Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Background and Objectives: The aim of this study was to examine the clinical characteristics and prognosis of chronic rhinosinusitis with nasal polyps (CRSwNP) following endoscopic sinus surgery (ESS), focusing on distinct histological endotypes characterized by eosinophil and neutrophil infiltration.Subjects and Method A total of 207 patients diagnosed with CRSwNP who underwent ESS between August 2014 and September 2018 were included in the study. Patients were categorized into different groups based on eosinophil and neutrophil counts in the tissues. The demographic data, Lund-Mackay score, Lund-Kennedy (L-K) endoscopic score, Sino-Nasal Outcome Test-22 and Kaplan-Meier estimation were analyzed according to different histologic endotypes. Results: The histologic types were divided into four groups: the eosinophilic polyp (EP)+ neutrophlic polyp (NP) group, the EP group, the NP group, and the nonEP+nonNP group. Among the groups, the highest level of inflammation (L-K score, p<0.05) was observed in the EP+NP group, and the worst prognosis was observed in the EP+NP group according to the results of the Kaplan-Meier analysis (p<0.001). Conclusion Compared to non-neutrophil-infiltration polyps, neutrophil infiltration was associated with worse outcome when it was accompanied with eosinophilic infiltration. This discovery underlines how crucial it is to take neutrophils in nasal polyps into account in order to better understand their clinical behavior and maybe design customized treatments for better patient outcomes.

Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for 12 weeks in HCV-infected Korean adults. Methods: This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir–velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir–velpatasvir–voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment. Results: Of 53 participants receiving sofosbuvir–velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir–velpatasvir–voxilaprevir achieved SVR 12. Overall, sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported. Conclusions: Treatment with sofosbuvir–velpatasvir or sofosbuvir–velpatasvir–voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.

Objective: Lower extremity lymphedema (LEL) is a well-known adverse effect related to cervical and endometrial cancer (CEC); however, very few studies have elucidated the clinicopathologic risk factors related to LEL. We investigated the incidence and risk factors in patients who received primary surgery and/or adjuvant radiotherapy (RT) or chemotherapy for CEC. Methods: We retrospectively reviewed 2,565 patients who underwent primary surgery following CEC diagnosis between January 2007 and December 2020. LEL diagnosis was based on objective and subjective assessments by experts. We identified important predictors of LEL to construct a nomogram predicting individual risks of LEL. For internal validation of the nomogram, the original data were separated using the split-sample method in a 7:3 ratio of training data and test data. Results: Overall, 858 patients (33.5%) received RT, 586 received external beam RT (EBRT), and 630 received intracavitary RT. During follow-up period, LEL developed in 331 patients, with an overall cumulative 5-year incidence of 13.3%. In multivariate analysis, age at primary treatment, use of docetaxel-based chemotherapy, type of hysterectomy, type of surgical pelvic lymph node (LN) assessment, number of dissected pelvic and para-aortic LNs, and EBRT field were the independent predictors of LEL. We subsequently developed the nomogram showing excellent predictive power for LEL. Conclusion LEL is associated with various treatment modalities, and their interactions may increase the possibility of occurrences. De-escalation strategies for treatment modalities should be considered to reduce LEL in patients with CEC.

Several medications are approved to treat coronavirus disease 2019 (COVID-19) in Korea including nirmatrelvir/ritonavir, remdesivir, and regdanvimab. There is potential drug-drug interaction between antiepileptic drugs (AEDs) and the medications used to treat COVID-19. Several AEDs such as phenytoin, carbamazepine, phenobarbital, and primidone are strong cytochrome P450 inducers and can inhibit the drugs used for COVID-19. Particularly, these drugs are contraindicated with nirmatrelvir/ritonavir (Paxlovid®). There is a weaker drug-drug interaction between the AEDs and remdesivir. No significant interaction has been reported between the AEDs and molnupiravir. Pharmacokinetic interactions of the AEDs are important in effective management of COVID-19 in patients with epilepsy.

Purpose: Use of cyclin-dependent kinase 4/6 inhibitors improved survival outcome of hormone receptor (HR) positive metastatic breast cancer (MBC) patients, including Asian population. However, Asian real-world data of palbociclib is limited. We analyzed the real-world clinical practice patterns and outcome in HR-positive, MBC Asian patients treated with palbociclib. Materials and Methods: Between April 2017 to November 2019, 169 HR-positive, human epidermal growth factor-2–negative MBC patients treated with letrozole or fulvestrant plus palbocilib were enrolled from eight institutions. Survival outcome (progression-free survival [PFS]), treatment response and toxicity profiles were analyzed. Results: Median age of letrozole plus palbociclib (145 patients, 85.8%) and fulvestrant plus palbociclib (24 patients, 14.2%) was 58 and 53.5 years, with median follow-up duration of 14.63 months (range 0.2 to 33.9 months). Median PFS (mPFS) of letrozole plus palbociclib and fulvestrant plus palbociclib was 25.6 (95% confidence interval [CI], 19.1 to not reached) and 6.37 months (95% CI, 5.33 to not reached), comparable to previous phase 3 trials. In letrozole plus palbociclib arm, luminal A (hazard ratio, 2.86; 95% CI, 1.20 to 6.80; p=0.017) and patients with good performance (Eastern Cooperative Oncology Group 0-1 [hazard ratio, 3.68; 95% CI, 1.70 to 7.96]) showed better mPFS. In fulvestrant plus palbociclib group, chemotherapy naïve patients showed better mPFS (hazard ratio, 12.51, 95% CI, 1.59 to 99.17; p=0.017). The most common grade 3 or 4 adverse event was neutropenia (letrozole 86.3%, fulvestrant 88.3%). Conclusion To our knowledge, this is the first real-world data of palbociclib reported in Asia. Palbociclib showed comparable benefit to previous phase 3 trials in Asian patients during daily clinical practice.

Objective: To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura. Materials and Methods: Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed.Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT). Results: At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI. Conclusion The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.

Objective: To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura. Materials and Methods: Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed.Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT). Results: At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI. Conclusion The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.