Autoimmune Diseases and Gastric Cancer Risk: A Systematic Review and Meta-Analysis / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Autoimmunity is an alternative etiology of gastric inflammation, the initiating event in the gastric carcinogenic cascade. This mechanism may be an increasingly important cause of gastric cancer with the waning prevalence of its primary etiologic factor, chronic Helicobacter pylori infection. MATERIALS AND METHODS: PubMed and EMBASE were searched up to September 2018. Autoimmunity and 96 specific manifestations were considered for associations with gastric cancer risk. Random effects analysis was used to calculate pooled relative risk estimates (RR) and 95% confidence intervals (CI). RESULTS: We found a total of 52 observational studies representing 30 different autoimmune diseases. Overall, the presence of an autoimmune condition was associated with a gastric cancer pooled RR of 1.37 (95% CI, 1.24 to 1.52). Among the 24 autoimmune conditions with two or more independent reports, nine were significantly associated with increased gastric cancer risk: dermatomyositis (RR, 3.69; 95% CI, 1.74 to 7.79), pernicious anemia (RR, 2.84; 95% CI, 2.30 to 3.50), Addison disease (RR, 2.11; 95% CI, 1.26 to 3.53), dermatitis herpetiformis (RR, 1.74; 95% CI, 1.02 to 2.97; n=3), IgG4-related disease (RR, 1.69; 95% CI, 1.00 to 2.87), primary biliary cirrhosis (RR, 1.64; 95% CI, 1.13 to 2.37), diabetes mellitus type 1 (RR, 1.41; 95% CI, 1.20 to 1.67), systemic lupus erythematosus (RR, 1.37; 95% CI, 1.01 to 1.84), and Graves disease (RR, 1.27; 95% CI, 1.06 to 1.52). CONCLUSION: Our analysis documents the wide range of autoimmune diseases associated with gastric cancer. These associations may reflect unreported links between these conditions and autoimmune gastritis. Further studies are warranted to investigate potential causal mechanisms.

Epidemiology and screening of gastric cancer in Korea

The age-standardized incidence and mortality rates of gastric cancer have been decreasing worldwide. However, due to the rapid increase in the aging population, the absolute number of cases is actually increasing, and some countries, including Korea, show a divergent trend in the incidence of gastric cancer in younger generations. Gastric cancer is the second most common cancer in Korea. In the present review, several epidemiologic factors associated with the risk of gastric cancer are evaluated, including family history of gastric cancer, Helicobacter pylori infection, cigarette smoking, and adverse dietary factors. The practice of and participation in gastric cancer screening are reviewed. Prevention strategies based on evidence from Korean epidemiologic studies and early detection by regular screening are important for the reduction of the burden from gastric cancer.

Epidemiology and screening of gastric cancer in Korea

The age-standardized incidence and mortality rates of gastric cancer have been decreasing worldwide. However, due to the rapid increase in the aging population, the absolute number of cases is actually increasing, and some countries, including Korea, show a divergent trend in the incidence of gastric cancer in younger generations. Gastric cancer is the second most common cancer in Korea. In the present review, several epidemiologic factors associated with the risk of gastric cancer are evaluated, including family history of gastric cancer, Helicobacter pylori infection, cigarette smoking, and adverse dietary factors. The practice of and participation in gastric cancer screening are reviewed. Prevention strategies based on evidence from Korean epidemiologic studies and early detection by regular screening are important for the reduction of the burden from gastric cancer.

Determinants of Poor Self-rated Health in Korean Adults With Diabetes / 예방의학회지

OBJECTIVES: Self-rated health is a measure of perceived health widely used in epidemiological studies. Our study investigated the determinants of poor self-rated health in middle-aged Korean adults with diabetes. METHODS: A cross-sectional study was conducted based on the Health Examinees Study. A total of 9759 adults aged 40 to 69 years who reported having physician-diagnosed diabetes were analyzed with regard to a range of health determinants, including sociodemographic, lifestyle, psychosocial, and physical variables, in association with self-rated health status using multivariate logistic regression models. A p-value <0.05 was considered to indicate statistical significance. RESULTS: We found that negative psychosocial conditions, including frequent stress events and severe distress according to the psychosocial well-being index, were most strongly associated with poor self-rated health (odds ratio [OR](Frequent stress events), 5.40; 95% confidence interval [CI], 4.63 to 6.29; OR(Severe distress), 11.08; 95% CI, 8.77 to 14.00). Moreover, younger age and being underweight or obese were shown to be associated with poor self-rated health. Physical factors relating to participants' medical history of diabetes, such as a younger age at diagnosis, a longer duration of diabetes, insulin therapy, hemoglobin A(1c) levels of 6.5% or more, and comorbidities, were other correlates of poor reported health. CONCLUSIONS: Our findings suggest that, in addition to medical variables, unfavorable socioeconomic factors, and adverse lifestyle behaviors, younger age, being underweight or obese, and psychosocial stress could be distinc factors in predicting negative perceived health status in Korean adults with diabetes.

Association of Selected Medical Conditions With Breast Cancer Risk in Korea / 예방의학회지

OBJECTIVES: To estimate the effect of medical conditions in the population of Korea on breast cancer risk in a case-control study. METHODS: The cases were 3242 women with incident, histologically confirmed breast cancer in two major hospitals interviewed between 2001 and 2007. The controls were 1818 women each admitted to either of those two hospitals for a variety of non-neoplastic conditions. Information on each disease was obtained from a standardized questionnaire by trained personnel. Odds ratios (ORs) for each disease were derived from multiple logistic regression adjusted for age, age of menarche, pregnancy, age of first pregnancy, and family history of breast cancer. RESULTS: Among all of the incident breast cancer patients, pre-existing diabetes (OR, 1.33; 95% confidence interval [CI], 0.99 to 1.78), hypertension (OR, 1.46; 95% CI, 1.18 to 1.83), thyroid diseases (OR, 1.26; 95% CI, 1.00 to 1.58), and ovarian diseases (OR, 1.70; 95% CI, 1.23 to 2.35) were associated with an increased risk of breast cancer when other factors were adjusted for. In a stratified analysis by menopausal status, pre-existing hypertension (pre-menopause OR, 0.80; 95% CI, 0.48 to 1.34 vs. post-menopause OR, 1.87; 95% CI, 1.44 to 2.43; p-heterogeneity <0.01) and ovarian disease (pre-menopause OR, 4.20; 95% CI, 1.91 to 9.24 vs. post-menopause OR, 1.39; 95% CI, 1.02 to 1.91; p-heterogeneity 0.01) showed significantly different risks of breast cancer. CONCLUSIONS: Our results suggest the possibility that medical conditions such as hypertension affect breast cancer development, and that this can differ by menopausal status. Our study also indicates a possible correlation between ovarian diseases and breast cancer risk.

Completeness of Cancer Case Ascertainment in Korea Radiation Effect and Epidemiology Cohort Study

The aim of this study was to evaluate whether the completeness of case ascertainment during the follow-up of a cohort differed between the exposed and the nonexposed groups in Korea Radiation Effect and Epidemiology Cohort (KREEC). The completeness was defined as the proportion of the number of detected cases to the number of estimated cases, in which the estimation was performed by capture-recapture method. Data were obtained from the cancer registries, death certificates, and medical records during years 2004-2007. Among 11,367 subjects in the exposed group and 24,809 subjects in the unexposed group, the completeness of cancer case ascertainment were 88.2% vs 87.2% in cancer registry, 38.2% vs 41.1% in death certificate and 57.9% vs 62.0% in medical records data, 96.9% vs 97.1% for all combined sources and were not statistically different between the two groups. In conclusion, the method of ascertaining the cases in the KREEC was not biased depending on the exposure status, and thus adds credibility to the outcomes of the KREEC study as well as confirming the incident cases in the two groups.

Power Estimation and Follow-Up Period Evaluation in Korea Radiation Effect and Epidemiology Cohort Study / 예방의학회지

OBJECTIVES: The objective of this study was to calculate sample size and power in an ongoing cohort, Korea radiation effect and epidemiology cohort (KREEC). METHOD: Sample size calculation was performed using PASS 2002 based on Cox regression and Poisson regression models. Person-year was calculated by using data from '1993-1997 Total cancer incidence by sex and age, Seoul' and Korean statistical informative service. RESULTS: With the assumption of relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, sample size calculation was 405 events based on a Cox regression model. When the relative risk was assumed to be 1.5 then number of events was 170. Based on a Poisson regression model, relative risk=1.3, exposure:non-exposure=1:2 and power=0.8 rendered 385 events. Relative risk of 1.5 resulted in a total of 157 events. We calculated person-years (PY) with event numbers and cancer incidence rate in the non-exposure group. Based on a Cox regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, 136 245PY was needed to secure the power. In a Poisson regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, person-year needed was 129517PY. A total of 1939 cases were identified in KREEC until December 2007. CONCLUSIONS: A retrospective power calculation in an ongoing study might be biased by the data. Prospective power calculation should be carried out based on various assumptions prior to the study.

Psychological Health in Residents Participating in Clean-up Works of Hebei Spirit Oil Spill / 예방의학회지

OBJECTIVES: Our objective was to examine and evaluate the psychological health of the residents of Taean during the cleanup of the Hebei Spirit (HS) oil spill and to review some factors associated with the results. METHODS: A community survey of 71 men and women was conducted 8 weeks after the HS oil spill. Questionnaires used were the PWI (Psychological Well-being Index) scale for psychosocial distress, the CES-D (Center for Epidemiologic Studies-Depression) scale for depressive symptoms, and a questionnaire created to assess suicidal impulses. RESULTS: The overall prevalence of high-risk psychosocial distress among the study group was 64.2%. The percentages of respondents with scores on the CES-D Scale above 16 and above 21 were 77.6% and 62.7%, respectively. The percentage of respondents categorized as having suicidal impulses was 18.3%. When compared with unexposed groups in the general population taken from various sources, the residents of Taean were 6.5 times as likely to have high stress and 9.4-9.7 times as likely to be depressed. No significant difference in the rate of suicidal impulse was found between the residents of Taean and the general population. Factors associated with high stress, depression, and suicidal impulses were age, a change in income, educational level, number of days working on the cleanup, and positive responses to questions about "affected daily activity" and "hospital visit due to work on cleanup." CONCLUSIONS: The results suggest that the HS oil spill had a significant impact on the psychological health of residents of Taean, but the comparability of the unexposed groups is a limitation of the study.