Polycythemia vera is a blood cancer that causes red blood cells to multiply. White blood cells and platelets may also multiply.
Polycythemia vera causes the red blood cells to multiply. Red blood cells are the oxygen-carrying cells of the body. Other cells of the blood can also multiply. White blood cells, the infection fighting cells in the body, and platelets, which help blood to clot, are also usually affected.
The cause of polycythemia vera is unknown. It is slightly more common in those who are Jewish. Men are more commonly affected than women. More than 95% of cases occur in people older than 40 years of age.
Symptoms of polycythemia vera are often related to the abnormally high number of blood cells. Symptoms usually come on gradually, and may include:
Some people have no symptoms at all, and the diagnosis is made accidentally when a routine blood test is done.
The diagnosis of polycythemia vera may be suspected after a history and physical exam. A blood test called a complete blood count (CBC) is the first step in making the diagnosis. This test counts the number of each of the kinds of blood cells. A person with polycythemia vera has an elevated red blood cell count, and usually has elevated white blood cell and platelet counts as well. Other blood tests, such as a vitamin B12 level or an erythropoietin level, may also be done.
Often, a procedure called a bone marrow biopsy is done to help confirm the diagnosis. This involves inserting a special needle through the skin of the upper buttock area and into the pelvic bone. The needle is used to take a sample of bone marrow, the soft material found inside certain bones where blood cells are made. The sample of marrow can be sent to the lab for examination and special testing.
There is no known prevention for polycythemia vera.
After diagnosis, most people with polycythemia vera live no more than 15 years with treatment. Without treatment, a person may only live a few years. This cancer increases the risk of life-threatening blood clots and bleeding. In some cases, polycythemia vera may transform into the more aggressive blood cancer leukemia.
Polycythemia vera is not contagious, and poses no risk to others.
Treatment does not cure polycythemia vera. The goal of treatment is to thin the blood enough to decrease the risk of clots and abnormal bleeding. One of the main treatments is to remove some of the person's blood, in a procedure called phlebotomy. The person has blood removed regularly to keep it from getting too thick. A needle is inserted through the skin and into a vein, usually in the hand or forearm. Blood is then removed with the needle.
Chemotherapy is also used in some cases to improve survival. Aspirin can be given to help decrease the risk of blood clots.
Aspirin can cause allergic reactions, stomach upset, and kidney damage. Chemotherapy can cause many different side effects, including nausea and damage to the kidney or liver. Removing blood can be painful and may result in an infection. If too much blood is removed, a person may feel weak and tired.
Most people die from polycythemia vera or its complications, with or without treatment. Treatment can allow a person to live longer in most cases, but cannot cure the cancer.
A CBC is done regularly to monitor blood cells counts and to guide further therapy. Other monitoring is related to any complications that occur, such as blood clots. Any new or worsening symptoms should be reported to the healthcare provider.
Author:James Broomfield, MD
Date Written:
Editor:Duff, Ellen, BA
Edit Date:10/09/00
Reviewer:Adam Brochert, MD
Date Reviewed:07/05/01
The Merck Manual, 1995, Berkow et al.