Background: Circulating tumor DNA (ctDNA) profiling from peripheral blood allows relatively noninvasive monitoring of solid tumors; however, its utility post-surgery or chemotherapy in colorectal cancer remains underexplored. We evaluated the clinical implications of a ctDNA next-generation sequencing (NGS) panel post-surgery or chemotherapy in patients with colorectal cancer. Methods: We collected samples from 23 patients with colorectal cancer (17 men, median age 65 yrs) at baseline and post-surgery or chemotherapy at the National Cancer Center, Korea, between January 2021 and September 2023. ctDNA was analyzed using an NGS panel including 46 genes, and variant allele frequencies (VAFs) were determined. Followup samples were analyzed using the NGS panel or droplet digital PCR (ddPCR) when probes were available. Clinical status was compared with ctDNA results, and survival was analyzed using a time-dependent Cox model. Results: Mutations were identified in 13 out of 14 patients (92.8%) with stage II/III cancer and in all nine patients (100%) with stage IV cancer. Mutations were detected in KRAS (N = 15, 65%), APC (N = 8, 35%), TP53 (N = 7, 30%), PIK3CA (N = 5, 22%), and RET (N = 4, 17%). A 1% increase in KRAS and TP53 VAFs was associated with 48% and 32% increased mortality risk, respectively. Changes in VAF correlated well with clinical findings. Conclusions The detection of and an increase in KRAS and TP53 VAFs were associated with poor prognosis. ddPCR-based ctDNA monitoring results were comparable to those obtained with the NGS panel. ctDNA monitoring during treatment is clinically informative in managing colorectal cancer.

Purpose: This study evaluates the viability of a new method that employs transperineal targeted biopsy with frozen section analysis immediately followed by robot-assisted radical prostatectomy (RARP), bypassing the traditional systematic biopsy deemed essential by current guidelines. Materials and Methods: Patient selection was based on the following inclusion criteria: those who underwent magnetic resonance imaging (MRI)-ultrasound fusion-targeted biopsy with frozen section analysis and concurrent RARP. Eligibility also required features indicative of Prostate Imaging-Reporting and Data System (PI-RADS) 5 lesion on multiparametric MRI, along with one of these additional criteria: (1) MRI evidence suggesting extracapsular extension (ECE) with a prostate-specific antigen (PSA) level >10 ng/mL, or (2) a PSA level > 20 ng/mL. Results: Twelve patients were enrolled in this study according to inclusion criteria. The median age (interquartile range) was 73.5 (69.5–75.3) years and PSA was 22.9 (17.0–29.9) ng/mL. Three patients had PI-RADS 5 lesions, and 9 had PI-RADS 5 lesions with findings of ECE. In all cases, the diagnosis based on frozen sections confirmed adenocarcinoma. Following confirmation, each patient underwent immediate RARP. According to the final pathology report, 2 patients had International Society of Urological Pathology (ISUP) grade 2 disease, 7 patients had ISUP grade 3, 1 had ISUP grade 4, and 2 had ISUP grade 5 disease. Four patients had stage pT2 disease, 3 had stage pT3a, and 5 had stage pT3b. The median immediate reporting time of the target biopsy frozen section was 20 (19.3–24.5) minutes. No perioperative complications related to target biopsy were observed. Conclusion For patients with a strong suspicion of prostate cancer and a PI-RADS 5 lesion, integrating simultaneous prostate frozen target biopsy with radical prostatectomy may offer a feasible treatment alternative, obviating the necessity for a preoperative systematic biopsy.

An implant-supported hybrid prosthesis is a fixed restoration composed of a metal framework and acrylic resin, offering advantages such as aesthetics, function, phonetics, and lip support, while providing retention and support through the splinting of implants with the metal framework. However, poor oral hygiene can lead to peri-implantitis, and long-term use may result in wear or fracture of the artificial teeth, causing reduced masticatory function and loss of vertical dimension. Traditionally, a new metal framework is cast for remanufacturing, but if the existing framework is intact, it can be reused for a more rapid and simplified protocol. This case involves a 58-year-old male patient with peri-implantitis, where some implants were removed and treated, and the superstructure was remanufactured using the existing metal framework. By preserving the existing metal framework during the remanufacturing of the implant-supported hybrid prosthesis, the treatment time and number of visits were reduced, minimizing patient discomfort.

Purpose: Recently, we developed allele-discriminating priming system (ADPS) technology. This method increases the sensitivity of conventional quantitative polymerase chain reaction up to 100 folds, with limit of detection, 0.01%, with reinforced specificity. This prospective study aimed to develop and validate the accuracy of ADPS epidermal growth factor receptor (EGFR) Mutation Test Kit using clinical specimens. Materials and Methods: In total 189 formalin-fixed paraffin-embedded tumor tissues resected from patients with non–small cell lung cancer were used to perform a comparative evaluation of the ADPS EGFR Mutation Test Kit versus the cobas EGFR Mutation Test v2, which is the current gold standard. When the two methods had inconsistent results, next-generation sequencing–based CancerSCAN was utilized as a referee. Results: The overall agreement of the two methods was 97.4% (93.9%-99.1%); the positive percent agreement, 95.0% (88.7%-98.4%); and the negative percent agreement, 100.0% (95.9%-100.0%). EGFR mutations were detected at a frequency of 50.3% using the ADPS EGFR Mutation Test Kit and 52.9% using the cobas EGFR Mutation Test v2. There were 10 discrepant mutation calls between the two methods. CancerSCAN reproduced eight ADPS results. In two cases, mutant allele fraction was ultra-low at 0.02% and 0.06%, which are significantly below the limit of detection of the cobas assay and CancerSCAN. Based on the EGFR genotyping by ADPS, the treatment options could be switched in five patients. Conclusion The highly sensitive and specific ADPS EGFR Mutation Test Kit would be useful in detecting the patients who have lung cancer with EGFR mutation, and can benefit from the EGFR targeted therapy.

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: An idiopathic outflow tract premature ventricular complex (OT-PVC) is a common arrhythmia, and the accuracy of site of origin prediction using the 12-lead electrocardiogram (ECG) algorithm is not high. There are no studies about a systematic strategy that can provide practical help to electrophysiologists in OT-PVC mapping and ablation. This study aims to evaluate the efficacy and safety of the proposed ablation protocol and establish an optimal catheter ablation strategy by simultaneously investigating and synthesizing various indicators observed during the mapping procedure. Methods: and designThis study (ABOUT-PVC) was designed as a prospective multicenter study to enroll 210 patients from 11 tertiary university hospitals over an estimated 27 months. Patients with idiopathic OT-PVC requiring catheter ablation will receive the procedure through a proposed ablation strategy and will be followed up for at least 12 months. The primary outcome is the acute procedural success rate. The secondary outcomes are clinical success rate, procedure time, complication rate, symptom relief, and changes in echocardiographic parameters. Conclusions The ABOUT-PVC study was designed to investigate the efficacy and safety of the proposed ablation strategy and establish an optimal catheter ablation strategy. We expect this study to overcome the limitations of the ECG prediction algorithms and provide a practical guide to electrophysiologists, increasing the procedure’s success rate and reducing complications and procedure time.

Background: Postpartum depression (PPD) can negatively affect infant well-being and child development. Although the frequency and risk factors of PPD symptoms might vary depending on the country and culture, there is limited research on these risk factors among Korean women. This study aimed to elucidate the potential risk factors of PPD throughout pregnancy to help improve PPD screening and prevention in Korean women. Methods: The pregnant women at 12 gestational weeks (GW) were enrolled from two obstetric specialized hospitals from March 2013 to November 2017. A questionnaire survey was administered at 12 GW, 24 GW, 36 GW, and 4 weeks postpartum. Depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale, and PPD was defined as a score of ≥ 10. Results: PPD was prevalent in 16.3% (410/2,512) of the participants. Depressive feeling at 12 GW and postpartum factors of stress, relationship with children, depressive feeling, fear, sadness, and neonatal intensive care unit admission of baby were significantly associated with a higher risk of PPD. Meanwhile, high postpartum quality of life and marital satisfaction at postpartum period were significantly associated with a lower risk of PPD. We developed a model for predicting PPD using factors as mentioned above and it had an area under the curve of 0.871. Conclusion Depressive feeling at 12 GW and postpartum stress, fear, sadness, relationship with children, low quality of life, and low marital satisfaction increased the risk of PPD. A risk model that comprises significant factors can effectively predict PPD and can be helpful for its prevention and appropriate treatment.

An implant-supported hybrid prosthesis is a fixed restoration composed of a metal framework and acrylic resin, offering advantages such as aesthetics, function, phonetics, and lip support, while providing retention and support through the splinting of implants with the metal framework. However, poor oral hygiene can lead to peri-implantitis, and long-term use may result in wear or fracture of the artificial teeth, causing reduced masticatory function and loss of vertical dimension. Traditionally, a new metal framework is cast for remanufacturing, but if the existing framework is intact, it can be reused for a more rapid and simplified protocol. This case involves a 58-year-old male patient with peri-implantitis, where some implants were removed and treated, and the superstructure was remanufactured using the existing metal framework. By preserving the existing metal framework during the remanufacturing of the implant-supported hybrid prosthesis, the treatment time and number of visits were reduced, minimizing patient discomfort.

Purpose: This study evaluates the viability of a new method that employs transperineal targeted biopsy with frozen section analysis immediately followed by robot-assisted radical prostatectomy (RARP), bypassing the traditional systematic biopsy deemed essential by current guidelines. Materials and Methods: Patient selection was based on the following inclusion criteria: those who underwent magnetic resonance imaging (MRI)-ultrasound fusion-targeted biopsy with frozen section analysis and concurrent RARP. Eligibility also required features indicative of Prostate Imaging-Reporting and Data System (PI-RADS) 5 lesion on multiparametric MRI, along with one of these additional criteria: (1) MRI evidence suggesting extracapsular extension (ECE) with a prostate-specific antigen (PSA) level >10 ng/mL, or (2) a PSA level > 20 ng/mL. Results: Twelve patients were enrolled in this study according to inclusion criteria. The median age (interquartile range) was 73.5 (69.5–75.3) years and PSA was 22.9 (17.0–29.9) ng/mL. Three patients had PI-RADS 5 lesions, and 9 had PI-RADS 5 lesions with findings of ECE. In all cases, the diagnosis based on frozen sections confirmed adenocarcinoma. Following confirmation, each patient underwent immediate RARP. According to the final pathology report, 2 patients had International Society of Urological Pathology (ISUP) grade 2 disease, 7 patients had ISUP grade 3, 1 had ISUP grade 4, and 2 had ISUP grade 5 disease. Four patients had stage pT2 disease, 3 had stage pT3a, and 5 had stage pT3b. The median immediate reporting time of the target biopsy frozen section was 20 (19.3–24.5) minutes. No perioperative complications related to target biopsy were observed. Conclusion For patients with a strong suspicion of prostate cancer and a PI-RADS 5 lesion, integrating simultaneous prostate frozen target biopsy with radical prostatectomy may offer a feasible treatment alternative, obviating the necessity for a preoperative systematic biopsy.

Purpose: Erectile dysfunction (ED) is considered a microvascular disorder and serves as an indicator for the potential development of cardiovascular disease (CVD). Although left ventricular diastolic dysfunction (LVDD) reflects early myocardial damage caused by microvascular disorders, the association between ED and LVDD remains poorly elucidated. Materials and Methods: A cross-sectional study was conducted on 123 patients with ED. They underwent RigiScan, and conventional echocardiography, and attempted International Index of Erectile Function (IIEF) questionnaire. ED severity was evaluated by measuring changes in the penile base circumference and duration of penile rigidity (≥70%) during erection. The early diastolic velocity of mitral inflow (E) and early diastolic velocity of the mitral annulus (e′) were measured using echocardiography. The patients were grouped based on the presence of CVD. Results: Among 123 patients, 29 had CVD and 94 did not. Patients with CVD exhibited more pronounced ED and more severe LVDD. Associations between increased penile circumference with echocardiographic parameters were more prominent in patients with CVD than in those without CVD (ΔTtop and e′ wave, r=0.508 and r=0.282, respectively, p for interaction=0.033; ΔTbase and E/e′ ratio, r=-0.338 and r=-0.293, respectively, p for interaction <0.001). In the multivariate linear regression, the increase of penile base circumference was an independent risk factor for LVDD (e′, B=0.503; E/e′ ratio, B=-1.416, respectively, p<0.001). Conclusions ED severity correlated well with LV diastolic dysfunction, particularly in the presence of CVD. This study highlighted the potential role of ED assessment as early indicator of CVD development.