Why Cancer Patients Might Need Blood Product Transfusions

[Bank of Blood.com]

Blood product transfusions are used to replace important components of
the blood when there are not enough in the body, either because they
are not being made or because they have been lost. 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.
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
create 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 commonly 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 measure the severity of anemia by doing the
following blood tests:

Hemoglobin (Hb) is the substance that carries oxygen inside RBCs. 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) 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 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 a cancer patient needs treatment for anemia, some may not
need a transfusion. 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). 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 medicines do not pose some of the risks of a
transfusion (see below), but they do have their own risks. They are
also expensive. These drugs 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.

RBC transfusions before 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, may be at higher risk
of the cancer coming back if given many transfusions. The topic is
controversial and the results of these studies still need to be
confirmed by further research. There also may be other reasons to
think twice about transfusions before surgery, such as the risks of
transfusion reactions or infections (described below).

Most doctors now feel that transfusions before surgery should not be
given just because of low lab values such as hemoglobin levels. 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 are used up or broken down in the
body. 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 may be at risk of bleeding because of surgery.

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,
Neumega®), that doctors can give to help raise platelet counts without
transfusion, but it does not work right away and is not widely used at
this time.

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,
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/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 prescribe
medicines called colony-stimulating factors or growth factors to help
the body make its own neutrophils. Examples include granulocyte colony-
stimulating factor (G-CSF), also known as filgrastim (Neupogen®) or
pegfilgrastim (Neulasta®), and granulocyte-macrophage colony-
stimulating factor (GM-CSF), also called sargramostim (Leukine®).

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