What are transfusions?

Blood product transfusions are used to replace important components of the blood when there are not enough in the body, either because they have been lost through bleeding or are not being made. There are many possible reasons people might need blood product transfusions, such as major bleeding (due to trauma or surgery) or diseases and treatments that slow production of blood cells.

People with cancer might need blood transfusions because of the cancer itself. For example:

• Some cancers (especially digestive system cancers) can cause internal bleeding, which can lead to anemia (too few red blood cells).
• Cancers that start in the bone marrow (such as leukemias) or cancers that spread there from other places may crowd out the normal blood-making cells, leading to low blood counts.
• People who have had cancer for some time may develop what is known as anemia of chronic disease. This anemia results from certain long-term medical conditions that affect the production and lifespan of red blood cells.
• Cancer can also lower blood counts in other ways by affecting organs such as the kidneys and spleen, which are involved in keeping enough cells in the blood.

Cancer treatments may also lead to the need for blood transfusions:

• Surgery to treat cancer is often a major operation, and blood loss may lead to a need for red blood cell or platelet transfusions.
• Most chemotherapy drugs affect cells in the bone marrow. This commonly leads to low levels of white blood cells and platelets, which can sometimes put a person at risk for life-threatening infections or bleeding.
• When radiation is used to treat a large area of the bones, it can affect the bone marrow and lead to low blood cell counts.
• Bone marrow transplant (BMT) or peripheral blood stem cell transplant (PBSCT) patients get large doses of chemotherapy and/or radiation therapy. This destroys the blood-making cells in the bone marrow. These patients often have very low blood cell counts after the procedure and may need transfusions.

Red blood cell transfusions

People who have low red blood cell (RBC) counts are said to have anemia or to be anemic. People who have anemia for any of the reasons above may need RBC transfusions because they don't have enough RBCs to carry oxygen to all of the cells in the body. Signs and symptoms of severe anemia can include paleness of the mouth, skin, and nail beds; dizziness; and shortness of breath.

Doctors check for and learn the severity of anemia by using blood tests to measure the following:

• Hemoglobin (Hb), which is the substance inside RBCs that carries oxygen. A normal hemoglobin count is about 14 to 18 grams per deciliter (g/dL) in men and about 12 to 16 g/dL in women. (Some labs may use slightly different values for normal.)
• Hematocrit (Hct), which is the percentage of blood made up of cells (as opposed to plasma). This is normally about 40% to 54% in men and about 37% to 47% in women. Again, this may vary slightly between labs.
• Other tests may look at the number, size, or shape of the RBCs; iron levels; or B12 levels to give doctors a better idea as to the possible causes of anemia.

Not all patients with anemia need blood transfusions. Whether you may need a transfusion depends on many factors, such as how long it took for the anemia to develop and how well your body is able to cope with it. Anemia due to a sudden loss of blood will probably need to be corrected right away. Anemia that develops slowly is less likely to cause problems, as the body has time to adjust to it to some extent. If your hemoglobin level is lower than normal but you are not dizzy, pale, or short of breath, you may not need a transfusion.

Patients who have certain heart or lung diseases may need transfusions even if their hemoglobin level is not very low because they are more sensitive to the effects of anemia. Other conditions that increase the need for oxygen may also require transfusions.

Even when cancer patients need treatment for anemia, not all of them will need transfusions. Erythropoietin is the chemical normally made by the kidneys that causes the bone marrow to make its own red blood cells. Man-made versions of this chemical, such as epoetin (Procrit®, Epogen®) and darbepoetin (Aranesp®) can be given as shots (injections). These medicines do not pose some of the risks of a transfusion (see below), but they do have their own risks. One of these drugs may be used instead of a red blood cell transfusion in patients whose chemotherapy is not expected to cure them. These drugs are expensive. And they don't work very quickly, so they can only be used if the need to raise the red blood cell levels is not urgent. It can take several weeks before these drugs increase the red blood count.

Low iron or B12 levels are less common causes of anemia in cancer patients. These problems can also be corrected, but it can take many weeks for these drugs to restore red blood cell counts.

RBC transfusions before and during surgery: Transfusions may be given during or after surgery to make up for blood loss. In the past, doctors sometimes gave them before surgery because they knew some blood would be lost during the operation, and they felt that keeping the blood counts normal might help the healing process. Usually a transfusion was considered if a patient's hemoglobin level was below 10 g/dL.

But some studies have suggested patients with certain cancers, like colorectal, prostate, lung, and breast cancer, had a slightly higher risk of their cancer coming back if many transfusions were given before or during surgery. Transfused blood is thought to affect the immune system in ways that may cause problems later. The information can be hard to make sense of because many of the studies only looked at people who had and hadn't been transfused, so the groups may have started with major differences. For instance, patients who need transfusions are often sicker to start with, and they may be treated in different ways afterward. These studies need to be confirmed by careful research. There are other reasons to think twice about transfusions before surgery, such as the risks of transfusion reactions (described below). Keep in mind too, that while it may be possible to reduce the number of transfusions, totally avoiding them can cause serious risks or even death in some people.

Most doctors now feel that transfusions before surgery should not be given just because of low lab values. The decision to transfuse should be made in the context of other factors as well, such as the patient's symptoms and overall health.

Plasma transfusions

Plasma is commonly given to patients who are bleeding because their blood is not clotting the way it should. Cancer patients might also be given fresh frozen plasma (FFP) if they have a problem called disseminated intravascular coagulation (DIC). This is a rare condition where all of the clotting factors in the body are used up or broken down. Signs and symptoms (such as excessive bleeding and bruising) and lab tests (such as measuring fibrin breakdown products) help the doctor identify DIC.

Platelet transfusions

Cancer patients may need transfusions of platelets if their bone marrow is not making enough. This happens when platelet-producing bone marrow cells are damaged by chemotherapy or radiation therapy or when they are crowded out of the bone marrow by cancer cells.

A normal platelet count is about 150,000 to 400,000 platelets per cubic millimeter (mm3). When platelet counts drop below a certain level (often 20,000/mm3), a patient is at risk for dangerous bleeding. Doctors may think about giving a platelet transfusion when the platelet count drops to this level, or even at higher levels if a patient needs surgery and may be at risk of bleeding.

If there are no signs of bleeding, a platelet transfusion may not be needed even if the platelet count is low.

Currently there is one drug, known as interleukin-11 (oprelvekin or Neumega®), that doctors can give to help raise platelet counts without transfusion. Like other medicines to help blood counts, it takes time for this drug to raise the platelet counts, anywhere from 10 to 21 days.

Cryoprecipitate transfusions

Cryoprecipitate may be given to replace several blood clotting factors such as:

• Factor VIII (missing in patients with hemophilia A)
• Von Willebrand factor (needed to help platelets work)
• Fibrinogen (the major part of a clot)

People with hemophilia are now more likely to get pure factor VIII or factor IX, which can be separated from the rest of the plasma. Unless they are bleeding, people with cancer rarely need cryoprecipitate.

Granulocyte transfusions

Chemotherapy can damage cells in the bone marrow, and patients getting chemo often have white blood cell (WBC) counts lower than the normal range of 4,000 per cubic millimeter (mm3) to 10,000/mm3.

Granulocytes, especially certain kinds of granulocytes known as neutrophils, are very important in fighting infections. When patients have low WBC counts, doctors carefully watch the number of neutrophils. The blood count that is watched is called the absolute neutrophil count, or ANC. People with neutropenia (an ANC below 1,000/mm3) are at risk for serious infections, even more so if the count stays down for longer than a week.

At one time, granulocyte transfusions were commonly given to cancer patients who could not make enough of these cells on their own or whose granulocytes had been destroyed by disease or medicines. But for many reasons, such transfusions are now rare. First, it is not clear how well the transfusions help in reducing the risk of serious infections. Granulocyte transfusions can also cause a fever known as a febrile transfusion reaction. And they can sometimes transmit infectious diseases, such as cytomegalovirus (CMV), which can be dangerous for people who have weak immune systems.

Instead of transfusing granulocytes, doctors now commonly use medicines called colony-stimulating factors or growth factors to help the body make its own neutrophils. There are 2 types of growth factors that help the body make neutrophils:

• Granulocyte colony-stimulating factor (G-CSF), such as
• Filgrastim (Neupogen®)
• Pegfilgrastim (Neulasta®)
• Granulocyte-macrophage colony-stimulating factor (GM-CSF), such as
• Sargramostim (Leukine®)