There are five types of white blood cells in the body, each with different responsibilities. Neutrophils make up the largest numbers of white blood cells, serving as the first line of immune defense. Chemotherapy-induced neutropenia is a low neutrophil count—normal counts are between 2,500 and 5,000, and a count of less than 1,500 indicates mild neutropenia. A count of between 500 and 1,000 is considered moderate, and a count of less than 500 is severe.
A low neutrophil count significantly increases the chances of contracting an infection because there are not enough white blood cells to attack invading bacteria. The lower the neutrophil count, the higher the risk of getting an infection. The cancer care team tracks blood counts throughout the treatment process.
There are a number of reasons one might develop neutropenia, but chemotherapy is one of the most common causes of neutropenia. These therapies can be very effective in treating cancer, but cannot differentiate between healthy cells and cancer cells. Chemotherapies treat cancer by targeting rapidly dividing cells, whether cancer cells or white blood cells—causing neutropenia.
Not everyone who receives chemotherapy will develop neutropenia, but there is no guaranteed way to prevent it. The care team plans the schedule and dosage of therapies to be most effective in treating the cancer, but neutropenia can cause delays treatments while waiting for blood cell counts to return to normal. Medications called growth factors can help maintain counts or shorten the duration of neutropenia, given in conjunction with treatment.
The number one way to prevent infection is hand washing, and encouraging others to do the same.
When neutrophils are low, the signs of an infection may look different. Many of the symptoms experienced normally are actually a sign that neutrophils are doing their jobs, such as high fever, swelling, redness, or pus. Without enough neutrophils, every sign of infection is serious. Call the care team immediately if experiencing these symptoms: