Bone Marrow Suppression

The medical term for a low WBC count is leukopenia.

Blood normally has between 4,000 and 10,000 WBCs per cubic millimeter (mm3). WBCs are divided into 2 main categories, based on how they look under the microscope:

• Granulocytes, which contain granules (visible specks) in the cytoplasm of the cell. This category includes 3 subtypes: neutrophils, eosinophils, and basophils.
• Agranulocytes, which do not contain granules in the cytoplasm of the cell. This category includes 3 subtypes: lymphocytes, monocytes, and macrophages.

Granulocytes, especially neutrophils, provide an important defense against infections and are the most numerous type of WBC. Neutropenia, an abnormally low number of neutrophils, is a common side effect that puts people with cancer at risk for infection. To determine how likely someone is to develop an infection, health care providers look at the number of neutrophils in the blood, called the absolute neutrophil count (ANC). The normal range of neutrophils is generally between 2,500 and 6,000 cells per cubic millimeter. The lower the ANC, the less able the person is to fight off infection. A person is neutropenicwhen their ANC is 1,000 or less. An ANC lower than 500 is considered severe neutropenia.

A person who is neutropenic has a high risk of developing an infection. Infections in neutropenic patients are very serious and can quickly become life threatening. Your doctor will watch your neutrophil count closely during chemotherapy.

Having a low WBC count or neutrophil count does not mean you will definitely get an infection. But you need to watch for these signs and symptoms:

• Fever
• Sore throat
• New cough or shortness of breath
• Nasal congestion (stuffy nose)
• Burning during urination
• Shaking chills
• Redness, swelling, pain, and warmth at the site of an injury or at an IV, CVC, or implanted catheter site

Fever is a very important sign and is often the first sign of an infection. Usually you will be instructed to call your doctor or nurse if you have a fever higher than or equal to 100.5° F when taken by mouth, or if you have any other signs or symptoms of infection (such as those listed above).

Your health care team may take measures to lower your risk of infection. For example, you might be told to stay away from small children or other people who are likely to be sick. When WBC counts are very low, doctors often prescribe antibiotics as a preventive measure. These anti-infection drugs can be given intravenously, but most often are given by mouth.

Because of the risk of infections, further chemotherapy doses may need to be delayed when you have a very low WBC count.

In some situations, doctors may prescribe growth factors (also called colony-stimulating factors) to keep the WBCs from falling too low so that chemotherapy can be given as scheduled. (As previously discussed, the timing of the chemotherapy cycle is important in killing the maximum number of cancer cells.) Your body normally produces several growth factors to prompt the bone marrow to make various types of blood cells. But the normal levels of these factors in the body are often not enough to keep up with demands during chemotherapy. Researchers have learned how to make these growth factors in the lab, and they are now available as drugs which help the body maintain normal blood cell levels.

The growth factors that stimulate production of WBCs are

• Granulocyte-macrophage colony-stimulating factor or GM-CSF, also called sargramostim or Leukine®
• Granulocyte colony-stimulating factor or G-CSF, also called filgrastim or Neupogen®

These drugs are often given daily, usually starting the day after you receive chemotherapy. They can be given for up to 2 weeks.

A longer lasting form of G-CSF is now available. It is called pegfilgrastim or Neulasta®. It is given only once each chemotherapy cycle, usually about 24 hours after completing chemotherapy.

These drugs help bone marrow recover and make WBCs more quickly, and reduce your risk of getting a serious infection. They are commonly given as injections under the skin (SQ). Nurses give the injections if you are in the hospital or at the doctor’s office, but you or your family members can learn how to give these injections at home.

You can learn more about this in the American Cancer Society document called Infections in People With Cancer .

Please share how this information is useful to you. 0 Comments