The effects of lifestyle and behavioural interventions on cancer recurrence, overall survival and quality of life in breast cancer survivors: A systematic review and network meta-analysis.

Lifestyle/behavioural interventions may improve breast cancer outcomes and quality of life (QoL); however, uncertainty remains about the most effective interventions due to limited evidence. This study aimed to assess and compare the effects of lifestyle/behavioural interventions on cancer recurrence, survival and QoL in breast cancer survivors. Electronic databases including Medline, EMBASE, PsycINFO, CINAHL and EBM Reviews were searched for relevant literature. Randomized controlled trials (RCTs) and quasi-RCTs comparing a lifestyle/behavioural intervention with a control condition in breast cancer survivors were included. Outcomes included cancer recurrence, overall survival and QoL. A network meta-analysis synthesized intervention effect. Studies not included in the analysis were reported narratively. Of 6251 identified articles, 38 studies met the selection criteria. Limited evidence exists on the impacts of lifestyle/behavioural interventions on breast cancer recurrence/survival. Exercise was identified as the most effective intervention in improving overall survival (HR 0.50, 95 % CI 0.36, 0.68). Lifestyle/behavioural interventions may improve QoL; psychosocial interventions (SMD 1.28, 95 % CI 0.80, 1.77) and aerobic-resistance exercise (SMD 0.33, 95 % CI -0.03, 0.69) were the most effective interventions to enhance QoL. This review highlights potential post-breast cancer benefits from lifestyle/behavioural interventions, notably exercise and psychosocial support for QoL and exercise for overall survival. Thus, encouraging active lifestyle, stress management and coping skills programs during and after cancer treatment may enhance physical wellbeing and QoL. However, the findings should be interpreted with caution due to the small number and sample sizes of studies. Future longer-term RCTs are required for conclusive recommendations.