New evidence of ‘chemo brain’ proves cognitive damage from cancer treatment isn't ‘all in your head’

Image: RSNA. The bright yellow and lime green in the left superior medial frontal gyrus sharply contrast the cool blue hues in the same region on the right. The brain uses glucose for energy; bright colors represent large decreases in glucose usage by the brain.

Cancer survivors everywhere are nodding in agreement today: "chemo brain" is real, as those of us who have experienced the cognitive damage associated with chemotherapy already know. Memory loss, problems with concentration and attention, speech and writing difficulties, even problems with everyday math or number identification are common during and long after chemo ends. But now, researchers understand a little more of the how and why.

As noted in my previous Boing Boing post, a new study presented this week at the annual meeting of the Radiological Society of North America (RSNA) used PET/CT scans to show physiological evidence of chemo brain, a common side effect in patients undergoing chemotherapy for cancer treatment.

The team led by Dr. Rachel A. Lagos at the West Virginia University School of Medicine and West Virginia University Hospitals in Morgantown, W.V. sought to identify the effect of chemotherapy on brain function, rather its effect on the brain's appearance. By using PET/CT, they were able to assess changes to the brain's metabolism after chemotherapy, and found measurable physiological changes.

In a group of 128 breast cancer patients, neuroradiology analysis software was used to calculate brain metabolism within 63 brain regions. Results were clinically correlated with documented patient history, neurologic examinations, and chemotherapy regimens. In women treated for breast cancer, the scans demonstrate "statistically significant decreases in regional brain metabolism" that correlate to "chemotherapy regimen, neurological examination and symptoms of chemobrain phenomenon."

On NBC Nightly News, cancer survivor and advocate Jody Schoger, whom I met on Twitter during my treatment, speaks about her experience with chemo brain and what the news means to her. She's an eloquent, powerful voice for all of us who suffer through the long-term side effects of treatment, and the challenges of living with this disease. NBC's science correspondent Robert Bazell did a great job with the story. You really gotta see this piece.

Below, the piece that ran on NBC Nightly News last night, followed by a longer-form edit of Jody's observations on how we heal from chemobrain. In a word: gradually.

Image: RSNA. A map shows the front of the brain with bright yellow and lime green hues predominating along the left half of the brain medially. This region corresponds to the left superior medial frontal gyrus, the part of the brain known for its role in prioritizing thoughts and actions.



  1. I don’t mean to be insensitive at all, so I hope I’m worrying for nothing, but is this particularly surprising? If you’re going to be damaging the body so significantly and profoundly for such an extended period of time, is it surprising that you’re also affecting the brain?

    1. I was just talking about this study with my physical therapist this morning, as he tortured my surgery site with deep tissue massage to help relieve my chronic post-operative pain. “How could anyone imagine that you could pump someone full of that much cell-destroying drugs and *not* have it affect the central nervous system,” he asked?

      It makes sense to those of us who’ve been through it, hell yeah. Totally logical. Chemo brings your body to the brink of death, to kill the cancer. You bet it’s gonna affect the brain.

      But this study is tremendously important because it validates what we subjectively know with evidence.

      For decades, patients’ complaints of chemobrain have been dismissed as depression, fatigue, or something we were imagining. We were ignored, we were told it was “all in our head,” and this major consequence of our treatment was not considered important. 

      Now there’s a growing acknowledgement that it is real. It is a mental disability. A big goddamned deal. Something that deserves respect and therapy. I know plenty of cancer patients who have trouble performing their jobs after chemo because of the cognitive changes. It is a huge, underappreciated thing.

      1. And I suppose that is the next question. With understanding, can we find solutions? Brain chemistry is almost hilariously easy to manipulate, you can do it with the addition and subtraction of sunlight. Maybe, as you say, therapy can mitigate or repair some of the “damage”?

        And yes, the official acknowledgement is huge. Subjective experience, especially when it comes to perception and brain related things is always such a difficult thing to have recognized by science. This is only good news.

        1. The hope is that with more serious research being done into the physiology of chemobrain, we’ll be able to learn more about how to treat it and/or cope with it.

          For now, the best advice we cancer patients get is pretty much, “try to live long enough for some of it to wear off,” which is some major fucking weaksauce.

          1. Pretty sure that advice can be applied to anything.

            “Had my arm run over by a truck”
            “Live long enough for some of it to wear off”

            “Ate some bad sushi”
            “Live long enough for some of it to wear off”

            “Got a bad tattoo”
            “Live long enough for some of it to wear off”

            Weaksauce indeed.

          2.  As a fellow cancer/chemo survivor, I agree.  What’s worse is that I learned about chemo brain from a fellow cancer patient, not from doctors.

            Also?  It’s been five years since I finished chemotherapy and I can *still* feel the effects of this in regards to my attention span and ability to concentrate as well as my ability to handle certain forms of language, like writing things longer than this comment.

            Thank you for talking about this.  I hope that they do more research into how to cope with it for all of us who have been through it.

      2. From my understanding, chemotherapy is designed to attack the fast replicating cells. For this reason it takes out the hair and damages the gastrointestinal system. Neurons aren’t fast replicating cells, so it is a little surprising that they would be impacted. In any case, every drug has a side effect and it is good that this one is better understood. Since the treatment of cancer seems to be the balancing act of picking the least harmful treatment, these findings might make doctors more likely to use radiation or surgery. Or perhaps certain types of chemotherapy are less damaging to the brain?

        1. I don’t have all the studies handy, but yes, in fact, there is some evidence that some chemotherapy drugs (and some specific regimens of dose and frequency) are more likely than others to cause acute cognitive damage. 

          The phenomenon is perplexing for health care providers precisely because of the reasons you outline. Chemo goes after fast-growing cells; how is it that neurons are affected, also?

          Maybe part of the answer is that just because chemo is *designed to target* fast-growing cells doesn’t mean it can’t impact other cells. It’s a powerful but very blunt tool.

          Just as chemo affects many parts of our body as collateral damage, fast growing cells or not, the brain and nervous system simply get hit, too.

          Chemo. It’s a motherfucker.

          1. Having sent a young child through a couple years of chemo, I can assure you that the childhood leukemia doctors are well aware of the damaging effects of chemo on the brain. Many of these effects do not make themselves apparent for several years after the chemo. They often are easy to detect as math processing problems – my other son is astoundingly good at math, while the cancer survivor is OK at math, but a bit slow.

            The difference is that childhood leukemia treatment requires injection of chemo drugs directly into the cerebra-spinal fluid, since a common recurrence site for leukemia is the brain. There is a blood-brain barrier that will keep the drugs out of the brain, but it obviously doesn’t keep the cancer out of the brain, so go figure.

          2. Man. I can’t imagine the pain and sorrow involved in watching your child be damaged in that way by the only treatment option available to save his/her life. My heart goes out to you guys, as you live and learn to cope with it. I hope your kid is doing great right now, too.

      3. Been 10 years since my chemo and my brain doesn’t work as well as it used to.  Bad enough that I was worried I was getting early onset Alzheimer’s or something. 

        Also, I can’t stand the cold as well as I could before chemo. 

    2. It’s also important to find things like this in order to start understanding HOW it happens. If science starts to get a picture of how patients’ brains are being injured that is an important step in figuring out how to reduce that risk. Are there things that can be done to help protect a patient from it? If not are there things that can be done to speed recovery? Even if you know that *something* seems to be happening, without good clear information on the nature of the phenomenon there can’t be progress towards solutions. 

  2. I’m a 16 year rectal cancer survivor that had chemo and radiation (diagnosed age 30).  To this day I still have issues and every time I talk to a doctor about them they just shrug and say I’m getting old.  And I mean many doctors—across states.  Even if I go to a cancer specialist they congratulate me for getting through it then *shrug*, if I go to a regular doctor they are baffled as to how to treat my linger issues then *shrug*.  From memory to fatigue to pain no one knows what to suggest.  I’m so so so grateful to have survived but frustrated at the lack of answers.  Sadly as much as I’ve tried to live above these issues they all have hurt my pass job performances.  To the point that I eventually quit applying for jobs.  I started working from home but the fatigue is just too much.   I’m glad this study came out and I’m glad there are more survivors.

  3. My daughter had kidney cancer when she was two years old; she went through months of chemo. She’s now 14 and appears normal (though gothy/emo/post-punk or something) and her teachers are almost always skeptical that she has a valid reason for being forgetful and occasionally absent (partly because she looks ‘weird’, I think).  

    So this research is hugely important in our effort to make an education system that is unevenly intolerant of invisible medical issues actually pay attention and not write this off as yet another kid and family looking for special consideration.  
    I really appreciate you sharing and publicizing this.

    1. Our younger son went through 2.5 years of chemo for ALL leukemia. The doctors we saw were quite aware of the damaging effects of the treatment on the in the neuro-psychological arena.

      Our hospital has set up a special “long-term care clinic” to deal with the aftermath of chemo and radiation treatments on the childhood cancer survivors. You should ask your hospital if they can do the same.

  4. My hope, like others have noted above, is that not only does this study lead to advances regarding chemobrain, but that it makes doctors realize they need to have a more open mind when it comes to patient issues.  I cannot tell you the number of times I was told, after detailing a particular problem or reaction I was having to treatments, “I’ve never heard that before” or “Oh, that would have happened anyway with menopause”.  (that’s the standard response to any issues connected to Tamoxifen).  

    1.  This…like all the time. “I’ve never heard that before” or “Oh, that would have happened anyway with menopause”.  I just want to poke them in the eye!

  5. At least in the future, I think it might be prudent to retire the “proves” from the presentation of new scientific evidence.  This evidence either “supports” or at most “demonstrates.”  In the interest of scientific literacy and changing how the public talks about new and evolving evidence, our language needs to be appropriate.  Especially when we are speaking about technology where the results are not always reproducible (fMRI) and with topics that are difficult and often disputed such as “chemo-brain.”

  6. One misconception is the idea that studies like this somehow provide evidence that chemo-brain exists.  The best evidence, and the only evidence you need, to demonstrate chemo-brain is to give cognitive tests to people before, during, and after chemotherapy, compare to matched controls, etc.  Evidence that actually looks at the clinical signs and symptoms itself is really the only evidence that matters as far as establishing the existence of the clinical entity.  Brain imaging might give you a clue as to the etiology, and that would be the hope, but the imaging by itself demonstrates nothing about the clinical effects of the changes.  There are a lot of treatments that will make your brain look different under some sort of functional imaging, but they don’t cause widespread cognitive dysfunction.

  7. It reminds me of some of the recent research on long-term use of antiviral drugs by HIV+ patients; in some of them, doctors are seeing onset of dementia much earlier than you’d expect from aging. There’s no obvious cause and effect.

  8. One thing that I noticed in yoga classes is that students who had chemo seemed to have serious balance problems.

  9. My mother was undergoing radical chemotherapy for ovarian cancer that had metastatized while the ob-gyns still thought she had stomach trouble. In December 2007, she suffered a brain aneurysm in my arms and went into a coma that she never left. I am not surprised that chemo causes brain damage.

  10. Xeni, thanks for posting this. While this study does not provide all the answers, and I agree that cognitive testing is also very much needed, it’s a first step. It hopefully opens the door for funding of more research. We need to know why chemobrain develops, why some patients receiving the same chemo will develop issues and some will not, why some patients improve and some don’t, and how it can be prevented and/or treated. Unfortunately, cancer is not going away (more research needed here, too!) and until we can get rid of this terrible disease or at least develop effective and less toxic treatments, we need to figure out how to manage the side effects of our treatments so that quality of life is maintained.  

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