Purpose: We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL). Materials and Methods: Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates. Results: Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination. Conclusion In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.

Purpose: We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL). Materials and Methods: Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates. Results: Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination. Conclusion In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.

Purpose: We assessed human papillomavirus (HPV) genotype-based risk stratification and the efficacy of cytology testing for cervical cancer screening in patients with atypical squamous cells of undetermined significance (ASCUS)/low-grade squamous intraepithelial lesion (LSIL). Materials and Methods: Between 2010 and 2021, we monitored 1,273 HPV-positive women with ASCUS/LSIL every 6 months for up to 60 months. HPV infections were categorized as persistent (HPV positivity consistently observed post-enrollment), negative (HPV negativity consistently observed post-enrollment), or non-persistent (neither consistently positive nor negative). HPV genotypes were grouped into high-risk (Hr) groups 1 (types 16, 18, 31, 33, 45, 52, and 58) and 2 (types 35, 39, 51, 56, 59, 66, and 68) and a low-risk group. Hr1 was subdivided into types (a) 16 and 18; (b) 31, 33, and 45; and (c) 52 and 58. Cox regression and machine learning (ML) algorithms were used to analyze progression rates. Results: Among 1,273 participants, 17.6% with persistent HPV infections experienced disease progression versus no progression in the HPV-negative group (p < 0.001). Cox analysis revealed the highest hazard ratios (HRs) for Hr1-a (11.6, p < 0.001), followed by Hr1-b (9.26, p < 0.001) and Hr1-c (7.21, p < 0.001). HRs peaked at 12-24 months, with Hr1-a maintaining significance at 24-36 months (10.7, p=0.034). ML analysis identified the final cytology change pattern as the most significant factor, with 14-15 months the optimal time for detecting progression from the first examination. Conclusion In ASCUS/LSIL cases, follow-up strategies should be based on HPV risk types. Annual follow-up was the most effective monitoring for detecting progression/regression.

Objective: There has been a rapid increase in the utilization of emergency departments (EDs), especially for non-emergent cases. The challenges of accessing medical services at night cause disparities in ED utilization between the day and night. Additionally, the coronavirus disease-2019 (COVID-19) pandemic has had a notable impact on ED visits. This study aimed to compare the characteristics of patients visiting the EDs in the daytime and at night before and after COVID-19. Methods: A retrospective observational study was conducted on adults (≥18 years) at three metropolitan EDs from January 1, 2019 to December 31, 2020. Data, including the Korean Triage Acuity System, Tenth Revision (ICD-10) codes, and ICU admissions, were collected. Characteristics of patients visiting the ED during the day (06:00-18:00) and night (18:00-06:00) periods before and after COVID-19 were analyzed. Results: During the pre-COVID-19 and COVID-19 periods, 117,896 and 92,915 patients visited the ED, respectively. Non-emergency nighttime visits were increased than daytime visits during both the pre-COVID-19 period (37.9% vs. 30.9%) and the COVID-19 period (35.4% vs. 28.8%) (P<0.01). During COVID-19, non-emergency patient visits to the ED during the nighttime decreased compared to those during the day (odds ratio, 0.96; 95% confidence interval [CI], 0.93-0.99, P=0.01). Among the top five diagnoses, the number of patients declined during the COVID-19 pandemic in most categories, except for the category of “Fever of other and unknown origin,” which saw an increase both during the day (incident rate ratio [IRR], 1.10; 95% CI, 1.05-1.17) and night (IRR, 1.23; 95% CI, 1.17-1.30). Conclusion The COVID-19 pandemic significantly influenced ED visit patterns, particularly by reducing non-emergent visits during nighttime.

The Korean Breast Cancer Society (KBCS) has collected nationwide registry data on clinicopathologic characteristics and treatment since 1996. This study aimed to analyze the clinical characteristics of breast cancer in Korea and assess changes in breast cancer statistics for 2021 using data from the KBCS registry and the Korean Central Cancer Registry. In 2021, 34,628 women were newly diagnosed with breast cancer. The median age of women diagnosed with breast cancer was 53.4 years, with the highest incidence occurring in the 40–49 age group. The most common molecular subtype was hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative, accounting for 69.1% of cases, while HER2-positive subtypes comprised 19.3%. During the coronavirus disease 2019 pandemic, the national breast cancer screening rate declined. However, the incidence of early-stage breast cancer (stages 0 and I) continued to increase, accounting for 65.6% of newly diagnosed cases in 2021. Our results showed that the overall survival rate for patients with breast cancer has improved, primarily due to a rise in early-stage diagnoses and advancements in treatment.

The Korean Breast Cancer Society (KBCS) has collected nationwide registry data on clinicopathologic characteristics and treatment since 1996. This study aimed to analyze the clinical characteristics of breast cancer in Korea and assess changes in breast cancer statistics for 2021 using data from the KBCS registry and the Korean Central Cancer Registry. In 2021, 34,628 women were newly diagnosed with breast cancer. The median age of women diagnosed with breast cancer was 53.4 years, with the highest incidence occurring in the 40–49 age group. The most common molecular subtype was hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative, accounting for 69.1% of cases, while HER2-positive subtypes comprised 19.3%. During the coronavirus disease 2019 pandemic, the national breast cancer screening rate declined. However, the incidence of early-stage breast cancer (stages 0 and I) continued to increase, accounting for 65.6% of newly diagnosed cases in 2021. Our results showed that the overall survival rate for patients with breast cancer has improved, primarily due to a rise in early-stage diagnoses and advancements in treatment.

Objective: There has been a rapid increase in the utilization of emergency departments (EDs), especially for non-emergent cases. The challenges of accessing medical services at night cause disparities in ED utilization between the day and night. Additionally, the coronavirus disease-2019 (COVID-19) pandemic has had a notable impact on ED visits. This study aimed to compare the characteristics of patients visiting the EDs in the daytime and at night before and after COVID-19. Methods: A retrospective observational study was conducted on adults (≥18 years) at three metropolitan EDs from January 1, 2019 to December 31, 2020. Data, including the Korean Triage Acuity System, Tenth Revision (ICD-10) codes, and ICU admissions, were collected. Characteristics of patients visiting the ED during the day (06:00-18:00) and night (18:00-06:00) periods before and after COVID-19 were analyzed. Results: During the pre-COVID-19 and COVID-19 periods, 117,896 and 92,915 patients visited the ED, respectively. Non-emergency nighttime visits were increased than daytime visits during both the pre-COVID-19 period (37.9% vs. 30.9%) and the COVID-19 period (35.4% vs. 28.8%) (P<0.01). During COVID-19, non-emergency patient visits to the ED during the nighttime decreased compared to those during the day (odds ratio, 0.96; 95% confidence interval [CI], 0.93-0.99, P=0.01). Among the top five diagnoses, the number of patients declined during the COVID-19 pandemic in most categories, except for the category of “Fever of other and unknown origin,” which saw an increase both during the day (incident rate ratio [IRR], 1.10; 95% CI, 1.05-1.17) and night (IRR, 1.23; 95% CI, 1.17-1.30). Conclusion The COVID-19 pandemic significantly influenced ED visit patterns, particularly by reducing non-emergent visits during nighttime.

The Korean Breast Cancer Society (KBCS) has collected nationwide registry data on clinicopathologic characteristics and treatment since 1996. This study aimed to analyze the clinical characteristics of breast cancer in Korea and assess changes in breast cancer statistics for 2021 using data from the KBCS registry and the Korean Central Cancer Registry. In 2021, 34,628 women were newly diagnosed with breast cancer. The median age of women diagnosed with breast cancer was 53.4 years, with the highest incidence occurring in the 40–49 age group. The most common molecular subtype was hormone receptor-positive and human epidermal growth factor receptor 2 (HER2)-negative, accounting for 69.1% of cases, while HER2-positive subtypes comprised 19.3%. During the coronavirus disease 2019 pandemic, the national breast cancer screening rate declined. However, the incidence of early-stage breast cancer (stages 0 and I) continued to increase, accounting for 65.6% of newly diagnosed cases in 2021. Our results showed that the overall survival rate for patients with breast cancer has improved, primarily due to a rise in early-stage diagnoses and advancements in treatment.

Objective: There has been a rapid increase in the utilization of emergency departments (EDs), especially for non-emergent cases. The challenges of accessing medical services at night cause disparities in ED utilization between the day and night. Additionally, the coronavirus disease-2019 (COVID-19) pandemic has had a notable impact on ED visits. This study aimed to compare the characteristics of patients visiting the EDs in the daytime and at night before and after COVID-19. Methods: A retrospective observational study was conducted on adults (≥18 years) at three metropolitan EDs from January 1, 2019 to December 31, 2020. Data, including the Korean Triage Acuity System, Tenth Revision (ICD-10) codes, and ICU admissions, were collected. Characteristics of patients visiting the ED during the day (06:00-18:00) and night (18:00-06:00) periods before and after COVID-19 were analyzed. Results: During the pre-COVID-19 and COVID-19 periods, 117,896 and 92,915 patients visited the ED, respectively. Non-emergency nighttime visits were increased than daytime visits during both the pre-COVID-19 period (37.9% vs. 30.9%) and the COVID-19 period (35.4% vs. 28.8%) (P<0.01). During COVID-19, non-emergency patient visits to the ED during the nighttime decreased compared to those during the day (odds ratio, 0.96; 95% confidence interval [CI], 0.93-0.99, P=0.01). Among the top five diagnoses, the number of patients declined during the COVID-19 pandemic in most categories, except for the category of “Fever of other and unknown origin,” which saw an increase both during the day (incident rate ratio [IRR], 1.10; 95% CI, 1.05-1.17) and night (IRR, 1.23; 95% CI, 1.17-1.30). Conclusion The COVID-19 pandemic significantly influenced ED visit patterns, particularly by reducing non-emergent visits during nighttime.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.