Purpose: To develop the 2025 update to the Korean colorectal cancer (CRC) screening guidelines by systematically evaluating recent evidence, integrating domestic data, and addressing changes since the 2015 guideline revision, thereby providing an evidence-based standard for clinicians and policymakers. Methods: A multidisciplinary committee developed the guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The process included formulation of three key questions addressing screening efficacy, diagnostic accuracy, and optimal screening age and interval. A systematic review of international guidelines and primary literature was conducted, yielding 327 eligible studies. In addition, a utility-based analysis using a Markov model was performed to determine optimal screening ages and intervals. Results: The evidence synthesis identified high-certainty evidence supporting the use of the fecal immunochemical test (FIT) for reducing CRC mortality and moderate-certainty evidence for colonoscopy. Evidence for computed tomographic colonography (CTC) and stool DNA testing was rated as very low certainty. Based on the evidence review and cost-utility analysis, the committee conditionally recommends CRC screening for asymptomatic, average-risk adults aged 45–74 years using either colonoscopy every 10 years or FIT every 1–2 years. CTC and stool DNA testing were not recommended owing to insufficient evidence. Conclusion The 2025 Korean Guidelines for Colorectal Cancer Screening present updated, evidence-based recommendations tailored to the domestic healthcare context. By conditionally endorsing both colonoscopy and FIT for individuals aged 45–74 years, these guidelines aim to improve population-level screening effectiveness and reduce the burden of CRC in South Korea.

OBJECTIVES: Kudoa septempunctata has been identified as the causative agent of food poisoning following the consumption of raw farmed Paralichthys olivaceus. However, cohort studies providing robust evidence for an association between K. septempunctata and gastrointestinal symptoms remain limited. This prospective cohort study investigated the association between the consumption of K. septempunctata–infected farmed P. olivaceus and the occurrence of gastrointestinal symptoms. METHODS: Individuals who purchased raw farmed P. olivaceus between 2020 and 2021 were selected as the study population. Study data included 2 rounds of questionnaire surveys administered before and after consumption, 2 muscle specimens obtained from each purchased fish, and human biological specimens collected from individuals who developed gastrointestinal symptoms within 24 hours after consumption. Data were analyzed using the chi-square test and t-test, and the association between consumption of K. septempunctata–infected farmed P. olivaceus and gastrointestinal symptoms was evaluated using relative risk estimates between exposure groups. RESULTS: The relative risk of gastrointestinal symptoms associated with exposure to K. septempunctata–infected P. olivaceus ranged from 71.2 (95% confidence interval [CI], 27.0 to 178.6) to 124.5 (95% CI, 43.5 to 355.0) across the 2 case definitions. A strong and statistically significant association was observed between exposure to K. septempunctata–infected P. olivaceus and the development of acute gastrointestinal symptoms. CONCLUSIONS These findings indicate both an association and a causal relationship between consumption of K. septempunctata–infected farmed P. olivaceus and the onset of gastrointestinal symptoms.

suggest that some reproductive factors associated with BC differ across ethnicities and time trends, perhaps due to the prevalence of reproductive factors and the baseline hazard of BC.

This paper reviews recent research findings on the population-attributable risk (PAR) of tobacco smoking in cancer incidence. It examines the components used in calculating PAR, specifically smoking prevalence and the relative risk of cancer associated with tobacco smoking.Current Concepts: The association between tobacco smoking and cancer risk is typically measured by the relative risk, which indicates how many times higher the cancer risk is in smokers compared to non-smokers. There is robust evidence that tobacco smoking is carcinogenic for cancers of the oral cavity, esophagus, stomach, colorectum, liver, pancreas, larynx, lung, cervix, ovaries, kidneys, bladder, and myeloid leukemia. Numerous epidemiological studies indicate that smoking increases the risk of these cancers by 2 to 10 times or more. The population attributable fraction of tobacco smoking for cancer quantifies the extent to which smoking contributes to cancer risk in a given population. Because PAR depends on smoking prevalence and relative risk, it is calculated and reported for each country and time point. According to a National Cancer Center report, in 2019 tobacco smoking accounted for 47% of esophageal cancers, 28% of stomach cancers, 27% of pancreatic cancers, 53% of lung cancers, and 43% of bladder cancers in Korean men.Discussion and Conclusion: The relative risk and population-attributable fraction serve as important indicators that inform policy development, prevention strategy formulation, resource allocation, health equity initiatives, public health awareness, and clinical practice.

This paper reviews recent research findings on the population-attributable risk (PAR) of tobacco smoking in cancer incidence. It examines the components used in calculating PAR, specifically smoking prevalence and the relative risk of cancer associated with tobacco smoking.Current Concepts: The association between tobacco smoking and cancer risk is typically measured by the relative risk, which indicates how many times higher the cancer risk is in smokers compared to non-smokers. There is robust evidence that tobacco smoking is carcinogenic for cancers of the oral cavity, esophagus, stomach, colorectum, liver, pancreas, larynx, lung, cervix, ovaries, kidneys, bladder, and myeloid leukemia. Numerous epidemiological studies indicate that smoking increases the risk of these cancers by 2 to 10 times or more. The population attributable fraction of tobacco smoking for cancer quantifies the extent to which smoking contributes to cancer risk in a given population. Because PAR depends on smoking prevalence and relative risk, it is calculated and reported for each country and time point. According to a National Cancer Center report, in 2019 tobacco smoking accounted for 47% of esophageal cancers, 28% of stomach cancers, 27% of pancreatic cancers, 53% of lung cancers, and 43% of bladder cancers in Korean men.Discussion and Conclusion: The relative risk and population-attributable fraction serve as important indicators that inform policy development, prevention strategy formulation, resource allocation, health equity initiatives, public health awareness, and clinical practice.

This paper reviews recent research findings on the population-attributable risk (PAR) of tobacco smoking in cancer incidence. It examines the components used in calculating PAR, specifically smoking prevalence and the relative risk of cancer associated with tobacco smoking.Current Concepts: The association between tobacco smoking and cancer risk is typically measured by the relative risk, which indicates how many times higher the cancer risk is in smokers compared to non-smokers. There is robust evidence that tobacco smoking is carcinogenic for cancers of the oral cavity, esophagus, stomach, colorectum, liver, pancreas, larynx, lung, cervix, ovaries, kidneys, bladder, and myeloid leukemia. Numerous epidemiological studies indicate that smoking increases the risk of these cancers by 2 to 10 times or more. The population attributable fraction of tobacco smoking for cancer quantifies the extent to which smoking contributes to cancer risk in a given population. Because PAR depends on smoking prevalence and relative risk, it is calculated and reported for each country and time point. According to a National Cancer Center report, in 2019 tobacco smoking accounted for 47% of esophageal cancers, 28% of stomach cancers, 27% of pancreatic cancers, 53% of lung cancers, and 43% of bladder cancers in Korean men.Discussion and Conclusion: The relative risk and population-attributable fraction serve as important indicators that inform policy development, prevention strategy formulation, resource allocation, health equity initiatives, public health awareness, and clinical practice.

Background: The increasing rate of excess body weight (EBW) in the global population has led to growing health concerns, including cancer-related EBW. We aimed to estimate the population attributable fraction (PAF) of cancer incidence and deaths linked to EBW in Korean individuals from 2015 to 2030 and to compare its value with various body mass index cutoffs. Methods: Levin’s formula was used to calculate the PAF; the prevalence rates were computed using the Korean National Health and Nutrition Examination Survey data, while the relative risks of specific cancers related to EBW were estimated based on the results of Korean cohort studies. To account for the 15-year latency period when estimating the PAF in 2020, the prevalence rates from 2015 and attributable cases or deaths from 2020 were used. Results: The PAF attributed to EBW was similar for both cancer incidence and deaths using either the World Health Organization (WHO) Asian-Pacific region standard or a modified Asian standard, with the WHO standard yielding the lowest values. In the Korean population, the PAFs of EBW for cancer incidence were 2.96% in men and 3.61% in women, while those for cancer deaths were 0.67% in men and 3.06% in women in 2020. Additionally, PAFs showed a gradual increase in both sexes until 2030. Conclusion The EBW continues to have a significant impact on cancer incidence and deaths in Korea. Effective prevention strategies targeting the reduction of this modifiable risk factor can substantially decrease the cancer burden.

The aim of this ecological study was to examine the correlation between cancer incidence and health behaviors such as smoking, alcohol consumption, and obesity, and investigated whether there were differences in this correlation between metropolitan areas and other regions. Data on health behaviors exposure/prevalence and cancer incidence rates for 227 administrative districts (cities and counties) were obtained. The average exposure proportion measured annually from 2008 to 2011 in the Korea Community Health Survey data and the age-standardized cancer incidence data from 2014 to 2018, obtained through the cancer registry data, were downloaded from the Statistics Korea website. To examine the relationship between smoking, alcohol consumption, obesity exposure rate (prevalence), and cancer incidence, a correlation analysis was conducted, and Pearson’s correlation coefficient was calculated. The correlation coefficient between male smoking and male cancer incidence rate across 227 districts was 0.259.This significance was more pronounced in large metropolitan areas, where the correlation coefficient was 0.631 in the 73 districts belonging to these areas. In large metropolitan areas, the correlation coefficient between alcohol consumption rate and cancer incidence rate was 0.390. In the correlation analysis between obesity prevalence and cancer incidence rate, no correlation was found in large metropolitan areas, while in areas outside of large cities, the correlation coefficient was –0.295, indicating a significant negative correlation. This ecological study demonstrated that the relationship between cancer incidence and health behaviors differed between large metropolitan areas and areas outside of large cities.

The Korea Nurses’ Health Study (KNHS) is an ongoing, large-scale, prospective cohort study of women nurses, focusing on the effects of occupational, environmental, and lifestyle factors on the health of women. The first KNHS survey was performed in 2013-2014 (n=20,613). As of December 2023, 11 follow-up surveys have been conducted. Participants who were pregnant were asked to participate in the early pregnancy survey (n=2,179) and postpartum survey after giving birth (n=2,790). The main variables included socio-demographic, work-related, lifestyle, physical, mental, and women’s health factors. Blood, urine, and toenail samples were collected from a participant subgroup of the first survey (n=1,983). The subgroups of the second survey completed a food frequency questionnaire in 2019 (n=300) and 2021 (n=871). In 2020, a subgroup of the first survey answered a coronavirus disease 2019-related survey (n=975). To examine various health-related factors in young adults, new participants were added to the KNHS cohort in the 11th (n=1,000) and 12th (n=1,002) surveys. The KNHS cohort will help identify health and illness determinants in Korean women. Data can be accessed at https://coda.nih.go.kr/frt/index.do.

Gastric cancer has been consistently decreasing worldwide, whereas cardia gastric cancer is on the rise. This indicates that the exposure rates to epidemiological causes are changing.In this study, we aim to review the risk factors for gastric cancer with respect to cardia and non-cardia types. One of the most significant risk factors for gastric cancer is Helicobacter pylori infection. H. pylori infection is known as a risk factor for non-cardia gastric cancer, and there have been results indicating that H. pylori infection is not associated with cardia gastric cancer. However, in the East Asian region, there is epidemiological evidence suggesting that H. pylori infection might be a risk factor for cardia gastric cancer. Smoking and alcohol consumption are known risk factors for gastric cancer, regardless of anatomical location.Obesity is considered a factor in the development of cardia gastric cancer. However, further research is needed to understand the specific relationship with non-cardia gastric cancer.The consumption of high-salt and processed meat is more distinctly associated with noncardia gastric cancer than in cardia gastric cancer. In addition to these factors, exposure to chemicals and radiation are considered risk factors for gastric cancer. Primary prevention of gastric cancer involves eliminating or avoiding risk factors such as H. pylori eradication and adopting a healthy lifestyle, including quitting smoking, reducing alcohol consumption, maintaining a healthy weight, and having a low-salt diet.