Physical activity in breast cancer survivors: A systematic review and meta-analysis on overall and breast cancer survival.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of observational cohort studies
PubMed 30780085 · doi:10.1016/j.breast.2019.02.001
What was done
PubMed was searched through November 2017 for observational studies evaluating the association between post-diagnosis physical activity (PA) and survival outcomes in breast cancer survivors. Random-effects meta-analyses were performed comparing highest versus lowest recreational PA categories for all-cause mortality, breast cancer mortality, and breast cancer recurrence across 10 studies with average follow-up ranging from 3.5 to 12.7 years.
What was found
Across 10 studies including 23,041 breast cancer survivors (2,522 total deaths, 841 breast cancer deaths, and 1,398 recurrences/remissions): - All-cause mortality was significantly lower in the highest versus lowest PA category (HR = 0.58, 95% CI: 0.45–0.75; 8 studies; I² = 52.4%). - Breast cancer mortality was significantly lower in the highest PA category (HR = 0.60, 95% CI: 0.36–0.99; 5 studies; I² = 77.7%). - Breast cancer recurrence showed a non-significant reduction (HR = 0.79, 95% CI: 0.60–1.05; 5 studies; I² = 66.4%).
Why it matters
This review quantifies a substantial survival benefit associated with higher recreational physical activity after a breast cancer diagnosis, reinforcing lifestyle recommendations for survivors while distinguishing overall from cancer-specific mortality benefits.
Limits
All included studies were observational, meaning reverse causation and residual confounding cannot be ruled out. Statistical heterogeneity was moderate to high across outcomes (I² = 52.4% to 77.7%). The search was limited to PubMed, only extreme PA categories (highest vs. lowest quartile/quintile) were compared, and the reduction in recurrence did not reach statistical significance.
Cited by
- partial In patients diagnosed with colon or breast cancer, engaging in aerobic exercise reduces circulating tumor cells, cancer recurrence (by up to 40%), and cancer mortality.