Physical activity and/or dietary interventions in breast cancer survivors: a systematic review of the maintenance of outcomes

Maintaining physical activity and dietary improvements achieved during an intervention is important for the long-term health outcomes of breast cancer survivors. This review aimed to determine: (a) the proportion of physical activity and/or dietary intervention trials in breast cancer survivors that assessed post-intervention maintenance of outcomes, (b) the proportion of trials that achieved successful post-intervention maintenance of outcomes, and (c) the sample, intervention, and methodological characteristics common among trials that achieved successful post-intervention maintenance of outcomes. A structured search of PubMed, CINAHL, Medline via Ovid, Web of Science, CENTRAL, and PsycInfo was conducted for articles published until March 2012. Included trials had to evaluate a randomized controlled trial of a physical activity and/or dietary behavior change intervention that targeted breast cancer survivors and report on between-group differences of behavioral outcomes at end-of-intervention and at least 3 months post-intervention follow-up. Methodological quality of included trials was also assessed. The search resulted in 1,298 publications. Of 63 identified trials that assessed end-of-intervention outcomes, 10 (16 %) assessed post-intervention maintenance of outcomes; four of these 10 trials achieved successful maintenance. Due to the limited number and heterogeneity of the four trials, few commonalities in sample, intervention, and methodological characteristics were identified. Assessing post-intervention maintenance of physical activity and dietary outcomes in breast cancer survivors is rare. There is a pressing need to direct more attention to this issue to inform the development of interventions to improve the long-term health outcomes for the growing number of breast cancer survivors. For breast cancer survivors, maintaining regular physical activity and a healthy diet are important to enhancing health and well-being over the long-term. More research is needed to identify the best ways of supporting survivors to make and maintain these lifestyle changes.