Physical activity has been shown to decrease the risk of certain cancers. Objective of this study was to assess the effect of physical activity on cancer incidence in former male athletes in older age. Design: A cohort of 2448 elite male athletes and 1712 referents was followed-up for cancer incidence during 1986-2010 through the Finnish Cancer Registry. Method: Standardized incidence ratios (SIR) were calculated with the general male population as the reference. Self-reported questionnaire-based data on covariates were used in Cox regression analyses comparing the risk of cancer in athletes and referents. Results: The overall cancer incidence was lower in athletes than in the general population, SIR 0.89 (95% confidence interval [95%CI] 0.81-0.97). It was lowest among middle-distance runners (SIR 0.51, 95%CI 0.22-1.01), long-distance runners (SIR 0.57, 95%CI 0.35-0.88) and jumpers (SIR 0.60, 95%CI 0.37-0.92). The SIR of lung cancer among athletes was 0.40 (95%CI 0.27-0.55) and that of kidney cancer 0.23 (95%CI 0.06-0.57). The hazard ratio for lung cancer between athletes and referents increased from the unadjusted ratio of 0.29 (95%CI: 0.18-0.48) to 0.61 (95%CI: 0.30-1.26) after adjustment for smoking status and pack-years of smoking. Conclusions: Former male elite athletes evidently have less cancer than men on the average. The lesser risk can be attributed to lifestyle factors, notably less frequent smoking among the athletes.
© Copyright 2014 Journal of Science and Medicine in Sport. Elsevier. Alle Rechte vorbehalten.