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.

By investigating the characteristics and prognosis of breast cancer (BC) patients who have undergone hormone replacement therapy (HRT), this study addresses a gap in the existing literature. A total of 17,355 postmenopausal patients with BC were analyzed using data from the Korea Breast Cancer Society database (2000–2014). Among them, 3,585 (20.7%) had a history of HRT before BC diagnosis (HRT group), while 13,770 (79.3%) never received HRT (non-HRT group). The HRT group exhibited an earlier pathologic stage, lower histologic and nuclear grades, and a higher rate of breast conservation surgery compared to the non-HRT group. Furthermore, this group had a higher rate of screening participation and a greater proportion of patients with a normal or overweight body mass index (BMI). The prognosis of the HRT group was better than that of the non-HRT group, with a 5-year overall survival rate of 93.9% versus 91.7% (p < 0.001). The hazard ratio for the HRT group was 0.7 (95% confidence interval, 0.608–0.805; p < 0.001). Increased screening participation, longer HRT duration, and a normal or overweight BMI were associated with a better prognosis in the HRT group. Patients with BC who underwent HRT showed better clinicopathological characteristics and prognosis than those who did not receive HRT. The results highlighted significant differences in patients who underwent screening and those with a normal or overweight BMI. Furthermore, a longer HRT duration was associated with a better prognosis.

Background: The benefits of transradial access (TRA) over transfemoral access (TFA) for bifurcation percutaneous coronary intervention (PCI) are uncertain because of the limited availability of device selection. This study aimed to compare the procedural differences and the in-hospital and long-term outcomes of TRA and TFA for bifurcation PCI using secondgeneration drug-eluting stents (DESs). Methods: Based on data from the Coronary Bifurcation Stenting Registry III, a retrospective registry of 2,648 patients undergoing bifurcation PCI with second-generation DES from 21 centers in South Korea, patients were categorized into the TRA group (n = 1,507) or the TFA group (n = 1,141). After propensity score matching (PSM), procedural differences, in-hospital outcomes, and device-oriented composite outcomes (DOCOs; a composite of cardiac death, target vessel-related myocardial infarction, and target lesion revascularization) were compared between the two groups (772 matched patients each group). Results: Despite well-balanced baseline clinical and lesion characteristics after PSM, the use of the two-stent strategy (14.2% vs. 23.7%, P = 0.001) and the incidence of in-hospital adverse outcomes, primarily driven by access site complications (2.2% vs. 4.4%, P = 0.015), were significantly lower in the TRA group than in the TFA group. At the 5-year follow-up, the incidence of DOCOs was similar between the groups (6.3% vs. 7.1%, P = 0.639). Conclusion The findings suggested that TRA may be safer than TFA for bifurcation PCI using second-generation DESs. Despite differences in treatment strategy, TRA was associated with similar long-term clinical outcomes as those of TFA. Therefore, TRA might be the preferred access for bifurcation PCI using second-generation DES.

Background: A decline in masticatory function may indicate brain dysfunction related to dementia, but the relationship between masticatory function and dementia risk remains unclear. This study aimed to investigate whether masticatory function is associated with the risk of cognitive decline and dementia. Methods: Data were obtained from the nationwide prospective cohort study of randomly sampled community-dwelling Koreans aged ≥ 60 years. The 5,064 non-demented participants, whose number of chewing cycles per bite was assessed by clinical interview, were followed for 8 years with biennial assessments of cognitive performance and clinical diagnoses of all-cause dementia and Alzheimer’s disease (AD). Structural brain magnetic resonance imaging was collected from a subset of cohort participants and their spouses for imaging analyses. Results: Males who chewed ≥ 30 cycles/bite had faster decline in global cognition and memory function and were at higher risk for incident all-cause dementia (hazard ratio [HR], 2.91; 95% confidence interval [CI], 1.18–7.18) and AD (HR, 3.22; 95% CI, 1.14–9.11) compared to males with less than 10 cycles/bite. Additionally, increased chewing cycles in males were associated with reduced brain volume, particularly in regions involved in compensatory cognitive control of mastication. There was no significant association between chewing cycles and the risk of dementia or brain volume in females. Conclusion Older men who frequently chew their meals could be considered a notable population at risk for dementia who should be carefully assessed for their cognitive trajectories.

Closed nontraumatic flexor tendon ruptures are classified as spontaneous, infiltrative tenosynovial, iatrogenic, or attritional ruptures based on their mechanism. Attritional ruptures occur over rough bone surfaces that result from various pathologies. Here, we present a case of attritional rupture of the flexor digitorum profundus of the little finger due to pisotriquetral arthritis.

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.

By investigating the characteristics and prognosis of breast cancer (BC) patients who have undergone hormone replacement therapy (HRT), this study addresses a gap in the existing literature. A total of 17,355 postmenopausal patients with BC were analyzed using data from the Korea Breast Cancer Society database (2000–2014). Among them, 3,585 (20.7%) had a history of HRT before BC diagnosis (HRT group), while 13,770 (79.3%) never received HRT (non-HRT group). The HRT group exhibited an earlier pathologic stage, lower histologic and nuclear grades, and a higher rate of breast conservation surgery compared to the non-HRT group. Furthermore, this group had a higher rate of screening participation and a greater proportion of patients with a normal or overweight body mass index (BMI). The prognosis of the HRT group was better than that of the non-HRT group, with a 5-year overall survival rate of 93.9% versus 91.7% (p < 0.001). The hazard ratio for the HRT group was 0.7 (95% confidence interval, 0.608–0.805; p < 0.001). Increased screening participation, longer HRT duration, and a normal or overweight BMI were associated with a better prognosis in the HRT group. Patients with BC who underwent HRT showed better clinicopathological characteristics and prognosis than those who did not receive HRT. The results highlighted significant differences in patients who underwent screening and those with a normal or overweight BMI. Furthermore, a longer HRT duration was associated with a better prognosis.

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.

Closed nontraumatic flexor tendon ruptures are classified as spontaneous, infiltrative tenosynovial, iatrogenic, or attritional ruptures based on their mechanism. Attritional ruptures occur over rough bone surfaces that result from various pathologies. Here, we present a case of attritional rupture of the flexor digitorum profundus of the little finger due to pisotriquetral arthritis.

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.