[Show abstract][Hide abstract] ABSTRACT: Background Breast and ovarian cancers are predominant female cancers with increasing prevalence. The purpose of this study was to estimate the population attributable risks (PARs) of breast and ovarian cancer occurrence based on the relative risks (RRs) of modifiable reproductive factors and population-specific exposure prevalence. Methods The PAR was calculated by using the 1990 standardized prevalence rates, the 2010 national cancer incidence with a 20 year lag period, the meta-analyzed RRs from studies conducted in the Korean population for breast cancer, and the meta-analyzed RRs from a Korean epithelial ovarian cancer study and a prior meta-analysis, and ovarian cancer cohort results up to 2012. For oral contraceptive and hormone replacement therapy use, we did not consider lag period. Results The summary PARs for modifiable reproductive factors were 16.7 % (95 % CI 15.8–17.6) for breast cancer (2404 cases) and 81.9 % (95 % CI 55.0–100.0) for ovarian cancer (1579 cases). The modifiable reproductive factors included pregnancy/age at first birth (8.0 %), total period of breastfeeding (3.1 %), oral contraceptive use (5.3 %), and hormone replacement therapy use (0.3 %) for breast cancer and included breastfeeding experience (2.9 %), pregnancy (1.2 %), tubal ligation (24.5 %), and oral contraceptive use (53.3 %) for ovarian cancer. Conclusions Despite inherent uncertainties in the risk factors for breast and ovarian cancers, we suggest that appropriate long-term control of modifiable reproductive factors could reduce breast and ovarian cancer incidences and their related burdens by 16.7 % and 81.9 %, respectively.
[Show abstract][Hide abstract] ABSTRACT: Background:
High intake of dietary calcium has been thought to be a protective factor against colorectal cancer. To explore the dose-response relationship in the associations between dietary calcium intake and colorectal cancer risk by cancer location, we conducted a case-control study among Korean population, whose dietary calcium intake levels are relatively low.
The colorectal cancer cases and controls were recruited from the National Cancer Center in Korea between August 2010 and August 2013. Information on dietary calcium intake was assessed using a semi-quantitative food frequency questionnaire and locations of the colorectal cancers were classified as proximal colon cancer, distal colon cancer, and rectal cancer. Binary and polytomous logistic regression models were used to evaluate the association between dietary calcium intake and risk of colorectal cancer.
A total of 922 colorectal cancer cases and 2766 controls were included in the final analysis. Compared with the lowest calcium intake quartile, the highest quartile group showed a significantly reduced risk of colorectal cancer in both men and women. (Odds ratio (OR): 0.16, 95 % confidence interval (CI): 0.11-0.24 for men; OR: 0.16, 95 % CI: 0.09-0.29 for women). Among the highest calcium intake groups, decrease in cancer risk was observed across all sub-sites of colorectum in both men and women.
In conclusion, calcium consumption was inversely related to colorectal cancer risk in Korean population where national average calcium intake level is relatively lower than Western countries. A decreased risk of colorectal cancer by calcium intake was observed in all sub-sites in men and women.
[Show abstract][Hide abstract] ABSTRACT: We aimed to assess the relationship between dietary soyfood and isoflavone intake and colorectal cancer risk in a case-control study. A total of 901 colorectal cancer cases and 2669 controls were recruited at the National Cancer Center, Korea. A semi-quantitative food frequency questionnaire was used to assess the usual dietary habits, and the isoflavone intake level was estimated from five soyfood items. A high intake of total soy products, legumes, and sprouts was associated with a reduced risk for colorectal cancer in men and women, although the middle quartiles of intake of total soy products were associated with an elevated risk. In contrast, a high intake of fermented soy paste was associated with an elevated risk for colorectal cancer in men. The groups with the highest intake quartiles of isoflavones showed a decreased risk for colorectal cancer compared to their counterparts with the lowest intake quartiles in men (odds ratio (OR): 0.67, 95% confidence interval (CI): 0.51-0.89) and women (OR: 0.65, 95% CI: 0.43-0.99). The reduced risk for the highest intake groups persisted for distal colon cancer in men and rectal cancer in women. The association between soyfood intake and colorectal cancer risk was more prominent among post-menopausal women than pre-menopausal women. In conclusion, a high intake of total soy products or dietary isoflavones was associated with a reduced risk for overall colorectal cancer, and the association may be more relevant to distal colon or rectal cancers.
[Show abstract][Hide abstract] ABSTRACT: A considerable number of infectious agents have been classified as human carcinogens Group 1 by the International Agency for Research on Cancer. Major infection-related cancers such as cancers of nasopharynx (53%), stomach (60%) and liver (63%) occur in the World Health Organization Western Pacific Region. Many infection-related cancers are preventable, particularly those associated with human papilloma virus, Helicobacter pylori, human immunodeficiency virus-I, hepatitis B virus and hepatitis C virus and liver flukes. Mongolia shows the highest prevalence of hepatitis B virus and hepatitis C virus, and China shows the highest prevalence of Helicobacter pylori. Chronic infection is attributable for 17-28% of overall cancer incidence or mortality in China, Japan and Korea. Through infant immunization for hepatitis B, 30 of 37 countries and areas in the Western Pacific Region have reached the 2012 milestone of chronic hepatitis B virus infection prevalence of <2% in 5-year-old children and countries and areas of the region are now striving toward reaching the regional goal of <1% by 2017. Human papilloma virus immunization program is implemented either by government funding or, in some low-income countries, by public and private sector organizations. Cervical cancer screening via visual inspection with acetic acid or Pap smear is available in many Western Pacific Region Member States. More efforts are needed to implement new World Health Organization guide to vaccinate 9- to 13-year-old girls with two doses of human papilloma virus vaccine, and use human papilloma virus tests to screen women to prevent and control cervical cancer including guaranteed monitoring and appropriate follow-up for abnormal results.
No preview · Article · Nov 2015 · Japanese Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Background
We aimed to estimate the effect of alcohol consumption on breast cancer risk and to test whether overweight and obesity modifies this association.
We included in the analysis 45,233 women enrolled in the Swedish Women’s Lifestyle and Health study between 1991 and 1992. Participants were followed for occurrence of breast cancer and death until December 2009. Poisson regression models were used, and analyses were done for overall breast cancer and for estrogen receptor positive or negative (ER+, ER-) and progesterone receptor positive and negative (PR+, PR-) tumors separately.
A total of 1,385 breast cancer cases were ascertained during the follow-up period. Overall, we found no statistically significant association between alcohol intake and breast cancer risk after adjustment for confounding, with an estimated relative risk (RR) of 1.01 (95 % CI: 0.98–1.04) for an increment in alcohol consumption of 5 g/day. A statistically significant elevated breast cancer risk associated with higher alcohol consumption was found only among women with BMI ≤25 (RR 1.03, 95 % CI 1.0–1.05 per 5 g/day increase).
An increase in breast cancer risk with higher alcohol consumption was found for breast cancers in women with a BMI ≤25 kg/m2.
[Show abstract][Hide abstract] ABSTRACT: Background: The relationship between tobacco smoking, including secondhand smoking, and depression has been assessed. The purpose of this study was to evaluate the association between secondhand smoking among current, former and never smokers and depressive symptoms. For secondhand smoking, gender differences and sources of exposure were examined.
Methods: Data from 34,693 participants from the fourth and fifth Korean Health and Nutritional Examination Survey (2007–2012) were analyzed in 2014. Self-reported exposure to active (current, former or never) and secondhand smoking and depressive symptoms experienced during the past year were analyzed using logistic regression. The dose–response relationship between duration of secondhand smoke exposure and depression was assessed with stratification by gender and sources of exposure (at home only, at the workplace only or both).
Results: Regardless of their smoking status, all women who had secondhand smoke exposure at home reported more depressive symptoms than non-smoking women without any exposure to secondhand cigarette smoking (OR 1.43, 95 % CI 1.04–1.96 for current smokers; OR 2.32, 95 % CI 1.04–5.16 for former smokers; OR 1.25, 95 % CI 1.08–1.43 for never smokers). There was also a significant dose–response pattern (p-trend <0.001) for the duration of secondhand smoke exposure at home among women. No significant association was found between smoking and depressive symptoms in men.
Conclusions: There was a significant association between secondhand smoke exposure at home and depressive symptoms in women. Secondhand smoke exposure at home was associated with depressive symptoms in a dose–response manner
Full-text · Article · Oct 2015 · BMC Public Health
[Show abstract][Hide abstract] ABSTRACT: Background
Spontaneous abortion (SA) affects 11.2% of recognized pregnancies in Korea. Many studies have focused on the increased risk of SA in obese populations, but there are few studies that have focused on underweight (Body mass index (BMI) <18.5 kg/m2) women, especially in relation to pre-pregnancy BMI. The aim of this study was to examine the role of pre-pregnancy BMI at age 18–20 in later SA.
Among the women who were ever pregnant in the Health Examinees Study (HEXA), which was one of the cohorts studied in the KoGES (Korean Genome and Epidemiology Study) from 2004 to 2012 (N = 80,447), the likelihood of SA based on pre-pregnancy BMI, classified by the criteria for Asians (Underweight: <18.5 kg/m2; Normal range: 18.5-22.9 kg/m2; Overweight at risk: 23–24.9 kg/m2; Obese I: 25–29.9 kg/m2; Obese II: ≥30 kg/m2), was presented as odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression models.
Being underweight or obese relative to the normal weight range was associated with a higher likelihood of SA (OR = 1.10 [95% CI = 1.05–1.15] in underweight women and OR = 1.06 [95% CI = 0.96–1.16] in obese women), and this effect was much greater in women who experienced recurrent SAs (for three or more SAs: OR = 1.29 [95% CI 1.14–1.46] in underweight women and OR = 1.39 [95% CI 1.09–1.78] in obese women). Obesity was associated with an increased likelihood of SA at a younger age (≤25 years), whereas underweight was associated with an increased OR of SA at an older age (≥26 years).
As this study was conducted with baseline data of original cohort which focused on other chronic diseases, recall for previous pregnancy-related information might be less accurate. However, this study shows strength in its large size and prospective potential.
Pre-pregnancy BMI at ages 18–20 years revealed a U-shaped association with SA, and underweight and obese women showed increased likelihood for SA during different age periods.
[Show abstract][Hide abstract] ABSTRACT: Background: Although there are plausible mechanisms of female hormones in depression, epidemiological evidence has shown conflicting results.
Objective: This study aimed to evaluate the associations between female hormonal events and post-
menopausal depression and further investigate the relative association between the age of menarche, the age of menopause and depression.
Methods: Among 111,589 women who took part in the Health Examinees (HEXA) Study, a total of 60,114 postmenopausal participants were included in the final analysis. Each participant provided information on depression and questions related to reproductive history. The outcome variable was self-reported by the history of depression diagnosed by physicians and the Center for Epidemiologic Studies Depression Scale (CES-D) score. With the multivariate logistic regression, odds ratios were calculated. Possible interactions between depression prevalence and the ages of menarche and menopause were assessed.
Results: A total of 2.2% (1342/60,114) women were diagnosed with depression after menopause, and 5.9% (500/8472) showed depressive symptoms. As the age of menopause and duration of reproductive years increased, the odds ratio of depression decreased (P-trend o0.001). As the age of menarche increased, the likelihood of physician-diagnosed depression also increased (P-trend 0.048). As the number of both spontaneous and induced abortions increased, the odds ratio of depression increased (P-trend <0.001).
Limitation: it is possible that women show inaccuracies in recalling their hormonal events and re-
porting other past mental disorders as depression.
Conclusion: Both the ages of the initiation and the termination of menstruation were associated with the increased odds ratio of post-menopausal depression. However, the age of menopause seems to be more important.
Full-text · Article · Aug 2015 · Journal of Affective Disorders
[Show abstract][Hide abstract] ABSTRACT: Background:
Predicting high risk groups for gastric cancer and motivating these groups to receive regular checkups is required for the early detection of gastric cancer. The aim of this study is was to develop a prediction model for gastric cancer incidence based on a large population-based cohort in Korea.
Based on the National Health Insurance Corporation data, we analyzed 10 major risk factors for gastric cancer. The Cox proportional hazards model was used to develop gender specific prediction models for gastric cancer development, and the performance of the developed model in terms of discrimination and calibration was also validated using an independent cohort. Discrimination ability was evaluated using Harrell's C-statistics, and the calibration was evaluated using a calibration plot and slope.
During a median of 11.4 years of follow-up, 19,465 (1.4%) and 5,579 (0.7%) newly developed gastric cancer cases were observed among 1,372,424 men and 804,077 women, respectively. The prediction models included age, BMI, family history, meal regularity, salt preference, alcohol consumption, smoking and physical activity for men, and age, BMI, family history, salt preference, alcohol consumption, and smoking for women. This prediction model showed good accuracy and predictability in both the developing and validation cohorts (C-statistics: 0.764 for men, 0.706 for women).
In this study, a prediction model for gastric cancer incidence was developed that displayed a good performance.
[Show abstract][Hide abstract] ABSTRACT: Defects in the DNA damage repair process can cause genomic instability and play an important role in cervical carcinogenesis. The purpose of this study was to analyze the association of 29 candidate single nucleotide polymorphisms (SNPs) in genes in the DNA repair pathway, TP53, and TP53BP1 with the risk of cervical cancer.
Twenty nine SNPs in 4 genes in the DNA repair pathway (ERCC2, ERCC5, NBS1, and XRCC1), TP53, and TP53BP1 were genotyped for 478 cervical cancer patients and 922 healthy control subjects, and their effects on cervical carcinogenesis were analyzed.
The most significant association was found for rs17655 in ERCC5, with an age adjusted p-value of 0.00004, for which a strong additive effect of the risk allele C was observed (odds ratio = 2.01 for CC to GG). On the other hand, another significant polymorphism rs454421 in ERCC2 showed a dominant effect (odds ratio = 1.68 for GA+AA to GG) with an age adjusted p-value of 0.00094. The association of these polymorphisms remained significant regardless of the age of onset. The significant result for rs17655 was also consistent for subgroups of patients defined by histology and HPV types. However, for rs454421, the association was observed only in patients with squamous cell carcinoma and non-HPV 18 type.
s The results of this study show a novel association of cervical cancer and the genes involved in the nucleotide excision pathway in the Korean population.
Full-text · Article · Jun 2015 · Cancer Research and Treatment
[Show abstract][Hide abstract] ABSTRACT: The present study aimed to examine the association between cigarette smoking, alcohol consumption and colorectal cancer risk among Korean adults.
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.
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 ≥ 30 years of consumption compared to non-drinkers; HR 2.24 [1.31-3.84] for ≥ 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.
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.
[Show abstract][Hide abstract] ABSTRACT: Purpose: The aim of the current study was to compare the vegetable and fruit intake between one person households and those living with family. Methods: The 24-hour recall data of 14,914 persons over 20 years old who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) from 2010 to 2012 were used for the final analysis. Consumption of non-salted vegetables and fruits (≥ 400 g/day), fruits (≥ 200 g/day), and kimchi (≥ 120 g/day) was compared between one person households and those living with family. Logistic regression models were used to assess the associations between potential determinants and adequate vegetable and fruit intake. Results: After additional adjustments for age, household income, and total energy intake, no statistically significant differences in likelihood of low intake of non-salted vegetable and fruit and kimchi were observed between one person households and those living with family. (Non-salted vegetables and fruits: odds ratio (OR) = 1.15, 95% confidence interval (CI) = 0.79-1.68 for the men; OR = 1.25, 95% CI = 0.98-1.59 for women). However one person households have greater likelihood of low intake of kimchi than those living with family in women (OR = 1.72, 95% CI = 1.31-2.26). Conclusion: Although there were no differences in likelihood of low intake of non-salted vegetables and between individuals living alone and those living with family, women of one person households were great likelihood of low intake of kimchi compared to those living with family.
Preview · Article · Jun 2015 · Journal of Nutrition and Health
[Show abstract][Hide abstract] ABSTRACT: Colorectal cancer mortality has started to decrease in several developed countries in Asia. The current study aimed to present the long-term trends in colorectal cancer mortality in Korea using joinpoint analysis and age-period-cohort modeling.
The number of colorectal cancer deaths and the population for each 5-year age group were obtained from Statistics Korea for the period 1984-2013 for adults 30 years and older. Joinpoint regression analysis was conducted to determine changes in trends in age-standardized mortality rates, and age-period-cohort analysis was performed to describe trends in colorectal cancer mortality using the intrinsic estimator method.
In men, the age-standardized mortality rate for colorectal cancer increased from 1984 to 2003, and the mortality rates stabilized thereafter, whereas the mortality rate of colorectal cancer in women has decreased since 2004. The age-specific mortality rate of colorectal cancer increased in both men and women over time, whereas decreases in the age-specific mortality rate in younger cohorts were observed. In the age-period-cohort analysis, old age and recent period were associated with higher mortality for both men and women. The birth cohort born after 1919 showed reduced colorectal cancer mortality in both men and women.
Our study showed a recent decreasing trend in colorectal cancer mortality in women and a stable trend in men after 2003-2004. These changes in colorectal cancer mortality may be attributed to birth cohort effects.
No preview · Article · May 2015 · Asian Pacific journal of cancer prevention: APJCP
[Show abstract][Hide abstract] ABSTRACT: We aimed to investigate the differences in health screening, including medical checkups and cancer screening, between HBV carriers and non-carriers in the Republic of Korea. In the fifth Korean National Health and Nutrition Examination Survey (KNHANES V), conducted between 2010 and 2012, 17,865 persons who answered regarding their HBV-infection status, medical checkup history, liver cancer screening and general cancer screening within the past years were included in the final analysis. In total, 295 persons were HBV carriers. Logistic regression models were used to compare the health check-up rate between the HBV carriers and non- HBV carriers. The HBV carriers were more likely to have been screened for liver cancer [adjusted odds ratio (OR): 2.83, 95% confidence interval (95%CI): 1.90-4.21] or cancer [OR: 1.44, 95%CI: 1.04-1.99]. The HBV carriers showed a probability of receiving medical checkups that was identical to that of the non-carriers [OR: 0.99, 95%CI: 0.72-1.35]. The HBV carriers, who were at higher risk of developing chronic liver disease, were more likely to be screened for cancer, including liver cancer, than the non-HBV carriers; no difference in the rate of medical checkups was observed between the HBV carriers and non-HBV carriers.
Full-text · Article · May 2015 · Asian Pacific journal of cancer prevention: APJCP
[Show abstract][Hide abstract] ABSTRACT: We aimed to assess individual and area-level determinants of gastric cancer screening participation.
Data on gastric cancer screening and individual-level characteristics were obtained from the 2007-2009 Fourth Korea National Health and Nutrition Examination Survey. The area-level variables were collected from the 2005 National Population Census, 2008 Korea Medical Association, and 2010 National Health Insurance Corporation. The data were analyzed using multilevel logistic regression models.
The estimated participation rate in gastric cancer screening adhered to the Korea National Cancer Screening Program guidelines was 44.0% among 10,658 individuals aged over 40 years who were included in the analysis. Among the individual-level variables, the highest income quartile, a college or higher education level, living with spouse, having a private health insurance, limited general activity, previous history of gastric or duodenal ulcer, and not currently smoking were associated with a higher participation rate in gastric cancer screening. Urbanization showed a significant negative association with gastric cancer screening attendance among the area-level factors (odds ratio (OR) = 0.73; 95% confidence interval (CI) = 0.57-0.93 for the most urbanized quartile vs. least urbanized quartile).
There are differences in gastric cancer screening attendance according to both individual and regional area characteristics.
[Show abstract][Hide abstract] ABSTRACT: Reliable biomarkers are required to predict the response to sorafenib. We investigated genomic variations associated with responsiveness to sorafenib for patients with unresectable hepatocellular carcinoma (HCC). Blood samples from 2 extreme, 2 strong and 3 poor responders to sorafenib were subjected to whole-genome analysis. Then, we validated candidate genomic variations with another 174 HCC patients, and performed in vitro functional analysis and in silico analyses. Genomic data of >96 gigabases/sample was generated at average of ~34X sequencing depth. In total, 1813 genomic variations were matched to sorafenib responses in clinical data; 708 were located within regions for sorafenib-target genes or drug absorption, distribution, metabolism, and excretion (ADME)-related genes. From them, 36 variants were within the coding regions and 6 identified as non-synonymous single-nucleotide variants from 4 ADME-related genes (ABCB1, FMO3, MUSK, and SLC15A2). Validation genotyping confirmed sequencing results and revealed patients genotype for rs2257212 in SLC15A2 showed longer progression-free survival (HR = 2.18). In vitro study displayed different response to sorafenib depending on the genotype of SLC15A2. Structural prediction analysis revealed changes of the phosphorylation levels in protein, potentially affecting sorafenib-associated enzymatic activity. Our finding using extreme responder seems to generate robust biomarker to predict the response of sorafenib treatment for HCC. INTRODUCTION Hepatocellular carcinoma (HCC) is one of the most common types of cancers (with the highest prevalence in the Asia-Pacific region) and the third leading cause of cancer death worldwide.  Because this disease is mostly diagnosed at an advance stage, potentially curative therapies are effective in less than 30–40% of HCC patients. [2, 3] While systemic therapies are indicated for advanced HCC, no effective systemic therapy for patients
[Show abstract][Hide abstract] ABSTRACT: Background:
Although hypotheses have been proposed regarding the biological mechanisms of hormonal fluctuations in mood disorders, few epidemiological studies have addressed this issue. The aim of this study was to examine the association between hormone-related life events and postmenopausal depression.
Of 13,918 women who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) V, a total of 4869 post-menopausal women who had completed information on depression onset age and additional reproductive factors were included in the analysis. A multivariate logistic regression was applied to calculate the odds ratios between reproductive factors and post-menopausal onset depression.
A total of 276 women (5.7%) were diagnosed with depression after menopause. Longer reproductive years were associated with a reduced risk of depression (for more than 35 reproductive years: OR=0.41, 95% CI: 0.27-0.62, P-trend<0.001). Similarly, a later age of menopause (52 years and older) corresponded to a decreased risk of depression (OR=0.35, 95% CI: 0.22-0.55) compared to the women with a menopausal age younger than 46 years. Greater numbers of pregnancies and exogenous hormone use were also associated with increased risk of depression.
All data were collected from interviews using questionnaires. There may be some inaccuracies in recall of lifetime reproductive events, but women generally recalled their hormonal events correctly.
Early menopause and the use of exogenous hormones were associated with the risk of post-menopausal depression. Clinicians should closely monitor and consider further screening for depressed women who undergo early menopause or those with exogenous hormone use.
Full-text · Article · Jan 2015 · Journal of Affective Disorders