In the process of destroying cancer cells, chemotherapy can also cause damage to other rapidly dividing cells, such as the bone marrow cells. Bone marrow is responsible for producing red blood cells (RBCs), white blood cells (WBCs) and platelets. The reduced activity of the bone marrow is named myelosuppression. Blood components will decrease after chemotherapy, but at different speeds. White blood cells will be affected more rapidly, because of their shortest life span. White blood cells are the soldiers defending the human body against infections, so a low number is associated with increased infections. Your doctor will follow the number of white blood cells (counts) throughout your cancer treatments. White blood cells will reach their lowest number 10 to 14 days after the end of chemotherapy. The lowest number is also known as the nadir. White blood cells will recover within 3 to 4 weeks, except for some drugs that can cause a slower decrease and a longer recovery, such as the nitrosoureas or mitomycin C. There are two methods of measuring your number of cells. The first one is by counting the total number of WBC, which is preferably over 3,000/mm³. The other method is to calculate the Absolute Neutrophil Count (ANC), which should be over 1,500/mm³ to reduce the risk of infections. If the WBC count or ANC does not come back fast enough, your doctor may decide to hold the next cycle of chemotherapy until your blood count are sufficient.
In order to speed up the recovery and the activity of your WBCs, drugs such as "colony-stimulating factors" (CSFs) can be administered. Two CSFs are used in the United States to increase the WBC count, G-CSF (Neupogen) and GM-CSF (Leukine). They are given according to the weight of the patient and the level of bone marrow recovery. GCSF is given by subcutaneous injection every day for about 1 week after chemotherapy. Patient experiencing bone pain (usually in the sternum or hips) may take acetaminophen or a non-steroidal analgesic (ibuprofen, naproxen) if necessary.
|Drug name||Usual dose||Side effects||Cost|
|G-CSF (Filgastrim, Neupogen)||5mcg/kg/day SQ for 7 to 10 days rounded to:
300 mcg if < 75kg
480 mcg if >75 kg
|Nausea, fever, bone pain||$$$$|
|GM-CSF (Sargramostim, Leukine)||250 mcg/m² SQ or IV for 14 day||Fever, flushing, hypotension, rigors, bone pain.||$$$$|
Your doctors will periodically monitor all of your blood counts. One of the blood counts is of the platelets. A normal value ranges from 150,000 to 300,000 per ml of blood. Low blood counts including a low platelet count can occasionally occur after receiving a lot of chemotherapy or radiation therapy. Thrombocytopenia, a very low platelet count (< 20,000/ml of blood) can result in bleeding from the nose, gums, urinary tract, or gastrointestinal tract. The usual time for a low platelet to occur is 10 to 21 days after chemotherapy, but any bleeding at any time should be reported immediately to your doctors. In order to keep the risk of having any bleeding during chemotherapy, it is best to avoid drugs that can affect the functioning of platelets. Such drugs include aspirin, ibuprofen (Advil), naprosyn (Aleve). If your platelet level is very low, you may be prescribed a platelet transfusion. In patients who have a low trend to thrombocytopenia, a drug called Neumega may be prescribed to prevent further fall in the platelet counts.
Your doctors will periodically monitor all of your blood counts. One of the blood counts is of the red blood cells. Cancer and its treatment with chemotherapy or radiation can depress the number of red blood cells to a low level and eventually produce tiredness, lack of energy, and anemia. A normal value of red blood cells produces a hematocrit of nearly 40 or a hemoglobin of 14 to 15. Symptoms of anemia appear when the hematocrit falls below 30 or the hemoglobin is less than 9. If you have severe symptoms of anemia, you may be prescribed a red blood cell transfusion. A trend toward anemia may be prevented with the early initiation of a weekly injection of epoetin alfa (Procrit). The usual therapy for anemia is outlined below.
|Drug or Therapy||Usual dose||Side effects||Cost|
|Red blood Cell||1 unit for each 3 HCT points below normal Intravenously||Hypersensitivity reactions, hepatitis||$250/unit|
|Procrit (Epoetin Alfa)||40,000 units per week subcutaneously||Hypertension||$150 to 300 per injection|