Cancer treatments linked to decline in mental abilities later on in life

Jun 1 2005

A study in the U.S. has found that cancer survivors who have undergone cancer treatment are twice as likely to develop cognitive problems than people who had never been treated for cancer, and they may be at risk of problems with mental abilities such as memory and learning.

According to the team at the University of Southern California, it is possible that damage from chemotherapy may be to blame. The team do however stress that more research is needed, and say the findings are not a reason for cancer patients to panic and refuse treatment.

Apparently the possibility that cancer, and its treatment, may be linked to cognitive dysfunction has been raised by previous studies, which at the time focused on the short term impact of cancer. The latest study which has examined the longer-term effect looked at 702 people who had survived following cancer treatment, and their cancer-free twins.

The researchers found that about 15% of the cancer survivors showed signs of cognitive dysfunction, and have raised the possibility that cognitive problems among cancer survivors got worse over time.

They argue that comparing cancer survivors with their cancer-free twins means the increased dysfunction cannot be attributed to the normal aging process.

Although the study does not suggest a cause for the cognitive problems in cancer survivors, the researchers say it is possible chemotherapy or other cancer treatments may cause long-term damage.

They do however accept that it is possible that the cognitive impairment was present before treatment began, and that factors such as alcohol consumption and a sedentary lifestyle, which increase the risk of cancer, also increase the risk of cognitive decline.

A follow-up study is planned which will compare survivors who received different treatments.

Researcher Professor Margaret Gatz suggests that those with cancer might be advised to have their cognition monitored as part of long-term follow-up.

Experts from the University of Texas also say they have found some evidence that cancer patients experience a short-term effect in cognitive function, but there is little firm evidence that patients are at long-term risk of developing problems.

Professor Lesley Fallowfield, of Cancer Research UK, says that although the study is interesting, a cautious interpretation of the results is advisable, as everyone is at risk of dementia as they age, and the actual increase in risk is fairly small.

The study features in the Journal of the National Cancer Institute.