Physical activity in relation to risk of prostate cancer: a systematic review and meta-analysis
A partir d'une revue systématique de la littérature publiée jusqu'en 2017 (48 études de cohorte et 24 études cas-témoins incluant au total 151 748 cas de cancer de la prostate), cette méta-analyse évalue l'association entre une activité physique (de loisir ou liée à l'activité professionnelle) et le risque de cancer de la prostate
Background : Prostate cancer (PCa) is one of the most common cancers among men, yet little is known about its modifiable risk and protective factors. This paper aims to quantitatively summarize observational studies relating physical activity (PA) to PCa incidence and mortality. Materials and methods : Published articles pertaining to PA and PCa incidence and mortality were retrieved in July, 2017 using the MEDLINE and EMBASE databases. The literature review yielded 48 cohort studies and 24 case-control studies with a total of 151 748 PCa cases. The mean age of the study participants at baseline was 61 years. Results : In random effects models, comparing the highest versus the lowest level of overall PA showed a summary relative risk (RR) estimate for total PCa incidence close to the null (RR = 0.99, 95% CI = 0.94-1.04). The corresponding RRs for advanced and non-advanced PCa were 0.92 (95% CI = 0.80-1.06) and 0.95 (95% CI = 0.85-1.07), respectively. We noted a statistically significant inverse association between long-term occupational activity and total PCa (RR = 0.83, 95% CI = 0.71-0.98, n studies=13), although that finding became statistically non-significant when individual studies were removed from the analysis. When evaluated by cancer subtype, an inverse association with long-term occupational activity was noted for non-advanced/non-aggressive PCa (RR = 0.51, 95% CI = 0.37-0.71, n studies=2) and recreational activity was inversely related to advanced/aggressive PCa (RR = 0.75, 95% CI = 0.60-0.95, n studies=2), although these observations are based on a low number of studies. Moreover, PA after diagnosis was related to reduced risk of PCa mortality among survivors of PCa (summary RR based on 4 studies=0.69, 95% CI = 0.55-0.85). Conclusions : Whether PA protects against PCa remains elusive. Further investigation taking into account the complex clinical and pathologic nature of PCa is needed to clarify the PA and PCa incidence relation. Moreover, future studies are needed to confirm whether PA after diagnosis reduces risk of PCa mortality.
Annals of Oncology 2018