1.A Real-World Efficacy and Safety of KEYNOTE-522 Regimen in Patients With Early Triple-Negative Breast Cancer
Shinyoung LEE ; Hyehyun JEONG ; Yeokyeong SHIN ; Jae Ho JEONG ; Kyung Hae JUNG ; Sung-Bae KIM ; Byung-Kwan JEONG ; Hee Jin LEE ; Gyungyub GONG ; Hee Jung SHIN ; Hye Joung EOM ; Young-Jin LEE ; Tae-Kyung YOO ; Sae Byul LEE ; Jisun KIM ; Il-Yong CHUNG ; Beom-Seok KO ; Hee Jeong KIM ; Jong Won LEE ; Byung Ho SON ; Jin-Hee AHN
Journal of Breast Cancer 2026;29(2):141-153
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.
2.Natural History of Gastric Subepithelial Lesions Measuring 1 to 2 cm
Younghee CHOE ; Byung-Wook KIM ; Soo-Young NA ; Joon Sung KIM
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2026;26(1):79-84
Objectives:
Management strategies for subepithelial lesions (SELs) measuring 1–2 cm remain undefined in most guidelines due to limited data. We aimed to establish a practical clinical approach by analyzing the long-term outcomes of SELs in this size range.
Methods:
We retrospectively reviewed cases of gastric SELs measuring 1–2 cm between 2011 and 2023. We reviewed esophagogastroduodenoscopy and endoscopic ultrasound images, alongside data from abdominal computed tomography, biopsy results, and long-term follow-up records.
Results:
Gastric SELs were initially identified in 648 patients. Of these, 88 patients (mean age, 57.1±10.6 years; 60% women) had lesions measuring 1–2 cm and underwent further evaluation or surveillance. The mean lesion size determined by endoscopy was 13.7±3.3 mm. Among the 52 patients with histological confirmation, 24 (46%) were diagnosed with gastrointestinal stromal tumors (GISTs), whereas the remainder had benign lesions. Most gastric SELs were located in the fundus and upper body. Pathological analysis indicated that the majority of GISTs were low-risk. Three GISTs were stratified as moderate-to-high risk; notably, one measured 0.9 cm upon pathological examination. The median surveillance period for the 28 patients without histological confirmation was 55 months (range, 43–115 months). Two of these patients underwent endoscopic or wedge resection due to tumor enlargement; both lesions were histologically confirmed as low-risk.
Conclusions
Approximately half of the gastric SELs measuring 1–2 cm were GISTs, representing an intermediate- to high-risk tumors. Given that GISTs in the upper stomach were associated with elevated risk even when smaller than 2 cm, we recommend strict short-term surveillance for such lesions.
3.Treatment of Helicobacter pylori Infection in Korea: An Evidence-Based Analysis of the Upcoming 2025 Guideline
Chang Seok BANG ; Seung Joo KANG ; Su Youn NAM ; Sung Eun KIM ; Seung Young KIM ; Hyunchul LIM ; Chung Hyun TAE ; Moon Won LEE ; Seung Han KIM ; Hye-Kyung JUNG ; Byung-Wook KIM
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2026;26(1):23-36
The efficacy of clarithromycin-containing triple therapy (TT) against Helicobacter pylori has declined in Korea, with recent first-line eradication rates falling below 70%. Clarithromycin resistance exceeded 30%, undermining the standard regimen for H. pylori. These trends necessitate a change in the treatment strategy. This review analyzed the shift proposed in the draft of the 2025 Korean H. pylori guidelines. We examined the rationale for abandoning TT as a first-line empirical therapy and the establishment of a new dual-pillar strategy: 1) the declining role of clarithromycin-containing TT as a first-line treatment and 2) polymerase chain reaction (PCR)-based tailored therapy as the recommended precision approach. We explored the 1) emergence of new empirical regimen options, 2) application of tailored therapy, and 3) adoption of potassium-competitive acid blockers (P-CABs). Empirical regimens have shifted toward four-drug combinations to achieve higher cure rates. Concomitant therapy (proton-pump inhibitor [PPI] or P-CAB+amoxicillin+clarithromycin+metronidazole) offers high efficacy but raises concerns about antibiotic overuse. As a compromise, bismuth-augmented triple regimens (adding bismuth to TT) are now recommended; these modified quadruple therapies (e.g., PACB: PPI+amoxicillin+clarithromycin+bismuth, or PAMB: PPI+amoxicillin+metronidazole+bismuth) significantly improve eradication rates without requiring a third antibiotic class. Regarding tailored therapy, PCR-based domestic clinical research data consistently achieves ≥90% cure rates in first-line treatment—markedly higher than empirical TT in Korea. Economic analyses supported the cost-effectiveness of this approach. The guideline algorithm for salvage therapy was clarified. Bismuth quadruple therapy has been confirmed as the standard second-line treatment. For third-line therapy, we analyzed the efficacy of levofloxacin-based regimens, rifabutin-based therapy, and bismuth add-on therapy with two previously unused antibiotics. The 2025 Korean guidelines establish quadruple therapies as the new standard through a dual strategy: pragmatic empirical treatment and PCR-guided tailored therapy, with P-CABs and bismuth-based regimens as key components.
4.Long-Term Evaluation of Cannabidiol in Pediatric Drug-Resistant Epilepsy: A Real-Time Single-Center Retrospective Study
Jong Ho CHA ; Hyeryung KIM ; Young Ho KIM ; Seungbok LEE ; Soo Yeon KIM ; Byung Chan LIM ; Jong-Hee CHAE ; Ki Joong KIM ; Woo Joong KIM
Annals of Child Neurology 2026;34(1):66-74
Purpose:
Cannabidiol (CBD) is a promising treatment option for pediatric drug-resistant epilepsy (DRE). The aim of this study was to assess the tolerability and safety of CBD in a single-center retrospective cohort based on real-world clinical experience.
Methods:
This study included 71 pediatric patients (median age, 8.9 years; interquartile range [IQR], 6.2 to 14.0) with Lennox–Gastaut syndrome who received purified CBD (Epidiolex, GW Pharmaceuticals) between March 2019 and July 2024. All patients had previously failed treatment with more than five anti-seizure medications (ASMs). Responder rate (≥50% seizure frequency reduction), retention rate, adverse effects (AEs), and predictors of favorable treatment response were analyzed over a median follow-up of 21.3 months (IQR, 2.8 to 38.5).
Results:
The initial responder rate during the first 3 months was 45.1%, which increased to 70.8% at 18 months and 63.0% at 24 months. The retention rate at 24 months was 52.4% (33/71). Seven patients (9.9%) achieved seizure freedom beyond 24 months of CBD therapy, and five of these patients were able to reduce their concomitant ASM burden. AEs were observed in 39.4% (28/71) of patients, with the most frequent being somnolence (20 cases) and increased seizure frequency (six cases); 92.9% of AEs occurred within the first 3 months of treatment. No serious AEs requiring treatment discontinuation were identified.
Conclusion
In this real-world study, CBD demonstrated potential as an adjunctive therapy with manageable AEs. These findings highlight that CBD can reduce seizure frequency while maintaining tolerability in pediatric patients with DRE.
5.Calorie Restriction Modulates Gene Expression of Il19 and Il24 during Renal Aging
Sang Gyun NOH ; Hyun Woo KIM ; Seungwoo KIM ; Mi Kyung KIM ; Byung Pal YU ; Ki Wung CHUNG ; Hae Young CHUNG
Annals of Geriatric Medicine and Research 2026;30(1):28-40
Background:
Renal function declines with age as the kidneys become more vulnerable to inflammation and cellular senescence. This study examined gene expression changes linked to renal aging and assessed whether short-term calorie restriction (CR), a known anti-aging intervention, could reverse these alterations.
Methods:
Using RNA-seq data, we applied bioinformatics, systems biology, and molecular biology approaches to identify differentially expressed genes during aging and under CR. Gene Ontology and pathway analyses revealed that both aging and CR altered the expression of key senescence-associated secretory phenotype (SASP) genes, including cytokines and chemokines (Il1b, Ccl3, Ccl5, Il19, and Il24) and growth factors (Timp1 and Mmp12).
Results:
Renal aging is also associated with an increased expression of cell cycle arrest markers (p15INK4B (Cdkn2b), p16INK4A (Cdkn2a), and p21 (Cdkn1a)), which are suppressed by CR, suggesting a link to cellular senescence. Quantitative analysis of renal tissue samples confirmed the age-associated upregulation of these genes at the transcriptional level, and CR effectively attenuated these changes. Among these genes, we focused on the members of the interleukin 20 (IL-20) family, particularly Il19 and Il24. Furthermore, experimental induction of cellular senescence using H2O2 resulted in elevated Il19 and Il24 expression alongside other senescence markers. These findings suggest that aging and short-term CR regulate the IL-20 family expression, potentially influencing cellular senescence.
Conclusion
Our study suggests that Il19 and Il24 are associated with age-related renal decline and may represent hypothesis-generating candidates, highlighting potential molecular targets for future mechanistic and therapeutic investigations.
6.Diagnostic Accuracy of Serological Tests for Mycoplasma pneumoniae Infections in Children with Pneumonia, Based on Symptom Onset
Gahee KIM ; Ki Wook YUN ; Dayun KANG ; Taek Jin LEE ; Byung Wook EUN ; Hyunju LEE ; Yae-Jean KIM ; Doo Ri KIM ; Areum SHIN ; Hyun Mi KANG ; Ye Ji KIM ; Byung Ok KWAK ; Younghee LEE ; Ye Kyung KIM ; Young June CHOE ; Woosuck SUH ; Kyo Jin JO ; Kyung-Ran KIM ; Eun Young CHO ; Kyung Min KIM ; Joon Kee LEE ; Su Eun PARK
Annals of Laboratory Medicine 2026;46(2):162-170
Background:
Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP.
Methods:
From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days).
Results:
Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days.
Conclusions
The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.
7.Impact of Intraoperative Parathyroid Hormone Monitoring on Surgical and Biochemical Outcomes in Tertiary Hyperparathyroidism: A Retrospective Cohort Study
Suh Yun CHUNG ; Young-min LEE ; Sookyung KIM ; Byung-Chang KIM ; Won Woong KIM ; Yu-mi LEE ; Tae-Yon SUNG ; Ki-Wook CHUNG
Journal of Endocrine Surgery 2026;26(1):9-20
Purpose:
Persistent hypercalcemia after parathyroidectomy (PTx) remains a significant concern in patients with tertiary hyperparathyroidism (THPT) following kidney transplant (KT). Complete resection of hyperfunctioning glands is challenging due to ectopic or intrathyroidal glands. This study evaluated whether intraoperative parathyroid hormone (ioPTH) monitoring during PTx in KT patients with THPT reduces the surgical failure rate.
Methods:
We retrospectively analyzed 111 patients with THPT who underwent PTx at a single tertiary center. Patients were divided into 2 groups: those without ioPTH monitoring (n=98) and those with ioPTH monitoring (n=13). Surgical procedures included less than subtotal, subtotal, or total PTx with autotransplantation. Surgical failure was defined as persistent hypercalcemia (serum calcium ≥10.3 mg/dL and intact parathyroid hormone [PTH] >65 pg/mL) on postoperative day 1 (POD1) or at ≥6 months postoperatively.
Results:
The ioPTH group demonstrated a significantly lower mean PTH level on POD1 (21±15.3 pg/mL vs. 39±39 pg/mL; P=0.006). Although not statistically significant, the ioPTH group showed a higher biochemical cure rate at 3 months (53.8% vs. 30.6%) and no cases of persistent hyperparathyroidism, compared to 15.3% in the non-ioPTH group.Despite adequate intraoperative PTH reduction, some patients in both groups exhibited isolated PTH elevation without hypercalcemia.
Conclusion
Although ioPTH monitoring did not significantly reduce the surgical failure rate in PTx for THPT, the use of ioPTH may meaningfully improve surgical completeness and reduce the risk of persistent or recurrent hyperparathyroidism, suggesting its substantial potential value as an intraoperative.
8.Clinical Guidance and Practical Recommendations for Probiotic Use in Patients With Irritable Bowel Syndrome, Functional Constipation, and Clostridioides difficile Infection Considering Sex-based Differences
Yong Sung KIM ; Seon-Young PARK ; Seung Joo KANG ; Min Woo LEE ; Yonghoon CHOI ; Byung Yong KIM ; Miyoung CHOI ; Cheol Min SHIN ; Young Sun KIM ; Nayoung KIM ; Moo In PARK ;
Journal of Neurogastroenterology and Motility 2026;32(2):198-216
Probiotics have gained increasing clinical attention as adjunctive treatment for lower gastrointestinal disorders. However, evidence supporting their therapeutic efficacy remains limited, particularly with regard to sex-related differences. This expert review provides evidence-based insights and practical recommendations for the use of probiotics in patients with irritable bowel syndrome (IBS), functional constipation (FC), and Clostridioides difficile infection (CDI), considering possible sex-related differences. Evidence from randomized controlled trials and meta-analyses indicates that probiotics can modestly improve global symptoms, abdominal pain, and bloating in IBS and enhance bowel movement frequency and stool consistency in FC. However, these effects are strain-specific and heterogeneous. Although clinical studies on probiotics in IBS have not confirmed significant sex-related differences, experimental animal studies using stress-induced IBS models have demonstrated sex-dependent responses to specific probiotic strains, supporting the biological plausibility of such differences. For CDI, the efficacy of probiotics in preventing primary or recurrent infections remains inconsistent across large trials, and current guidelines usually do not recommend their routine use. However, sex and age difference of immunology supports the clinical differences of CDI. Probiotics are generally considered safe for healthy individuals, although caution is advised in patients who are immunocompromised or critically ill. Clinicians should select probiotic products based on strain-specific clinical evidence, adequate viable doses, patient's characteristics, or patient’s sex. In conclusion, probiotics might play a role as adjunctive therapy for IBS and FC, with variability in responses influenced by microbial, host, and potential sex-related factors. Further research is needed to establish optimized personalized probiotic strategies.
9.Clinical guidance and practical recommendations for probiotic use in patients with irritable bowel syndrome, functional constipation, and Clostridioides difficile infection considering sex-based differences: a Korean translation
Yong Sung KIM ; Seon-Young PARK ; Seung Joo KANG ; Min Woo LEE ; Yonghoon CHOI ; Byung Yong KIM ; Miyoung CHOI ; Cheol Min SHIN ; Young Sun KIM ; Nayoung KIM ; Moo In PARK ;
The Ewha Medical Journal 2026;49(2):e10-
Probiotics have gained increasing clinical attention as adjunctive treatment for lower gastrointestinal disorders. However, evidence supporting their therapeutic efficacy remains limited, particularly with regard to sex-related differences. This expert review provides evidence-based insights and practical recommendations for the use of probiotics in patients with irritable bowel syndrome (IBS), functional constipation (FC), and Clostridioides difficile infection (CDI), considering possible sex-related differences. Evidence from randomized controlled trials and meta-analyses indicates that probiotics can modestly improve global symptoms, abdominal pain, and bloating in IBS and enhance bowel movement frequency and stool consistency in FC. However, these effects are strain-specific and heterogeneous. Although clinical studies on probiotics in IBS have not confirmed significant sex-related differences, experimental animal studies using stress-induced IBS models have demonstrated sex-dependent responses to specific probiotic strains, supporting the biological plausibility of such differences. For CDI, the efficacy of probiotics in preventing primary or recurrent infections remains inconsistent across large trials, and current guidelines usually do not recommend their routine use. However, sex- and age-related immunologic differences support the clinical differences of CDI. Probiotics are generally considered safe for healthy individuals, although caution is advised in patients who are immunocompromised or critically ill. Clinicians should select probiotic products based on strain-specific clinical evidence, adequate viable doses, patient characteristics and sex. In conclusion, probiotics might play a role as adjunctive therapy for IBS and FC, with variability in responses influenced by microbial, host, and potential sex-related factors. Further research is needed to establish optimized personalized probiotic strategies.
10.Are the long-term oncologic outcomes different between appendiceal cancer and right-sided colon cancer? An exact matching analysis of a 10-year institutional cohort
Gunwoo LEE ; Eun Jung PARK ; Soo Young OH ; Young Il KIM ; Min Hyun KIM ; Jong Lyul LEE ; Chan Wook KIM ; Yong Sik YOON ; In Ja PARK ; Seok-Byung LIM ; Chang Sik YU
Annals of Surgical Treatment and Research 2026;110(4):246-258
Purpose:
Due to its rarity, treatment guidelines for appendiceal cancer have traditionally followed those established for colorectal cancer, despite showing distinct histologic and clinical features. This study aimed to compare the clinicopathologic characteristics and long-term oncologic outcomes of appendiceal cancer with those of right-sided colon cancers.
Methods:
We retrospectively reviewed the records of patients with stage I–III appendiceal, cecal, or ascending colon cancer who underwent curative resection between 2010 and 2020 at our center. A 1:3:3 exact matching for age, sex, TNM stage, and adjuvant chemotherapy was performed. Survival outcomes were analyzed using the Kaplan-Meier and Cox regression methods.
Results:
Overall, 245 patients with appendiceal cancer (n = 35), ascending colon cancer (n = 105), and cecal cancer (n = 105) were analyzed. Appendiceal cancer exhibited a higher proportion of T4 tumors and fewer harvested lymph nodes compared with ascending or cecal cancers. The mean follow-up duration was 9.5 years. The 5- and 10-year overall survival rates were lower in appendiceal cancer (66.2% and 52.9%) than in ascending (91.2% and 78.4%) or cecal cancer (88.5% and 78.3%). Similarly, the 10-year disease-free survival rate was lower in appendiceal cancer (59.2%) compared with ascending (83.1%) and cecal cancers (78.4%). Cox regression analysis identified age (≥65 years), perforation, nodal metastasis, and lymphovascular invasion as independent predictors of poor prognosis.
Conclusion
Appendiceal cancer exhibited significantly worse long-term survival compared to cecal or ascending colon cancer. Tumor perforation, nodal metastasis, and lymphovascular invasion were adverse prognostic factors for overall and disease-free survival.

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