White blood cells (WBCs) are part of your immune system. They help fight infections and are an important sign of health. The main job of WBCs is to look for germs in your body and attack them. If the number of white cells drops too low, your risk of infection goes up. When this happens, you’re more likely to catch a cold, the flu, or other infections.

Neutrophils are a specific type of WBC often affected by cancer treatments. When neutrophil counts are low, it is called neutropenia. As you progress through your treatment, your healthcare team will check your WBC levels regularly for signs of neutropenia through a simple blood test.

Lung cancer treatments, including chemotherapy, radiation therapy, immunotherapy, and targeted therapy, destroy cancer cells, but they can also affect WBC levels. Chemotherapy treatments, as well as some immunotherapy and targeted therapies, can affect bone marrow. Since bone marrow produces WBCs, these treatments can lead to lower WBC levels, which increases your risk of infection.

To learn more about cancer treatments and low WBC counts visit:

• Mayo Clinic ‍
• American Cancer Society

If your healthcare team tells you that you have a low WBC counts, take extra care to prevent infections.

Practical tips:

• Avoid people who may be sick.
• Avoid crowded spaces.
• Keep your hands clean.
• Wash and pat dry any small wounds, apply an antibiotic ointment, and cover them with a bandage if needed.
• Shower or bathe your whole body every day and floss your teeth twice a day, unless your healthcare team recommends otherwise.
• Don’t share cups or eating utensils.

Regularly testing your blood is the best way to know as early as possible whether your WBC counts are low. If your WBC count becomes a concern, your healthcare team will guide you on how best to address it. Medicine may be given to increase WBCs, but sometimes cancer treatment is paused until WBC counts increase to a healthier level. In most cases, WBC levels will return to normal within a few weeks of ending treatment. You can also ask your healthcare team about ways to prevent low WBC levels before they occur.