Effects of an oncologist’s recommendation to exercise on self-reported exercise behavior in newly diagnosed breast cancer survivors: a single-blind, randomized controlled trial

Abstract

BACKGROUND: Increased attention has focused on exercise as a quality of life intervention for breast cancer survivors during and after adjuvant therapy. PURPOSE: Our objective was to examine the effects of an oncologist's recommendation to exercise on self-reported exercise behavior in newly diagnosed breast cancer survivors attending their first adjuvant therapy consultation. METHODS: Using a single-blinded, 3-armed, randomized controlled trial, 450 breast cancer survivors were randomly assigned to receive an oncologist exercise recommendation only, an oncologist exercise recommendation plus referral to an exercise specialist, or usual care. The primary outcome was self-reported total exercise (in metabolic equivalent [MET] hours per week) at 5 weeks postconsultation. RESULTS: The follow-up assessment rate was 73% (329 of 450). Intention-to-treat analysis based on participants with follow-up data indicated a significant difference in total exercise in favor of the recommendation-only group over the usual care group (mean difference, 3.4 MET hr per week; 95% confidence interval [CI], 0.7-6.1 MET hr per week; p = .011). There was no significant difference between the recommendation-plus-referral group and the usual care group (mean difference, 1.5 MET hr per week; 95% CI, -1.0 to 4.0 MET hr per week; p = .244). Ancillary "on-treatment" analyzes showed that participants who recalled an exercise recommendation reported significantly more total exercise than participants who did not recall an exercise recommendation (mean difference, 4.1 MET hr per week: 95% CI, 1.9-6.4 MET hr per week; p < .001). CONCLUSIONS: Our findings suggest that an oncologist recommendation may increase exercise behavior in newly diagnosed breast cancer survivors, particularly if it is recalled 1 week after the recommendation.