In recent years, next-generation sequencing (NGS)–based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

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.

Background/Aims: Tegoprazan is a novel potassium-competitive acid blocker that has beneficial effects on acid-related disorders such as gastroesophageal reflux and peptic ulcer diseases.This study aimed to validate the effect of tegoprazan on endoscopic submucosal dissection (ESD)-induced artificial ulcers. Methods: Patients from 16 centers in Korea who underwent ESD for gastric neoplasia were enrolled. After ESD, pantoprazole was administered intravenously for 48 hours. The patients were randomly allocated to either the tegoprazan or esomeprazole group. Tegoprazan 50 mg or esomeprazole 40 mg were administered for 4 weeks, after which gastroscopic evaluation was performed. If the artificial ulcer had not healed, the same dose of tegoprazan or esomeprazole was administered for an additional 4 weeks, and a gastroscopic evaluation was performed. Results: One hundred sixty patients were enrolled in this study. The healing rates of artificial ulcers at 4 weeks were 30.3% (23/76) and 22.1% (15/68) in the tegoprazan and esomeprazole groups, respectively (p=0.006). At 8 weeks after ESD, the cumulative ulcer healing rates were 73.7% (56/76) and 77.9% (53/68) in the tegoprazan and esomeprazole groups, respectively (p=0.210). Delayed bleeding occurred in two patients in the tegoprazan group (2.6%) and in one patient in the esomeprazole group (1.5%). Other adverse events were negligible in both groups. Conclusions Tegoprazan showed similar effects on post-ESD artificial ulcer healing in comparison with esomeprazole.

In recent years, next-generation sequencing (NGS)–based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

Human Q fever, a zoonosis caused by Coxiella burnetii, presents with diverse clinical manifestations ranging from mild self-limited febrile illnesses to life-threatening complications such as endocarditis or vascular infection. Although acute Q fever is a benign illness with a low mortality rate, a large-scale outbreak of Q fever in the Netherlands led to concerns about the possibility of blood transfusion-related transmission or obstetric complications in pregnant women. Furthermore, a small minority (< 5%) of patients with asymptomatic or symptomatic infection progress to chronic Q fever. Chronic Q fever is fatal in 5–50% of patients if left untreated. In South Korea, Q fever in humans was designated as a notifiable infectious disease in 2006, and the number of Q fever cases has increased sharply since 2015. Nonetheless, it is still considered a neglected and under-recognized infectious disease. In this review, recent trends of human and animal Q fever in South Korea, and public health concerns regarding Q fever outbreaks are reviewed, and we consider how a One Health approach could be applied as a preventive measure to prepare for zoonotic Q fever outbreaks.

Mucosal environments harbour lymphocytes, which express several adhesion molecules, including intestinal homing receptors and integrin αE/β7 (CD103). CD103 binds E-cadherin, an integrin receptor expressed in intestinal endothelial cells. Its expression not only enables homing or retention of T lymphocytes at these sites but is also associated with increased T lymphocyte activation. However, it is not yet clear how CD103 expression is related to the clinical staging of breast cancer, which is determined by factors such as the size of the tumor (T), the involvement of nearby lymph nodes (N), and presence of metastasis (M). We examined the prognostic significance of CD103 by FACS in 53 breast cancer patients and 46 healthy controls enrolled, and investigated its expression, which contributes to lymphocyte recruitment in tumor tissue. Patients with breast cancer showed increased frequencies of CD103+ , CD4+ CD103+ , and CD8+ CD103+ cells compared to controls. CD103 was expressed at a high level on the surfaces of tumor-infiltrating lymphocytes in patients with breast cancer. Its expression in peripheral blood was not correlated with clinical TNM stage. To determine the localisation of CD103+ cells in breast tissue, tissue sections of breast tumors were stained for CD103. In tissue sections of breast tumors stained for CD103, its expression in T lymphocytes was higher compared to normal breast tissue. In addition, CD103+ cells expressed higher levels of receptors for inflammatory chemokines, compared to CD103 − cells. CD103+ cells in peripheral blood and tumor tissue might be an important source of tumor-infiltrating lymphocyte trafficking, homing, and retention in cancer patients.

Liquid biopsy for detection of mutation from circulating tumor DNA is a new technology which is attractive in that it is non-invasive. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) is an effective first line drug for advanced non-small cell lung cancer patients who harbor activating EGFR mutation. During the course of treatment, resistance against TKI arises which can be contributed to EGFR T790M mutation in about 50–60% of patients. Third generation TKI may overcome the resistance. In patients who cannot undergo tissue biopsy due to variable reasons, liquid biopsy is an excellent alternative for the detection of EGFR T790M mutation. However, this relatively novel method requires standardization and vigorous quality insurance. Thus, a standard set of guideline recommendations for liquid biopsy for EGFR mutation testing suitable for the Korean medical community is necessary. In this article, we propose a set of provisional guideline recommendations that was discussed and approved by the Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists.
Biopsy ; Carcinoma, Non-Small-Cell Lung ; DNA ; Genes, erbB-1 ; Humans ; Insurance ; Lung Neoplasms ; Lung ; Methods ; Pathology ; Protein-Tyrosine Kinases ; Receptor, Epidermal Growth Factor

BACKGROUND: The shortage of human hearts for allotransplantation makes xenotransplantation a possible option for controllable organ providers. To detect acute xenograft rejection, invasive biopsy seems inevitable; however, this occasionally results in poor incision wound healing or infection. To date, no method of noninvasive imaging for early detection of xenograft rejection has been established. We hypothesized that ultrasound speckle tracking would better detect xenograft failure than routine left ventricular ejection fractions (EF). METHODS: From August 2013 to July 2015, a total of six cardiac heterotopic xenotransplants (α 1, 3-galactosyltransferase gene-knockout porcine heart) into cynomolgus monkeys were monitored with echocardiography every 3 to 7 days. M-mode and two-dimensional (2D)-EF measurements and myocardial strain analyses were performed. Cardiac xenograft pathology was reviewed from the immediate postoperative biopsy, as well as the necropsy. RESULTS: Myocardial speckle tracking analysis was feasible in all six cases. The longest survival was 43 days. Only one pathology-proven immunologic rejection occurred. Cardiac xenograft failure appeared as two types: a dilated pattern with decreased EF or a myocardial-thickening pattern with preserved EF. Both antibody-mediated rejection (n=1) and sepsis-induced myocardial dysfunction (n=2) revealed decreased radial or circumferential strains, but normal-range EF. Xenograft functional decline was significant with respect to radial or circumferential strain (P=0.028), but not to conventional M-mode or 2D-EFs (P=0.600, P=0.340, respectively). CONCLUSIONS: Radial and circumferential strains were significantly decreased in both types of xenograft failure, regardless of EF. Further studies are warranted to correlate the strain analysis and immunopathological details.
Biopsy ; Echocardiography ; Heart ; Heart Transplantation ; Heterografts ; Humans ; Macaca fascicularis ; Methods ; Pathology ; Stroke Volume ; Transplantation, Heterologous* ; Transplants* ; Ultrasonography ; Wound Healing

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

Central venous catheterization is frequently performed for perioperative management and intravenous access. However, the complications of central venous catheterization are numerous and include malposition, pneumothorax, hemothorax, chylothorax, thrombosis, extravasation of the infusate and infection. Although the malpositioning of the central venous catheter has been widely reported, there are few reports of ipsilateral subclavian vein catheterization via the right internal jugular venous route. In this case, we describe a misplacement of a right internal venous catheterization into the ipsilateral subclavian vein and suggest the possible causative factors.
Catheterization ; Catheterization, Central Venous ; Catheters ; Central Venous Catheters ; Chylothorax ; Hemothorax ; Pneumothorax ; Subclavian Vein ; Thrombosis