Abstract des Autors

Few modifiable lifestyle factors have been shown to be associated with reduced cancer risk. For physical activity, more than 200 epidemiologic studies have provided evidence that its association with cancer risk is convincing for colon and breast cancers; probable for endometrial cancer; possible for prostate, gastric, and ovarian cancers; and insufficient for all other cancer sites. Relative risk reductions are in the range of 10–30 %. On the absolute scale, about 9–19 % of the most frequent cancers can be attributed to a lack of sufficient physical activity. As modifiable health behavior, exercise thus has a strong potential for primary cancer prevention and the evidence is sufficiently established to recommend physical activity as a means for the primary prevention of cancer. Current recommendations call for at least 30–60 min of moderate to vigorous activity daily. However, further research is needed to provide a stronger evidence base specifically for these recommendations. The exact type, dose, and timing of physical activity remain unclear but ongoing and planned research will elucidate these associations. In addition, possible biologic mechanisms
whereby physical activity may influence carcinogenesis, independently and/or jointly with other factors of the energy balance equation, need further attention in future research. Verf.-Referat