Purpose: Lack of physical activity (PA), weight gain, and overweight have been associated with increased risk of recurrence and mortality after breast cancer diagnosis. We evaluated the feasibility of implementing an individualized exercise program and nutritional counseling during adjuvant treatment of localized invasive breast cancer.
Methods: Sixty-one patients eligible for adjuvant chemotherapy were randomized 2:1 to receive a 6-month program of weekly aerobic exercises associated with nutritional counseling (n = 41) or usual care with nutritional counseling (n = 20, one withdrawal). The primary endpoints were the proportion of patients compliant with two weekly supervised sessions and their overall adherence (i.e., proportion of supervised and unsupervised sessions completed versus planned sessions).
Results: Ten percent of patients in the intervention group were compliant with the two weekly supervised sessions for 6 months, but the overall median adherence rate was 85% of supervised and non-supervised sessions completed. Non-adherence was mainly due to intrinsic reasons (medical, organizational, psychological barriers). Adherence was positively associated with education and baseline PA level and inversely associated with baseline weight and tumor grade. No statistically significant benefits were observed in the intervention group, even if overall PA level and body composition improved and anthropometrics were maintained over time (p < 0.05).
Conclusions: Overall, there was good adherence with the 6-month exercise program during adjuvant treatment for breast cancer, despite poor compliance to twice-weekly supervised sessions. This study highlights the need for flexible exercise modalities and innovative experimental design to reach patients who would most adhere and benefit from intervention.
Trial registration: ClinicalTrials.gov Identifier: NCT01331772. Registered 8 April 2011, https://clinicaltrials.gov/ct2/show/NCT01331772?term=pasapas&rank=1.
Keywords: Breast cancer; Clinical trial; Exercise; Nutrition; Obesity; Physical activity.