The Long-term Effects of Physical Exercise on Cognitive Function in Chemotherapy-treated Breast Cancer Patients Follow-up study of a Randomized Controlled Trial

Abstract

Background Patients with breast cancer who have previously been treated with chemotherapy may continue to suffer from cognitive complaints for years after diagnosis and treatment. These cognitive complaints include problems with memory and concentration, and slower processing and reaction speed. These types of problems can have a major impact on a person's daily functioning and negatively affect their quality of life. Research in people with dementia and healthy elderly people shows that exercise can help reduce cognitive problems. The PAM study was set up to investigate whether this can also help patients with breast cancer.

Method Participants in the PAM study had been treated with chemotherapy, experienced cognitive complaints and also showed abnormalities on neuropsychological tests. Study participants were relatively inactive and two to four years after diagnosis. At the beginning of the study period, participants took an online neuropsychological test to measure their cognitive functioning and completed questionnaires to determine their own perception of cognitive functioning, quality of life, anxiety and depressive symptoms and fatigue. The 181 participants of the PAM study were then randomly divided into an intervention and a control group. The intervention group was asked to follow an exercise program for six months. This program consisted of two hours per week of fitness and strength training under the supervision of a physiotherapist and two hours per week of Nordic or power walking. The control group was asked to maintain their regular exercise habits. At the end of the study period, they were offered a three-month exercise program, which forty percent took advantage of. After the exercise program, the online neuropsychological test and questionnaires were administered again.

Results The data showed that there was no effect of the exercise program on cognition measured with neuropsychological tests. The intervention group showed an improvement in areas of quality of life and suffered less from depressive and cognitive complaints and fatigue compared to the control group. These outcomes were measured using the SQUASH questionnaire. One year after the end of the study period, participants were asked to complete the same test and questionnaires.

Conclusion It was already known that exercise has a positive effect on fatigue in cancer patients. This study shows that, one year after completing the exercise program, the cognitive complaints experienced by participants have decreased slightly. Offering an exercise program helps to keep moving in patients who have had breast cancer.