During cancer treatment, blood test are one of the tools used to better understand how your body is reacting to chemo. Specifically, before starting a new cycle of chemo, they will look at your various blood counts to make sure you are cleared for treatment. Many treatments knock down your immune system, so they need to be sure you’ve recovered enough to start again. There are several things they look at, but one of the most important are the white blood cell counts.

White blood cell help protect the body from infection. There are different types of white blood cells and a CBC may show results from various types of white blood cells via a differential that includes:

• Basophils (0.5-1.0%) - Digest bacteria and foreign material
• Eosinophils (0-4%) - Related to allergies as well as parasitic infections
• Lymphocytes (20-40%) - Important role in infection and inflammation
• Monocytes (2-6%) - Respond to inflammation
• Neutrophils (50-60%) - Most common, fight against infection.

I found this helpful when reviewing the white blood cell makeup (https://www.glowm.com/resources/glowm/cd/pages/resources/Lab/white.htm).

Below is a chart of a patient receiving 2 cycles of “REPOCH”, followed by 4 cycles of “RCHOP”. After each cycle of “REPOCH”, a shot of pegfilgrastim was given in an effort to encourage bone marrow to make new cells. When reviewing these blood counts, there were several measurements where the reported percents did not add up to 100%? I’m not clear on this, but I used the absolute values to recaculate the percentages for the chart below.

The primary value the office used to determine a “go/no-go” for starting another round of chemo was the absolute neutrophil count, or ANC. In general, they want this to be over 1 (k/UL). The plot below does not have the absoluate numbers, but you can see how much smaller this section is at the top of the table. These represent the checks before starting the final three rounds and the ANC was 0.9, 1.0, and 0.9 respectively.