Background: Although serological severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests from several manufacturers have been introduced in South Korea and some are commercially available, the performance of these test kits has not yet been sufficiently validated. Therefore, we compared the performance of Elecsys Anti-SARS-CoV-2 (ACOV2) and Anti-SARS-CoV-2 S (ACOV2S) and Atellica IM SARS-CoV-2 Total (COV2T) and SARS-CoV-2 IgG (sCOVG) serological tests in this study. Methods: A total of 186 patient samples were used. For each test, we analyzed the positive rate of serological antibody tests, precision, linearity, and agreement among the four assays. Results: The positive rates of COV2T, sCOVG, and ACOV2S were high (81.7%–89.2%) in total, with those for ACOV2S being the highest, while those of ACOV2 were as low as 44.6%. This may be related to the high completion rate of vaccination in Korea. The repeatability and within-laboratory coefficients of variation were within the claimed allowable imprecision; however, further research is needed to establish an allowable imprecision at low concentrations. COV2T showed a linear fit, whereas sCOVG and ACOV2S were appropriately modeled with a nonlinear fit. Good agreement was found among COV2T, sCOVG, and ACOV2S; however, the agreement between ACOV2 and any one of the other methods was poor. Conclusions Considering the different antigens used in serological SARS-CoV-2 antibody assays, the performance of the tested assays is thought to show no significant difference for the qualitative detection of antibodies to SARS-CoV-2.

Objective: This study aimed to introduce a 4-week long fully immersive virtual reality-based cognitive training (VRCT) program that could be applied for both a cognitively normal elderly population and patients with mild cognitive impairment (MCI). In addition, we attempted to investigate the neuropsychological effects of the VRCT program in each group. Methods: A total of 56 participants, 31 in the MCI group and 25 in the cognitively normal elderly group, underwent eight sessions of VRCT for 4 weeks. In order to evaluate the effects of the VRCT, the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease Assessment Packet was administered before and after the program. The program’ s safety was assessed using a simulator sickness questionnaire (SSQ), and availability was assessed using the presence questionnaire. Results: After the eighth session of the VRCT program, cognitive improvement was observed in the ability to learn new information, visuospatial constructional ability, and frontal lobe function in both groups. At the baseline evaluation, based on the SSQ, the MCI group complained of disorientation and nausea significantly more than the cognitively normal elderly group did. However, both groups showed a reduction in discomfort as the VRCT program progressed. Conclusion We conclude that our VRCT program helps improve cognition in both the MCI group and cognitively normal elderly group. Therefore, the VRCT is expected to help improve cognitive function in elderly populations with and without MCI.

Objective: We aimed to determine the differences in stage at diagnosis of cervical cancer among Korean women according to screening history. Methods: Using linkage data from the Korean Central Cancer Registry and Korean National Cancer Screening Program (KNCSP), we included 18,388 women older than 30 years who were newly diagnosed with cervical cancer between 2013 and 2014 and examined their screening history. Between individuals, age group and socioeconomic status were matched to control for potential confounders. Results: Significantly more cases of carcinoma in situ (CIS) were diagnosed in the ever-screened (71.77%) group than in the never-screened group (54.78%), while localized, regional, distant, and unknown stage were more frequent in the never-screened group. Women in the ever-screened group were most likely to be diagnosed with CIS than with invasive cervical cancer (adjusted odds ratio [aOR]=2.40; 95% confidence interval [CI]=2.18–2.65). The aOR for being diagnosed with CIS was highest among women who were screened 3 times or more (aOR=5.10; 95% CI=4.03–6.45). The ORs were highest for women screened within 24 months of diagnosis and tended to decrease with an increasing time since last screening (p-trend <0.01). Conclusion The KNCSP for cervical cancer was found to be positively associated with diagnosis of cervical cancers at earlier stages among women aged 30 years or older. The benefit of screening according to time was highest for women screened within 24 months of diagnosis.

More than 4 million women undergo breast cancer (BC) screening with mammography each year in Korea. Digital mammography (DM) was introduced in 2000, and it has been reported to have a higher diagnostic accuracy than screen-film mammography (SFM) or computed radiography (CR) in women with dense breasts. According to a study using data from the National Cancer Screening Program for BC, the diagnostic accuracy of DM was higher than those of SFM and CR, regardless of age, breast density, and screening round. Currently, despite high supply rate among OECD countries, the distribution of DM equipment is approximately 35% in Korea.For quick replacement with DM, it will be necessary to improve its fee for the National Health Insurance and support an educational program for radiologists. In addition, efforts should be made to increase the accessibility of DM.

Objective: This study aimed to introduce a 4-week long fully immersive virtual reality-based cognitive training (VRCT) program that could be applied for both a cognitively normal elderly population and patients with mild cognitive impairment (MCI). In addition, we attempted to investigate the neuropsychological effects of the VRCT program in each group. Methods: A total of 56 participants, 31 in the MCI group and 25 in the cognitively normal elderly group, underwent eight sessions of VRCT for 4 weeks. In order to evaluate the effects of the VRCT, the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease Assessment Packet was administered before and after the program. The program’ s safety was assessed using a simulator sickness questionnaire (SSQ), and availability was assessed using the presence questionnaire. Results: After the eighth session of the VRCT program, cognitive improvement was observed in the ability to learn new information, visuospatial constructional ability, and frontal lobe function in both groups. At the baseline evaluation, based on the SSQ, the MCI group complained of disorientation and nausea significantly more than the cognitively normal elderly group did. However, both groups showed a reduction in discomfort as the VRCT program progressed. Conclusion We conclude that our VRCT program helps improve cognition in both the MCI group and cognitively normal elderly group. Therefore, the VRCT is expected to help improve cognitive function in elderly populations with and without MCI.

Purpose: This study aimed to report the projected cancer incidence and mortality for the year 2021 to estimate Korea’s current cancer burden. Materials and Methods: Cancer incidence data from 1999 to 2018 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2019 were acquired from Statistics Korea. Cancer incidence and mortality were projected by fitting a linear regression model to observed age-specific cancer rates against their respective years and then by multiplying the projected age-specific rates by the anticipated age-specific population for 2021. A joinpoint regression model was used to determine the year in which the linear trend changed significantly; we only used the data of the latest trend. Results: In total, 259,999 new cancer cases and 81,567 cancer deaths are expected to occur in Korea in 2021. The most common cancer site is expected to be the lung, followed by the thyroid, colon and rectum, breast, and stomach. These five cancers are expected to represent half of the overall burden of cancer in Korea. The most common type of cancer leading to death is expected to be lung cancer, followed by liver, colorectal, pancreatic, and stomach cancers. Conclusion The incidence rates for all types of cancer in Korea are estimated to gradually decrease. These up-to-date estimates of the cancer burden in Korea could be an important resource for planning and evaluating cancer-control programs.

Purpose: The current study provides national cancer statistics and their secular trends in Korea, including incidence, mortality, survival, and prevalence in 2018. Materials and Methods: Incidence, survival, and prevalence rates of cancer were calculated using the Korea National Cancer Incidence Database, from 1999 to 2018, with survival follow-up until December 31, 2019. Deaths from cancer were assessed using causes-of-death data obtained from Statistics Korea. Crude and age-standardized rates (ASRs) for incidence, mortality, prevalence, and 5-year relative survival rates were calculated, and temporal trends for incidence and mortality rates were evaluated, with annual percentage changes. Results: In 2018, newly diagnosed cancer cases and deaths from cancer were reported as 243,837 (ASR, 270.4 per 100,000) and 79,153 (ASR, 73.3 per 100,000), respectively. The overall cancer incidence rates increased by 3.3% annually from 1999 to 2012, and decreased by 5.4% annually from 2012 to 2015, thereafter, followed by nonsignificant changes. Cancer mortality rates have been decreasing since 2002, with more rapid decline in recent years (annual decrease of 2.7% from 2007 to 2014; 3.7% from 2014 to 2018). The 5-year relative survival between 2014 and 2018 was 70.3%, which contributed to prevalent cases reaching over 2 million by the end of 2018. Conclusion Cancer statistics have improved significantly during the past two decades. However, there remain important challenges to be solved, such as controlling cancers with low survival rates. Cancer statistics can be used to discover blind spots in cancer control, and as evidence for developing and implementing future cancer control strategies.

Purpose: The Korean National Cancer Screening Survey (KNCSS) is a nationwide annual cross-sectional survey conducted for the past 15 years. This study aimed to report trends in the overall screening rates of both organized and opportunistic cancer screening programs from 2004–2018. Materials and Methods: KNCSS data were collected using a structured questionnaire. For five major cancers (i.e., stomach, liver, colorectal, breast, and cervical cancer), we evaluated both the lifetime screening rate and the screening rate with recommendations. The study population included men aged 40–74 years and women aged 20–74 years with no cancer histories. Results: Screening rate with recommendations increased from 2004 annually by 4.4% and 1.5% until 2013 for stomach and liver cancers, respectively, by 4.0% until 2012 for breast cancer, and by 3.6% and 1.2% until 2014 for colorectal and cervical cancers, respectively, followed by nonsignificant trends thereafter. In 2018, screening rates with recommendations for these cancers were 72.8%, 26.2%, 63.1%, 58.4%, and 55.6%, respectively. Conclusion Screening rates for the five types of cancer demonstrated a marked increase between 2004 and 2018. However, many recent screening rates have been flattened with nonsignificant trends, and there are lower rates for cervical cancer screening among young age groups. Steady efforts are needed to achieve higher screening participation rates overall, especially for the cervical cancer screening of young women in their 20s.

Purpose: This study aimed to report the projected cancer incidence and mortality for the year 2021 to estimate Korea’s current cancer burden. Materials and Methods: Cancer incidence data from 1999 to 2018 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2019 were acquired from Statistics Korea. Cancer incidence and mortality were projected by fitting a linear regression model to observed age-specific cancer rates against their respective years and then by multiplying the projected age-specific rates by the anticipated age-specific population for 2021. A joinpoint regression model was used to determine the year in which the linear trend changed significantly; we only used the data of the latest trend. Results: In total, 259,999 new cancer cases and 81,567 cancer deaths are expected to occur in Korea in 2021. The most common cancer site is expected to be the lung, followed by the thyroid, colon and rectum, breast, and stomach. These five cancers are expected to represent half of the overall burden of cancer in Korea. The most common type of cancer leading to death is expected to be lung cancer, followed by liver, colorectal, pancreatic, and stomach cancers. Conclusion The incidence rates for all types of cancer in Korea are estimated to gradually decrease. These up-to-date estimates of the cancer burden in Korea could be an important resource for planning and evaluating cancer-control programs.

Purpose: The current study provides national cancer statistics and their secular trends in Korea, including incidence, mortality, survival, and prevalence in 2018. Materials and Methods: Incidence, survival, and prevalence rates of cancer were calculated using the Korea National Cancer Incidence Database, from 1999 to 2018, with survival follow-up until December 31, 2019. Deaths from cancer were assessed using causes-of-death data obtained from Statistics Korea. Crude and age-standardized rates (ASRs) for incidence, mortality, prevalence, and 5-year relative survival rates were calculated, and temporal trends for incidence and mortality rates were evaluated, with annual percentage changes. Results: In 2018, newly diagnosed cancer cases and deaths from cancer were reported as 243,837 (ASR, 270.4 per 100,000) and 79,153 (ASR, 73.3 per 100,000), respectively. The overall cancer incidence rates increased by 3.3% annually from 1999 to 2012, and decreased by 5.4% annually from 2012 to 2015, thereafter, followed by nonsignificant changes. Cancer mortality rates have been decreasing since 2002, with more rapid decline in recent years (annual decrease of 2.7% from 2007 to 2014; 3.7% from 2014 to 2018). The 5-year relative survival between 2014 and 2018 was 70.3%, which contributed to prevalent cases reaching over 2 million by the end of 2018. Conclusion Cancer statistics have improved significantly during the past two decades. However, there remain important challenges to be solved, such as controlling cancers with low survival rates. Cancer statistics can be used to discover blind spots in cancer control, and as evidence for developing and implementing future cancer control strategies.