Anemia During Cancer

Cross section of blood vessel with normal amounts of red blood cells. Below it is another cross section of blood vessel showing too few red blood cells because of anemia.

When levels of healthy red blood cells (RBCs) in the body drop to levels that are below normal, the condition is called anemia. Anemia can occur during cancer and its treatment for many reasons. Read below to learn more about anemia during cancer and how it’s treated.

What is anemia?

RBCs are made in the bone marrow. Normal blood has about 35% to 50% RBCs. Anemic blood has less than 35% RBCs. RBCs carry oxygen around the body. If you have low levels of RBCs, not enough oxygen is delivered to your body. This may cause symptoms of dizziness, weakness, or tiredness. You may have trouble doing daily tasks. You may often feel cold. And you may be short of breath and have a rapid heartbeat. But some people with anemia have no symptoms.

Why anemia can occur with cancer

Anemia during cancer can have several causes:. These include:

  • Treatments that destroy bone marrow, such as chemotherapy and radiation therapy

  • Blood loss during surgery

  • Low levels of certain B vitamins or iron

  • Kidney disease leading to low levels of EPO (erythropoietin), a substance the body needs to make RBCs

  • Wasting (nutritional problems and weight loss) from cancer that lower the body’s ability to make RBCs

Testing for anemia

A blood sample is taken from your arm and then tested. Several different types of tests may be done on this blood. Some count the numbers of blood cells. Others test for substances the body uses to make RBCs, such as vitamins and iron.

Treating anemia during cancer

Your treatment will depend on the cause of your anemia. It will also depend on how severe your symptoms are. Your doctor can tell you more about treatment options and their risks and benefits for you. Treatments include the following:

  • RBC transfusion. A tube (cannula) is put into a vein in the hand or arm. RBCs from a donor are sent through the tube into the body. This increases the number of healthy RBCs in the body. This can reverse anemia very quickly. RBC transfusions are safe. However, there are some risks. Your doctor will discuss them with you. Be sure you understand these risks.You may need to sign a consent form before receiving treatment.

  • Erythropoiesis stimulating agent (ESA). This is medicine that causes the body to make more RBCs. An ESA is given as a shot. It may be given along with iron (see below). An ESA takes several weeks or months to reverse anemia. There are special risks with ESA treatment. Your doctor will discuss them with you. Be sure you understand these risks.You may need to sign a consent form before receiving treatment.

  • Intravenous (IV) iron. A liquid medicine containing iron is given by shots or IV line. Several treatments may be given. IV iron is usually used if you are being given an ESA. IV iron usually takes 1 to 4 weeks to reverse anemia.

  • Oral supplements. Iron or vitamin B supplements may be given. These come in liquid or pill form, to take by mouth or they may be by injection. Oral supplements can take weeks or months to reverse anemia.

Checking your progress

During the course of your treatment, you’ll likely have more blood tests. These are to check your blood levels and your response to the treatment.

Risks and complications

Each treatment has its own risks. Your healthcare provider will tell you what risks apply to you. These may include:

  • Fever

  • Hives or other allergic reactions

  • Iron overload

  • High or low blood pressure

  • Nausea

  • Liver inflammation

  • Blood clots


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