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.


RESULTS
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). Projections suggest that cancers attributable to obesity will increase by 40% in men and 16% in women by 2020.


CONCLUSIONS
With a significantly increasing overweight and physically inactive population, and increasing incidence of breast and colorectal cancers, Korea faces a large cancer burden attributable to these risk factors. Had the obese population of Korea remained stable, a large portion of obesity-related cancers could have been avoided. Efficient cancer prevention programs that aim to reduce obesity- and physical inactivity-related health problems are essential in Korea.
Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea.
Sohee
S
Park
Division of Cancer Early Detection, National Cancer Center, Goyang, Korea.
Yeonju
Y
Kim
Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea; Western Pacific Regional Office, World Health Organization, Manila, the Philippines.
Hai-Rim
HR
Shin
Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea.
Boram
B
Lee
Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea.
Aesun
A
Shin
Division of Cancer Registration and Surveillance, National Cancer Center, Goyang, Korea.
Kyu-Won
KW
Jung
Department of Epidemiology and Health Promotion, Institute for Health Promotion, Graduate School of Public Health, Yonsei University, Seoul, Korea.
Sun Ha
SH
Jee
Department of Social and Preventive Medicine, Hallym University, Chuncheon, Korea.
Dong Hyun
DH
Kim
College of Medicine, Korea University, Seoul, Korea.
Young Ho
YH
Yun
Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Korea.
Sue Kyung
SK
Park
International Prevention Research Institute, Lyon, France.
Mathieu
M
Boniol
International Prevention Research Institute, Lyon, France; The Tisch Cancer Institute, Mount Sinai School of Medicine, New York, New York, United States of America.
Paolo
P
Boffetta
D015992:Body Mass Index; D001835:Body Weight; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D015233:Models, Statistical; D009043:Motor Activity; D009369:Neoplasms / Q000150:complications* / Q000453:epidemiology / Q000209:etiology*; D009765:Obesity / Q000150:complications*; D050177:Overweight; D015995:Prevalence; D011446:Prospective Studies; D012042:Registries; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D057185:Sedentary Behavior