Cancer Fatigue and Chemo-Brain
Arline Kallick: Tonight’s speaker is Dr. John Glaspy. Dr. Glaspy is a professor, researcher and director at UCLA Oncology/Hematology. Welcome, Dr. Glaspy.
Dr. John Glaspy: Thank you. It’s a pleasure to have a chance to spend a few minutes and talk about this topic. I am going to start with fatigue because I think the flow of how we have come to understand this field starts best there.
Until the mid 1990’s, just over 10 years ago, fatigue was not on anyone’s radar screen in terms of people working on the cancer problem and it was not recognized that fatigue was a common problem among cancer patients. It was thought that pain was the dominant driver of quality of life. The identification of fatigue as the most frequent severe symptom in people undergoing cancer treatment in the United States occurred in 1997. It was a rude awakening for us because we found that we had not been working at all on the problem that most drove quality of life for cancer patients. A lot of work has been done since then and only a little bit of progress has been made. So maybe we should review that first.
First of all, because at the same time that fatigue was identified as a problem, anemia treatment to treat mild and moderate degrees of anemia was also becoming common in oncology practice. The first piece of this puzzle turned out to be the anemia that we were willing to tolerate in cancer patients and had been willing to tolerate for decades. We were willing to tolerate it for two reasons. One, transfusions have risks and we didn’t want to transfuse levels of anemia that were not life threatening. Secondly, we had been trained that it was asymptomatic; that patients did not have symptoms when they had mild and moderate amounts of anemia.
It became very clear very quickly when we had these new drugs to treat the anemia of cancer that didn’t have the risks of transfusions; that patients’ fatigue improved when they were treated for their anemia. That proved to us that it had been symptomatic all along even though we didn’t realize it.
If you look real carefully at the huge amount of data that is available out there it is fairly well documented that fatigue is caused by these levels of anemia and that there is a lot of fatigue out there even in patients who are not anemic. Around 20% of the variations in fatigue that cancer patients have are explainable by variations in their hemoglobin or by anemia.
So we have a small part of the puzzle solved and treatment of anemia has become a touchstone to the fatigue movement in oncology, if you will, because it’s one thing we understand and it makes a significant fraction of the fatigue better but it leave us with a huge problem. We have 80% of the fatigue that our patients experience completely impendent of their anemia and we don’t have any real good treatments for this. We don’t understand fully what causes it.
The field has advanced a great deal in the sense that we now know that there are cytokines, compounds that the body makes in response to cancer or to being sick that drive a fraction of this fatigue. We know that depression and sleep deprivation drive a portion of the fatigue. We know that if you successfully treat the cancer this fatigue will improve. It takes a long time -- we know that -- but it does improve. So successfully treated cancer patients who can get away from their treatment and get away from their cancer and recover have improvements in their fatigue level that go on sometimes for a year or more before they are completely resolved but the fatigue improves.
How do we make fatigue better for patients who can’t get away from their cancer, have to live with it, and have to live on cancer treatment? That has been a much tougher problem to solve. There is work going on exploring the ability of cytokine blockers. You will see TV commercials now for medicines that are aimed at arthritis. Those are a new class of medicines that work by blocking the effects of these chemicals that the body makes in response to inflammation and makes rheumatoid arthritis and other rheumatologic disorders better. Because the cytokines that the rheumatologists are fighting are the same cytokines that we believe cause a fair amount of the fatigue in our patients, there is an interest in developing those drugs as fatigue drugs in cancer and there are some clinical trials ongoing looking at that.
In addition, there are some less expensive and less complicated endeavors to treat patients. The anti-inflammatory TV commercial drugs have as one of their potential side effects an increase in infection risk. So everyone is a little worried about what this will do if it becomes something that gets used in cancer what it will do to infection risk. You will notice one of the TV commercials says if you have ever had tuberculosis make sure you tell your doctor. That’s because these drugs block to some extent the body’s ability to fight infections.
The other concern is that blocking the immune system can block your body’s ability to fight the cancer itself. So the effects on infection risk and on tumor progression are effects that are going need to be watched carefully and these drugs are not ready for prime time as cancer fatigue treatments.
The simpler treatments are relatives of the drug Ritalin. There is now a randomized trial that says if fatigue gets better with one particular relative of Ritalin and that drug is out there and available it can be prescribed and makes fatigue better in some patients.
