The incidence of colorectal cancer in Korea has recently increased, making it the second most common cancer in men and the third most common cancer in women. Risk factors for colorectal cancer have been studied worldwide, but risk factors specific for the Korean population have not been established. In this study, we investigated incidence trends and risk factors of colorectal cancer in Korea. Methods: A total of 8,846,749 subjects were included. Colorectal cancer incidence was investigated using Korea National Health Insurance Service claim data from 2004 to 2014. Colorectal cancer diagnoses were obtained by evaluating colorectal cancer diagnostic codes and the cancer registry for cost sharing. Risk factor identification for colorectal cancer was obtained from National Health Examination data from 2004 to 2005. Cox proportional hazard model statistical analysis was used to determine risk factors of colorectal cancer. Results: The incidence of colorectal cancer gradually increased from 2006 to 2014 (from 45.4/100,000 to 54.5/100,000). There was a predominance among men (1.47:1), but incidence trends were similar in both sexes. Old age, high body mass index, and no history of colonoscopy were identified as risk factors in both sexes. High fasting blood glucose, familial history of cancer, frequent alcohol intake, and current smoker were identified as risk factors, especially in men. Conclusion: The incidence of colorectal cancer has been increasing in Korea. Colonoscopy screening was a protective factor for colorectal cancer, and active use of colonoscopy may reduce incidence. Early diagnosis and care are important, particularly for the high-risk group.

Because healthcare workers (HCWs) are at high risk for tuberculosis (TB) infection, it is essential to research the prevalence of latent TB infection (LTBI) and to implement health interventions including early treatment of LTBI and TB infection control measures. The purpose of the study was to determine the prevalence and risk factors for LTBI using interferon-γ release assay (IGRA) among HCWs in South Korea. The cross-sectional study was carried in the National Health Insurance Service Ilsan Hospital, which is a 740-bed general hospital, South Korea. HCWs who participated in this survey were required to complete a questionnaire and IGRA was performed. Of the 1,655 HCWs, 271 results were positive and the prevalence of LTBI was 16% (95% CI; 15–18%). In the multivariate analysis, age (OR; 2.201, 95% CI; 1.911–2.536, P < 0.001), male sex (OR; 1.523, 95% CI; 1.133–2.046, P = 0.005), contact active TB patients (OR; 1.461, 95% CI; 1.061–2.010, P = 0.02) and diabetes (OR; 2.837, 95% CI; 1.001–8.044, P = 0.05) were significant risk factors for LTBI. LTBI among HCWs in Korea, although prevalent, might not exceed the background level of the general population. Because contact with active TB patients has been identified as a risk factor for LTBI, more effective TB infection control measures are essential in healthcare facilities and congregate settings.

Purpose: The colorectal cancer (CRC) is the third leading cause of death in Korea. Ulcerative colitis (UC) is regarded as a risk factor of CRC. The aim of study is to confirm the incidence of CRC among subjects with and without a diagnosis of UC based on a sample of the Korean population. This study identified the effect of UC on incidence of CRC in Korea.Method: The data were from the population-based cohort containing National Health Insurance (NHI) claims from 2002 to 2013. We washed out first year (2002) for newly detected cases. Subjects who were under 20 years of age, diagnosed UC and CRC in 2002 development of CRC before diagnosis of UC since 2003, were excluded from analyses. Among 745,641 subjects during 11 years of follow-up (2003-2013), 7,448 patients with CRC were newly detected. Cox proportional hazard regression model was used to estimate the hazard ratio (HR) of UC for CRC incidence. Confounding variables including gender, baseline age, type of social security, income level, residence, Charlson Comorbidity Index, hypertension and diabetes mellitus were incorporated into the model.Results: Overall annual incidence of UC and CRC were 6.7 and 95.4 per 100,000 during 11 years (2003~2013), respectively. Among 522 of newly detected UC cases, CRC incident cases were 12 cases during 11 years. The effects were stronger for male. Advancing age and Charlson Comorbidity Index, hypertension and diabetes mellitus increased the risk of CRC. This study showed that the adjusted hazard ratio of UC in incidence of CRC is 1.92 (95% confidence interval: 1.09-3.38). Also, male patients with UC have more HR than female patients with UC.Conclusion: The results of this study showed that patients with UC are the high risk group in incidence of CRC. Furthermore, the effects of UC in male patients are higher than those in female. The future study is needed to identify the effect of UC on mortality of CRC.