Recreational physical activity reduces breast cancer recurrence in female survivors of breast cancer: A meta-analysis.

Purpose: The aim of this review was to systematically collect the published evidence to assess the effect of recreational physical activity (PA) in reducing breast cancer (BC) recurrence in female survivors.

Methods: A bibliographic search was carried out in PubMed Medline, CINAHL Complete, Scopus and Lilacs until June 2021. We selected observational studies or clinical trials comprising women diagnosed with BC, in which the risk of recurrence of BC was measured before or after performing recreational PA. As a secondary outcome, we analyzed disease free survival for recurrence/disease-specific mortality. The methodological quality of observational studies was assessed with the Newcastle-Ottawa Scale and clinical trials with the PEDro scale. A random effects model was used to estimate the relative risks (RR) and their 95% confidence intervals (CI) to infer the results for any female survivor of BC. We performed separate meta-analyses for prediagnosis and postdiagnosis recreational PA.

Results: Eleven studies were included, providing data from 29,677 surviving women with BC with an age range of 18-79 years old. Postdiagnosis recreational PA reduced the risk of BC recurrence by 16% (RR, 0.84; 95% CI: 0.78 to 0.91) and the risk of recurrence/disease-specific mortality by 23% (RR, 0.77; 95% CI: 0.66 to 0.93). Prediagnosis PA reduced the risk of BC by 18% (RR, 0.82; 95% CI: 0.74 to 0.91).

Conclusion: This systematic review with meta-analysis shows that recreational PA can be an interesting therapeutic tool to protect against recurrence of BC in female survivors.