Purpose: Mutations in the PIK3CA gene occur frequently in breast cancer patients. Activating PIK3CA mutations confer resistance to human epidermal growth factor receptor 2 (HER2)-targeted treatments. In this study, we investigated whether PIK3CA mutations were correlated with treatment response or duration in patients with HER2-positive (HER2+) breast cancer. Materials and Methods: We retrospectively reviewed the clinical information of patients with HER2+ breast cancer who received HER2-targeted therapy for early-stage or metastatic cancers. The pathologic complete response (pCR), progression-free survival (PFS), and overall survival were compared between patients with wild-type PIK3CA (PIK3CAw) and those with mutated PIK3CA (PIK3CAm). Next-generation sequencing was combined with examination of PFS associated with anti-HER2 monoclonal antibody (mAb) treatment. Results: Data from 90 patients with HER2+ breast cancer were analyzed. Overall, 34 (37.8%) patients had pathogenic PIK3CA mutations. The pCR rate of the PIK3CAm group was lower than that of the PIK3CAw group among patients who received neoadjuvant chemotherapy for early-stage cancer. In the metastatic setting, the PIK3CAm group showed a significantly shorter mean PFS (mPFS) with first-line anti-HER2 mAb. The mPFS of second-line T-DM1 was lower in the PIK3CAm group than that in the PIK3CAw group. Sequencing revealed differences in the mutational landscape between PIK3CAm and PIK3CAw tumors. Conclusion Patients with HER2+ breast cancer with activating PIK3CA mutations had lower pCR rates and shorter PFS with palliative HER2-targeted therapy than those with wild-type PIK3CA. Precise targeted-therapy is needed to improve survival of patients with HER2+/PIK3CAm breast cancer.

Purpose: BRCA1 and BRCA2 are among the most important genes involved in DNA repair via homologous recombination (HR). Germline BRCA1/2 (gBRCA1/2)-related cancers have specific characteristics and treatment options but conducting gBRCA1/2 testing and interpreting the genetic imprint are sometimes complicated. Here, we describe the concordance of gBRCA1/2 derived from a panel of clinical tumor tissues using next-generation sequencing (NGS) and genetic aspects of tumors harboring gBRCA1/2 pathogenic variants. Materials and Methods: Targeted sequencing was performed using available tumor tissue from patients who underwent gBRCA1/2 testing. Comparative genomic analysis was performed according to gBRCA1/2 pathogenicity. Results: A total of 321 patients who underwent gBRCA1/2 testing were screened, and 26 patients with gBRCA1/2 pathogenic (gBRCA1/2p) variants, eight patients with gBRCA1/2 variants of uncertain significance (VUS; gBRCA1/2v), and 43 patients with gBRCA1/2 wild-type (gBRCA1/2w) were included in analysis. Mutations in TP53 (49.4%) and PIK3CA (23.4%) were frequently detected in all samples. The number of single-nucleotide variants (SNVs) per tumor tissue was higher in the gBRCA1/2w group than that in the gBRCA1/2p group (14.81 vs. 18.86, p=0.278). Tumor mutation burden (TMB) was significantly higher in the gBRCA1/2w group than in the gBRCA1/2p group (10.21 vs. 13.47, p=0.017). Except for BRCA1/2, other HR-related genes were frequently mutated in patients with gBRCA1/2w. Conclusion We demonstrated high sensitivity of gBRCA1/2 in tumors analyzed by NGS using a panel of tumor tissues. TMB value and aberration of non-BRCA1/2 HR-related genes differed significantly according to gBRCA1/2 pathogenicity in patients with breast cancer.

In May 2023, the Committee of Clinical Practice Guidelines of the Korean Diabetes Association published the revised clinical practice guidelines for Korean adults with diabetes and prediabetes. We incorporated the latest clinical research findings through a comprehensive systematic literature review and applied them in a manner suitable for the Korean population. These guidelines are designed for all healthcare providers nationwide, including physicians, diabetes experts, and certified diabetes educators who manage patients with diabetes or individuals at risk of developing diabetes. Based on recent changes in international guidelines and the results of a Korean epidemiological study, the recommended age for diabetes screening has been lowered. In collaboration with the relevant Korean medical societies, recently revised guidelines for managing hypertension and dyslipidemia in patients with diabetes have been incorporated into this guideline. An abridgment containing practical information on patient education and systematic management in the clinic was published separately.

Objective: The characteristics and prognosis of out-of-hospital cardiac arrest (OHCA) patients can vary due to a variety of factors, including the time of the day. We tried to identify the characteristics and prognosis of OHCA in a Korean metro city based on the time of the day. Methods: This citywide retrospective observational study was conducted from January 1, 2015, to November 31, 2020, in Daegu, Korea on patients over 18 years of age who were suspected of having a medical etiology of OHCA. We evaluated the characteristics and outcomes of OHCA, according to the time of day, divided into dawn (00:00-05:59), morning (06:00-11:59), afternoon (12:00-17:59), and night (18:00-23:59). The outcome variables were survival to hospital discharge and favorable neurological outcomes. Results: The median age of the total of 4,783 OHCA patients in the study was 72.0 years of which 3,096 (64.7%) were males. The number of patients who survived was 317 (7.8%) and 301 (6.3%) were discharged with favorable neurological outcomes. There were 672 (14.0%) patients admitted at dawn, 1,607 (33.6%) in the morning, 1,379 (28.8%) in the afternoon, and 1,125 (23.5%) at night. After adjusting for the possible confounding variables, compared with the morning group, the survival to hospital discharge was low in the afternoon and the night (adjusted odds ratio [aOR], 0.69; 95% confidence interval [CI], 0.48-0.98 and aOR, 0.48; 95% CI, 0.32-0.74). In addition, favorable neurological outcomes were also low in the afternoon and the night compared with the morning (aOR, 0.59; 95% CI, 0.40-0.85 and aOR, 0.62; 95% CI, 0.41-0.93). Conclusion Diurnal differences in OHCA outcomes were observed. Identification of the diurnal OHCA characteristics will be necessary to devise an appropriate regional emergency medical services strategy.

Background/Aims: This study assessed the efficacy and safety of adalimumab (ADA) and explored predictors of response in Korean patients with ulcerative colitis (UC). Methods: A prospective, observational, multicenter study was conducted over 56 weeks in adult patients with moderately to severely active UC who received ADA. Clinical response, remission, and mucosal healing were assessed using the Mayo score. Results: A total of 146 patients were enrolled from 17 academic hospitals. Clinical response rates were 52.1% and 37.7% and clinical remission rates were 24.0% and 22.0% at weeks 8 and 56, respectively. Mucosal healing rates were 39.0% and 30.1% at weeks 8 and 56, respectively. Prior use of anti-tumor necrosis factor-α (anti-TNF-α) did not affect clinical and endoscopic responses. The ADA drug level was significantly higher in patients with better outcomes at week 8 (P<0.05). In patients with lower endoscopic activity, higher body mass index, and higher serum albumin levels at baseline, the clinical response rate was higher at week 8. In patients with lower Mayo scores and C-reactive protein levels, clinical responses, and mucosal healing at week 8, the clinical response rate was higher at week 56. Serious adverse drug reactions were identified in 2.8% of patients. Conclusions ADA is effective and safe for induction and maintenance in Korean patients with UC, regardless of prior anti-TNF-α therapy. The ADA drug level is associated with the efficacy of induction therapy. Patients with better short-term outcomes were predictive of those with an improved long-term response.

Objective: Early identification of patients at risk for deterioration is crucial to reduce in-hospital mortality. Various early warning scores have been widely applied in the emergency department (ED) of hospitals. This study evaluates and compares the effectiveness of three early warning scores_Modified Early Warning Score, Rapid Acute Physiology Score (RAPS), Worthing Physiological Scoring System (WPS), and Rapid Emergency Medicine Score. These scores help predict the need for critical care and 24- and 72-hour mortalities among alert patients presenting to the ED with dyspnea. Methods: This retrospective cohort study used data from electronic medical records of patients admitted between 2018 and 2020 and included all consecutive alert patients who presented with dyspnea in the ED. The primary outcome was to evaluate the performance of early warning scores regarding the need for critical care. The secondary outcomes were the prediction of 24- and 72-hour in-hospital mortalities. Results: Among 4,322 patients evaluated, 255 received critical care, and 17 and 84 died within 24 and 72 hours, respectively. The WPS had the overall highest performance for predicting the need for critical care (area under the curve [AUC], 0.781; 95% confidence interval [CI], 0.751-0.810) and 24-hour (AUC, 0.816; 95% CI, 0.738-0.894) and 72-hour mortalities (AUC, 0.794; 95% CI, 0.750-0.838), but differed significantly only from the RAPS. Conclusion The WPS might better predict the need for critical care and short-term mortality in alert patients with dyspnea in the ED. However, owing to a lack of its superiority in statistics, further studies are warranted to conclude the optimal tools applicable for these patients.

Purpose: Although adjuvant chemotherapy (CTx) is still recommended for high-risk patients with hormone receptorpositive and human epidermal receptor (HER)-2-negative breast cancer, recent studies found that selected patients with low disease burden may be spared from CTx and receive hormonal treatment (HT) alone. This study aims to evaluate the trends of treatment (CTx + HT vs. HT alone) in Korea and to assess the impact on overall survival (OS) according to treatment pattern. Methods: The Korean Breast Cancer Society Registry was queried (2000 to 2018) for women with pT1-2N0-1 hormone receptor-positive and HER2-negative disease who underwent surgery and adjuvant systemic treatment (CTx and HT). Clinicopathologic factors, change in pattern of treatment over time, and OS for each treatment option were analyzed. Results: A total of 40,938 women were included in the study; 20,880 (51.0%) received CTx + HT, while 20,058 (49.0%) received HT only. In recent years, there has been a steady increase in the use of HT alone, from 21.0% (2000) to 64.6% (2018). In Cox regression analysis, age, type of breast and axillary operations, T and N stages, body mass index, histologic grade,and presence of lymphovascular invasion were prognostic indicators for OS. There was no significant difference between CTx + HT and HT alone in terms of OS (P = 0.126). Conclusion Over the years, there has been a shift from CTx + HT to HT alone without a significant difference in OS. Therefore, HT alone could be a safe treatment option in selected patients, even those with T2N1 disease.

Background: South Korea has been experiencing a third wave of coronavirus disease 2019 (COVID-19) since mid-November 2020. Our hospital in Gwangju metropolitan city experienced a healthcare-associated COVID-19 outbreak early in the third wave. The first confirmed COVID-19 patient was a symptomatic neurosurgery resident with high mobility throughout the hospital. We analyzed the transmission routes of nosocomial COVID-19 and discussed infection control strategies. Methods: We retrospectively analyzed the severe acute respiratory syndrome coronavirus 2 reverse transcription-polymerase chain reaction (RT-PCR) testing results according to time point and evaluated transmission routes. Results: Since COVID-19 was first confirmed in a healthcare worker (HCW) on 11/13/2020, we performed RT-PCR tests for all patients and caregivers and four complete enumeration surveys for all HCWs. We detected three clusters of nosocomial spread and several sporadic cases. The first cluster originated from the community outbreak spot, where an asymptomatic HCW visited, which led to a total of 22 cases. The second cluster, which included patient-to-patient transmission, originated from a COVID-19 positive caregiver before diagnosis and the third cluster involved a radiologist and a banker. We took measures to isolate Building 1 of the hospital for 17 days and controlled the outbreak during a period of increasing community COVID-19 prevalence. Universal screening of all inpatients upon admission and resident caregivers was made mandatory and hospital-related employees are now screened monthly. Conclusion Infection control strategies to prevent the nosocomial transmission of emerging infectious diseases must correspond with community disease prevalence. Our data reinforce the importance of multi-time point surveillance of asymptomatic HCWs and routine surveillance of patients and caregivers during an epidemic.