[Physical activity after breast cancer diagnosis and survival: A systematic review]

The benefits of physical activity (PA) in breast cancer are currently recognized in primary prevention. The World Cancer Research Fund (WCRF) and then the National Cancer Institute (INCa) have reported conflicting results regarding the impact of post-diagnosis PA on breast cancer outcomes. The aim of this systematic review is to assess the association between PA after breast cancer diagnosis and overall mortality, specific mortality and risk of breast cancer recurrence in the literature.

Randomized trials, prospective cohorts and meta-analyses studying post-diagnosis PA and overall mortality, breast cancer mortality or risk of recurrence after breast cancer published between January 1, 2014 and October 1, 2019 were included. The articles selected by the INCa report prior to 2014 were included in the literature review.

Eighteen articles have been selected. Studies unanimously concluded that overall mortality was reduced by post-diagnosis PA practice. For specific mortality, 5 meta-analyses showed a significant decrease in breast cancer mortality and 2 found a decrease in the risk of recurrence.

Post-diagnosis PA reduces overall mortality and appears to impact specific breast cancer mortality and risk of recurrence. However, these results need to be confirmed by larger randomized trials.