Reviewed by Barbara E. Livingston, RN,
NP, AOCN, Oncology Nurse Practitioner, The Mount Sinai Medical Center, New York,
Red blood cells (RBC) are produced in the spongy center of large bones called the bone marrow. Chronic diseases, cancer, cancer treatment, blood loss and poor nutrition can all lower the number of red blood cells. Almost all people treated with chemotherapy will experience some degree of anemia. Anemia following radiation therapy will depend on the area of the body receiving the beam of radiation. Fatigue, a hallmark symptom of anemia, is the number one symptom described by people with cancer.
There are many checkpoints located in the body that detect when oxygen levels are too low. A healthy, active individual might compensate for lower oxygen levels (from a low hemoglobin level) simply by increasing the number of breaths per minute. This is not a conscious effort but an automatic one made by the body in an effort to bring more oxygen into the blood. In contrast, it would be difficult for a person with heart and lung disease to attempt this sort of compensation in the face of anemia.
Another way to assure there is enough oxygen circulating in the blood is a release of more erythropoietin (EPO) from the kidneys. EPO is a growth factor that stimulates the production and release of more red blood cells from the bone marrow. When the kidneys detect a decrease in oxygen in the blood (as it would with anemia) it increases EPO to step-up the release of more red blood cells. EPO release is then slowed when the number of red blood cells and the amount of oxygen returns to normal.
Although EPO continues to be produced in people with cancer, their levels tend to be low. Myelosuppressive chemotherapy agents (cisplatin, carboplatin), which are processed by the kidneys, prevent enough EPO from being released. EPO also requires iron to work properly. People with cancer tend to store more iron but release less into the blood stream than people without cancer, limiting the release of EPO when it is most needed. EPO can also be manufactured in the laboratory as recombinant human EPO and given as treatment to people who have anemia.
Knowing the signs and symptoms of anemia and reporting them early is key. If the anemia develops slowly however, there may be no symptoms at all.
Symptoms of anemia include:
How Red Blood Cells Are Measured
Many laboratories use their own reference standards for measuring red blood cells, hemoglobin and hematocrit.
Adult female is 12 - 16 grams per deciliter
Adult male it is 14 - 18 grams per deciliter
Red Blood Cell Count
Adult female is 4.2 - 5.4 x 106/micro liter
Adult male is 4.7 - 6.1 x 106/micro liter
Adult female is 37 - 47 percent
Adult male 42 - 52 percent
Anemia is diagnosed when the hemoglobin falls below 13 g/dL for men and 12g/dL for women.