The Role of Genetic Polymorphism of Cytochrome P450 2E1 in Bladder Cancer in Korea / 한국역학회지

Although the association of genetic polymorphisms in glutathione S-transferase(GST) and N-acetyltransferase(NAT) with bladder cancer has been reported, limited numbers of studies have been indicated the association of CYP2E1 with bladder cancer, particularly in Asian population. A hospital based case-control study was conducted in South Korean, consisting of 232 histologically confirmed prevalent bladder cancer cases and 165 controls to evaluate the association between genetic polymorphisms of CYP2E1(RsaI) and development of bladder cancer. The frequency of CYP2E1(RsaI) c1/c1 genotype in bladder cancer cases was higher than in controls; 114 of 201(56.7%) vs. 62 of 146(42.5%). Men with CYP2E1(RsaI) c1/c1 genotype had increased risk of development of bladder cancer compared to men with at least one c2 allele(OR=1.7, 95% CI=1.1-2.7). The bladder cancer risk increased as the number of c1 allele increased(p for trend=0.005). The risk increased as the amount of smoking increased(p for trend=0.009). When data were analyzed for the interaction between smoking and CYP2E1 genetic polymorphisms, smokers with c1/c1 genotype have 2.5 greater risk in development of bladder cancer(95% CI=1.0-6.2) compared to nonsmokers with c2 allele(p for interaction=0.008). Our findings suggest that the interaction between genetic polymorphisms of CYP 2E1 (RsaI, c1/c1) and smoking may play an important role for development of bladder cancer among Koreans.

The Usefulness of the Secondary Database for Occupational Asthma Surveillance System in Korea / 한국역학회지

Occupational asthma is defined as a disease that is characterized by airway narrowing and bronchial hyperresponsiveness caused by specific working environment. It is estimated that occupational asthma cases in Korea have been underreported. This study, using Korean Medical Insurance Data(KMID), examined the distribution of asthma patients' occupations and the frequency of high risk occupations for occupational asthma in Seoul, Korea to evaluate the usefulness of the KMID data as a database for active occupational asthma surveillance system. Six hundreds and forty two(30.7%) of 2093 patients who were finally chosen as a study population by using 1995-year KMID, were contacted by telephone. 296 persons(47.4%) of 642 patients replied that they were diagnosed as asthma. The occupations of 296 asthma patients were classified by Korean standardized industrial classfication (KSIC). The most common occupations included Wholesale and Retail trade(19.5%), Real estate, Renting and Business activities(14.9%), Construction(14.9%), Manufacturing(12.3%). Forty(13.5%) of 296 patients who could be classified by KSIC were working at high risk jobs for occupational asthma. KMID could be used as a useful data for occupational asthma surveillance system if the limitations of KMID, which is the accuracy of diagnosis, data accessibility, difficulty of following up study subjects, would be solved. The prevalence of occupational asthma could be estimated if the follow-up study diagnosing occupational asthma for asthma patients working in high risk jobs would be held.

Occupational Cancer Surveillance System Using Data Linkage Analysis in Korea / 한국역학회지

To develop the occupational cancer surveillance system in Korea, data linkage analysis was performed on the subjects of Health-monitoring-pocketbook (the list of subjects who were exposed to selected occupational carcinogens) and the retired workers of a cokes manufacturing factory using the Korean medical insurance data, Korean death certificate data and Korean cancer registry data. Study subjects comprised the 822 retired subjects and the 3101 present-post subjects of Health-monitoring-pocketbook and the 182 retired workers of a cokes manufacturing factory. The incidence of cancer of these study subjects was ascertained by linkage of Korean medical insurance data of year 1995-6, Korean death certificate data of year 1992-8 and Korean cancer registry data of year 1993-5. In the study subjects, Eighty seven percent were males and mean age was 39.3+/-8.9 year-old, Average work duration was 8.0+/-5.5 years. Chrome, asbestos and cokes were the most frequent exposed agents. In the study subjects, total 13 cancer cases were ascertained by data linkage analysis. In the ascertained cancer cases, 8 cases were male and 5 cases were female, and 7 cases were aged 40-49 yr, 5 cases were aged 50-59 yr and 1 cases were aged 30-39 yr. The commonest exposure agent in the ascertained cancer cases was asbestos and cokes. By the site of cancer, 3 stomach cancer cases, 2 hematopoietic cancer cases and 2 biliary tract cancer cases were ascertained. The occupational cancer surveillance system using data linkage analysis on the workers exposed to hazardous agents was the most feasible and efficient method in Korea. And to do this, establishment of occupational history information in several disease registry database is needed with the effort of estimating the proper size of workers exposed hazardous agents.