Effects of Theory-Based Behavioral Interventions on Physical Activity Among Overweight and Obese Female Cancer Survivors: A Systematic Review of Randomized Controlled Trials.

PURPOSE: To determine whether theory-based physical activity (PA) interventions for overweight and obese female cancer survivors lead to increased PA and improved health.

METHODS: This systematic review examined randomized controlled trials analyzing the impact of theory-based PA interventions on overweight and obese female cancer survivors through December 2016. Searches of 5 electronic databases revealed 10 articles that included 1351 participants who met the inclusion criteria.

RESULTS: Participants were primarily non-Hispanic white (74%-100%) breast or endometrial cancer survivors. Intervention characteristics and PA assessment tools varied greatly. Adherence (68%-99%) and retention (79%-100%) were relatively high. Social cognitive theory was utilized as the theoretical construct in 9 of the 10 studies. Home-based interventions led to small improvements in PA (Cohen's d range = 0.25-0.31), whereas home-based plus center-based interventions led to moderate to large improvements (Cohen's d range = 0.45-1.02). Only three of the studies assessed psychosocial behavioral processes associated with PA, and the results were mixed. Health-related outcomes included improvements in aerobic fitness (Cohen's d = 0.32-1.1 in 5 studies), large absolute decreases in waist circumferences (>6 cm in 3 of 5 studies; Cohen's d = -0.31 to -1.02), and no change in inflammatory biomarkers (in 2 studies). Only one serious adverse event (pelvic stress fracture) was attributed to the interventions.

CONCLUSIONS: Theory-based PA interventions are safe and feasible for overweight and obese female cancer survivors. Interventions that include a center-based component showed moderate to large effect sizes for PA. Future studies should evaluate behavioral variables and more health-related clinical outcomes.