Long-term effect of physical activity during adjuvant chemotherapy on quality of life in breast cancer patients. The follow-up study of two randomized control trials.

Abstract

Background Yearly 15.000 patients are diagnosed with breast cancer. Incidence increases due to aging and adjuvant therapies improve. This results in increased number of survivors dealing with the long-term side effects of chemotherapy like a diminished quality of life. Studies have previously investigated the short-term effect of physical activity during adjuvant chemotherapy on the quality of life, but the long-term effects are yet to be established. Therefore, the aim of this study is to evaluate the long-term effect of physical activity during adjuvant chemotherapy on quality of life in breast cancer patients

Methods This study is prospective follow-up study, being a sub analysis of the ongoing PACT-PACES-HEART study. Patients are recruited from the original PACT and PACES studies. The EORTC quality of life questionnaire was used to calculate the overall quality of life and the quality of life on five subscales. A linear mixed effects model was used to assess the between-group differences and account for four timepoint measurements.

Results 177 patients were included. The mean age of all participants was 59 years. The mean BMI was 25,8. Most women were post-menopausal, above 90% both the intervention and control group. An ER-positive, PR-positive, Her2Neu-negative tumor was most common. The mean follow-up was 8,5 years. At 8,5-year follow-up, both intervention and control groups showed improved results compared to timepoint one on the quality of life scales, except for three scales. The overall quality of life in the intervention group and the cognitive functioning both the intervention and control group decreased. Analyzing the between-group differences, the overall quality of life, physical functioning, role functioning, emotional functioning and social functioning resulted in an adjusted mean difference in favor of the intervention group. The between-group difference for cognitive functioning resulted in an adjusted mean difference in favor of the control group. All results were not significant or clinically notable.

Conclusions Although results are not significant, being assigned to the intervention group did seem to have a slight positive effect on the overall quality of life, the physical functioning, the role functioning, the emotional functioning and the social functioning. Cognitive functioning decreases in both the intervention as control group, with a between-group difference in favor of the control group.