Background/Aims: In Korea, changes in the prevalence of irritable bowel syndrome (IBS) after the Rome IV update have not been extensively studied.The aim of this study is to compare the prevalence and psychosocial risk factors of IBS according to Rome III and Rome IV criteria in medical and nursing students. Methods: From August 13, 2021 to October 22, 2021, participants were enrolled and surveyed online. The survey includes general and specific questions for disease diagnosis and regarding participants’ social and psychological characteristics using the 36-item short form survey, the Brief Encounter Psychosocial Instrument-Korean version, and the Hospital Anxiety and Depression Scale. Results: In total, 338 medical students and 102 nursing students completed the survey. IBS was diagnosed in 78 students (17.7%) using Rome III criteria and in 51 students (11.6%) using Rome IV criteria. Significant differences in physical functioning score and severity score were observed between patients diagnosed using Rome IV criteria and patients diagnosed using Rome III criteria. Multiple logistic regression revealed that severity score (adjusted odds ratio = 1.01; 95% confidence interval: 1.00-1.21; P = 0.022) is the only predictor of IBS that differentiates Rome IV criteria from Rome III criteria. Conclusions Even after updating the Rome IV diagnostic criteria, the prevalence of IBS in medical and nursing students in Korea remained high.Patients who met the Rome IV criteria had more severe symptoms and lower quality of life than patients who met the Rome III criteria.

Purpose: Unnecessary prostate biopsies for detecting prostate cancer (PCa) should be minimized. Therefore, this study developed a machine learning (ML) model to predict PCa in Korean men and evaluated its usability. Materials and Methods: We retrospectively analyzed clinical data from 928 patients who underwent prostate biopsies at Kangwon National University Hospital between May 2013 and May 2023. Of these, 377 (41.6%) were diagnosed with PCa, and 551 (59.4%) did not have cancer. For external validation, clinical data from 385 patients aged 48–89 years who underwent prostate biopsies from September 2005 to September 2023 at Wonju Severance Christian Hospital were also included. Twenty-two clinical features were used to develop an ML model to predict PCa. Features were selected based on their contributions to model performance, leading to the inclusion of 15 features. A meta-learner was constructed using logistic regression to predict the probability of PCa, and the classifier was trained and validated on randomly extracted training and test sets at an 8:2 ratio. Results: The prostate health index, prostate volume, age, nodule on digital rectal examination, and prostate-specific antigen were the top 5 features for predicting PCa. The area under the receiver operating characteristic curve (AUC) of the meta-learner logistic regression model was 0.89, and the accuracy, sensitivity, and specificity were 0.828, 0.711, and 0.909, respectively. Our model also showed excellent prediction performance for high-grade PCa, with a Gleason score of 7 or higher and an AUC of 0.903. Furthermore, we evaluated the performance of the model using external cohort clinical data and achieved an AUC of 0.863. Conclusions Our ML model excelled in predicting PCa, specifically clinically significant PCa. Although extensive cross-validation in other clinical cohorts is needed, this ML model is a promising option for future diagnostics.

Background/Aims: In Korea, changes in the prevalence of irritable bowel syndrome (IBS) after the Rome IV update have not been extensively studied.The aim of this study is to compare the prevalence and psychosocial risk factors of IBS according to Rome III and Rome IV criteria in medical and nursing students. Methods: From August 13, 2021 to October 22, 2021, participants were enrolled and surveyed online. The survey includes general and specific questions for disease diagnosis and regarding participants’ social and psychological characteristics using the 36-item short form survey, the Brief Encounter Psychosocial Instrument-Korean version, and the Hospital Anxiety and Depression Scale. Results: In total, 338 medical students and 102 nursing students completed the survey. IBS was diagnosed in 78 students (17.7%) using Rome III criteria and in 51 students (11.6%) using Rome IV criteria. Significant differences in physical functioning score and severity score were observed between patients diagnosed using Rome IV criteria and patients diagnosed using Rome III criteria. Multiple logistic regression revealed that severity score (adjusted odds ratio = 1.01; 95% confidence interval: 1.00-1.21; P = 0.022) is the only predictor of IBS that differentiates Rome IV criteria from Rome III criteria. Conclusions Even after updating the Rome IV diagnostic criteria, the prevalence of IBS in medical and nursing students in Korea remained high.Patients who met the Rome IV criteria had more severe symptoms and lower quality of life than patients who met the Rome III criteria.

Purpose: Unnecessary prostate biopsies for detecting prostate cancer (PCa) should be minimized. Therefore, this study developed a machine learning (ML) model to predict PCa in Korean men and evaluated its usability. Materials and Methods: We retrospectively analyzed clinical data from 928 patients who underwent prostate biopsies at Kangwon National University Hospital between May 2013 and May 2023. Of these, 377 (41.6%) were diagnosed with PCa, and 551 (59.4%) did not have cancer. For external validation, clinical data from 385 patients aged 48–89 years who underwent prostate biopsies from September 2005 to September 2023 at Wonju Severance Christian Hospital were also included. Twenty-two clinical features were used to develop an ML model to predict PCa. Features were selected based on their contributions to model performance, leading to the inclusion of 15 features. A meta-learner was constructed using logistic regression to predict the probability of PCa, and the classifier was trained and validated on randomly extracted training and test sets at an 8:2 ratio. Results: The prostate health index, prostate volume, age, nodule on digital rectal examination, and prostate-specific antigen were the top 5 features for predicting PCa. The area under the receiver operating characteristic curve (AUC) of the meta-learner logistic regression model was 0.89, and the accuracy, sensitivity, and specificity were 0.828, 0.711, and 0.909, respectively. Our model also showed excellent prediction performance for high-grade PCa, with a Gleason score of 7 or higher and an AUC of 0.903. Furthermore, we evaluated the performance of the model using external cohort clinical data and achieved an AUC of 0.863. Conclusions Our ML model excelled in predicting PCa, specifically clinically significant PCa. Although extensive cross-validation in other clinical cohorts is needed, this ML model is a promising option for future diagnostics.

Background/Aims: In Korea, changes in the prevalence of irritable bowel syndrome (IBS) after the Rome IV update have not been extensively studied.The aim of this study is to compare the prevalence and psychosocial risk factors of IBS according to Rome III and Rome IV criteria in medical and nursing students. Methods: From August 13, 2021 to October 22, 2021, participants were enrolled and surveyed online. The survey includes general and specific questions for disease diagnosis and regarding participants’ social and psychological characteristics using the 36-item short form survey, the Brief Encounter Psychosocial Instrument-Korean version, and the Hospital Anxiety and Depression Scale. Results: In total, 338 medical students and 102 nursing students completed the survey. IBS was diagnosed in 78 students (17.7%) using Rome III criteria and in 51 students (11.6%) using Rome IV criteria. Significant differences in physical functioning score and severity score were observed between patients diagnosed using Rome IV criteria and patients diagnosed using Rome III criteria. Multiple logistic regression revealed that severity score (adjusted odds ratio = 1.01; 95% confidence interval: 1.00-1.21; P = 0.022) is the only predictor of IBS that differentiates Rome IV criteria from Rome III criteria. Conclusions Even after updating the Rome IV diagnostic criteria, the prevalence of IBS in medical and nursing students in Korea remained high.Patients who met the Rome IV criteria had more severe symptoms and lower quality of life than patients who met the Rome III criteria.

Purpose: Unnecessary prostate biopsies for detecting prostate cancer (PCa) should be minimized. Therefore, this study developed a machine learning (ML) model to predict PCa in Korean men and evaluated its usability. Materials and Methods: We retrospectively analyzed clinical data from 928 patients who underwent prostate biopsies at Kangwon National University Hospital between May 2013 and May 2023. Of these, 377 (41.6%) were diagnosed with PCa, and 551 (59.4%) did not have cancer. For external validation, clinical data from 385 patients aged 48–89 years who underwent prostate biopsies from September 2005 to September 2023 at Wonju Severance Christian Hospital were also included. Twenty-two clinical features were used to develop an ML model to predict PCa. Features were selected based on their contributions to model performance, leading to the inclusion of 15 features. A meta-learner was constructed using logistic regression to predict the probability of PCa, and the classifier was trained and validated on randomly extracted training and test sets at an 8:2 ratio. Results: The prostate health index, prostate volume, age, nodule on digital rectal examination, and prostate-specific antigen were the top 5 features for predicting PCa. The area under the receiver operating characteristic curve (AUC) of the meta-learner logistic regression model was 0.89, and the accuracy, sensitivity, and specificity were 0.828, 0.711, and 0.909, respectively. Our model also showed excellent prediction performance for high-grade PCa, with a Gleason score of 7 or higher and an AUC of 0.903. Furthermore, we evaluated the performance of the model using external cohort clinical data and achieved an AUC of 0.863. Conclusions Our ML model excelled in predicting PCa, specifically clinically significant PCa. Although extensive cross-validation in other clinical cohorts is needed, this ML model is a promising option for future diagnostics.

Background: Charcot-Marie-Tooth disease type 1A (CMT1A) is caused by duplication of the 17p12 region including PMP22 gene. In CMT1A patients, anticipation showing increased severity by generations has been reported in the CMT1A patients. It has also been reported that severity increases in the non-de novo cases than in the de novo cases. This study was performed to examine epigenetic differences between CMT1A cases and controls as well as between de novo cases and non-de novo cases. Methods: This study examined 40 Korean CMT1A patients and 11 controls. Methylation level was determined using the SureSelect XT Methyl-Seq reagent kit and bisulfite sequence mapping program. Results: Many differentially methylated CpG sites (DMCs) were identified in the comparisonbetween cases and controls and between de novo cases and non-de novo cases. Most DMCs were located within or nearby genes related to the nervous system, mental stress, and motor ability. Conclusions This study is the first epigenetic study to uncover the mechanism of clinical heterogeneity among CMT1A patients. We suggest that weak severity in the de novo cases than the non-de novo cases may be related to the epigenomic differences in the nerve and stress-related genes.

Purpose: To present a case of sinonasal neuroendocrine cancer initially manifesting with orbital involvement.Case summary: A 63-year-old female patient visited a neuro-ophthalmologic clinic due to a 3-week history of decreased visual acuity (VA), color vision abnormalities, and swelling of the upper eyelid in right eye. Best-corrected VA (BCVA) in the right eye was 0.8. Clinical findings included a relative afferent pupillary defect, restricted eye movement in lateral, superior, and medial gaze, and exophthalmos in the right eye. Wide-field fundus photography and optical coherence tomography indicated swelling of right optic disc. Magnetic resonance imaging was performed revealing a mass invading nasal cavity, sinus, and right orbital apex, and compressing the medial rectus, inferior rectus, superior oblique, and optic nerve. An otolaryngological nasal biopsy was conducted and immunohistochemical staining showed positive results for Ki-67, NSE, p16, P-53, and CD56, leading to a diagnosis of small cell neuroendocrine carcinoma with an irreducible tumor stage. Prior to initiation of treatment (concurrent chemoradiotherapy, CCRT), there was rapid worsening of VA and eye movement in the right eye. CCRT commenced alongside high-dose steroid treatment. One month following treatment, the BCVA of the right eye improved and protrusion of the right eye resolved. Six months after starting CCRT, a contrast-enhanced orbital computed tomography scan showed no residual lesion. The BCVA of the right eye stabilized at 0.3 with complete recovery of color vision and eye movement. Conclusions Neuroendocrine cancer should be considered as a possible diagnosis in cases of rapidly progressing compressive optic neuropathy.

Background: Although the primary vaccine coverage rate for coronavirus disease 2019 (COVID-19) in South Korea has exceeded 80%, the coronavirus continues to spread, with reports of a rapid decline in vaccine effectiveness. South Korea is administering booster shots despite concerns about the effectiveness of the existing vaccine. Methods: Neutralizing antibody inhibition scores were evaluated in two cohorts after the booster dose. For the first cohort, neutralizing activity against the wild-type, delta, and omicron variants after the booster dose was evaluated. For the second cohort, we assessed the difference in neutralizing activity between the omicron infected and uninfected groups after booster vaccination. We also compared the effectiveness and adverse events (AEs) between homologous and heterologous booster doses for BNT162b2 or ChAdOx1 vaccines. Results: A total of 105 healthcare workers (HCWs) that were additionally vaccinated with BNT162b2 at Soonchunhyang University Bucheon Hospital were enrolled in this study.Significantly higher surrogate virus neutralization test (sVNT) inhibition (%) was observed for the wild-type and delta variants compared to sVNT (%) for the omicron after the booster dose (97%, 98% vs. 75%; P < 0.001). No significant difference in the neutralizing antibody inhibition score was found between variants in the BNT/BNT/BNT group (n = 48) and the ChA/ChA/BNT group (n = 57). Total AEs were not significantly different between the ChA/ ChA/BNT group (85.96%) and the BNT/BNT group (95.83%; P = 0.11). In the second cohort with 58 HCWs, markedly higher sVNT inhibition to omicron was observed in the omicroninfected group (95.13%) compared to the uninfected group (mean of 48.44%; P < 0.001) after four months of the booster dose. In 41 HCWs (39.0%) infected with the omicron variant, no difference in immunogenicity, AEs, or effectiveness between homogeneous and heterogeneous boosters was observed. Conclusion Booster vaccination with BNT162b2 was significantly less effective for the neutralizing antibody responses to omicron variant compared to the wild-type or delta variant in healthy population. Humoral immunogenicity was sustained significantly high after 4 months of booster vaccine in the infected population after booster vaccination.Further studies are needed to understand the characteristics of immunogenicity in these populations.

Purpose: Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation–positive non–small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation–positive non–small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea. Materials and Methods: Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints. Results: A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects. Conclusion Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation–positive in Korean patients with no new safety signals.