PURPOSE: Few studies investigated roles of body mass index (BMI) on gastric cancer (GC) risk according to Helicobacter pylori infection status. This study was conducted to evaluate associations between BMI and GC risk with consideration of H. pylori infection information. MATERIALS AND METHODS: We performed a case-cohort study (n=2,458) that consists of a subcohort, (n=2,193 including 67 GC incident cases) randomly selected from the Korean Multicenter Cancer Cohort (KMCC) and 265 incident GC cases outside of the subcohort. H. pylori infection was assessed using an immunoblot assay. GC risk according to BMI was evaluated by calculating hazard ratios (HRs) and their 95% confidence intervals (95% CIs) using weighted Cox hazard regression model. RESULTS: Increased GC risk in lower BMI group (< 23 kg/m²) with marginal significance, (HR, 1.32; 95% CI, 0.98 to 1.77) compared to the reference group (BMI of 23-24.9 kg/m²) was observed. In the H. pylori non-infection, both lower (< 23 kg/m²) and higher BMI (≥ 25 kg/m²) showed non-significantly increased GC risk (HR, 10.82; 95% CI, 1.25 to 93.60 and HR, 11.33; 95% CI, 1.13 to 113.66, respectively). However, these U-shaped associations between BMI and GC risk were not observed in the group who had ever been infected by H. pylori. CONCLUSION: This study suggests the U-shaped associations between BMI and GC risk, especially in subjects who had never been infected by H. pylori.
Body Mass Index ; Cohort Studies ; Helicobacter pylori ; Helicobacter ; Stomach Neoplasms

PURPOSE: Despite the low mortality rate of breast cancer among women in Korea, the breast cancer mortality rate has increased. The aim of this study was to examine trends in breast cancer mortality from 1983 to 2012 in Korea, assessing the importance of age, period, and birth cohort as risk factors. MATERIALS AND METHODS: Data on the annual number of deaths due to female breast cancer and on female population statistics from 1983 to 2012 were obtained from Statistics Korea. A log-linear Poisson age-period-cohort model was used to estimate age, period, and cohort effects. RESULTS: The increasing breast cancer mortality can be explained predominantly by a birth cohort effect: the risk of breast cancer death showed a steady increase until the 1968 birth cohort, and decreased thereafter. There was a sharp increase in the magnitude of the age effect up to 60 years old, then a moderate increase in the effect during the sixties, followed by another sharp increase from 70 years old. The period effect on breast cancer mortality seems negligible based on its adjusted relative risk, even though it was statistically significant after adjusting for age and cohort effects. CONCLUSION: In this study, the mortality pattern of breast cancer in Korea can be explained predominantly by a birth cohort effect. Hence, the overall mortality rate of breast cancer may increase for a while, and show a gradual decrease in the future, which will start from the younger age group.
Breast Neoplasms* ; Breast* ; Cohort Effect ; Cohort Studies ; Female* ; Humans ; Korea* ; Linear Models ; Mortality* ; Parturition ; Population Characteristics ; Risk Factors

BACKGROUND: The present study aimed to examine the association between cigarette smoking, alcohol consumption and colorectal cancer risk among Korean adults. METHODS: Data from the Korean Multi-center Cancer Cohort between 1993 and 2005 were analyzed. The study population comprised 18,707 subjects aged older than 20 years old. The subjects were followed until December 31, 2011 (median follow-up of 11.2 years). The Cox proportional hazard model was used to estimate the hazard ratio (HR) and 95% confidence intervals of cigarette smoking and alcohol consumption for colorectal cancer risk. RESULTS: In men, longer duration and higher average amount of alcohol consumption were associated with elevated risk of colorectal cancer (HR 1.93 [1.17-3.18] for > or = 30 years of consumption compared to non-drinkers; HR 2.24 [1.31-3.84] for > or = 30 g/d). Former smokers showed a non-significantly elevated risk of colorectal cancer in men. There was no apparent association between alcohol consumption or cigarette smoking and colorectal cancer risk among women. CONCLUSIONS: Alcohol consumption was associated with increased colorectal cancer risk among Korean men, and both a longer duration and a higher amount of consumption were associated with elevated risk.
Adult ; Alcohol Drinking* ; Cohort Studies* ; Colorectal Neoplasms* ; Female ; Follow-Up Studies ; Humans ; Male ; Proportional Hazards Models ; Prospective Studies ; Smoking* ; Tobacco Products*

No abstract available.

OBJECTIVES: Emerging evidence indicates that sleep duration is associated with health outcomes. However, the relationship of sleep duration with long-term health is unclear. This study was designed to determine the relationship of sleep duration with mortality as a parameter for long-term health in a large prospective cohort study in Korea. METHODS: The study population included 13 164 participants aged over 20 years from the Korean Multi-center Cancer Cohort study. Information on sleep duration was obtained through a structured questionnaire interview. The hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using a Cox regression model. The non-linear relationship between sleep duration and mortality was examined non-parametrically using restricted cubic splines. RESULTS: The HRs for all-cause mortality showed a U-shape, with the lowest point at sleep duration of 7 to 8 hours. There was an increased risk of death among persons with sleep duration of < or =5 hours (HR, 1.21; 95% CI, 1.03 to 1.41) and of > or =10 hours (HR, 1.36; 95% CI, 1.07 to 1.72). In stratified analysis, this relationship of HR was seen in women and in participants aged > or =60 years. Risk of cardiovascular disease-specific mortality was associated with a sleep duration of < or =5 hours (HR, 1.40; 95% CI, 1.02 to 1.93). Risk of death from respiratory disease was associated with sleep duration at both extremes (< or =5 and > or =10 hours). CONCLUSIONS: Sleep durations of 7 to 8 hours may be recommended to the public for a general healthy lifestyle in Korea.
Adult ; Aged ; Body Mass Index ; Cardiovascular Diseases/mortality ; Cause of Death ; *Cohort Studies ; Female ; Humans ; Interviews as Topic ; Middle Aged ; Neoplasms/*mortality ; Proportional Hazards Models ; Prospective Studies ; Questionnaires ; Republic of Korea ; Respiratory Tract Diseases/mortality ; *Sleep ; Waist Circumference

OBJECTIVES: Diabetes and obesity each increases mortality, but recent papers have shown that lean Asian persons were at greater risk for mortality than were obese persons. The objective of this study is to determine whether an interaction exists between body mass index (BMI) and diabetes, which can modify the risk of death by cardiovascular disease (CVD). METHODS: Subjects who were over 20 years of age, and who had information regarding BMI, past history of diabetes, and fasting blood glucose levels (n=16 048), were selected from the Korea Multi-center Cancer Cohort study participants. By 2008, a total of 1290 participants had died; 251 and 155 had died of CVD and stroke, respectively. The hazard for deaths was calculated with hazard ratio (HR) and 95% confidence interval (95% CI) by Cox proportional hazard model. RESULTS: Compared with the normal population, patients with diabetes were at higher risk for CVD and stroke deaths (HR, 1.84; 95% CI, 1.33 to 2.56; HR, 1.82; 95% CI, 1.20 to 2.76; respectively). Relative to subjects with no diabetes and normal BMI (21 to 22.9 kg/m2), lean subjects with diabetes (BMI <21 kg/m2) had a greater risk for CVD and stroke deaths (HR, 2.83; 95% CI, 1.57 to 5.09; HR, 3.27; 95% CI, 1.58 to 6.76; respectively), while obese subjects with diabetes (BMI > or =25 kg/m2) had no increased death risk (p-interaction <0.05). This pattern was consistent in sub-populations with no incidence of hypertension. CONCLUSIONS: This study suggests that diabetes in lean people is more critical to CVD deaths than it is in obese people.
Aged ; Blood Glucose/analysis ; *Body Mass Index ; Cardiovascular Diseases/etiology/*mortality ; Cohort Studies ; Diabetes Complications ; Diabetes Mellitus/*pathology ; Female ; Humans ; Male ; Middle Aged ; Proportional Hazards Models ; Risk Factors ; Stroke/etiology/mortality

OBJECTIVES: To examine the association between alcohol consumption habit, types of beverages, alcohol consumption quantity, and overall and cancer-specific mortality among Korean adults. METHODS: The alcohol consumption information of a total of 16 320 participants who were 20 years or older from the Korean Multi-center Cancer Cohort were analyzed to examine the association between alcohol consumption habit and mortality (median follow-up of 9.3 years). The Cox proportional hazard model was used to estimate the hazard ratio (HR) of alcohol consumption to mortality adjusting for age, sex, geographic areas, education, smoking status, and body mass index. RESULTS: Alcohol drinkers showed an increased risk for total mortality compared with never drinkers (HR, 1.72; 95% confidence interval [CI], 1.38 to 2.14 for past drinkers; HR, 1.21; 95% CI, 1.06 to 1.39 for current drinkers), while past drinkers only were associated with higher risk for cancer deaths (HR, 1.84; 95% CI, 1.34 to 2.53). The quantity of alcohol consumed per week showed a J-shaped association with risk of mortality. Relative to light drinkers (0.01 to 90 g/wk), never drinkers and heavy drinkers (>504 g/wk) had an increased risk for all-cause and cancer deaths: (HR, 1.18; 95% CI, 0.96 to 1.45) and (HR, 1.39; 95% CI, 1.05 to 1.83) for all-cause mortality; and (HR, 1.55; 95% CI, 1.15 to 2.11) and (HR, 2.07; 95% CI, 1.39 to 3.09) for all cancer mortality, respectively. Heavy drinkers (>504 g/wk) showed an elevated risk for death from stomach and liver cancers. CONCLUSIONS: The present study supports the existence of a J-shaped association between alcohol consumption quantity and the risk of all-cause and cancer deaths. Heavy drinkers had an increased risk of death from cancer overall and liver and stomach cancer.
Adult ; Age Factors ; Aged ; Alcohol Drinking/adverse effects/*mortality ; Analysis of Variance ; Cohort Studies ; Female ; Humans ; Male ; Middle Aged ; Neoplasms/etiology/*mortality ; Proportional Hazards Models ; Republic of Korea/epidemiology ; Risk Factors ; Sex Factors ; Young Adult

Little is known about the prevalence and seroprevalence of low-risk human papillomavirus (HPV) and the risk factors for HPV infection in Korean women. We determined the prevalence of low-risk HPV among 902 women aged 20-59 yr and the seroprevalence of low-risk HPV subtypes 6 and 11 among 1,094 women aged 9-59 yr in the general population. Genital low-risk HPV DNA was assessed by liquid hybridization and polymerase chain reaction. Antibody titers against HPV 6 and 11 were measured by a multiplexed competitive luminex technique. The prevalence of genital low-risk HPV was 4.9%. It reached its highest peak of 10.3% at 20-29 yr of age and a second peak of 3.2% at 50-59 yr of age. The seroprevalence of HPV 6 or 11 was 9.4%. It reached its highest peak of 12.7% at 25-29 yr of age and a second peak of 12.3% at 50-59 yr of age. In multivariable analysis, the number of lifetime sexual partners and past history of sexually transmitted diseases were associated with the seroprevalence but not prevalence of HPV. It is suggested that younger women should receive prophylactic HPV vaccination before they become sexually active and exposed to HPV in their 20s. This study provides baseline data for developing HPV vaccination programs and monitoring vaccine efficacy in Korea.
Adolescent ; Adult ; Antibodies/blood/immunology ; Child ; DNA, Viral/analysis ; Female ; Human papillomavirus 11/genetics/immunology ; Human papillomavirus 6/genetics/immunology ; Humans ; Middle Aged ; Odds Ratio ; Papillomavirus Infections/diagnosis/*epidemiology ; Prevalence ; Republic of Korea/epidemiology ; Risk Factors ; Seroepidemiologic Studies ; Sexual Behavior ; Young Adult

In 2009, infection with the liver fluke Clonorchis sinensis (C. sinensis) was classified as "carcinogenic to humans" (Group 1) based on its involvement in the etiology of cholangiocarcinoma by the International Agency for Research on Cancer. However, little is known about the descriptive epidemiology of cholangiocarcinoma in Korea. We examined incidence trends of intrahepatic and extrahepatic cholangiocarcinomas, using data from the Korea National Cancer Incidence database for 1999-2005. The prevalence of C. sinensis infection was estimated from a recent population-based survey in rural endemic areas. Cholangiocarcinoma incidence rates are currently rising, even while primary liver cancer incidence rates are decreasing. Annual percent changes in cholangiocarcinoma incidence rates were 8% for males and 11% in females. Known areas of C. sinensis endemicity showed high incidence rates of cholangiocarcinoma. The positivity of C. sinensis eggs in stool samples from endemic areas was more than 25% of adults tested during 2005-2008. From a meta-analysis, the summary odds ratio for cholangiocarcinoma due to C. sinensis infection was 4.7 (95% confidence interval: 2.2-9.8). Approximately 10% of cholangiocarcinomas in Korea were caused by chronic C. sinensis infections. More specific policies, including health education and an extensive effort for early detection in endemic areas, are needed.
Adult ; Aged ; Aged, 80 and over ; Animals ; Bile Duct Neoplasms/*epidemiology/parasitology ; Bile Ducts, Intrahepatic/parasitology/*pathology ; Cholangiocarcinoma/*epidemiology/parasitology ; Clonorchiasis/*epidemiology ; Female ; Humans ; Korea/epidemiology ; Male ; Middle Aged

Cancer has been the leading cause of death in Korea. Korea is facing a very rapid change and increase in cancer incidence, which draws much attention in public health. This paper overviews the nationwide cancer statistics, including incidence, mortality, and survival rates, and their trends in Korea based on the cancer incidence data from The Korea Central Cancer Registry (KCCR) in year 2006 and 2007. In Korea, there were 153,237 cancer cases and 65,519, cancer deaths observed in 2006, and 161,920 cancer cases and 67,561 cancer deaths in 2007, respectively. The incidence rate for all cancer combined showed an annual increase of 2.8% from 1999 to 2007. Specifically, there was significant increase in the incidence of colorectal, thyroid, female breast, and prostate cancers. The number of cancer deaths has increased over the past two decades, due mostly to population aging, while the age-standardized mortality rates have decreased in both men and women since 2002. Notable improvement has been observed in the 5-yr relative survival rates for most major cancers and for all cancer combined, with the exception of pancreatic cancer. The nationwide cancer statistics in this paper will provide essential data for cancer research and evidence-based health policy in Korea.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Female ; Humans ; Incidence ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Neoplasms/*epidemiology/mortality ; Republic of Korea/epidemiology ; Survival Rate