wait to treat their cancer only if it causes signs and symptoms. The majority of people with hairy cell leukemia will eventually need treatment.
Though you may be eager to rid your body of cancer if you've been diagnosed with hairy cell leukemia, know that there's no advantage to early treatment. Unlike some other types of cancer, hairy cell leukemia is quite treatable at all stages, meaning that waiting to treat your cancer won't make remission any less likely.
If your hairy cell leukemia causes signs and symptoms, you may decide to undergo treatment. There is no cure for hairy cell leukemia. But the good news is that new treatments are effective at putting hairy cell leukemia in remission for years.
Chemotherapy
Doctors consider chemotherapy drugs the first line of treatment for hairy cell leukemia. About 90 percent of people will experience complete or partial remission through the use of chemotherapy. Two chemotherapy drugs are used in hairy cell leukemia:
- Cladribine (Leustatin). Most treatment regimens for hairy cell leukemia begin with cladribine. You receive a continuous infusion of the drug into a vein over seven days. Most people who receive cladribine experience a complete remission that can last for several years. If your hairy cell leukemia returns, you can be treated with cladribine again. Side effects of cladribine include infection and fever.
- Pentostatin (Nipent). Pentostatin causes remission rates similar to cladribine, but it's given on a different schedule. People who take pentostatin receive infusions every other week for three to six months. Side effects of pentostatin include fever, infection, sensitivity to light, eye inflammation (keratoconjunctivitis), and nausea and vomiting.
Biological treatments
Biological therapy (immunotherapy) attempts to make cancer cells more recognizable to your immune system. Once your immune system identifies cancer cells as intruders, it can set about destroying your cancer. Two types of biological treatments are used in hairy cell leukemia:
- Interferon alpha. Interferon alpha was the first biologic drug approved for cancer treatment. You might use interferon alpha if chemotherapy hasn't been effective or if you can't take chemotherapy. Most people experience partial remission with interferon alpha, which is taken over a year. Side effects include flu-like symptoms, such as fever and fatigue.
- Rituximab (Rituxan). Rituximab is a monoclonal antibody approved to treat non-Hodgkin's lymphoma, though it's sometimes used in hairy cell leukemia. If chemotherapy drugs haven't worked for you or you can't take chemotherapy, your doctor might consider rituximab. Side effects of rituximab include bleeding, fatigue, headache and infection.
Surgery to remove your spleen (splenectomy) was the first treatment used in hairy cell leukemia, though it's used only rarely today. Your doctor might recommend splenectomy if your spleen ruptures or if it's enlarged and causing you pain. Though removing your spleen can't cure hairy cell leukemia, it can usually restore normal blood counts. For that reason, splenectomy may be useful in people with uncontrollable infections. All surgery carries a risk of bleeding and infection. Removal of your spleen can cause inflammation of your blood vessels (vasculitis) and can make you susceptible to infection.
Credit: National Institute of Health.