Daehee Kang

BackgroundThe birth cohort effect has been suggested to influence the rate of breast cancer incidence and the trends of associated reproductive and lifestyle factors. We conducted a cohort study to determine whether a differential pattern of associations exists between certain factors and breast cancer risk based on birth cohorts.MethodsThis was a cohort study using pooled data from 12 cohort studies. We analysed associations between reproductive (menarche age, menopause age, parity and age at first delivery) and lifestyle (smoking and alcohol consumption) factors and breast cancer risk. We obtained hazard ratios (HRs) with 95% confidence intervals (CIs) using the Cox proportional hazard regression analysis on the 1920s, 1930s, 1940s and 1950s birth cohorts.ResultsParity was found to lower the risk of breast cancer in the older but not in the younger birth cohort, whereas lifestyle factors showed …

Background Physical activity (PA) is recommended to improve the survival of cancer patients. However, the prognostic impact of specific PAs is not well understood. Therefore, we investigated the associations of the duration, type, intensity, and number of PAs one participates in pre‐ and post‐diagnosis with mortality in Korean patients with cancer. Methods Among the participants aged 40–69 years recruited from the Health Examines study, those diagnosed with cancer after baseline (n = 7749) and within 10 years before baseline (n = 3008) were included in the analyses for pre‐ and post‐diagnosis PA, respectively. Duration, intensity, type, and number of leisure‐time physical activities participated in were assessed using questionnaires. The Cox proportional hazard model was used to characterize the association between PA and cancer‐specific mortality, adjusting for demographics, behaviors …

Background & aimsWe conducted a systematic review and meta-analysis of current evidence for the association between food groups, dietary patterns, and breast cancer risk among the Asian population.MethodsThis systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We performed a systematic literature search up to December 2022 in English in the PubMed, Web of Science, Embase, and Cochrane databases. Risk ratios (RRs) with 95% confidence intervals (CIs) were extracted as effect sizes. Publication bias was estimated by two different funnel plot methods.ResultsWe collected the data from 15 cohort studies and 34 case−control studies meeting the search criteria. The meta-analysis found that the consumption of fruits and, likewise, vegetables were associated with a 29% lower risk of breast cancer, respectively [RR …

Background: The association between excessive sugar intake and the risk of breast cancer has been considered in epidemiologic studied, however, the results are unclear. This study examined to evaluated between high-sugar food intake and breast cancer in a prospective cohort study. Methods: This prospective cohort study included a total of 71,266 women aged 40-69 years from the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Information on cancer diagnosis was retrieved from the Korea Central Cancer Registry until 31 December 2018. Multivariate hazard ratios (HRs) and 95% of confidence intervals (CIs) for the risk of gastric cancer according to the consumption of high-sugar food were estimated using Cox proportional hazards models with age as the time scale. Results: A total of 713 incident cases of breast cancer occurred over an average follow-up period of 9.20 years. The top food …

Although the protective effects of physical activity against several cancers are well established, evidence is inconsistent concerning Asian populations. Therefore, we assessed the association between the characteristics of physical activity and overall and type-specific cancer incidence in Koreans and examined the differences in association according to obesity status. Using prospective data from 112,108 participants in the Health Examinees study-G from 2004 to 2013, we evaluated the association between leisure-time physical activity (LTPA) and the incidence of overall and type-specific cancers using the Cox proportional hazards model. Self-reported LTPA participation, duration per week, intensity, type, and diversity were assessed. The incidence of overall and type-specific cancers, including colorectal, gastric, lung, breast, and prostate cancer and 13 obesity-related cancers, was identified …

BackgroundThis study aimed to explore the potential interaction between dietary intake and genetics on incident colorectal cancer (CRC) and whether adherence to healthy dietary habits could attenuate CRC risk in individuals at high genetic risk.MethodsWe analyzed prospective cohort data of 374,004 participants who were free of any cancers at enrollment in UK Biobank. Dietary scores were created based on three dietary recommendations of the World Cancer Research Fund (WCRF) and the overall effects of 11 foods on CRC risks using the inverse-variance (IV) method. Genetic risk was assessed using a polygenic risk score (PRS) capturing overall CRC risk. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs (confidence intervals) of associations. Interactions between dietary factors and the PRS were examined using a likelihood ratio test to compare models with and …

BackgroundLow-frequency variants play an important role in breast cancer (BC) susceptibility. Gene-based methods can increase power by combining multiple variants in the same gene and help identify target genes.MethodsWe evaluated the potential of gene-based aggregation in the Breast Cancer Association Consortium cohorts including 83,471 cases and 59,199 controls. Low-frequency variants were aggregated for individual genes’ coding and regulatory regions. Association results in European ancestry samples were compared to single-marker association results in the same cohort. Gene-based associations were also combined in meta-analysis across individuals with European, Asian, African, and Latin American and Hispanic ancestry.ResultsIn European ancestry samples, 14 genes were significantly associated (q < 0.05) with BC. Of those, two genes, FMNL3 (P = 6.11 × 10−6) and AC058822.1 …

Background: Increasing evidence suggests that metabolic disorders are a risk factor for gastric cancer. However, there is a lack of evidence on whether changes and persistence of metabolic disorders affect the subsequent gastric cancer occurrence. Therefore, this study aimed to evaluate the effects of changes or persistence in metabolic syndrome and its components' status on the incidence of gastric cancer among Korean population. Methods: This study comprised 59,671 individuals from the Health Examinees Study who had baseline surveys from 2004 to 2012 and repeated measurements from 2012 to 2016; and were followed up until 2018. Metabolic syndrome and its components were defined according to the National Cholesterol Education Program Adult Treatment Panel III and modified based on Korean population criteria. Participants were categorized into free, developed, recovered, and persistent …

BackgroundPrevious studies suggested that metabolic syndrome (MetS) might create a pro-cancer environment and increase cancer incidence. However, evidence on the risk of gastric cancer (GC) was limited. This study aimed to evaluate the association between MetS and its components and GC in the Korean population.MethodsIncluded were 108,397 individuals who participated in the large-scale prospective cohort study, the Health Examinees-Gem study during 2004–2017. The multivariable Cox proportional was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) on the association between MetS and its components with GC risk. Age was used as the time scale in the analyses. The stratified analysis was performed to determine the joint effect of lifestyle factors and MetS on GC risk in different groups.ResultsDuring the mean follow-up of 9.1 years, 759 cases of newly diagnosed cancer …

ImportanceDespite evidence of an association between reproductive factors and endometrial cancer risk, prospective studies have been conducted mainly in non-Asian countries.ObjectiveTo assess the association between reproductive factors, such as number of deliveries, age at menarche, or menopause, and endometrial cancer risk.Design, Setting, and ParticipantsThis cohort study used pooled individual data from 13 prospective cohort studies conducted between 1963 and 2014 in the Asia Cohort Consortium. Participants were Asian women. Data analysis was conducted from September 2019 to April 2023.ExposuresReproductive factors were assessed using a questionnaire in each cohort.Main Outcomes and MeasuresThe main outcome was time to incidence of endometrial cancer. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% CIs.ResultsA total of 1005 endometrial …

OBJECTIVESLifestyles, including exercise behaviors, change continually over time. This study examined whether the clinical biomarkers (CBs) related to cardiometabolic diseases (CMDs) and their relationships differed with changes in exercise behavior.METHODSThe Ansan-Ansung cohort study (third to fifth phases; n= 2,668) was used in the current study. Regular exercise behavior was investigated using a yes/no questionnaire. Changes in exercise behavior were classified into 4 groups: YN, NY, YY, and NN, with “Y” indicating that a participant regularly engaged in exercise at a given time point and “N” indicating that he or she did not. Fourteen CBs related to CMDs were used, and the associations between changes in exercise behavior and relative changes in CBs were examined. CB networks were constructed and topological comparisons were conducted.RESULTSYN was associated with increases in …

PURPOSE A polygenic risk score (PRS) consisting of 313 common genetic variants (PRS313) is associated with risk of breast cancer and contralateral breast cancer. This study aimed to evaluate the association of the PRS313 with clinicopathologic characteristics of, and survival following, breast cancer. METHODS Women with invasive breast cancer were included, 98,397 of European ancestry and 12,920 of Asian ancestry, from the Breast Cancer Association Consortium (BCAC), and 683 women from the European MINDACT trial. Associations between PRS313 and clinicopathologic characteristics, including the 70-gene signature for MINDACT, were evaluated using logistic regression analyses. Associations of PRS313 (continuous, per standard deviation) with overall survival (OS) and breast cancer–specific survival (BCSS) were evaluated with Cox regression, adjusted for clinicopathologic characteristics and …

BackgroundEpidemiological findings on the association between soybean product consumption and gastric cancer risk remain inconsistent. We evaluated the relationship between soybean product consumption and the risk of gastric cancer in a prospective cohort study in Korea.MethodsThis prospective cohort study included a total of 139,267 participants aged 40–69 years from the Health Examinees-Gem (HEXA-G) study between 2004 and 2013. Information on cancer diagnosis was retrieved from the Korea Central Cancer Registry until 31 December 2018. Multivariate hazard ratios (HRs) and 95% of confidence intervals (CIs) for the risk of gastric cancer according to the consumption of soybean products were estimated using Cox proportional hazards models.ResultsA total of 767 incident cases of gastric cancer occurred over an average follow-up period of 9.21 years. We found that men who consumed two …

ObjectivesThe association between long sleep duration and mortality is frequently attributed to the confounding influence of comorbidities. Nevertheless, past efforts to account for comorbidities have yielded inconsistent outcomes. The objective of this study was to evaluate this relationship using a large prospective cohort in Korea.MethodsThe study included 114 205 participants from the Health Examinees Study, who were followed for a median of 9.1 years. A composite comorbidity score was developed to summarize the effects of 21 diseases. Using Cox proportional hazards regression, hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cancer, and cardiovascular mortality associated with sleep duration were estimated. These estimates were adjusted for socio-demographic factors, lifestyle factors, body mass index, and comorbidity score. Additionally, a stratified analysis by subgroups with and …

BackgroundDespite the increasing incidence in colorectal cancer (CRC) among the young population, the involvement of modifiable early-life exposures is understudied.MethodsWe prospectively investigated the association of lifestyle score, which measures adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations, in adolescence and adulthood with risk of CRC precursors in 34,509 women enrolled in the Nurses’ Health Study II. Participants reported adolescent diet in 1998 and subsequently underwent at least one lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression for clustered data.ResultsDuring follow-up (1998–2015), 3036 women had at least one adenoma, and 2660 had at least one serrated lesion. In …

Background Asia has experienced a large increase in meat intake in the past decade, yet the health impact of meat intake is not well studied. Objective We examined the association of meat intake with all-cause, cancer and cardiovascular disease (CVD) mortality in an Asian country. Methods Participants were 113,568 adults with dietary data at recruitment (2004–2013) of the Health Examinees-Gem (HEXA-G) study, a prospective cohort study conducted in 8 regions of Korea. Participants were followed until 31 December 2020. Total, red, white, and organ meat intake were computed based on a 106-item questionnaire. Multivariable Cox proportional hazard models were implemented using the lowest quintile of meat intake as the reference category. Findings For 1,205,236 person-years, 3,454 deaths were recorded. High intake of processed red meat was positively associated with all-cause mortality [men: hazard ratio (HR) 1.21, 95% confidence interval (95% CI) 1.07–1.37; women: HR 1.32, 95% CI 1.12–1.56]. Increased risk of all-cause mortality (HR 1.21, 95% CI 1.05–1.39) and cancer mortality (HR 1.24, 95% CI 1.03–1.50) was observed in women with high intake of organ meat. Moderate intake of pork belly was associated with reduced risk of all-cause mortality in men (HR 0.76, 95% CI 0.62–0.93) and women (HR 0.83, 95% 0.69–0.98) but high intake was associated with increased risk of CVD mortality in women (HR 1.84, 95% CI 1.20–2.82). Low beef intake decreased the risk of CVD mortality in men (HR 0.58, 95% CI 0.40–0.84), but roasted pork increased cancer mortality in women (HR 1.26, 95% CI 1.05–1.52). Conclusion There was …

BackgroundObesity is the major cause of chronic diseases and the leading cause of mortality. We aimed to assess the impact of obesity on mortality in middle-aged Koreans using data from a Health Examinees study.MethodsWe used data from 39,689 men and 76,272 women who had complete information on body size and gave informed consent for the linkage of their data with the national death certificate data. Cox proportional hazard model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of body mass index (BMI) for all-cause, cardiovascular, and cancer mortality. The educational level and habits of cigarette smoking, alcohol consumption, and regular physical activity were adjusted. The menopausal status was additionally adjusted in women.ResultsWe found increased risks of all-cause mortality among those with a BMI of< 18.5 kg/m 2 (adjusted HRs [95% CIs]: men, 2.24 [1.73–2.91]; women, 1.47 [0.98–2.22]) and 18.0–< 21 kg/m 2 (men, 1.18 [1.00–1]; women, 1.23 [1.01–1.50]) than in those with a BMI of 21–< 23 kg/m 2. We also observed that men with BMIs of 23–< 25 kg/m 2 (0.85 [0.74–0.97]) and 25.0–26.9 kg/m 2 (0.87 [0.75-1.00]) had decreased risks of all-cause mortality.ConclusionThis large prospective study found significant associations between BMI and mortality. Especially, being underweight was associated with an increased risk of mortality in both sexes.

This study aimed to identify genetic risk loci associated with dietary intake using recently revealed data of over 93 million variants from the UK Biobank. By adjusting for familial relatedness among individuals in a linear mixed model, we identified a total of 399 genomic risk loci for the consumption of red meat (n= 15), processed meat (n= 12), poultry (n= 1), total fish (n= 28), milk (n= 50), cheese (n= 59), total fruits (n= 82), total vegetables (n= 50), coffee (n= 33), tea (n= 40), and alcohol (n= 57). Of these, 13 variants in previous study did not reach suggestive significant level (p= 1.0 e-5). Under the LDAK model, the heritability (h 2) was highest for the consumption of cheese (h 2= 10.48%), alcohol (h 2= 9.71%) and milk (h 2= 9.01%), followed by tea (h 2= 8.34%) and fruits (h 2= 7.83%). Of these, the highest genetic correlation (r 2) was observed between milk and tea consumption (r 2= 0.86). Post-GWA analyses were further conducted to identify variant annotations and functional pathways using summary statistics. Overall, by analyzing the updated data with adjustment for familial relatedness in this large-scale database, we identified several novel loci for food intake. Further investigations in other populations are needed to understand the contribution of genetic factors to dietary habits in populations of various ethnic backgrounds.

OBJECTIVE To examine the associations between modifiable risk factors and glycemic status changes in individuals with prediabetes. RESEARCH DESIGN AND METHODS A total of 10,358 individuals with prediabetes defined by their fasting blood glucose and HbA1c levels from the Health Examinees-Gem study were included in the present study. Modifiable factors, including BMI, abdominal obesity, smoking status, physical activity, alcohol consumption, diet quality, hypertension, and dyslipidemia, were examined to determine their associations with changes in glycemic status during follow-up. In addition, modifiable-factor scores were calculated, and their association with changes in glycemic status was also analyzed. RESULTS The median follow-up time for this study was 4 years (range, 1–7 years). BMI ≥25 kg/m2 (adjusted odds ratio [OR] 0.71 [95% CI 0 …

Introduction: Lifetime estrogen exposure is an essential factor for breast carcinogenesis. While adiposity impacts circulating hormones throughout a woman's life, weight gain in adulthood appears to have paradoxical effects at premenopausal and postmenopausal breast cancer risk. Thus, we evaluated the association between weight change throughout distinct lifetime periods with breast cancer risk stratified by menopausal status. Methods: We conducted a prospective cohort study of 73,347 Korean women aged 40 to 69 years who were enrolled in the population-based Health Examines-Gem Study (HEXA, 2004-2013). Using anthropometry obtained from physical examination and self-reported weights at ages 18-20, 35 and 50 assessed through a validated questionnaire at enrollment, we calculated body mass index (BMI), absolute weight change and weight change per year for the following 5 age periods …