Neutropenia in Breast Cancer Treatment: Do you know what your counts are?
by Lisa Schwartz, MD
Breast cancer treatment is full of ups and downs. The highs usually come from completing a portion of treatment or getting good news about a procedure or test. The lows generally involve dealing with the many side effects that come with treatment (and the simple fact that you have to go through treatment at all). Most of the side effects to breast cancer treatment are annoying or impact your quality of life, but there is at least one that can be life threatening. That side effect is neutropenia or a low white blood count. Read on and I will teach you how to recognize the problems that neutropenia can cause and how to avoid them.
Neutropenia is an abnormally low level of neutrophils, which are white blood cells. White blood cells are your body’s first line of defense against infections. Neutrophils are the types of white blood cells which are especially important in fighting bacterial and fungal infections.
Neutropenia is a common side effect of many chemotherapies. Your white blood cell count will reach its nadir (lowest point) at about 7 to 14 days after chemotherapy. This is when you are at the highest risk for infection. The longer the neutropenia lasts, the more likely you are to develop an infection. White blood cell counts are important to cancer patients receiving chemotherapy since low counts can delay treatment or cause a reduction in dose or a change in type of chemotherapy.
The number of neutrophils is evaluated with a complete blood count (or CBC), and a neutrophil count of less than 1500 cells per microliter is considered mildly low, 1000 or less is moderately low, and less than 500 is severely low. When your white cell counts get very low, even the normal bacteria in your body can cause infections and even minor infections can become serious quickly.
Red and white blood cells and platelets are made in the bone marrow. The bone marrow releases billions of these cells each day. The white cells only live for a few hours. That means that the bone marrow cells that are producing them are very, very active and divide rapidly. And as you know, chemotherapy kills very rapidly dividing cells. So chemotherapy kills a lot of the cells which produce the white blood cells. Once the chemotherapy effects on the bone marrow have cleared, your bone marrow will start to make more white cells.
There are medicines called growth factors that can stimulate the bone marrow to make more white blood cells. Another name for these medications are granulocyte colony stimulating factors so you may see them abbreviated as G-CSF. These medicines are made in the laboratory but mimic the factors your body normally produces to increase white blood cell counts.
G-CSF is usually given by injection the day after chemotherapy. The medication itself can cause a low grade fever, general malaise, and bone aches. The bone aches actually mean that the medication is working and the bone marrow is producing new cells. Whether or not you receive growth factors depends on your risk for developing neutropenia. This in turn depends on the chemotherapy you are receiving, your general health, age, and other medical problems.
Your doctor may recommend growth factors even with your first dose of chemotherapy (prophylactically) if that particular chemotherapy regimen has a significant risk of causing neutropenia. In the US, if the risk that a particular chemotherapy regimen will cause neutropenia is 20% or more, you may receive growth factors. You may also receive prophylactic growth factors if you have health problems that increase your risk of neutropenia.
In patients who have developed significant neutropenia with a cycle of chemotherapy, growth factors are recommended for subsequent cycles of chemotherapy if a reduction in the chemotherapy dose or a delay in treatment would be considered harmful.
The two more common growth factors are neupogen and neulasta.
Common side effects of Neupogen include bone or muscle aches, diarrhea or constipation, hair loss, headache, fatigue, rash, nosebleeds, or injection site skin reactions. Neupogen is given daily after chemotherapy for several days until the neutrophil counts comes up.
Common side effects of Neulasta include bone pain, pain in the arms or legs, and a skin reaction at the injection site. Neulasta is given as a single injection the day after chemotherapy.
If your counts are low, you will want to take certain precautions. You should avoid people who are sick or who could be sick. Avoid large crowds and wear a face mask to cover your nose and mouth in public places. Wash your hands frequently since many infections are transitted from the hands and things that you touch such as doorknobs. Prevent cuts or scrapes to your skin. Cook your food thoroughly as many bacteria can be transmitted in raw or undercooked food and your immune system won’t be able to handle this like it normally would.
You should tell your doctor immediately if you have a fever of 100.5 °F (38 °C) or higher. This is called febrile neutropenia and is an urgent medical condition usually requiring hospitalization and broad spectrum antibiotics. If left untreated an infection can spread to the bloodstream causing septicemia.
Neutropenia makes it difficult for you to fight infections
You should try to avoid situations which could lead to infections
Tell your doctor immediately if you develop a fever after you have had chemo
Take these action steps:
Discuss whether or not you need growth factors with your doctor. The important factors here are the following
Are you on a chemotherapy that is likely to cause significant neutropenia?
Did you get neutropenic with the last cycle?
So I hope this has helped you to take control of one common but potentially life threatening side effect of treatment.
About the Author: Lisa M. Schwartz, MD is a board certified internist and radiation oncologist who has treated, cared for, and advised cancer patients for over two decades. Her interest in how patients deal with their diagnosis and treatment both emotionally and physically led her to investigate many forms of complementary therapies and patient support strategies. She has a master’s degree in Traditional Chinese Medicine and completed an associate fellowship in Integrative Medicine under Dr. Andrew Weil at the University of Arizona. She is currently the founder and medical director of The Breast Cancer Collective, an online membership community for women with breast cancer. Click here for more information.