A Cochrane review (abstract , review ) included 32 trials involving a total of 2626 women. Physical exercise (aerobic or resistance exercise or both) during adjuvant treatment for breast cancer improved physical fitness (SMD 0.42, 95% CI 0.25 to 0.59, 15 trials, n=13100; moderate-quality evidence) and, slightly reduced fatigue (SMD -0.28, 95% CI -0.41 to -0.16; 19 trials; n=1698; moderate-quality evidence) compared to non-exercising control groups. Exercise showed non-significant improvement in cancer site-specific quality of life (MD 4.24, 95% CI -1.81 to 10.29; 4 studies; n=262), and in depression (SMD -0.15, 95% CI -0.30 to 0.01; 5 studies; n=674).
Another Cochrane review (abstract , review ) included 63 trials involving a total of 5761 women with breast cancer. Compared to control, physical activity interventions (aerobic exercise and/or resistance training) resulted in small-to-moderate improvements in HRQoL (health related quality of life), emotional function, perceived physical function, anxiety, and cardiorespiratory fitness (table ). Small improvements sustained for 3 months or longer postintervention in fatigue, cardiorespiratory fitness, and self-reported physical activity.
| Outcome (follow-up: median 12 weeks) | Assumed risk - Control | Risk with intervention - Physical activity (95% CI) | No. of participants (studies) Quality of evidence |
|---|---|---|---|
| HRQoL using FACT-G (0 to 104 scale) | -2.70 to 2.72 standard deviation units (SD) | 0.39 SD higher (0.21 to 0.57 higher); FACT-points: 5.9 (3.2 to 8.6) points higher | 1996 (22) Low |
| Perceived physical function using FACT-PBW (0 to 28 scale) | -2.64 to 1.64 SD | 0.33 SD higher (0.18 to 0.49 higher); FACT-points: 1.7 (0.9 to 2.5) points higher | 2129 (25) Moderate |
| Anxiety using PROMIS (0 to 9 scale) | -1.33 to 1.19 SD | 0.57 SD lower (0.95 to 0.19 lower); PROMIS-points: 1.9 (3.2 to 0.6) points lower | 326 (7) Very low |
| Depression using FACT-F (0 to 52 scale) | -0.79 to 2.84 SD | 0.34 SD lower (0.62 to 0.05 lower); FACT-points: 2.8 (4.1 to 1.6) points lower | 657 (12) Low |
| Fatigue using FACT-F (0 to 52 scale) | -1.83 to 1.69 SD | 0.32 SD lower (0.47 to 0.18 lower); FACT-points 2.8 (4.1 to 1.6) points lower | 2020 (26) Moderate |
| Cardiorespiratory fitness: VO2max (mL/kg/min) | 0.51 to 3.59 SD | 0.44 SD higher (0.30 to 0.58 higher); VO2max 2.1 (1.4 to 2.7) mL/kg/min higher | 1265 (23) Moderate |
Comment: The quality of evidence is downgraded by study quality (no blinding of outcome assessment, unclear allocation concealment).