Purpose: Notable effectiveness of trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2 (HER2)–low advanced breast cancer (BC) has focused pathologists’ attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results. Materials and Methods: The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected. Results: Total 11,416 patients from 25 institutions included in this study. Of these patients, 40.7% (range, 6.0% to 76.3%) were classified as HER2-zero, 41.7% (range, 10.5% to 69.1%) as HER2-low, and 17.5% (range, 6.7% to 34.0%) as HER2-positive. HER2-low tumors were associated with positive estrogen receptor and progesterone receptor statuses (p < 0.001 and p < 0.001, respectively). Antigen retrieval times (≥ 36 minutes vs. < 36 minutes) and antibody incubation times (≥ 12 minutes vs. < 12 minutes) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3,259) of the patients. Conclusion The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Purpose: The aim of this study was to analyze the perioperative complications and oncological outcomes of radical prostatectomy (RP) in patients who underwent multiple prostate biopsies.
Materials and Methods: A total of 1,112 patients who underwent RP between January 2009 and April 2016 at 4 different centers were included in this study. We divided these patients into 2 groups: patients who underwent only 1st biopsy, and those who underwent 2nd or more repeated biopsies. The association between the number of prior biopsies and perioperative complications and biochemical recurrence (BCR) was analyzed.
Results: Of 1,112 patients, 1,046 patients (94.1%) underwent only 1st biopsy, and 66 (5.9%) underwent 2nd or more repeated biopsies. There were no significant differences in preoperative prostate-specific antigen levels, operation times, blood loss volumes, or hospital stay durations (all p＞0.05). Patients who underwent multiple prostate biopsies presented with a localized tumor significantly more often (p＜0.05). The Gleason score and rate of positive surgical margins were significantly lower in patients with multiple biopsies (all p＜0.05). The Cox proportional hazards model analysis indicated that there was no association between the number of prior prostate biopsies and BCR (p＞0.05). Kaplan-Meier curve analysis indicated that BCR-free survival rates between the 2 groups were similar (p＞0.05).
Conclusions Multiple prostate biopsies are not associated with an increased risk of perioperative complications, adverse pathological outcomes, or higher rates of BCR in patients who have undergone RP. (Korean J Urol Oncol 2020;18:24-31)

PURPOSE: To report the first case of cystoid macular edema in a retinitis pigmentosa patient with pars plana vitrectomy. CASE SUMMARY: A 43-year-old female visited our hospital with visual disturbances of both eyes. Corrected visual acuity was 20/22 in the right eye and 20/25 in the left eye. Peripheral depigmentation and atrophy of the retinal pigment epithelium, pigmentary retinal degeneration, and attenuated arterioles were observed in both eyes. Cystoid macular edema was observed on optical coherence tomography which showed that the central macular thickness was 308 µm in the right eye and 422 µm in left eye. Intravitreal aflibercept was injected into the left eye. One month after injection, the central macular thickness showed no response with a thickness of 449 µm. An intravitreal dexamethasone implant was then injected, 1 month after injection, the central macular thickness was 367 µm. Six months after injection, the patient again complained of visual disturbance of the left eye with a corrected visual acuity of 20/70. Vitreous opacity was observed and the central macular thickness was 501 µm. The patient underwent pars plana vitrectomy. Three days after surgery, the central macular thickness was 320 µm. One year after surgery, the corrected visual acuity was 20/33 and the central macular thickness was 311 µm. CONCLUSIONS: Pars plana vitrectomy due to cystoid macular edema in a retinitis pigmentosa patient has not been previously reported in the Republic of Korea. Pars plana vitrectomy can therefore be an effective treatment for cystoid macular edema in retinitis pigmentosa patients.
Adult ; Arterioles ; Atrophy ; Dexamethasone ; Female ; Humans ; Macular Edema ; Republic of Korea ; Retinal Degeneration ; Retinal Pigment Epithelium ; Retinitis Pigmentosa ; Retinitis ; Tomography, Optical Coherence ; Visual Acuity ; Vitrectomy

Hepatitis E outbreaks are a serious public health concern in developing countries. The disease causes acute infections, primarily in young adults. The mortality rate is approximately 2%; however, it can exceed 20% in pregnant women in some regions in India. The causative agent, hepatitis E virus (HEV), has been isolated from several animal species, including pigs. HEV genotypes 3 and 4 have been isolated from both humans and animals, and are recognized as zoonotic pathogens. Seroprevalence studies in animals and humans indirectly suggest that HEV infections occur worldwide. The virus is primarily transmitted to humans via undercooked animal meats in developed countries. Moreover, transfusion- and transplantation-mediated HEV infections have recently been reported. This review summarizes the general characteristics of hepatitis E, HEV infection status in animals and humans, the zoonotic transmission modes of HEV, and HEV vaccine development status.
Animals ; Genotype ; Hepatitis E/*epidemiology/mortality/*transmission/virology ; Hepatitis E virus/genetics/*physiology ; Humans ; Zoonoses/epidemiology/mortality/*transmission/virology

BACKGROUND/AIMS: The management of job-related stress among health-care workers is critical for the improvement of healthcare services; however, there is no existing research on endoscopy unit workers as a team. Korea has a unique health-care system for endoscopy unit workers. In this study, we aimed to estimate job stress and job satisfaction among health-care providers in endoscopy units in Korea. METHODS: We performed a cross-sectional survey of health-care providers in the endoscopy units of three university-affiliated hospitals in Korea. We analyzed the job stress levels by using the Korean occupational stress scale, contributing factors, and job satisfaction. RESULTS: Fifty-nine workers completed the self-administered questionnaires. The job stress scores for the endoscopy unit workers (46.39±7.81) were relatively lower compared to those of the national sample of Korean workers (51.23±8.83). Job stress differed across job positions, with nurses showing significantly higher levels of stress (48.92±7.97) compared to doctors (42.59±6.37). Job stress and job satisfaction were negatively correlated with each other (R2=0.340, p<0.001). CONCLUSIONS: An endoscopy unit is composed of a heterogeneous group of health-care professionals (i.e., nurses, fellows, and professors), and job stress and job satisfaction significantly differ according to job positions. Job demand, insufficient job control, and job insecurity are the most important stressors in the endoscopy unit.
Cross-Sectional Studies ; Delivery of Health Care ; Endoscopy* ; Job Satisfaction* ; Korea*

BACKGROUND/AIMS: Obstructive sleep apnea (OSA) is associated with an increased risk of obesity and non-alcoholic fatty liver disease (NAFLD), but it remains unclear whether the risk of NAFLD is independently related to OSA regardless of visceral obesity. Thus, the aim of the present study was to examine whether OSA alone or in combination with excessive daytime sleepiness (EDS) or short sleep duration was associated with NAFLD independent of visceral fat in Korean adults. METHODS: A total of 621 participants were selected from the Korean Genome and Epidemiology Study (KoGES). The abdominal visceral fat area (VFA) and hepatic fat components of the participants were assessed using computed tomography scans and they were then categorized into four groups depending on the presence of OSA and EDS. RESULTS: The proportions of NAFLD were 21.1%, 18.5%, 32.4%, and 46.7% in participants without OSA/EDS, with only EDS, with only OSA, and with both OSA and EDS, respectively. A combination of OSA and EDS increased the odds ratio (OR) for developing NAFLD (OR, 2.75; 95% confidence interval [CI], 1.21 to 6.28) compared to those without OSA/EDS, and this association remained significant (OR, 2.38; 95% CI, 1.01 to 5.59) even after adjusting for VFA. In short sleepers (< 5 hours) with OSA, the adjusted OR for NAFLD was 2.50 (95% CI, 1.08 to 5.75) compared to those sleeping longer than 5 hours without OSA. CONCLUSIONS: In the present study, OSA was closely associated with NAFLD in Korean adults. This association was particularly strong in those with EDS or short sleep duration regardless of VFA.
*Adiposity ; Aged ; Asian Continental Ancestry Group ; Chi-Square Distribution ; Disorders of Excessive Somnolence/diagnosis/*epidemiology/physiopathology ; Female ; Humans ; Intra-Abdominal Fat/*physiopathology ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Non-alcoholic Fatty Liver Disease/diagnosis/*epidemiology/physiopathology ; Obesity, Abdominal/diagnosis/*epidemiology/physiopathology ; Odds Ratio ; Republic of Korea/epidemiology ; Risk Factors ; *Sleep ; Sleep Apnea, Obstructive/diagnosis/*epidemiology/physiopathology

BACKGROUND: Analysis of mutations in the epidermal growth factor receptor gene (EGFR) is important for predicting response to EGFR tyrosine kinase inhibitors. The overall rate of EGFR mutations in Korean patients is variable. To obtain comprehensive data on the status of EGFR mutations in Korean patients with lung cancer, the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists initiated a nationwide survey. METHODS: We obtained 1,753 reports on EGFR mutations in patients with lung cancer from 15 hospitals between January and December 2009. We compared EGFR mutations with patient age, sex, history of smoking, histologic diagnosis, specimen type, procurement site, tumor cell dissection, and laboratory status. RESULTS: The overall EGFR mutation rate was 34.3% in patients with non-small cell lung cancer (NSCLC) and 43.3% in patients with adenocarcinoma. EGFR mutation rate was significantly higher in women, never smokers, patients with adenocarcinoma, and patients who had undergone excisional biopsy. EGFR mutation rates did not differ with respect to patient age or procurement site among patients with NSCLC. CONCLUSIONS: EGFR mutation rates and statuses were similar to those in published data from other East Asian countries.
Adenocarcinoma ; Asian Continental Ancestry Group ; Biopsy ; Carcinoma, Non-Small-Cell Lung* ; Diagnosis ; Epidermal Growth Factor* ; Female ; Humans ; Lung Neoplasms ; Mutation Rate ; Pathology ; Protein-Tyrosine Kinases ; Receptor, Epidermal Growth Factor* ; Smoke ; Smoking

BACKGROUND/AIMS: Primary aldosteronism (PA) is now widely recognized to have a higher prevalence than was once thought. In view of its increasing prevalence, we compared chronological changes in clinical manifestations of PA according to different times of diagnosis. METHODS: In total, 85 patients diagnosed with PA from January 1986 through March 2012 were reviewed retrospectively, based on their medical records. During two periods-1986 to 2005 and 2006 to 2012-41 and 44 patients, respectively, were diagnosed with PA. We compared the clinical and biological characteristics of PA between these periods. RESULTS: The results demonstrate an increasing trend in the prevalence of idiopathic hyperaldosteronism (IHA; p = 0.19). In the 2006 to 2012 period, patients with PA presented with higher serum potassium levels at the time of diagnosis than in the 1986 to 2005 period (p < 0.0002). Adrenal vein sampling (AVS) was performed mostly in the latter period (82.3%) and the diagnostic accuracy of adrenal computed tomography, compared with AVS, was only 56.2%. About 78.0% versus 86.3% of patients had at least one target organ damage (TOD) in the 1986 to 2005 and 2006 to 2012 periods, respectively (p = 0.39). However, patients with TOD were older and had longer durations of hypertension than patients without, in both periods. CONCLUSIONS: PA is becoming more prevalent. There was an increasing tendency for IHA, and more PA patients presented with normokalemia than in the earlier period. Early and accurate diagnosis of PA with AVS and proper treatment should have substantial prognostic value.
Adrenal Cortex Neoplasms/diagnosis/epidemiology ; Adrenal Glands/radiography ; Adrenocortical Adenoma/diagnosis/epidemiology ; Adult ; Biological Markers/blood ; Female ; Humans ; Hyperaldosteronism/blood/*diagnosis/epidemiology/therapy ; Hyperkalemia/diagnosis/epidemiology ; Hyperplasia ; Hypertension/diagnosis/epidemiology ; Male ; Middle Aged ; Potassium/blood ; Predictive Value of Tests ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors ; Time Factors ; Tomography, X-Ray Computed ; Treatment Outcome

BACKGROUND: Previously, cutaneous lymphomas were classified according to either the European Organization for the Research and Treatment of Cancer (EORTC) or the World Health Organization (WHO) classification paradigms. The aim of this study was to determine the relative frequency of Korean cutaneous lymphoma according to the new WHO-EORTC classification system. METHODS: A total of 517 patients were recruited during a recent 5 year-period (2006-2010) from 21 institutes and classified according to the WHO-EORTC criteria. RESULTS: The patients included 298 males and 219 females, and the mean age at diagnosis was 49 years. The lesions preferentially affected the trunk area (40.2%). The most frequent subtypes in order of decreasing prevalence were mycosis fungoides (22.2%), peripheral T-cell lymphoma (17.2%), CD30+ T-cell lymphoproliferative disorder (13.7%), and extranodal natural killer/T (NK/T) cell lymphoma, nasal type (12.0%). Diffuse large B-cell lymphoma accounted for 11.2% of cases, half of which were secondary cutaneous involvement; other types of B-cell lymphoma accounted for less than 1% of cases. CONCLUSIONS: In comparison with data from Western countries, this study revealed relatively lower rates of mycosis fungoides and B-cell lymphoma in Korean patients, as well as higher rates of subcutaneous panniculitis-like T-cell lymphoma and NK/T cell lymphoma.
Academies and Institutes ; Classification* ; Diagnosis ; Female ; Humans ; Korea ; Lymphoma* ; Lymphoma, B-Cell ; Lymphoma, T-Cell ; Lymphoma, T-Cell, Peripheral ; Lymphoproliferative Disorders ; Male ; Mycosis Fungoides ; Prevalence ; T-Lymphocytes ; World Health Organization

The potential role of topical valproate (VPA) in hair regrowth has been recently suggested. However, safety reports of VPA as a topical formulation are lacking. Therefore, in the present study, we investigated whether VPA causes skin irritation in humans. We first performed a cell viability test and showed that VPA did not exhibit toxicity toward HaCaT keratinocytes, fibroblasts, and RBL-3H mast cells. We then performed clinical patch test and skin irritation test through transdermal drug delivery with the help of microneedle rollers. No significant findings were obtained in the clinical patch test. In the skin irritation test, only 1 patient showed erythema at 1 hr, but the irritation reaction faded away within a few hours. Erythema and edema were not observed at 24 hr. We concluded that VPA has minimal potential to elicit skin irritation. Therefore, we consider that VPA can safely be applied to human skin.
Cell Survival ; Edema ; Erythema ; Fibroblasts ; Hair ; Humans ; Keratinocytes ; Mast Cells ; Patch Tests ; Skin ; Valproic Acid