Effectiveness of the Korean National Cancer Screening Program in Reducing Gastric Cancer Mortality.

BACKGROUND & AIMS: It is not clear whether screening for gastric cancer by upper endoscopy or upper gastrointestinal (UGI) series examinations (looking at the upper and middle sections of the gastrointestinal tract by imaging techniques) reduces mortality. Nevertheless, the Korean National Cancer Screening Program for gastric cancer was launched in 1999 to screen individuals 40 years and older for gastric cancer using these techniques. We evaluated the effectiveness of these techniques in gastric cancer detection and compared their effects on mortality in the Korean population. METHODS: We performed a nested case-control study using data from the Korean National Cancer Screening Program for gastric cancer since 2002. A total of 16,584,283 Korean men and women, aged 40 years and older, comprised the cancer-free cohort. Case subjects (n = 54,418) were defined as individuals newly diagnosed with gastric cancer from January 2004 through December 2009 and who died before December 2012. Cases were matched with controls (subjects who were alive on the date of death of the corresponding case subject, n = 217,672) for year of entry into the study cohort, age, sex, and socioeconomic status. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained via conditional logistic regression analysis. RESULTS: Compared with subjects who had never been screened, the overall OR for dying from gastric cancer among ever-screened subjects was 0.79 (95% CI, 0.77-0.81). According to screening modality, the ORs of death from gastric cancer were 0.53 (95% CI, 0.51-0.56) for upper endoscopy and 0.98 (95% CI, 0.95-1.01) for UGI series. As the number of endoscopic screening tests performed per subject increased, the ORs of death from gastric cancer decreased: 0.60 (95% CI, 0.57-0.63), 0.32 (95% CI, 0.28-0.37), and 0.19 (95% CI, 0.14-0.26) for once, twice, and 3 or more times, respectively. CONCLUSIONS: Within the Korean National Cancer Screening Program, patients who received an upper endoscopy were less likely to die from gastric cancer; no associations were found for UGI series.

Linezolid for treatment of chronic extensively drug-resistant tuberculosis.

BACKGROUND: Linezolid has antimycobacterial activity in vitro and is increasingly used for patients with highly drug-resistant tuberculosis. METHODS: We enrolled 41 patients who had sputum-culture-positive extensively drug-resistant (XDR) tuberculosis and who had not had a response to any available chemotherapeutic option during the previous 6 months. Patients were randomly assigned to linezolid therapy that started immediately or after 2 months, at a dose of 600 mg per day, without a change in their background regimen. The primary end point was the time to sputum-culture conversion on solid medium, with data censored 4 months after study entry. After confirmed sputum-smear conversion or 4 months (whichever came first), patients underwent a second randomization to continued linezolid therapy at a dose of 600 mg per day or 300 mg per day for at least an additional 18 months, with careful toxicity monitoring. RESULTS: By 4 months, 15 of the 19 patients (79%) in the immediate-start group and 7 of the 20 (35%) in the delayed-start group had culture conversion (P=0.001). Most patients (34 of 39 [87%]) had a negative sputum culture within 6 months after linezolid had been added to their drug regimen. Of the 38 patients with exposure to linezolid, 31 (82%) had clinically significant adverse events that were possibly or probably related to linezolid, including 3 patients who discontinued therapy. Patients who received 300 mg per day after the second randomization had fewer adverse events than those who continued taking 600 mg per day. Thirteen patients completed therapy and have not had a relapse. Four cases of acquired resistance to linezolid have been observed. CONCLUSIONS: Linezolid is effective at achieving culture conversion among patients with treatment-refractory XDR pulmonary tuberculosis, but patients must be monitored carefully for adverse events. (Funded by the National Institute of Allergy and Infectious Diseases and the Ministry of Health and Welfare, South Korea; ClinicalTrials.gov number, NCT00727844.).

Sudden death in the first 2 years of life following immunization in the Republic of Korea.

BACKGROUND: Because the peak age for incidence of sudden deaths in infancy temporally coincides with the age of infant primary immunization, some have raised the question as to whether immunization is a risk factor for sudden death in infancy. Recent occurrence of two sudden deaths in infants in Korea has renewed concerns about the causal association between immunization and sudden deaths in infants. METHODS: We carried out a retrospective review of data from the Korea Centers for Disease Control and Prevention Adverse Events Following Immunization Surveillance System and Vaccine Compensation programs. RESULTS: From 1994 to 2011, a total of 45 cases of sudden deaths in the first 2 years of life following immunization were reported in Korea. The causes of death were classified as follows: infectious diseases (n= 13); accidental injuries (n= 7); congenital abnormalities (n= 2); and malignancy (n= 1). Of 20 sudden deaths in infancy, nine deaths met Brighton Collaboration case definition level I and II, and therefore were classified as possible sudden infant death syndrome cases. Hepatitis B vaccine (n= 13) was the most frequent vaccine with temporal association with sudden deaths in the first 2 years of life. CONCLUSION: Few sudden deaths in the first 2 years of life following immunization have been reported, despite the use of universal immunization in Korea. The majority of deaths in infancy did not meet case definition for sudden infant death syndrome. Encouraging investigators to perform thorough investigation, including postmortem autopsy and death scene examination, may promote data comparability and provide guidance on decision-making in the vaccine-safety monitoring and response system in Korea.

Radiotherapy can increase the risk of ischemic cerebrovascular disease in head and neck cancer patients: A Korean population-based cohort study.

BACKGROUND AND PURPOSE: Several reports suggested that radiotherapy (RT) was related to an increased risk of cerebrovascular disease (CVD) in head and neck cancer (HNC) patients, but other risk factors of CVD were not properly considered in estimating the risk of RT. The purpose of this study is to analyze the effect of RT on the risk of CVD in HNC patients. MATERIALS AND METHODS: The Korean Central Cancer Registry data and Korean National Health Insurance Service data were used. A total of 5570 patients with newly diagnosed HNC between the years 2003-2005 was included in our study cohort. We analyzed the effect of treatment modality and other socioeconomic variables on ischemic CVD incidence using the Cox proportional hazard regression model both in the entire cohort (n = 5570) and in the propensity score matching (PSM) cohort (n = 3310). RESULTS: RT increased the CVD risk by 40.8% (aHR: 1.408, p = 0.006) in the entire cohort and by 44.3% (aHR: 1.443, p = 0.047) in the PSM cohort, respectively. CONCLUSION: The risk of ischemic CVD increased by RT after adjusting for other socioeconomic and clinical risk factors. Regular follow up and appropriate screening for CVD are required for HNC patients who received RT, and focus should be on advanced-age patients with a low socioeconomic status and known clinical risk factors of CVD.

The incidence of tuberculosis after a measles outbreak.

Among 53,974 cases of measles that occurred during the 2000-2001 outbreak in Korea, the incidence of tuberculosis following measles was 47 cases per 214,949.6 person-years, which was significantly lower than that in the general population (standardized incidence ratio, 0.73; 95% confidence interval, 0.54-0.96). In conclusion, we did not find a positive relationship between measles and tuberculosis.

Tuberculosis prevention and care in Korea: Evolution of policy and practice.

Tuberculosis (TB) in Korea remains a serious health problem with an estimated 77 per 100,000 incidence rate for 2016. This makes Korea as the only OECD country with high incidence of TB. The government has increased budgets and strengthened patient management policies since 2011. The management of latent tuberculosis was added to the response with strengthened and extensive contact investigations in the five-year tuberculosis control plan (2013-2017) and implementation was established in 2013. Due to these efforts Korea has achieved an average 5.2% reduction annually in tuberculosis incidence rate between 2011 and 2016. To further expedite the reduction of the TB burden the government has introduced additional measures including mandatory screening of latent tuberculosis infection for community workers in congregate settings including daycare centers for children, kindergarten, and teachers in schools and health care workers in clinics and hospitals to solve the problems identified through contact investigations in 2017. Providing high quality free diagnosis and treatment of active TB including for multidrug resistant TB combined with active contact investigations is the mainstay of the current programmatic response in Korea. However, the limitation of existing tools for LTBI pose challenge including absence of best mechanism for effective communication with professionals and the public, the need for at least 3 months of treatment and the risk of side effects. Developing effective tools will help to overcome these challenges.

Redefining the role of etoposide in first-line treatment of peripheral T-cell lymphoma.

Peripheral T-cell lymphomas (PTCLs) have an aggressive biological course and poor clinical outcomes. Despite producing somewhat less-than-satisfactory results, the combination of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) remains the de facto standard in PTCL treatment. Addition of etoposide to CHOP backbone to overcome such unsatisfactory results has yielded contradictory information. We aimed to thoroughly analyze the impact of incorporating etoposide into first-line treatment. Using merged data from the Korean National Health Insurance Service and National Cancer Registry, a total of 1933 patients (median age, 58 years) were evaluated for clinical characteristics and treatment outcomes. Thirty-eight percent (n = 748) of the 1933 patients received CHOP or CHOP-like regimen, 35.1% (n = 678) received CHOP-like regimen plus etoposide, 5.9% (n = 113) received other backbone chemotherapy plus etoposide, and 20.3% (394) received other treatments in the first-line setting. When we divided the patients into 3 groups according to regimen (group 1, CHOP or CHOP-like regimen; group 2, CHOP or CHOP-like regimen plus etoposide; group 3, all others), group 1 was associated with longest progression-free survival (PFS; P < .001) and overall survival (OS; P < .001). This lack of benefit with etoposide addition was observed across different PTCL subtypes and age groups. Adding etoposide led to longer hospitalizations and cytopenias requiring more transfusion. Upfront hematopoietic stem-cell transplantation led to better OS. Addition of etoposide to CHOP-like regimens does not result in better PFS or OS for patients with PTCL. Overall, Asian patients with PTCL do not benefit from chemotherapy intensification of first-line treatment. We hereby provide crucial information on establishing standardized PTCL treatment.

Public Perceptions on Cancer Incidence and Survival: A Nation-wide Survey in Korea.

PURPOSE: The aim of this study was to compare the public perceptions of the incidence rates and survival rates for common cancers with the actual rates from epidemiologic data. MATERIALS AND METHODS: We conducted a survey of Korean adults without history of cancer (n=2,000). The survey consisted of questions about their perceptions regarding lifetime incidence rates and 5-year survival rates for total cancer, as well as those of eight site-specific cancers. To investigate associated factors, we included questions about cancer worry (Lerman's Cancer Worry Scale) or cared for a family member or friend with cancer as a caregiver. RESULTS: Only 19% of Korean adults had an accurate perception of incidence rates compared with the epidemiologic data on total cancer. For specific cancers, most of the respondents overestimated the incidence rates and 10%-30% of men and 6%-18% of women had an accurate perception. A high score in "cancer worry" was associated with higher estimates of incidence rates in total and specific cancers. In cancers with high actual 5-year survival rates (e.g., breast and thyroid), the majority of respondents underestimated survival rates. However, about 50% of respondents overestimated survival rates in cancers with low actual survival rates (e.g., lung and liver). There was no factor consistently associated with perceived survival rates. CONCLUSION: Widespread discrepancies were observed between perceived probability and actual epidemiological data. In order to reduce cancer worry and to increase health literacy, communication and patient education on appropriate risk is needed.

Trends in Cancer Screening Rates among Korean Men and Women: Results of the Korean National Cancer Screening Survey, 2004-2013.

PURPOSE: The Korean National Cancer Screening Survey (KNCSS), a nationwide cross-sectional survey, has been conducted annually since 2004. The current study was conducted to report on the trends in screening rates among Korean men and women, and to evaluate policies regarding cancer screening programs implemented to reduce the burden of cancer. MATERIALS AND METHODS: The current study used KNCSS data. The eligible study population included men aged 40-74 years and women aged 30-74 years with no cancer history. The lifetime screening rate, screening rate with recommendation, and changes in annual rates were calculated for five major cancers (i.e., stomach, liver, colorectal, breast, and cervix uteri). RESULTS: The screening rates with recommendation increased by 4.2% (95% confidence interval [CI], 3.7% to 4.8%) annually for stomach cancer, 1.2% (95% CI, 0.1% to 2.4%) for liver cancer, 3.0% (95% CI, 1.8% to 4.1%) for colorectal cancer, 3.7% (95% CI, 2.7% to 4.8%) for breast cancer, and 1.3% (95% CI, 0.8% to 1.8%) for cervical cancer. In 2013, the screening rates with recommendation for stomach, liver, colorectal, breast, and cervical cancers were 73.6%, 33.6%, 55.6%, 59.7%, and 67.0%, respectively. CONCLUSION: Both the lifetime screening rates and screening rates with recommendation for the five above-mentioned cancers increased annually from 2004 to 2013.

The economic burden of cancer in Korea in 2009.

BACKGROUND: Cancer imposes a significant economic burden on individuals, families and society. The purpose of this study was to estimate the economic burden of cancer using the healthcare claims and cancer registry data in Korea in 2009. MATERIALS AND METHODS: The economic burden of cancer was estimated using the prevalence data where patients were identified in the Korean Central Cancer Registry. We estimated the medical, non-medical, morbidity and mortality cost due to lost productivity. Medical costs were calculated using the healthcare claims data obtained from the Korean National Health Insurance (KNHI) Corporation. Non-medical costs included the cost of transportation to visit health providers, costs associated with caregiving for cancer patients, and costs for complementary and alternative medicine (CAM). Data acquired from the Korean National Statistics Office and Ministry of Labor were used to calculate the life expectancy at the time of death, age- and gender-specific wages on average, adjusted for unemployment and labor force participation rate. Sensitivity analysis was performed to derive the current value of foregone future earnings due to premature death, discounted at 3% and 5%. RESULTS: In 2009, estimated total economic cost of cancer amounted to $17.3 billion at a 3% discount rate. Medical care accounted for 28.3% of total costs, followed by non-medical (17.2%), morbidity (24.2%) and mortality (30.3%) costs. CONCLUSIONS: Given that the direct medical cost sharply increased over the last decade, we must strive to construct a sustainable health care system that provides better care while lowering the cost. In addition, a comprehensive cancer survivorship policy aimed at lower caregiving cost and higher rate of return to work has become more important than previously considered.

Revision of the national action plan in response to poliovirus importation in Korea.

The polio outbreak in China in 2011 makes it necessary to revise the 2010 polio National Action Plan (NAP) in Korea. The revised plan was provided after evaluation of the 2010 NAP, literature reviews, and expert advice. It was discussed and confirmed by the Polio National Certificate Committee (NCC). The revised NAP (2012 NAP) has structured the action to take by patient phase and the role of each institution. It also provides the specified classification and management actions on the contacts. It includes a new recommendation of onetime additional immunization for the contacts regardless of the immunization history. The 2012 NAP could provide an effective countermeasure if there are imported poliomyelitis patients in Korea.

Reemergence of measles in South Korea: implications for immunization and surveillance programs.

Following the implementation of the national measles elimination program, the Republic of Korea declared in 2006 that measles had been eliminated. However in 2011, a measles outbreak was reported in Gyeongnam Province in the southeastern part of the country. We conducted active case-based surveillance and analyzed the data of cases reported in 2011 to identify the factors contributing to the reemergence of measles in this province. Of 41 confirmed measles cases reported in Korea, 32 were from within the Gyeongnam Province. Among cases identified in the outbreak, 97% had inadequate history of immunization, 28% were not immunized at the recommended ages, and 22% were infants aged 6-11 months. The outbreak involved transmission in 3 hospitals, 1 kindergarten, 1 day-care center, and 3 households. Molecular analysis of measles virus isolates from 11 cases revealed the same D9 genotype, which was the first to be discovered in Korea. In conclusion, inadequate immunization coverage, non-timely immunization, infants under 12 months of age, nosocomial transmission, and international importation may play important roles in the reemergence of measles in Korea during the attempted sustained elimination of the disease.

No association between influenza A(H1N1)pdm09 vaccination and narcolepsy in South Korea: an ecological study.

BACKGROUND: There is concern about a possible association between influenza A(H1N1)pdm09 vaccination and narcolepsy. In this study, we assessed the incidence and incidence rate of narcolepsy in the South Korean population before and after the implementation of an A(H1N1)pdm09 vaccination campaign to see if vaccination led to a change in the occurrence of narcolepsy. METHODS: We conducted an ecological study, comparing incident cases and incidence rates for newly diagnosed narcolepsy case-patients in South Korea, between July 2006 and June 2011. We used data from the Health Insurance Review Agency and Korea Centers for Disease Control and Prevention, which have limited information on case ascertainment. During vaccination campaign period, South Korea used non-adjuvanted and MF59-adjuvanted A(H1N1)pdm09 vaccines. RESULTS: Generally, incidence rate was highest in prepandemic period. No trend toward increase in the incidence of narcolepsy after pandemic period was found. Observation of incidence by season did not suggest any time pattern for occurrence of narcolepsy. CONCLUSION: No increase in cases or incidence rate for narcolepsy during the A(H1N1)pdm09 vaccination campaign was found in South Korea. Our data do not support the use of MF59-adjuvanted or non-adjuvanted A(H1N1)pdm09 vaccine as a trigger for narcolepsy on a population level.

National pertussis surveillance in South Korea 1955-2011: epidemiological and clinical trends.

BACKGROUND: Although there has been substantial progress in controlling pertussis in South Korea, the reported number of pertussis case-patients has gradually been increasing during the last decade. To address this, we summarized the surveillance data on pertussis collected during the period 1955-2011. Detailed epidemiologic and clinical data were determined, primarily using data from recent years. METHODS: We analyzed data from the national surveillance system to describe the occurrence of pertussis. The annual numbers of reported pertussis case-patients were identified for the period 1955-2000. For 2001-2009, information including limited demographic characteristics and the date of onset of symptoms were identified. For 2010-2011, detailed epidemiologic and clinical information of reported pertussis case-patients were collected. RESULTS: During 1955-2011, the secular trend was characterized by a gradual decrease in the reported number of cases from 1955 to the late 1990s, then a recent increase starting in the early 2000s. In 2009, a large number of reported cases occurred in infants <1 year of age. In 2011, an increase in reported cases among adolescents and adults aged ≥15 years was observed. During 2010-2011, 29.8% of reported cases were not immunized and 11.3% had not been immunized in a timely manner. Of adolescents and adults aged ≥15 years, 91.7% did not have a record of immunization. CONCLUSIONS: During 2010-2011, a shift in age group was observed in pertussis case-patients: 33.8% were young infants <3 months of age and 29.0% were adolescents and adults ≥15 years of age. Considering that infants without timely vaccination may be vulnerable to an increased risk of pertussis infection, steps to provide timely vaccination to infants, to provide Tdap vaccination to adolescents and adults, and to enhance surveillance to capture adult pertussis cases should be taken in South Korea.

Seroprevalence of measles among children affected by national measles elimination program in Korea, 2010.

BACKGROUND: Following the implementation of national measles elimination plan in Korea, the elimination was declared in 2006. In order to sustain the elimination, high population immunity should be continuously monitored. To evaluate the current age-related susceptibility within the Korean population, we conducted the seroprevalence in children and adolescents who were affected by the national measles elimination plan. METHODS: We used residual serum specimens to measure measles specific IgG and geometric mean titer (GMT) in birth cohorts 2007-2008 and 1997-2003. Among birth cohorts, 2007-2008 cohorts were grouped to evaluate the timeliness of first dose of MMR, 1994-2003 cohorts were grouped to evaluate the effect of keep-up MMR2 campaign, and 1992-1993 cohorts were grouped to evaluate the effect of catch-up campaign in 2001. RESULTS: Overall, measles seropositivity rate was 86%. The highest seroprevalence of measles IgG was in birth cohorts 2007-2008. Measles seropositivity declined continuously in age groups. The birth cohorts 1994-1996 showed significantly lower levels of seropositivity and GMT than did the other birth cohorts. CONCLUSION: Despite efforts to eliminate measles for the past 10 years in Korea, our study revealed specific birth cohorts remaining at risk for transmission. The adolescents born during 1994-1996 had the lowest measles seropositivity levels, and might represent a 'pocket' that has potential at increased risk for measles transmission. Further discussion for follow-up immunization should be placed for consideration in the near future.

Nationwide cancer incidence in Korea, 2003-2005.

PURPOSE: To estimate the current cancer burden in Korea, newly diagnosed cancer cases and cancer incidence rates were calculated for the years 2003~2005. MATERIALS AND METHODS: The cancer incidence cases and rates were calculated from the Korea National Cancer Incidence Database. Crude and age-standardized incidence rates were calculated by gender for specified cancer sites in 5-year age groups. RESULTS: From 2003 to 2005, 398,824 cases of cancer were newly diagnosed in Korea (218,856 in men and 179,968 in women). For all sites combined, the crude incidence rate (CR) was 300.0 and 248.2 for men and women and the age-standardized incidence rate (ASR) was 297.0 and 191.2 per 100,000, respectively. Among men, five leading cancers were stomach (CR 66.0, ASR 64.2), lung (CR 48.5, ASR 50.3), liver (CR 44.9, ASR 42.1), colon and rectum (CR 37.9, ASR 37.2), and prostate cancer (CR 12.7, ASR 13.8). Among women, five leading cancers were breast (CR 37.3, ASR 29.0), thyroid (CR 36.2, ASR 28.8), stomach (CR 34.1, ASR 25.4), colon and rectum (CR 28.0, ASR 21.1), and lung cancer (CR 17.9, ASR 12.8). In the 0~14-year-old group, leukemia was the most common in both sexes; in the 15~34 group, the most common cancer was stomach cancer for men and thyroid cancer for women; in the 35~64 group, stomach cancer for men and breast cancer for women; among those 65 and over, lung cancer for men and stomach cancer, for women, respectively. CONCLUSION: The cancer incidence rates have increased in recent years, and more cancers are expected to develop as Korea is quickly becoming an aged society. The cancer incidence statistics in this report can be used as an important source to effectively plan and evaluate the cancer control program in Korea.

Reemerging vivax malaria: changing patterns of annual incidence and control programs in the Republic of Korea.

Changing patterns of the reemerging Plasmodium vivax malaria in the Republic of Korea (South Korea) during the period 1993 to 2005 are briefly analyzed with emphasis on the control measures used and the effects of meteorological and entomological factors. Data were obtained from the Communicable Diseases Monthly Reports published by the Korea Center for Disease Control and Prevention, and webpages of World Health Organization and United Nations. Meteorological data of Kangwon-do (Province) were obtained from local weather stations. After its first reemergence in 1993, the prevalence of malaria increased exponentially, peaking in 2000, and then decreased. In total, 21,419 cases were reported between 1993 and 2005 in South Korea. In North Korea, a total of 916,225 cases were reported between 1999 and 2004. The occurrence of malaria in high risk areas of South Korea was significantly (P > 0.05) correlated with the mosquito population but not with temperature and rainfall. Control programs, including early case detection and treatment, mass chemoprophylaxis of soldiers, and international financial aids to North Korea for malaria control have been instituted. The situation of the reemerging vivax malaria in the Republic of Korea is remarkably improving during the recent years, at least in part, due to the control activities undertaken in South and North Korea.

[The preparedness plan for influenza pandemic].

Influenza A viruses periodically cause worldwide epidemics, or pandemics, with high rates of illness and death. A pandemic can occur at any time, with the potential to cause serious illness, death and social and economic disruption throughout the world. Historic evidence suggests that pandemics occurred three to four times per century. In the last century there were three influenza pandemics. The circumstances still exist for a new influenza virus with pandemic potential to emerge and spread. The unpredictability of the timing of the next pandemic is underlined by the occurrence of several large outbreaks of highly pathogenic avian influenza since the early 1980s. In 1999, the World Health Organization published the Influenza pandemic plan. The role of WHO and guidelines for national and regional planning. And in 2005, WHO revised the global influenza preparedness plan for new national measures before and during pandemics. This document outlines briefly the Korean Centers for Disease Control's plan for responding to an influenza pandemic. According to the new pandemic phases of WHO, we set up the 4 national levels of preparedness and made guidelines for preventing and control the epidemics in each phase. And also we described the future plans to antiviral stockpiles and pandemic vaccine development.