WBC, RBC are produced by the bone marrow, and can be suppressed from treatment. As mentioned, see the doctor to have a physical, blood work up to see any other causes like the kidneys, infections, low iron, B-12, low vitamin D, even a colonoscopy is sometimes ordered to find the bleeding. Protein helps the bone marrow make more cells, and the life cycle for RBC is 90-120 days, WBC 4-5 days, and are constantly being replaced. The bone marrow may not be making enough or are dying off at a faster rate are some reasons. I assume it's not low enough for intervention by blood transfusion, epogen or nuprogen injections, but they have risks too.

Good luck

10/09 T1N2bM0 Tonsil
11/09 Taxo Cisp 5-FU, 6 Months Hosp
01/11 35 IMRT 70Gy 7 Wks
06/11 30 HBO
08/11 RND PNI
06/12 SND PNI LVI
08/12 RND Pec Flap IORT 12 Gy
10/12 25 IMRT 50Gy 6 Wks Taxo Erbitux
10/13 SND
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10/13 RND Carotid Remove IORT 10Gy PNI
12/13 25 Protons 50Gy 6 Wks Carbo
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03/15 Sequestromy Buccal Flap ORN
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04/17 Regraft hypergranulation Donor Site
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02/19 Finally Cancer Free Took 10 yrs