Low white blood cell count and cancerNeutropenia and cancer; Absolute neutrophil count and cancer; ANC and cancer
White blood cells (WBCs) fight infections from bacteria, viruses, fungi, and other pathogens (organisms that cause infection). One important type of WBC is the neutrophil. These cells are made in the bone marrow and travel in the blood throughout the body. They sense infections, gather at sites of infection, and destroy the pathogens.
When the body has too few neutrophils, the condition is called neutropenia. This makes it harder for the body to fight off pathogens. As a result the person is more likely to get sick from infections. In general, an adult who has fewer than 1,000 neutrophils in a microliter of blood has neutropenia.
If the neutrophil count is very low, fewer than 500 neutrophils in a microliter of blood, it is called severe neutropenia. When the neutrophil count gets this low, even the bacteria normally living in a person's mouth, skin, and gut can cause serious infections.
American Cancer Society website. Infections in people with cancer. www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/infections/infections-in-people-with-cancer.html. Updated February 25, 2015. Accessed May 2, 2019.
Centers for Disease Control and Prevention website. Preventing infections in cancer patients. www.cdc.gov/cancer/preventinfections/index.htm. Updated November 28, 2018. Accessed May 2, 2019.
Freifeld AG, Kaul DR. Infection in the patient with cancer. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 34.