The Korea Cohort Consortium: The Future of Pooling Cohort Studies.

Objectives: We introduced the cohort studies included in the Korea Cohort Consortium (KCC), focusing on large-scale cohort studies established in Korea with a prolonged follow-up period. Moreover, we also provided projections of the follow-up and estimates of the sample size that would be necessary for big-data analyses based on pooling established cohort studies, including population-based genomic studies.

Methods: We mainly focused on the characteristics of individual cohort studies from the KCC.

Body Mass Index and Thyroid Cancer Risk: A Pooled Analysis of Half a Million Men and Women in the Asia Cohort Consortium.

Although previous meta-analyses have suggested a dose-response relationship between body mass index (BMI) and thyroid cancer risk, limited evidence has been presented about Asian populations. To assess this association among Asian populations, where underweight is more prevalent than in other regions, a pooled analysis from the Asia Cohort Consortium was conducted. Baseline height and weight were measured in five cohorts and self-reported in eight cohorts.

Association of Sleep Duration With All- and Major-Cause Mortality Among Adults in Japan, China, Singapore, and Korea.

Importance: The association between long sleep duration and mortality appears stronger in East Asian populations than in North American or European populations.

Objectives: To assess the sex-specific association between sleep duration and all-cause and major-cause mortality in a pooled longitudinal cohort and to stratify the association by age and body mass index.

Design, Setting, And Participants: This cohort study of individual-level data from 9 cohorts in the Asia Cohort Consortium was performed from January 1, 1984, to December 31, 2002.

Coffee and tea consumption and mortality from all causes, cardiovascular disease and cancer: a pooled analysis of prospective studies from the Asia Cohort Consortium.

Background: Accumulating evidence suggests that consuming coffee may lower the risk of death, but evidence regarding tea consumption in Asians is limited. We examined the association between coffee and tea consumption and mortality in Asian populations.

Methods: We used data from 12 prospective cohort studies including 248 050 men and 280 454 women from the Asia Cohort Consortium conducted in China, Japan, Korea and Singapore.

Gene-Environment Interactions Relevant to Estrogen and Risk of Breast Cancer: Can Gene-Environment Interactions Be Detected Only among Candidate SNPs from Genome-Wide Association Studies?

In this study we aim to examine gene-environment interactions (GxEs) between genes involved with estrogen metabolism and environmental factors related to estrogen exposure. GxE analyses were conducted with 1970 Korean breast cancer cases and 2052 controls in the case-control study, the Seoul Breast Cancer Study (SEBCS). A total of 11,555 SNPs from the 137 candidate genes were included in the GxE analyses with eight established environmental factors.

High-Risk Population Based on BC Risk Factors.

Breast cancer (BC) is the second leading cause of female cancers worldwide in 2018, followed by lung cancer, and the fifth fatal cancer, followed by lung, colorectal, gastric, and liver cancers. The incidence and mortality rates of breast cancer in Western women have been shown to decrease for a long period of time, while the incidence and mortality rates of Asian women are rapidly increasing. The incidence and mortality rates of BC in Western women have been changing to a recent decrease from a fluctuation in rates for a long time, while in Asian women, the incidence and mortality rates have increased rapidly.

Associations of coffee and tea consumption with lung cancer risk.

Associations of coffee and tea consumption with lung cancer risk have been inconsistent, and most lung cancer cases investigated were smokers. Included in this study were over 1.1 million participants from 17 prospective cohorts.

Quantifying the association of low-intensity and late initiation of tobacco smoking with total and cause-specific mortality in Asia.

Background: Little is known about the health harms associated with low-intensity smoking in Asians who, on average, smoke fewer cigarettes and start smoking at a later age than their Western counterparts.

Methods: In this pooled analysis of 738 013 Asians from 16 prospective cohorts, we quantified the associations of low-intensity (<5 cigarettes/day) and late initiation (≥35 years) of smoking with mortality outcomes. HRs and 95% CIs were estimated for each cohort by Cox regression.

Pickled Vegetable and Salted Fish Intake and the Risk of Gastric Cancer: Two Prospective Cohort Studies and a Meta-Analysis.

An increased risk of gastric cancer for pickled vegetable and salted fish intake has been suggested, yet the lack of a dose-response association warrants a quantitative analysis. We conducted a meta-analysis, combining results from our analysis of two large Korean cohort studies and those from previous prospective cohort studies. We investigated the association of pickled vegetable and salted fish intake with gastric cancer in the Korean Genome Epidemiology Study and the Korean Multi-center Cancer Cohort Study using Cox proportional hazard models.

Gender differences in respiratory health outcomes among farming cohorts around the globe: findings from the AGRICOH consortium.

: Respiratory hazards of farming have been identified for centuries, with little focus on gender differences. We used data from the AGRICOH consortium, a collective of prospective cohorts of agricultural workers, to assess respiratory disease prevalence among adults in 18 cohorts representing over 200,000 farmers, farm workers, and their spouses from six continents.: Cohorts collected data between 1992 and 2016 and ranged in size from 200 to >128,000 individuals; 44% of participants were female.

The establishment of the Household Air Pollution Consortium (HAPCO).

Household air pollution (HAP) is of public health concern with ~3 billion people worldwide (including >15 million in the US) exposed. HAP from coal use is a human lung carcinogen, yet the epidemiological evidence on carcinogenicity of HAP from biomass use, primarily wood, is not conclusive. To robustly assess biomass's carcinogenic potential, prospective studies of individuals experiencing a variety of HAP exposures are needed.

The U-shaped association between body mass index and gastric cancer risk in the Helicobacter pylori Biomarker Cohort Consortium: A nested case-control study from eight East Asian cohort studies.

The association between body mass index (BMI) and noncardia gastric cancer (NCGC) risk remains controversial. The purpose of our study was to examine the association of BMI with NCGC risk with consideration of Helicobacter pylori (HP) biomarkers. This international nested case-control study, composed of 1,591 incident NCGC cases and 1,953 matched controls, was established from eight cohorts in China, Japan and Korea, where the majority of NCGCs are diagnosed worldwide.

Hepatocyte Growth Factor in Blood and Gastric Cancer Risk: A Nested Case-Control Study.

Background: Potential of hepatocyte growth factor (HGF)-stimulating signaling pathways related to cytotoxin-associated gene A (CagA) to predict gastric cancer development has not been fully investigated.

Methods: We conducted a nested case-control study consisting of 238 gastric cancer cases and 238 matched controls within the Korean Multicenter Cancer Cohort. Plasma HGF concentrations were measured with a human HGF ELISA.

Association between educational level and total and cause-specific mortality: a pooled analysis of over 694 000 individuals in the Asia Cohort Consortium.

Objective: To study the association of educational level and risk of death from all causes, cardiovascular disease (CVD) and cancer among Asian populations.

Design: A pooled analysis of 15 population-based cohort studies.

Setting And Participants: 694 434 Asian individuals from 15 prospective cohorts within the Asia Cohort Consortium.

Association of BMI, Smoking, and Alcohol with Multiple Myeloma Mortality in Asians: A Pooled Analysis of More than 800,000 Participants in the Asia Cohort Consortium.

Background: To date, few epidemiologic studies have been conducted to elucidate lifestyle-related risk factors for multiple myeloma in Asia. We investigated the association of body mass index (BMI), smoking, and alcohol intake with the risk of multiple myeloma mortality through a pooled analysis of more than 800,000 participants in the Asia Cohort Consortium.

Methods: The analysis included 805,309 participants contributing 10,221,623 person-years of accumulated follow-up across Asia Cohort Consortium cohorts.

Smoking, Serology, and Gastric Cancer Risk in Prospective Studies from China, Japan, and Korea.

Smoking is an established risk factor for gastric cancer development. In this study, we aimed to assess prospectively the association of smoking with gastric cancer risk in 1,446 non-cardia gastric cancer cases and 1,796 controls from China, Japan, and Korea with consideration of infection as a potential effect modifier. Applying logistic regression models stratified by study and adjusted for age and sex we found that current, but not former, smoking was significantly associated with gastric cancer risk [OR = 1.

Association of Diabetes With All-Cause and Cause-Specific Mortality in Asia: A Pooled Analysis of More Than 1 Million Participants.

Importance: Asia is home to the largest diabetic populations in the world. However, limited studies have quantified the association of diabetes with all-cause and cause-specific mortality in Asian populations.

Objectives: To evaluate the association of diabetes with all-cause and cause-specific mortality in Asia and to investigate potential effect modifications of the diabetes-mortality associations by participants' age, sex, education level, body mass index, and smoking status.

Tobacco Smoking and Mortality in Asia: A Pooled Meta-analysis.

Importance: Understanding birth cohort-specific tobacco smoking patterns and their association with total and cause-specific mortality is important for projecting future deaths due to tobacco smoking across Asian populations.

Objectives: To assess secular trends of tobacco smoking by countries or regions and birth cohorts and evaluate the consequent mortality in Asian populations.

Design, Setting, And Participants: This pooled meta-analysis was based on individual participant data from 20 prospective cohort studies participating in the Asia Cohort Consortium.

Association between Body Mass Index and Gastric Cancer Risk According to Effect Modification by Helicobacter pylori Infection.

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.

Altered Hypothalamus-Pituitary-Adrenal Axis Function: A Potential Underlying Biological Pathway for Multiple Concurrent Symptoms in Patients With Advanced Lung Cancer.

Objective: Patients with advanced cancer commonly experience multiple symptoms that present as groups or clusters. The present study aimed to examine whether hypothalamus-pituitary-adrenal (HPA) axis dysfunction underlies the concurrent multiple symptoms in patients with advanced cancer.

Methods: Patients' cortisol levels were determined in saliva samples collected after awakening (0, 30, and 60 minutes after awakening) and at nighttime (21:00-22:00 PM) from 46 patients with lung cancer (15.

Validation of a Blood Biomarker for Identification of Individuals at High Risk for Gastric Cancer.

Background: is the leading cause of gastric cancer, yet the majority of infected individuals will not develop neoplasia. Previously, we developed and replicated serologic biomarkers for gastric cancer risk among prospective cohorts in East Asia and now seek to validate the performance of these biomarkers in identifying individuals with premalignant lesions.

Methods: This cross-sectional study included 1,402 individuals from Linqu County screened by upper endoscopy.

Epstein-Barr Virus Antibody Titers Are Not Associated with Gastric Cancer Risk in East Asia.

Background: Epstein-Barr virus (EBV)-positive gastric cancers represent a distinct subtype of gastric cancers and account for nearly 10% of the gastric cancer burden, yet risk detection strategies for this cancer subtype are lacking.

Methods: We conducted a nested case-control study where we assayed 4 EBV antigens [viral capsid antigen (VCA), early antigen (EA), Epstein-Barr nuclear antigen (EBNA), and BZLF1-encoded replication activator protein (ZEBRA)] in either sera or plasma from 1447 gastric cancer cases and 1797 controls obtained from seven prospective cohorts representing individuals from the high gastric cancer-risk countries of China, Japan, and Korea.

Results: The prevalence of EBV sero-positivity was universal with the exception of one sero-negative individual, and the highest titers of the EBV antigens VCA (OR 0.

Associations between genetic polymorphisms of membrane transporter genes and prognosis after chemotherapy: meta-analysis and finding from Seoul Breast Cancer Study (SEBCS).

Membrane transporters can be major determinants of the pharmacokinetic profiles of anticancer drugs. The associations between genetic variations of ATP-binding cassette (ABC) and solute carrier (SLC) genes and cancer survival were investigated through a meta-analysis and an association study in the Seoul Breast Cancer Study (SEBCS). Including the SEBCS, the meta-analysis was conducted among 38 studies of genetic variations of transporters on various cancer survivors.

Association of leisure-time physical activity with total and cause-specific mortality: a pooled analysis of nearly a half million adults in the Asia Cohort Consortium.

Background: Most previous studies evaluating the association between leisure-time physical activity (LTPA) and risk of death were conducted among generally healthy individuals of European ancestry. We investigated the association of LTPA with all-cause and cause-specific mortality among East Asian populations, including healthy individuals and those with existing chronic diseases, which has been less well characterized.

Methods: We performed pooled analyses among 467 729 East Asian individuals recruited in nine prospective cohorts included in the Asia Cohort Consortium.