Jan. 14, 2002 -- Evidence has been building that cancer chemotherapy can impair memory for at least a few years after treatment. Now, a new study shows that this effect can linger as long as 10 years.
Previous medical research has suggested that cancer survivors who receive chemotherapy have memory and thinking problems immediately, and up to two years, after treatment. Researchers wanted to see if these difficulties persist even longer.
They tested the memory and thinking skills of 128 healthy breast cancer and lymphoma survivors, at an average of 10 years after completing cancer treatment. Some of the study participants had undergone chemotherapy as part of their treatment, while others had received only radiation and/or surgery without chemotherapy.
The findings are published in the Jan. 15 issue of the Journal of Clinical Oncology.
Patients treated with chemotherapy scored significantly lower on the tests than did those treated without chemotherapy. And at any given performance level, those who'd received chemotherapy were twice as likely to fall within the impaired range.
To make sure that the memory difficulties were not caused by depression, anxiety, or fatigue, each person was also evaluated for these problems. Since there were no differences between those who'd received chemotherapy and those who hadn't, psychological problems couldn't explain the memory troubles.
Although those who'd received chemo performed more poorly than those who hadn't, their overall test scores generally were not below average.
"The cognitive [thinking and memory] effects of chemotherapy on patients were relatively subtle and most of the scores fell within the normal range of performance. However, patients tell their physicians that these changes are very recognizable," study leader Tim A. Ahles, PhD, says in a news release. He is a professor of psychiatry and program director of the center for psycho-oncology at the Dartmouth-Hitchcock Medical Center in Lebanon, N.H.
The benefits of chemotherapy outweigh the potential risks for most people, since any memory and thinking problems appear to be subtle, the researchers write. Studies such as this should help inform people of the potential risks involved, however, for those deciding which treatment route to take.