Population-Attributable Causes of Cancer in Korea: Obesity and Physical Inactivity

Background: Changes in lifestyle including obesity epidemic and reduced physical activity influenced greatly to increase the cancer burden in Korea. The purpose of the current study was to perform a systematic assessment of cancers attributable to obesity and physical inactivity in Korea. Methodology/Principal Findings: Gender- and cancer site-specific population-attributable fractions (PAF) were estimated using the prevalence of overweight and obesity in 1992–1995 from a large-scale prospective cohort study, the prevalence of low physical activity in 1989 from a Korean National Health Examination Survey, and pooled relative risk estimates from Korean epidemiological studies. The overall PAF was then estimated using 2009 national cancer incidence data from the Korea Central Cancer Registry. Excess body weight was responsible for 1,444 (1.5%) and 2,004 (2.2%) cancer cases among men and women, respectively, in 2009 in Korea. Among men, 6.8 % of colorectal, 2.9 % of pancreatic, and 16.0 % of kidney cancer was attributable to excess body weight. In women, 6.6 % of colorectal, 3.9 % of pancreatic, 18.7 % of kidney, 8.2 % of postmenopausal breast, and 32.7 % of endometrial cancer was attributable to excess body weight. Low leisure-time physical activity accounted for 8.8 % of breast cancer, whereas the PAF for overall cancer was low (0.1 % in men, 1.4 % in women)