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Concerning Blood Counts


Hi everyone!

Has anyone experienced decreasing blood counts months after finishing chemo? I had my last round of chemo on 9/1/2021, but continue to receive Herceptin/Perjeta every 3 weeks (HER2+). My white blood cell counts were great all throughout chemo, but they have been decreasing over the last few months. My neutrophil counts are now considered “critically low.” My doctor doesn’t seem concerned, but it worries me a little to see the downward trend the last few months, and now that they are so low, I am starting to worry something more might be going on. Has anyone else experienced decreasing counts months after completing chemo?


  • specialk
    specialk Member Posts: 9,234
    edited January 2022

    What was your chemo regimen and did you have a Neulasta injection or On-Pro during chemo? If you did, it artificially elevated your WBC as your bone marrow was stimulated to produce white cells to protect you from opportunistic infection. If you received a white cell booster and your body has now normalized because you have stopped the booster you may be seeing the true picture of your WBC/neutrophils at this point. Recovery of normal counts is a process and can take 6 months to a year, sometimes longer. Herceptin and Perjeta both list depressed blood counts in their known side effects. Whether this is caused by either drug is hard to tell because they usually are either given with, or follow, chemo - so the question is do you have depressed counts during, but not directly related to, both drugs. How much longer will you be on H&P? Does your MO have any concerns about your ability to fend off infection? I had Neulasta and had quite high WBC counts. During Herceptin they fell, then rebounded to a low end of normal. All of the components in my CBC are variable and tend to be low, sometimes below the range long after chemo. IT is also important to note that lab ranges were established for adult males - females sometimes have consistently lower values, and it is not indicative of a problem. My WBC has now been below the range on all CBC for the last few years - my MO is unconcerned, and he is also a hematologist. He regards it as my normal, absent any other issues. Counts can also fall with age. My annual appointment is in a few weeks and I will have a CBC done prior - I will be discussing this with him again at that time.

  • pattik
    pattik Member Posts: 5
    edited January 2022

    I'm in a similar situation. I finished up chemo a few months ago and my WBC is now below the low threshold. As SpecialK mentioned, I did get Neulasta so that certainly elevated it during chemo. The only thing really mentioned at my last appointment was it was probably still the chemo. I do have another follow up this month though.

  • btwnstars
    btwnstars Member Posts: 81
    edited January 2022

    My wbc have been lower or on the low end since ending chemo 10/14/21. I also had a dip during radiation as that can take it's toll too. My understanding is it takes a while for the chemo to totally get out of the system. What SpecialK says also makes a lot of sense in how it relates to neulasta increasing levels synthetically.

    As long as your doctor is ok with it and continues to monitor, just keep asking for explanation.

  • micheleh57
    micheleh57 Member Posts: 19
    edited April 2022

    I did NOT have chemo when I went through all the paces in 2020. I wound up the active treatment with a month of radiation. However, a broad panel of lab tests taken this past month - as the naturopath I'm working with tries to find some good strategies and tactics for hand joint stiffness and pain apparently due to the AI - showed I have a very low WBC count. Mine came back at 2.0 while normal or "normal" (!) is 4.0 to 10.7.

    There are many reason for low WBC. They can be very serious. And they all are conditions I do not want to think about. I'll have another blood test for a read on the WBC in early May.

    Personally, I did not know until I came home from an appointment last week with the regular oncologist - who checked all of the blood test results - that low WBC can be a side effect of the AI. And even in the meeting appointment, she did NOT bring that up. At all. I'll admit I did not ask, "So what might be causing that?" But she did not just say "It could be the AI or it could be something else."

    So meantime, despite changes in mask mandates in various places, I wear a mask when I'm out at stores. No restaurants for me. A trip to see family possibly in late May is off the table. I hate this.