Jae Kwan Jun

Trends in cancer screening rates among Korean men and women: Results from the Korean National Cancer Screening Survey (KNCSS), 2004-2010

Purpose The Korean National Cancer Screening Survey (KNCSS) is a continuous nationwide survey implemented by the National Cancer Center in Korea since 2004. The purpose of the present study was to report trends in cancer screening rates for the five major cancers (stomach, liver, colorectal, breast, and cervix uteri) in Korean men and women. Materials and Methods The study used KNCSS data collected between 2004 and 2010. The survey was conducted on Korean men aged 40-74 years and Korean women aged 30-74 years with no history of cancer diagnosis. The annual percentage change and corresponding 95% confidence intervals were used to examine changes in annual screening rates. Results Screening rates with recommendation increased by 4.4% annually for stomach cancer, 1.5% for liver cancer, 2.8% per year for colorectal cancer, 4.5% for breast cancer, and 1.2% for cervix uteri cancer. The increasing trend in cancer screening rates, with the exception of liver cancer, was significant. Conclusion Cancer screening rates have increased consistently from 2004 to 2010 among Korean men and women. Stomach and breast cancer screening rates in particular have increased markedly.

Gastric cancer screening in Korea: report on the national cancer screening program in 2008.

Purpose The National Cancer Screening Program (NCSP) began in 1999. The objective of this report is to evaluate the results of the NCSP in 2008 and provide essential evidence associated with the gastric cancer screening program in Korea. Materials and Methods Data was obtained from the National Cancer Screening Information System; participation rates in gastric cancer screening were calculated. According to screening modalities, recall rates were estimated with 95% confidence intervals (CIs). Results The target population of the gastric cancer screening program in 2008 was 7,132,820 Korean men and women aged 40 and over, 2,076,544 of whom underwent upper endoscopy or upper gastrointestinal (UGI) series as screening tools (participation rate, 29.1%). Disparities in participation rates were observed relating to gender and health insurance type. Overall, recall rates of upper endoscopy and UGI series were 3.1% (95% CI, 3.0 to 3.1) and 33.3% (95% CI, 33.3 to 33.4), respectively. Conclusion According to our research, efforts to facilitate participation and to reduce disparities in gastric cancer screening among Korean men and women are needed. These results will provide essential data for evidence-based strategies in gastric cancer control in Korea.

Results of Colorectal Cancer Screening of the National Cancer Screening Program in Korea, 2008

Purpose This study aims to investigate the current situation of national colorectal cancer screening by analyzing participation rates, positive rates of screening methods and screening rate of secondary screening tests in colorectal screening of the national cancer screening program in 2008. Materials and Methods With database about target population and screened individuals of the national cancer screening program, the results of target population and participants of colorectal cancer screening in 2008 were analyzed. Among adults aged over 50 years of medical aid and beneficiaries of national health insurance paying lower 50% premiums in the total subscribers, 4,640,365 were target population of colorectal cancer screening and the data of 984,915 undergoing fecal occult blood test (FOBT) as a primary screening were analyzed. Results The colorectal cancer screening rate was 21.2% and the rates of national health insurance subscribers, females and the elderly aged 60-64 years were higher than those of others. The recipients with a positive result in FOBT recorded approximately 7.5%. Medical aid beneficiaries (7.9%), males (8.8%) and seniors aged over 75 years (9.1%) showed higher positive rates than the average one. Out of the FOBT positive recipients, 43.0% took a secondary screening and the rate undergoing colonoscopy (31.4%) was higher than that of doing double-contrast barium enema test (11.6%). Conclusion Colorectal cancer screening rate of medical aid beneficiaries and people paying lower 50% premiums among national health insurance subscribers, was different according to demographic characters (gender, age and types of health insurance). This finding meant that screening for the vulnerable needed to be encouraged by considering socio-demographic characters. Additionally, more efforts were necessary to increase the secondary screening rate of people with a positive result in primary one.

Performance of Different Gastric Cancer Screening Methods in Korea: A Population-Based Study

Background There is a lack of agreement on which gastric cancer screening method is the most effective in the general population. The present study compared the relative performance of upper-gastrointestinal series (UGIS) and endoscopy screening for gastric cancer. Methods A population-based study was conducted using the National Cancer Screening Program (NCSP) database. We analyzed data on 2,690,731 men and women in Korea who underwent either UGIS or endoscopy screening for gastric cancer between January 1, 2002 and December 31, 2005. Final gastric cancer diagnosis was ascertained through linkage with the Korean Central Cancer Registry. We calculated positivity rate, gastric cancer detection rate, interval cancer rate, sensitivity, specificity, and positive predictive value of UGIS and endoscopy screening. Results The positivity rates for UGIS and endoscopy screening were 39.7 and 42.1 per 1,000 screenings, respectively. Gastric cancer detection rates were 0.68 and 2.61 per 1,000 screenings, respectively. In total, 2,067 interval cancers occurred within 1 year of a negative UGIS screening result (rate, 1.17/1,000) and 1,083 after a negative endoscopy screening result (rate, 1.17/1,000). The sensitivity of UGIS and endoscopy screening to detect gastric cancer was 36.7 and 69.0%, respectively, and specificity was 96.1 and 96.0%. The sensitivity of endoscopy screening to detect localized gastric cancer was 65.7%, which was statistically significantly higher than that of UGIS screening. Conclusion Overall, endoscopy performed better than UGIS in the NCSP for gastric cancer. Further evaluation of the impact of these screening methods should take into account the corresponding costs and reduction in mortality.

Association of the interval between endoscopies with gastric cancer stage at diagnosis in a region of high prevalence

Endoscopy screening in high‐risk populations may reduce gastric cancer mortality by detecting cancer earlier. We evaluated the association between the interval between upper gastrointestinal endoscopies and the gastric cancer stage at diagnosis in patients from a region of high prevalence.

Performance of gastric cancer screening by endoscopy testing through the National Cancer Screening Program of Korea

Recent reports have proposed endoscopy as an alternative strategy to radiography for gastric cancer (GC) screening. The current study presents the first reported population‐based data from a large GC screening program that provided endoscopic examinations. A retrospective population‐based study was conducted using the National Cancer Screening Program (NCSP) database. We evaluated GC detection rates, sensitivity, specificity, and the positive predictive value of an endoscopic screening program for the average‐risk Korean population, aged 40 years and older, who underwent the NCSP from 2002 to 2005. The detection rates of GC by endoscopy in the first and subsequent rounds were 2.71 and 2.14 per 1000 examinations, respectively. Localized cancer accounted for 45.7% of screen‐detected GC cases. The sensitivity of endoscopy was 69% (95% confidence interval [CI]: 66.3–71.8). The endoscopic screening was less sensitive for the detection of localized GC (65.7%, 95% CI = 61.8–69.5) than for regional or distant GC (73.6%, 95% CI = 67.4–79.8). In the multiple logistic models for localized GC and all combined GC, the odds ratio (OR) of sensitivity for the undifferentiated type was statistically significantly higher than that for the differentiated type, whereas the OR of sensitivity for the mixed type was lower than that for the differentiated type. The sensitivity of the endoscopic test in a population‐based screening was slightly higher for the detection of regional or distant GC than for localized GC. Further evaluation of the impact of endoscopic screening should take into account the balance of cost and mortality reduction. (Cancer Sci 2011; 102: 1559–1564)

Sociodemographic gradients in breast and cervical cancer screening in Korea: the Korean National Cancer Screening Survey (KNCSS) 2005-2009.

BackgroundCancer screening rates in Korea for five cancer types have increased steadily since 2002. With regard to the life-time cancer screening rates in 2009 according to cancer sites, the second highest was breast cancer (78.1%) and the third highest was cervical cancer (76.1%). Despite overall increases in the screening rate, disparities in breast and cervical cancer screening, based on sociodemographic characteristics, still exist.MethodsData from 4,139 women aged 40 to74 years from the 2005 to 2009 Korea National Cancer Screening Survey were used to analyze the relationship between sociodemographic characteristics and receiving mammograms and Pap smears. The main outcome measures were ever having had a mammogram and ever having had a Pap smear. Using these items of information, we classified women into those who had had both types of screening, only one screening type, and neither screening type. We used logistic regression to investigate relationships between screening history and sociodemographic characteristics of the women.ResultsBeing married, having a higher education, a rural residence, and private health insurance were significantly associated with higher rates of breast and cervical cancer screening after adjusting for age and sociodemographic factors. Household income was not significantly associated with mammograms or Pap smears after adjusting for age and sociodemographic factors.ConclusionsDisparities in breast and cervical cancer screening associated with low sociodemographic status persist in Korea.

Effect of endoscopy screening on stage at gastric cancer diagnosis: results of the National Cancer Screening Programme in Korea

Background:Although gastric cancer screening is common among countries with a high prevalence of gastric cancer, there is little data to support the effectiveness of this screening. This study was designed to determine the differences in stage at diagnosis of gastric cancer according to the screening history and screening method (upper gastrointestinal series (UGIS) vs endoscopy).Methods:The study population was derived from the National Cancer Screening Programme (NCSP), a nationwide organised screening programme in Korea. The study cohort consisted of 19 168 gastric cancer patients who had been diagnosed in 2007 and who were invited to undergo gastric cancer screening via the NCSP between 2002 and 2007.Results:Compared with never-screened patients, the odds ratios for being diagnosed with localised gastric cancer in endoscopy-screened patients and UGIS-screened patients were 2.10 (95% CI=1.90–2.33) and 1.24 (95% CI=1.13–1.36), respectively.Conclusions:Screening by endoscopy was more strongly associated with a diagnosis of localised stage gastric cancer compared with screening by UGIS.

Adherence to follow‐up after a positive fecal occult blood test in an organized colorectal cancer screening program in Korea, 2004–2008

Background and Aim:  To investigate the participation rates, positivity rates, and follow‐up rates from 2004 to 2008 in an organized colorectal cancer (CRC) screening program using a fecal occult blood test (FOBT) in Korea.

Association between screening and the thyroid cancer “epidemic” in South Korea: evidence from a nationwide study

Objective To investigate whether screening for thyroid cancer led to the current “epidemic” in South Korea. Design Review of the medical records of nationally representative samples of patients with a diagnosis of thyroid cancer in 1999, 2005, and 2008. Setting Sample cases were randomly selected from South Korea’s nationwide cancer registry, using a systematic sampling method after stratification by region. Participants 5796 patients with thyroid cancer were included (891 in 1999, 2355 in 2005, and 2550 in 2008). Main outcome measures The primary outcome was age standardised incidence of thyroid cancer and the changes in incidence between 1999 and 2008 according to the methods used to detect tumours (screen detection versus clinical detection versus unspecified). Results Between 1999 and 2008, the incidence of thyroid cancer increased 6.4-fold (95% confidence interval 4.9-fold to 8.4-fold), from 6.4 (95% confidence interval 6.2 to 6.6) per 100 000 population to 40.7 (40.2 to 41.2) per 100 000 population. Of the increase, 94.4% (34.4 per 100 000 population) were for tumours less than 20 mm, which were detected mainly by screening. 97.1% of the total increase was localised and regional tumours according to the Surveillance, Epidemiology, and End Results (SEER) summary stage. Where cases were clinically detected, 99.9% of the increased incidences (6.4 per 100 000 population) over the same period were tumours less than 20 mm. Conclusion The current “epidemic” of thyroid cancer in South Korea is due to an increase in the detection of small tumours, most likely as a result of overdetection. Concerted efforts are needed at a national level to reduce unnecessary thyroid ultrasound examinations in the asymptomatic general population.