1991 cancer incidence in Seoul, Korea: results of the Implementation Study of the Seoul Cancer Registry

Relationship between meat and cereal consumption and colorectal cancer in Korea and Japan

BACKGROUND AND AIM

The incidence of colorectal cancer in Asian countries is increasing. The change to a more westernized diet is known to be related to these increases, and there are reports on the relationship between meat consumption and colorectal cancer in Japan. The aim of this study was to investigate the relationship between dietary change and colorectal cancer in Korea and Japan.

METHODS

The data of meat and cereal consumption in Japan (1950-2002) and Korea (1970-2003), and the data of colorectal cancer incidence in Japan (1975-1998) and Korea (1992-2002) were investigated with a 20-year difference between the two countries.

RESULT

We found that the changes in meat and cereal consumption, as well as the increases in the incidence of colon and rectal cancer, were similar between those two countries with a 20-year difference.

CONCLUSION

These similarities between Korea and Japan could be helpful for predicting future colorectal cancer incidences for Korea and other Asian countries.

Genetic alterations of APC, K-ras, p53, MSI, and MAGE in Korean colorectal cancer patients

BACKGROUND AND AIM

Colorectal cancer (CRC) is one of the most rapidly increasing cancers in Korea, but no comprehensive analysis has been performed to speculate the genetic basis of CRC development. We investigated the presence of adenomatous polyposis coli gene (APC), Kirsten-ras (K-ras), p53, microsatellite instability (MSI), and melanoma antigen gene (MAGE) alterations in CRC and correlated the results obtained with clinical data.

MATERIALS AND METHODS

We collected 78 cancer tissues from CRC patients. Genetic analyses were performed on APC, K-ras, p53, and MSI (BAT 25 and BAT 26), and in addition, MAGE expression was tested by reverse transcription polymerase chain reaction. Correlations between genetic markers and clinical factors were analyzed after reviewing medical records.

RESULT

The positive rates for alterations of APC, K-ras, p53, MSI, and MAGE in 78 tissue samples were 33.3, 29.5, 34.6, 9.0, and 68.4%, respectively. Mutations were frequently detected in codons 1291 and 1450 of APC, in codon 12 of K-ras and in codons 248, 282, and 176 of p53. APC mutations were frequently noted in early-stage cancer, whereas MSI was observed in right-sided and multiple cancers. No associations were found between the presence of alterations in APC, K-ras, p53, MSI, and MAGE.

INTERPRETATION

In Koreans, positive rates of alterations in APC and p53 were slightly lower than those of APC and p53 in Caucasians, and the genetic alterations including MAGE expression are involved in 92.1% of CRCs. The lack of multiple mutations and of a relation between mutation rates and clinical stage suggest that genetic alterations might have independent influences on CRC development in Koreans.

[Cancer registration in Korea: the present and furtherance]

It was not until 1975 that cancer registration was initiated in Korea; voluntary registration of cancer patients of training hospitals throughout the country began under the auspices of the Korean Cancer Society(KCS). However, an official cancer registration, the Korea Central Cancer Registry(KCCR), began on July 1st, 1980. Forty-five training and two non-training hospitals throughout the country initiated registration of patients in whom neoplasms had been found. Data related to case information specified are to be sent to the KCCR at the National Medical Center(it moved at National Cancer Center in 2000). The initial cancer registration of KCS was merged to the KCCR in 1980. Although the KCCR covers most all the large training hospitals in Korea, it cannot provide incidence data. It is, however, the only of its kind in the world, being neither hospital nor population based. The first population based cancer registry(PBCR) was launched in a small county, Kangwha(it has around 80,000 inhabitants), by Yonsei University Medical College in 1983. All data were collected by active methods, and incidence statistics for 1986-1992 appeared in Vol VII of the CI5. Another PBCR, Seoul Cancer Registry(SCR), started in 1991. It was supported by a civilian foundation, the Korean Foundation for Cancer Research. The basic idea of case registration of SCR was the incorporation of KCCR data to PBCR, e. g. dual sources of case registration, i.e., from the KCCR and also including cases diagnosed in small hospitals and other medical facilities. Assessing completeness and validity of case registration of SCR, the program and methodology used by the SCR was later extended to other large cities and areas in Korea, and the PBCR in each area was established. Cancer incidence statistics of Seoul for 1993- 1997, Busan for 1996-1997, and Daegu for 1997-1998, as well as Kangwha for 1993-1997, appeared eventually in Vol VIII of the CI5. The Korean or 'pillar' model for a PBCR is a new one. The KCCR data file is a reliable basis, as a pillar, for a PBCR in each area. The main framework of the model for such a registry is the incorporation of a KCCR data file with data from additionally surveyed cases; the data related to cancer deaths, medical insurance claims, and visit-and abstract surveillance of non-KCCR medical facilities. Cancer registration has been adopted as a national cancer control program by Korean government in 2004 as the Anti-Cancer Act was enacted. Since then, some officers have tried to launch a nation-wide PBCR covering whole country. In the meantime, however, cancer registration was interrupted and discontinued for years due to the Privacy Protection Law, which was solved by an amendment of the Anti-Cancer Act in 2006. It would be premature to establish the nation-wide PBCR in Korea. Instead, continuous efforts to improve the completeness of registration of the KCCR, to progress existing PBCRs, and to expand PBCRs over other areas are still to be devoted. The nation-wide PBCR in Korea will be established eventually with summation of the PBCRs of the Korean model.

Cigarette smoking and risk of lung cancer in Korean men: the Seoul Male Cancer Cohort Study

Lung cancer is the leading cause of cancer deaths in Korea. The aim of this study was to estimate lung cancer risk of cigarette smoking in Korean men by a 10-yr follow-up prospective cohort study using the primary databases. The number of subjects was 14,272 men, who had full information of smoking habits among participants in the Seoul Male Cancer Cohort Study (SMCC). Total 125,053 person-years were calculated by determining the number of days from the start of followup, January 1, 1993, until the date of lung cancer diagnosis, death from another cause, or the end of follow-up, December 31, 2002, followed by converting the number of days to years. The information of outcome was obtained by the database of Korea Central Cancer Registry, Seoul Regional Cancer Registry, and Korea Statistical Office. The relative risk (RR) and its 95% confidence interval (CI) values of smoking were calculated using Cox proportional hazards regression stratified on potential confounders. During the follow-up periods, 78 cases of lung cancer occurred. The cigarette smoking is the major risk factor and increases the 4.18-fold risk of lung cancer in Korean men. In order to control lung cancer, intervention of quitting smoking is needed.

Cancer incidence among Korean-American immigrants in the United States and native Koreans in South Korea

BACKGROUND

While previous studies demonstrated contrasting patterns of cancer risk among migrant populations from different ethnic groups in the United States, few studies have focused on the Korean-American population. This study compares cancer incidence rates between Korean-Americans, whites, and blacks in the United States and native Koreans.

METHODS

Data from the Surveillance, Epidemiology, and End Results (SEER) program and International Association for Research on Cancer were used to calculate age-standardized incidence rates among whites, blacks, and Korean Americans in the United States and native Koreans.

RESULTS

The risk of stomach, liver, gallbladder, larynx, and esophageal cancer has sharply declined in Korean-American men compared with their native counterparts while prostate, colon, and rectum cancer risk has increased. In women, stomach, liver, gallbladder, and cervical cancers have declined, and breast, lung, colon, rectum, and endometrial cancers have increased. Cancer rates for stomach, liver, gallbladder, and esophagus are higher in native Koreans compared to US whites. Recently, cancer rates for Korean-American immigrants have increased for prostate, breast, colon, and rectal cancers.

CONCLUSIONS

The study provides evidence that the risk of cancers common in Western countries is higher for Korean Americans than for their native counterparts. Recent trends among Korean Americans also revealed a stronger Western profile.

Seroepidemiological study of Helicobacter pylori infection in asymptomatic people in South Korea

BACKGROUND

Helicobacter pylori infection occurs throughout the world and causes gastroduodenal diseases in all age groups. The prevalence of H. pylori infection varies between countries and races. The aim of this study was to evaluate the seroprevalence of H. pylori infection in asymptomatic healthy people in South Korea.

METHODS

From March 1998 to October 1998, 5732 asymptomatic subjects who responded to the self-assessment questionnaires from 54 hospitals in South Korea were enrolled in this study. The serum levels of antibodies for H. pylori immunoglobulinG were measured by using an ELISA test.

RESULTS

The overall seroprevalence of H. pylori infection was 46.6% and there was no statistical difference between males (47.2%) and females (45.9%). In adults, a significant difference was observed between genders. According to the geographic areas, the high prevalent provinces were Kangwon (53.4%), Cheju (52.9%) and Cholla province (50.6%); Seoul (41.9%) was the lowest prevalent area. The seroprevalence increased with age and was highest when patients were aged in their 40s (78.5%). The characteristic feature of our study was that the infection rate was steeply increased in three age groups (10-12 year olds, 16-19 year olds and those aged in their 20s). In Seoul, there was no difference in the prevalence rate among the districts studied.

CONCLUSIONS

This nation-wide seroprevalence of H. pylori infection in South Korea was 46.6%, which showed the transition from a developing country to a developed country. More studies on the epidemiological factors and the route of transmission of H. pylori infection should be warranted.

Development of a breast self-examination program for the Internet: health information for Korean women

Internet-based health information will enable us to interact with many people despite distance and time constraints. Informational media by computer is expected to become an important factor that affects health behavior. This study was done to develop an accessible multimedia program about breast self-examination on the Internet. This study was designed by using the two steps of need assessment and program development. For the need assessment step, a survey was carried out. The sample consisted of the 82 women of Yonsei University selected by convenient random sampling. At the program development step, screen design took into account perspectives of computer engineering. A storyboard for every screen was made via screen design and then ported to computer using the Netscape Navigator program. A breast self-examination program was developed using Netscape 4.0 on the Windows 98 platform. The multimedia program, including text, graphics, animation, and sound, was constructed with HTML language using Memo Sheet in Netscape Navigator. The contents of health information posted on the Internet included general information about breast cancer, the importance of breast self-examination, self-risk appraisal of breast cancer, the diverse methods about breast self-examination, the monthly check list graph, and social network for consultation. It is possible to interact with clients through the Question and Answer function on screen. This Internet-based health information program provides enough information, which can be accessed using search systems on the Internet.

Cyclin D1 overexpression in hepatocellular carcinoma

BACKGROUND/AIMS

Cyclin D1 gene amplification and cyclin D1 protein overexpression have been reported in various human tumors, including hepatocellular carcinoma (HCC). However, their significance is still controversial. In the present study, we examined the expression of cyclin D1 and its relationships to p53 and Ki-67 in HCCs.

METHODS

The expression and topological distribution of cyclin D1, p53 and Ki-67 in 50 cases of HCC were examined immunohistochemically, and the relationship between the expression of these proteins and their pathologic features was investigated.

RESULTS

Overexpression of cyclin D1 was noted in 58% of the HCC cases, and significantly associated with a well-differentiated histology and a low Ki-67 labeling index (LI). Cyclin D1 overexpression was also observed in all (7 of 7) dysplastic nodules and in non-neoplastic hepatocytes. On the other hand, aberrant p53 expression was detected in 36% of the cases, which showed positive relationships with poor differentiation, portal vein invasion, and KI-67 LI. Only eight of the 50 cases examined (16%) were positive for both cyclin D1 and p53, which showed only a small number of cyclin D1-positive cells. There was no significant relationship between the expressions of cyclin D1 and p53.

CONCLUSIONS

Our results suggest that cyclin D1 overexpression may be an early event in hepatocarcinogenesis and that it plays a role in tumor differentiation. In addition, cyclin D1 expression is not correlated with tumor cell proliferation in HCCs.

Expression of promyelocytic leukaemia protein in thyroid neoplasms

AIMS

Promyelocytic leukaemia protein (PML) is an oncoprotein involved in the pathogenesis of acute promyelocytic leukaemia and is localized in distinct PML nuclear bodies. Our previous observation of overexpression of the PML in hormone-sensitive normal tissues and malignant solid tumours, including the thyroid, led to this analysis of the PML expression in various thyroid neoplasms to characterize the importance of the PML in thyroid carcinogenesis.

METHODS AND RESULTS

Immunohistochemistry was performed on paraffin-embedded tissue samples from 106 thyroid neoplasms after antigen retrieval by microwave. Immunoblotting was done with fresh frozen tissues in a few tumours. The PML was strongly expressed in all papillary carcinomas in diffuse or ball-shaped patterns. In the follicular neoplasms, the PML expression was variable, but there was no significant difference between adenomas and carcinomas. In the medullary carcinomas, the PML expression was either not detectable or was lower than in non-neoplastic thyroids. Quantitatively different expression of the PML in various thyroid neoplasms was confirmed by immunoblotting.

CONCLUSION

A significant difference of the PML expression according to the type of thyroid neoplasms suggests that the PML is important in papillary thyroid carcinomas, and furthermore, that PML expression may be used in differential diagnosis of thyroid neoplasms.

Management of cervical cancer in pregnancy

Carcinoma of the cervix is the most common gynecologic cancer found during pregnancy. Management and treatment of this condition depend on cancer stage, estimated gestational age, and ethical, religious, and personal desires. Review of the medical literature in English from 1965 to 1998 is presented with recommendations for management.

Comparison of Helicobacter pylori infection between Fukuoka, Japan and Chinju, Korea

BACKGROUND

Helicobacter pylori is the causative agent of type B chronic gastritis, and plays a major role in the pathogenesis of gastroduodenal ulcer and gastric cancer. Because gastric cancer has been the leading cause of cancer mortality in Japan and Korea, we conducted a seroepidemiological study to estimate the prevalence of H. pylori infection in Japan and Korea in order to explain the current change in the gastric cancer incidences between two countries.

MATERIALS AND METHODS

Samples used for this study included 1204 sera from Chinju, Korea and 580 sera from Fukuoka, Japan. Immunoblotting, using a sonicated crude H. pylori antigen and 1:5 dilution of serum, was performed, considering the immunoblot shows reactivity to the 120 Kd antigen of H. pylori as a specific marker of H. pylori infection.

RESULTS

Seroepidemiology data from Fukuoka, Japan showed a prevalence of H. pylori infection of 20% before school age, 40% by teenage years, and over 80% beyond 20 years of age. Seroepidemiology data from Chinju, Korea, showed a 50% infection rate in preschool ages, and over 80% prevalence rate after 7 years of age.

CONCLUSIONS

Lower rates of childhood H. pylori infection in Fukuoka may explain the recent decline and shift in the incidence of stomach cancer in Japan, supporting the hypothesis that H. pylori is a major determinant in the pathogenesis of stomach cancer.

Diet and stomach cancer in Korea

Stomach cancer is the most prevalent malignant neoplasm in Korea. As of 1991-1992 in Seoul, the cumulative rates reported for the age span 0-74 were 7.6% in males and 3.1% in females. A recent case-control study reported that several food items and cooking methods are associated with increased or decreased risk of stomach cancer among Koreans. An increased risk of stomach cancer was noted among people who frequently consume broiled meats and fishes, salted side dishes (salted/fermented fish products) and salty stewed foods, such as soybean paste thick stew. Frequent consumption of mung bean pancake, tofu, cabbage, spinach and sesame oil decreased the risk. Analysis by cooking method showed that risk of stomach cancer from the same foods varied with preparation. For meat and fish, pan frying was associated with decreased risk, whereas stewing or broiling was associated with increased risk. Pickled vegetables increased the risk, whereas fresh vegetables did not. In a recent cohort study in Seoul, green vegetables and soybean foods were associated with a decreased risk of stomach cancer. Case-control and cohort studies have reported that ginseng intake decreased the risk of gastric cancer.