Association between physical activity and mortality among breast cancer and colorectal cancer survivors: a systematic review and meta-analysis
A partir d'une revue systématique de la littérature (23 études, 49 095 survivants de cancer), cette méta-analyse évalue l'association entre une activité physique et la mortalité chez des survivants d'un cancer du sein ou du côlon-rectum
Résumé en anglais
Background : Physical activity improves physical function during and after cancer treatment, but whether physical activity imparts survival benefit remains uncertain.
Design : Using prospective studies published through June 2013, we conducted a systematic review and random-effects meta-analysis of pre- and post-diagnosis physical activity in relation to total and cancer mortality among breast or colorectal cancer survivors.
Results : Sixteen studies of breast cancer survivors and seven studies of colorectal cancer survivors yielded 49 095 total cancer survivors, including 8 129 total mortality cases and 4826 cancer mortality cases. Comparing the highest versus lowest levels of pre-diagnosis physical activity among breast cancer survivors, the summary relative risks (RRs) of total and breast cancer mortality were 0.77 [95% confidence interval (CI) = 0.69–0.88] and 0.77 (95% CI = 0.66–0.90, respectively. For post-diagnosis physical activity, the summary RRs of total and breast cancer mortality were 0.52 (95% CI = 0.42–0.64) and 0.72 (95% CI = 0.60–0.85), respectively. For pre-diagnosis physical activity among colorectal cancer survivors, the summary RRs of total and colorectal cancer mortality were 0.74 (95% CI = 0.63–0.86) and 0.75 (95% CI = 0.62–0.91), respectively. For post-diagnosis physical activity, the summary RRs of total and colorectal cancer mortality were 0.58 (95% CI = 0.48–0.70) and 0.61 (95% CI = 0.40–0.92), respectively. Each 10 metabolic equivalent task-hour/week increase in post-diagnosis physical activity (equivalent to current recommendations of 150 min/week of at least moderate intensity activity) was associated with 24% (95% CI = 11–36%) decreased total mortality risk among breast cancer survivors and 28% (95% CI = 20–35%) decreased total mortality risk among colorectal cancer survivors. Breast or colorectal cancer survivors who increased their physical activity by any level from pre- to post-diagnosis showed decreased total mortality risk (RR = 0.61; 95% CI = 0.46–0.80) compared with those who did not change their physical activity level or were inactive/insufficiently active before diagnosis.
Conclusion : Physical activity performed before or after cancer diagnosis is related to reduced mortality risk among breast and colorectal cancer survivors.
