Onkologie und Bewegung

Abstract

Evidence for a protective role of physical activity in cancer prevention is rapidly accumulating. The most convincing epidemiologic data in support of a beneficial effect of physical activity on cancer risk exists for colon, breast, and endometrial cancers. Evidence is weaker for cancers of the lung, pancreas, stomach, prostate, and ovary. Inconsistent findings for a physical activity and cancer relation in the literature may reflect methodologic constraints of available studies, including the use of inaccurate physical activity measurement instruments, failure to assess physical activity performed at etiologically relevant time periods of carcinogenesis, inadequate assessment of the dose of physical activity (frequency, duration, and intensity), incomplete control for potential confounding, and lack of consideration of subgroup findings. These methodologic issues require heightened attention in future studies. Several biologic mechanisms mediate the relation between physical activity and cancer but most etiologic pathways remain poorly understood. Most research on physical activity and primary cancer prevention has been conducted in observational settings, which are not designed to provide evidence of causal associations. controlled physical activity intervention studies of cancer risk are needed to solidify existing mechanistic evidence and to further develop biologic models relating increased physical activity to decreased cancer risk. Key Words: Physical activity, cancer prevention, epidemiology, methodologic considerations