Primary Prevention

Abstract

Cancer burden can be greatly reduced through primary prevention. Increases in physical activity alone can have a large public health impact, as some estimates suggest that physical inactivity accounts for approximately 2.9% of all cancer cases in the United States. Epidemiologic studies have previously identified associations of physical activity with the decreased risk of colon, endometrial, and breast cancers, but more recent studies have further identified potential associations between physical activity and decreased risk of esophageal, liver, bladder, gastric, and renal cancers. While evidence is too limited to draw conclusions, a few studies suggest that there may also be a relationship between physical activity and decreased risk of pancreas, ovary, head and neck, prostate, and hematologic cancers. Similarly, there is some evidence for an association between excess sedentary time and an increased risk of colon and endometrial cancers. The American Cancer Society (ACS) guidelines for cancer prevention recommend that adults avoid inactivity and engage in at least 150 minutes of moderate-intensity (e.g., brisk walking) or 75 minutes of vigorous-intensity (e.g., running or biking) physical activity (or an equivalent combination of moderate- and vigorous-intensity physical activity) each week. For greater cancer prevention benefits, these guidelines should be doubled.