Postdiagnosis recreational physical activity and breast cancer prognosis: Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational cohort studies
PubMed 36279903 · doi:10.1002/ijc.34324
What was done
A systematic review and dose-response meta-analysis (searched PubMed and Embase through October 31, 2021) evaluated the association between postdiagnosis recreational physical activity and breast cancer prognosis. The review included 20 observational studies and 3 follow-up observational cohorts nested in clinical trials, assessing all-cause mortality, breast cancer-specific mortality, recurrence, and second primary cancers.
What was found
In linear dose-response meta-analysis, each 10 MET-hour/week increase in recreational physical activity was associated with a 15% lower risk of all-cause mortality (95% CI: 8%–22%; 12 studies, 3,670 deaths) and a 14% lower risk of breast cancer-specific mortality (95% CI: 4%–23%; 11 studies, 1,632 deaths). Non-linear models showed reductions of up to 48% for all-cause mortality and 38% for breast cancer-specific mortality at activity levels up to 20 MET-hours/week, with plateauing thereafter. Physical activity was not associated with breast cancer recurrence (HR = 0.97, 95% CI: 0.91–1.05; 6 studies, 1,705 events). Findings were consistent across body mass index, hormone receptor status, and menopausal status.
Why it matters
These findings reinforce global survivorship recommendations that engaging in regular recreational physical activity after a breast cancer diagnosis may meaningfully improve long-term survival, with maximal risk reduction observed at moderate activity volumes (~20 MET-hours/week).
Limits
All included data derive from observational studies or observational follow-ups of trials, creating vulnerability to reverse causation (sicker patients being less active) and residual confounding. The independent Expert Panel formally classified the overall certainty as 'limited-suggestive' rather than conclusive. Specific data on second primary cancers were not detailed in the abstract.
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.