What Is Absolute Neutrophil Count (ANC)?
The absolute neutrophil count (ANC) is the actual number of infection-fighting neutrophils in the blood. The white blood cell (WBC) count reports all white cells together, so the ANC multiplies the total WBC count by the fraction that is made up of neutrophils.
To get the neutrophil fraction, the percentages of segmented neutrophils (mature cells, or 'segs') and band neutrophils (slightly immature cells) are added together. The ANC matters most in patients receiving chemotherapy, because a low ANC — neutropenia — sharply raises the risk of serious infection and often guides treatment decisions such as delaying a dose or starting growth factors.
Formula
ANC = WBC count × (Segs % + Bands %) ÷ 100
Applications
- Assessing infection risk in patients on chemotherapy
- Determining whether a patient qualifies for growth-factor support
- Evaluating fever in an immunocompromised patient
- Deciding whether to hold or delay a chemotherapy dose
- Tracking marrow recovery after transplantation
Sources
- National Cancer Institute (NCI). Common Terminology Criteria for Adverse Events (CTCAE).