Does chemotherapy cause memory loss?
Publication Date:25/04/2008
You may have read reports in the news this week that chemotherapy drugs used to treat cancer can cause brain damage. Here we look at what the research says, and explain what it means for people undergoing chemotherapy.
What do we know already?
People with cancer often take chemotherapy drugs to kill the cancer cells. But chemotherapy can also kill healthy cells, causing problems such as hair loss and nausea. People often feel unwell while they’re having chemotherapy. But they usually think it’s worth putting up with these side effects, in order to kill the cancer cells and live longer.
Many people who have chemotherapy also have problems with memory and concentration during treatment. It’s sometimes even referred to as "chemo brain". Most people recover after the treatment ends but, for some, these problems last for months or even years. In rare cases, people have more serious problems like seizures (fits) and loss of sight.
Doctors aren’t sure what causes these problems. It was thought that they might happen because of the stress people go through during an illness like cancer, or because of the body’s reaction to having cancer. Also, because lots of different drugs may be used together for chemotherapy, doctors don’t know whether the problems could be a reaction to one particular drug, or to a combination of drugs.
Now researchers have studied the effects of one common chemotherapy drug on the nervous system of mice, to see if they could find out the cause of the problems.
What does the new study say?
The researchers gave mice a drug called 5-fluorouracil, also known as 5-FU. It is often used to treat people with breast, ovarian, stomach, bowel, lung and pancreatic cancer. It’s commonly given in combination with other cancer drugs.
Months later, the mice’s nerve cells had become badly damaged. The cells affected produce a substance called myelin, which coats the nerves and helps them transmit signals to and from the brain. Large areas of the mice’s brains didn’t have enough myelin. We know from other studies that, without enough myelin, people get all sorts of nerve problems, including memory loss.
The research suggests that nerve damage may be the cause of memory and concentration problems suffered by some people having chemotherapy. Nerve damage makes it hard for the brain to send and receive signals around the body.
Where does the study come from?
The study was carried out by researchers from the University of Rochester Medical Centre in New York State, US, and Harvard Medical School, Massachusetts, US. It is published in the Journal of Biology, which is owned by a company called BioMed Central.
How reliable are the findings?
As far as we can tell, the study findings are reliable. However, they don’t tell us for certain how chemotherapy affects human nerve cells. Scientists do experiments using mice or other animals when they can’t safely carry out the same experiments with people. Studies using mice may give us interesting and useful information. But the results can’t be directly translated to people, because people are very different from mice.
What does this mean for me?
If you need chemotherapy to treat your cancer, stories like this can be upsetting and worrying. However, there are a few important points to remember:
- Not everyone who has chemotherapy has long-term problems. Most people have memory and concentration problems in the short term but these problems don't usually last.
- All effective treatments, especially for serious diseases like cancer, have side effects. You should discuss the benefits and risks of chemotherapy with your doctors.
- These are not new side effects. Chemotherapy and 5-FU have been used for many years for treating cancer. What’s new is that scientists are beginning to find out what causes these side effects.
What should I do now?
If you are concerned about the possible side effects from chemotherapy, the best person to talk to is your doctor. Ask your doctor what the chances are that you’ll have long-lasting side effects. And remember to ask what is likely to happen if you choose not to have chemotherapy. Only you can make the decision about whether to go ahead with treatment. But you need to have all the facts before you decide.
From:
Han R, Yang YM, Dietrich J, et al. Systemic 5-fluorouracil treatment causes a syndrome of delayed myelin destruction in the central nervous system. Journal of Biology. 2008; 7: 12.
To find out more about cancer treatment, see our information on breast cancer, bowel cancer, lung cancer, ovarian cancer and pancreatic cancer.
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© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
