Understanding - and Overcoming - Neutropenia
Probably one of the most frustrating-and potentially dangerous-side effects from chemotherapy is the lowering of your blood counts.
Chemotherapy works by targeting fast-growing cells in your body-a primary characteristic of cancer cells. However, there are other normal fast-growing cells that exist naturally in your body, including those in the bone marrow that are responsible for producing most of the body's new blood cells. Unfortunately, these can also be affected by chemotherapy.
When the production of red blood cells is adversely affected by chemotherapy, and the total red blood cell count in your body drops, fatigue and anemia can result. When white cells are similarly affected, there is a much greater risk of infection. A condition called neutropenia occurs when you have a dangerously low total of white blood cells called neutrophils in your body.
One of the primary treatments for building up blood counts, including neutrophils, is by giving injections of colony-stimulating factors or CSFs.
Colony-stimulating factors (sometimes called hematopoietic growth factors) are hormone-like substances which are naturally produced by the body. They stimulate the bone marrow to produce more blood cells. In recent years, researchers have discovered ways to manufacture CSFs synthetically as medications for patients with low blood cell counts.
There are several types of growth factors, which are named according to the type of blood cell they promote:
Normally, colony-stimulating factor injections are given once a day, often by the patient herself. But a new study by researchers in England has found that twice-daily injections, each at half the normal daily dose, may be far superior in stimulating new cell production-without any increase in side effects.
Writing in the British Journal of Haematology, Dr. Nicolaus Kroger and colleagues from the University of Hamburg found that twice-a-day G-CSF injections (at 5 mcg/kg) stimulated the production of significantly more stem cells-new, immature cells-than standard once-a-day injections (at 10 mcg/kg).
Specifically, 5.4 million/kg stem cells were induced using the twice-daily regimen, compared to 4 million/kg for the once-daily injections. Importantly, there was no change in side effects between the two regimens, which included mild to moderate bone pain, mild headache, and mild fatigue.
Neutropenia affects as many as one-in-three patients receiving chemotherapy treatment for cancer. Patients with neutropenia can develop fever and infections, particularly in the mouth, throat, sinuses, lungs and skin.
Furthermore, if neutrophil counts become too low, chemotherapy treatments may have to be delayed until the body can produce more neutrophils. Sometimes a lower chemotherapy dosage may have to be given, which may result in the treatment being less effective.
By using colony-stimulating factors to stimulate blood cell production, doctors can maintain the optimal dosage of anti-cancer drugs without increasing the risk of infection or the need for blood transfusions.
On a regular basis, however, you can also minimize your infection risk when your counts are low by washing your hands throughout the day, staying away from people with illnesses, avoiding crowds, and maintaining good mouth care.
SOURCES:
British Journal of Haematology, February 2001; 111:761-765
The National Cancer Institute (http://www.nci.nih.gov)
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