Purpose: Based on the KEYNOTE-522 study, neoadjuvant pembrolizumab plus chemotherapy has become the standard treatment for early-stage triple-negative breast cancer (TNBC).This study evaluated the real-world efficacy, safety, and predictors of pathologic complete response (pCR) in Korean patients. Methods: We conducted a retrospective cohort study of 174 patients with early-stage TNBC who received the KEYNOTE-522 regimen (neoadjuvant pembrolizumab plus paclitaxel and carboplatin, followed by doxorubicin and cyclophosphamide) at a tertiary cancer center between August 2022 and July 2024. We assessed the primary endpoints, including pCR rate and event-free survival (EFS). We performed univariable and multivariable logistic regression analyses to identify independent predictors of pCR. Results: The median patient age was 50 years (range, 24–74 years). The clinical stages were II and III in 79.3% and 20.1% of patients, respectively, and 10.9% had clinical N3 disease. The overall pCR rate was 62.1%, and the N3 subgroup had a pCR rate of 47.4%. On multivariable analysis, high baseline Ki-67 expression (≥ median, 75%) was significantly associated with pCR (odds ratio, 2.84; 95% confidence interval, 1.45 to 5.66; p = 0.002). At a median followup of 18.4 months, the 12-month EFS rate was 97.4%, with significantly superior outcomes observed in patients who achieved pCR compared with those who did not achieve pCR (100% vs. 93.1%, p = 0.007). The treatment completion rate was 92.0%, and immune-related adverse events occurred in 13.8% of patients. Conclusion In this real-world analysis of one of the largest Asian cohorts of patients with earlystage TNBC treated with neoadjuvant pembrolizumab, the KEYNOTE-522 regimen demonstrated substantial efficacy and manageable toxicity, consistent with the original trial findings.

Purpose: This study aimed to develop pilot clinical skills assessment (CSA) modules for Korean medicine-specific procedures and to examine their preliminary appropriateness, perceived necessity, and feasibility as a foundation for future licensing-related assessment development. Methods: A participatory action research framework, supplemented by qualitative interviews, was used to develop 4 CSA modules—acupuncture, Chuna manual therapy, pulse diagnosis, and constitutional diagnosis—in collaboration with expert evaluators, students, and standardized patients. The modules were implemented as formative examinations for third-year Korean medicine students, after which semi-structured interviews were conducted to obtain feedback on module content, implementation processes, and scoring procedures. Each module was also reviewed using the RUMBA checklist (Realistic, Understandable, Measurable, Behavioral, and Achievable), together with ratings of perceived necessity and feasibility for possible future use in licensing-related assessment. Interview data were analyzed inductively at the level of individual responses and then compared across modules and participant groups. Results: Qualitative analysis yielded 3 themes: content and scoring criteria, physical environment or simulators, and education or training. Participants emphasized the need to make key aspects of performance more observable, improve authenticity through simulators or task trainers, and strengthen the capacity of scoring systems to distinguish between levels of student performance. Across all modules, mean RUMBA scores were high in the understandable, behavioral, and achievable domains, whereas measurability was more problematic, especially for pulse diagnosis. Conclusion These pilot findings clarify both the strengths and the limitations of Korean medicine-specific CSA modules. The modules received favorable ratings for understandability and achievability, whereas lower ratings for measurability and realism identified priorities for refinement before wider use. This study provides preliminary guidance for the continued development and broader evaluation of Korean medicine-specific performance assessments.

Purpose: This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control. Methods: We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR. Results: Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37). Conclusion Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Background: A novel botulinum toxin type A (Protoxin; Protox Inc.) has been developed. Objective: To evaluate the efficacy and safety of the newly developed Protoxin compared to the approved drug onabotulinumtoxinA (OBoNT) in moderate to severe glabellar lines. Methods: Adults with a glabellar line Facial Wrinkle Scale (FWS) score of 2 (moderate) or 3 (severe) were enrolled in the study. Subjects were randomized in a 1:1 ratio to receive either Protoxin or OBoNT. A total of 20 units of botulinum toxin was injected at five sites in the glabellar region (4 units at each site). FWS scores were assessed at baseline and at weeks 4, 8, 12, and 16 post-injection. The primary endpoint was the proportion of subjects at week 4 who had a reduction of 2 or more points in FWS and a final score of 0 (none) or 1 (mild). Results: A total of 274 subjects were randomized, of whom 78.1% were female. At week 4 post-treatment, the improvement rate of glabellar lines was 62.22% in the Protoxin group and 62.96% in the OBoNT group. The lower limit of the two-sided 95% confidence interval (−12.24%) exceeded the −15% margin, confirming the non-inferiority of the new drug. Safety profiles were comparable between the two groups. Conclusion Protoxin demonstrated efficacy and safety profiles comparable to those of OBoNT in the treatment of moderate to severe glabellar lines.

The gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the gastrointestinal tract. Between the 1990s and early 2000s, GIST was identified as a tumor characterized by KIT or PDGFRA mutations, resulting in imatinib being established as an effective targeted therapy. However, with advances in molecular diagnostics, approximately 10%–15% of GISTs have been reported to harbor alternative mutations, such as those in the succinate dehydrogenase subunit genes and BRAF, leading to the development of additional targeted therapies. GISTs exhibit a wide spectrum of clinical behaviors, ranging from indolent to highly aggressive, prompting the development of diverse risk classification systems. However, multiple systems remain in use, leading to inconsistent pathologic reports. Moreover, the mitotic counting method—a key factor in risk stratification—has become a major source of confusion among pathologists owing to the adoption of digital pathology and discrepancies between updated international guidelines and outdated reimbursement requirements. These inconsistencies have hindered pathologic reporting and communication between pathologists and clinicians. This review comprehensively overviews the historical background, molecular subtypes, and risk classification systems of GIST, focusing on evolving issues in mitotic rate evaluation and the application of risk classification systems in clinical practice.

Purpose: We aimed to compare broad-spectrum antibiotic use between hospice and nonhospice patients with cancer at the end of life using nationwide data from Korea. Methods: In this retrospective cohort study, we analyzed the Korean National Health Insurance Service data of adult patients with cancer who died between 2018 and 2021. Hospice users were defined as patients who received inpatient, home-based, or consultation-based hospice care before death. We applied propensity score matching (1:2) to balance the baseline characteristics of the hospice and non-hospice groups. Broad-spectrum antibiotic use, including anti-pseudomonal penicillins, anti-pseudomonal cephalosporins, carbapenems, and glycopeptides, was assessed during the last 3 months of life using prescription proportions and days of therapy per 1,000 patient-days. Results: After matching, 38,102 hospice and 75,736 non-hospice users were analyzed. During the last 3 months of life, 74.6% of hospiceand 79.0% of non-hospice users received at least one broad-spectrum antibiotic (P＜0.001).The proportion of patients receiving broad-spectrum antibiotics was generally lower amonghospice users across all time intervals (P＜0.001), and the number of days of therapy wasalso lower, with the largest differences observed during the final week and last 3 days of life.Subgroup analyses showed the highest antibiotic exposure among patients with hematologic and pancreatobiliary cancers, particularly in the non-hospice group. Conclusion Hospice involvement was associated with lower use and reduced exposure to broad-spectrum antibiotics among patients with cancer near the end of life. These findings support the alignment of end-of-life treatment decisions with the comfort-oriented goals of hospice care.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

BACKGROUND/OBJECTIVES: The illustrated Healthy Eating Practice Questionnaire (HEPQ) was previously developed to assess food preferences, eating behaviors, hand/oral hygiene practices, and nutrition knowledge among Korean preschool children. Nevertheless, the lack of an integrated scoring system has limited its interpretability. This study developed a scoring system and a web-based platform with tailored feedback using a child-parent dyad approach. SUBJECTS/METHODS: The development process consisted of 5 phases: 1) questionnaire preparation for online use, 2) formulation of the scoring system, 3) determination of the cut-off values for three levels of healthy eating practices based on a child-parent survey, 4) technical development of the online platform, and 5) usability evaluation. A scoring system was established by standardizing the domain scores to a 100-point scale. One hundred child– parent pairs participated in the survey to calculate the Healthy Eating Practice Score (HEPS) and determine cut-off values for the HEPS levels. The validity of the cut-off values was examined by a comparison with the Nutrition Quotient for Preschoolers (NQ-P). A web-based platform was developed, and 47 child–parent pairs were used to assess its usability. RESULTS: Significant positive correlations were observed between child and parent HEPS across all domains. The HEPS-based classification showed good discriminative ability because higher HEPS levels were consistently associated with higher NQ-P scores in children and parents. The web-based HEPQ was easy to use and understand, and almost all participants (97.9% of children and 93.6% of parents) reported no difficulties using the platform. CONCLUSION The web-based HEPQ platform with an integrated scoring system provides a valid, user-friendly tool for assessing and interpreting healthy eating practices in preschool children. This platform supports parental engagement in children’s healthy eating practices and provides a practical tool for evaluating the effectiveness of nutrition education in early childcare settings.

Purpose: Previous studies from mostly Western populations have suggested possible associations between obesity and melanoma risk. This study aimed to investigate associations between obesity status and melanoma using a nationwide cohort of Koreans. Materials and Methods: A total of 4,441,403 adults who received a national health examination in 2012 were included from the Korean National Health Insurance Service database, and followed until December 31, 2022. Obesity status was defined based on the body mass index at the baseline health examination. Cox proportional hazards analyses were performed to evaluate associations between obesity status and incident melanoma, with adjustment for confounders. Stratified analyses were performed by sex and menopausal status (in women). Results: Overall, melanoma risk increased according to obesity status (p for trend=0.024); adjusted hazard ratios (95% confidence intervals) for melanoma risk were 0.766 (0.438–1.340) in underweight; 1.292 (1.072–1.557) in overweight; 1.202 (1.002–1.442) in obesity; and 1.191 (0.798–1.778) in severe obesity compared to normal weight (reference). In stratified analyses, similar trends to those of the overall study population were observed among men and premenopausal women (p for trend=0.052 in men and 0.036 in premenopausal women). Among premenopausal women, the risk of melanoma increased linearly with obesity status. Meanwhile, among postmenopausal women, melanoma risk showed no significant difference or trend according to obesity status. Conclusion Overweight and obesity were associated with increased risk of melanoma in a population-based cohort of Koreans. Obese individuals, especially men and premenopausal women, may require more thorough prevention and screening strategies for melanoma.