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.Ischemic Neuropathy as a Possible Complication of Percutaneous Coronary Intervention: A Case Report
Jisun BAE ; Seungyup SONG ; Dongwook SONG ; Sun IM ; Geun-Young PARK
Journal of Electrodiagnosis and Neuromuscular Diseases 2026;28(1):10-15
Ischemic neuropathy is an uncommon cause of peripheral nerve injury that results from compromised blood flow or oxygen delivery to the vasa nervorum. We report a rare case of multiple ischemic mononeuropathies of the right lower limb that developed after percutaneous coronary intervention (PCI). A 57-year-old man who underwent PCI for ST-elevation myocardial infarction presented with persistent weakness, sensory disturbance, and pain in the right lower limb. Electrodiagnostic studies performed 4 weeks after symptom onset revealed findings consistent with multiple mononeuropathies of the right lower limb. In cases of ischemic neuropathy associated with arterial occlusion, prompt vascular imaging and revascularization of the occluded artery are essential to minimize neurological deficits and optimize motor recovery.
3.Impact of HER2-Low Status on Pathologic Complete Response and Survival Outcome Among Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy
Young Joo LEE ; Tae-Kyung YOO ; Sae Byul LEE ; Il Yong CHUNG ; Hee Jeong KIM ; Beom Seok KO ; Jong Won LEE ; Byung Ho SON ; Sei Hyun AHN ; Hyehyun JEONG ; Jae Ho JUNG ; Jin-Hee AHN ; Kyung Hae JUNG ; Sung-Bae KIM ; Hee Jin LEE ; Gyungyub GONG ; Jisun KIM
Journal of Breast Cancer 2025;28(1):11-22
Purpose:
This study analyzed the pathological complete response (pCR) rates, long-term outcomes, and biological features of human epidermal growth factor receptor 2 (HER2)-zero, HER2-low, and HER2-positive breast cancer patients undergoing neoadjuvant treatment.
Methods:
This single-center study included 1,667 patients who underwent neoadjuvant chemotherapy from 2008 to 2014. Patients were categorized by HER2 status, and their clinicopathological characteristics, chemotherapy responses, and recurrence-free survival (RFS) rates were analyzed.
Results:
Patients with HER2-low tumors were more likely to be older (p = 0.081), have a lower histological grade (p < 0.001), and have hormone receptor (HorR)-positive tumors (p < 0.001). The HER2-positive group exhibited the highest pCR rate (23.3%), followed by the HER2-zero (15.5%) and HER2-low (10.9%) groups. However, the pCR rate did not differ between HER2-low and HER2-zero tumors in the HorR-positive or HorR-negative subgroups.The 5-year RFS rates increased in the following order: HER2-low, HER2-positive, and HER2-zero (80.0%, 77.5%, and 74.5%, respectively) (log-rank test p = 0.017). A significant survival difference between patients with HER2-low and HER2-zero tumors was only identified in HorR-negative tumors (5-year RFS for HER2-low, 74.5% vs. HER2-zero, 66.0%; log-rank test p-value = 0.04). Multivariate survival analysis revealed that achieving a pCR was the most significant factor associated with improved survival (hazard ratio [HR], 4.279; p < 0.001).Compared with HER2-zero, the HRs for HER2-low and HER2-positive tumors were 0.787 (p = 0.042) and 0.728 (p = 0.005), respectively. After excluding patients who received HER2-targeted therapy, patients with HER2-low tumors exhibited better RFS than those with HER2-zero (HR 0.784, p = 0.04), whereas those with HER2-positive tumors exhibited no significant difference compared with those with HER2-low tumors (HR, 0.975; p = 0.953).
Conclusion
Patients with HER2-low tumors had no significant difference in pCR rate compared to HER2-zero but showed better survival, especially in HorR-negative tumors.Further investigation into biological differences is warranted.
4.Impact of HER2-Low Status on Pathologic Complete Response and Survival Outcome Among Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy
Young Joo LEE ; Tae-Kyung YOO ; Sae Byul LEE ; Il Yong CHUNG ; Hee Jeong KIM ; Beom Seok KO ; Jong Won LEE ; Byung Ho SON ; Sei Hyun AHN ; Hyehyun JEONG ; Jae Ho JUNG ; Jin-Hee AHN ; Kyung Hae JUNG ; Sung-Bae KIM ; Hee Jin LEE ; Gyungyub GONG ; Jisun KIM
Journal of Breast Cancer 2025;28(1):11-22
Purpose:
This study analyzed the pathological complete response (pCR) rates, long-term outcomes, and biological features of human epidermal growth factor receptor 2 (HER2)-zero, HER2-low, and HER2-positive breast cancer patients undergoing neoadjuvant treatment.
Methods:
This single-center study included 1,667 patients who underwent neoadjuvant chemotherapy from 2008 to 2014. Patients were categorized by HER2 status, and their clinicopathological characteristics, chemotherapy responses, and recurrence-free survival (RFS) rates were analyzed.
Results:
Patients with HER2-low tumors were more likely to be older (p = 0.081), have a lower histological grade (p < 0.001), and have hormone receptor (HorR)-positive tumors (p < 0.001). The HER2-positive group exhibited the highest pCR rate (23.3%), followed by the HER2-zero (15.5%) and HER2-low (10.9%) groups. However, the pCR rate did not differ between HER2-low and HER2-zero tumors in the HorR-positive or HorR-negative subgroups.The 5-year RFS rates increased in the following order: HER2-low, HER2-positive, and HER2-zero (80.0%, 77.5%, and 74.5%, respectively) (log-rank test p = 0.017). A significant survival difference between patients with HER2-low and HER2-zero tumors was only identified in HorR-negative tumors (5-year RFS for HER2-low, 74.5% vs. HER2-zero, 66.0%; log-rank test p-value = 0.04). Multivariate survival analysis revealed that achieving a pCR was the most significant factor associated with improved survival (hazard ratio [HR], 4.279; p < 0.001).Compared with HER2-zero, the HRs for HER2-low and HER2-positive tumors were 0.787 (p = 0.042) and 0.728 (p = 0.005), respectively. After excluding patients who received HER2-targeted therapy, patients with HER2-low tumors exhibited better RFS than those with HER2-zero (HR 0.784, p = 0.04), whereas those with HER2-positive tumors exhibited no significant difference compared with those with HER2-low tumors (HR, 0.975; p = 0.953).
Conclusion
Patients with HER2-low tumors had no significant difference in pCR rate compared to HER2-zero but showed better survival, especially in HorR-negative tumors.Further investigation into biological differences is warranted.
5.Impact of HER2-Low Status on Pathologic Complete Response and Survival Outcome Among Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy
Young Joo LEE ; Tae-Kyung YOO ; Sae Byul LEE ; Il Yong CHUNG ; Hee Jeong KIM ; Beom Seok KO ; Jong Won LEE ; Byung Ho SON ; Sei Hyun AHN ; Hyehyun JEONG ; Jae Ho JUNG ; Jin-Hee AHN ; Kyung Hae JUNG ; Sung-Bae KIM ; Hee Jin LEE ; Gyungyub GONG ; Jisun KIM
Journal of Breast Cancer 2025;28(1):11-22
Purpose:
This study analyzed the pathological complete response (pCR) rates, long-term outcomes, and biological features of human epidermal growth factor receptor 2 (HER2)-zero, HER2-low, and HER2-positive breast cancer patients undergoing neoadjuvant treatment.
Methods:
This single-center study included 1,667 patients who underwent neoadjuvant chemotherapy from 2008 to 2014. Patients were categorized by HER2 status, and their clinicopathological characteristics, chemotherapy responses, and recurrence-free survival (RFS) rates were analyzed.
Results:
Patients with HER2-low tumors were more likely to be older (p = 0.081), have a lower histological grade (p < 0.001), and have hormone receptor (HorR)-positive tumors (p < 0.001). The HER2-positive group exhibited the highest pCR rate (23.3%), followed by the HER2-zero (15.5%) and HER2-low (10.9%) groups. However, the pCR rate did not differ between HER2-low and HER2-zero tumors in the HorR-positive or HorR-negative subgroups.The 5-year RFS rates increased in the following order: HER2-low, HER2-positive, and HER2-zero (80.0%, 77.5%, and 74.5%, respectively) (log-rank test p = 0.017). A significant survival difference between patients with HER2-low and HER2-zero tumors was only identified in HorR-negative tumors (5-year RFS for HER2-low, 74.5% vs. HER2-zero, 66.0%; log-rank test p-value = 0.04). Multivariate survival analysis revealed that achieving a pCR was the most significant factor associated with improved survival (hazard ratio [HR], 4.279; p < 0.001).Compared with HER2-zero, the HRs for HER2-low and HER2-positive tumors were 0.787 (p = 0.042) and 0.728 (p = 0.005), respectively. After excluding patients who received HER2-targeted therapy, patients with HER2-low tumors exhibited better RFS than those with HER2-zero (HR 0.784, p = 0.04), whereas those with HER2-positive tumors exhibited no significant difference compared with those with HER2-low tumors (HR, 0.975; p = 0.953).
Conclusion
Patients with HER2-low tumors had no significant difference in pCR rate compared to HER2-zero but showed better survival, especially in HorR-negative tumors.Further investigation into biological differences is warranted.
6.Post-Intubation Hypoglossal Nerve Injury Presenting as Tongue Mass: A Case Report
Jisun BAE ; Sejoon KIM ; Young-Hoon JOO ; Jung Ho LEE ; Jisoo PARK ; Dongwook SONG ; Geun-Young PARK ; Hae-Yeon PARK ; Sun IM
Journal of the Korean Dysphagia Society 2025;15(2):176-181
Hypoglossal nerve palsy is a rare complication related to airway management during general anesthesia. Its diagnosis can be delayed when postoperative tongue swelling mimics a neoplasm. This paper reports a case of isolated hypoglossal nerve palsy after endotracheal intubation. A 65-year-old woman developed dysphagia and impaired tongue protrusion after orbital floor fracture surgery. Fiberoptic endoscopic evaluation revealed a 3-mm mass-like lesion at the tongue base, and magnetic resonance imaging showed asymmetric swelling of the left tongue and oropharyngeal wall. The tongue strength measured using the Iowa Oral Performance Instrument (IOPI) at six days post-onset was 10 kPa, which was markedly lower than the age norms. Electromyography revealed the fibrillation potentials and positive sharp waves in the left tongue muscle, confirming isolated hypoglossal nerve palsy. Oral methylprednisolone was administered for five days, followed by a five-day taper, with concurrent tongue-strengthening rehabilitation. One month later, the tongue strength improved, reaching a maximal pressure of 24 kPa. The mass-like lesion had resolved on follow-up and was interpreted as a pseudotumor caused by edema and mechanical compression. Complete recovery was achieved by the six-month follow-up. This case highlights the utility of IOPI for early quantitative assessment of tongue weakness and highlights that early diagnosis and steroid treatment can facilitate recovery.
7.Ataxin-3 Overexpression via Adeno-associated Viral Vector Injection in the Primate Cerebellum: A Novel Model of Spinocerebellar Ataxia Type 3
Keonwoo KIM ; Aryun KIM ; Jinyoung WON ; Junghyung PARK ; Kyung Seob LIM ; Chang-Yeop JEON ; Jisun MIN ; Jee-Hyun CHO ; Youngkyu SONG ; Bon-Sang KOO ; Gyu-Seo BAE ; Eunsu JEON ; Kang-Jin JEONG ; Sung-Hyun PARK ; Hwal-Yong LEE ; Won Seok CHOI ; Dong-Seok LEE ; Youngjeon LEE
Experimental Neurobiology 2025;34(6):248-262
Spinocerebellar ataxia type 3 (SCA3) is an autosomal-dominant neurodegenerative disorder caused by an expanded polyglutamine repeat in the ataxin-3 gene. The resulting mutant ataxin-3 protein forms intraneuronal inclusions that lead to neurodegeneration in the cerebellum and other brain regions. This study aimed to develop a novel nonhuman primate model of SCA3 to address the limitations of existing knock-in and transgenic models using an adeno-associated virus (AAV) to deliver the mutant gene. AAV viral vectors carrying mutant ataxin-3 were stereotaxically injected into the cerebellum of monkeys. The animals were monitored over an 8-week period, during which behavioral and neuroimaging assessments were conducted. This was followed by a detailed pathological examination. The AAV vector successfully spread throughout the cerebellum, and the expression of mutant ataxin-3 was confirmed. Neuroimaging revealed a reduction in N-acetylaspartate (NAA) levels, whereas histological analysis showed significant damage to the Purkinje cell layer. Notably, the monkeys exhibited sleep disturbances, a prodromal symptom commonly observed in human patients with SCA3. AAV-mediated delivery of mutant ataxin-3 can effectively replicate the key pathological and clinical features of SCA3 in primates. This approach offers a promising new model for studying disease mechanisms and evaluating potential therapies.
8.A Rare Case of Eosinophilic Esophagitis Accompanied by Oropharyngeal Dysphagia and Aspiration
Jisun BAE ; Soohoan LEE ; Jisoo PARK ; Hae-Yeon PARK ; Sun IM
Journal of the Korean Dysphagia Society 2024;14(Supple):155-160
A 74-year-old woman presented with a progressive pattern of dysphagia and odynophagia over one month.Magnetic resonance imaging of the neck revealed diffuse swelling from the tongue base and velum extending to the posterior pharyngeal wall. Instrumental evaluation of swallowing showed decreased peristalsis in the esophageal phase, accompanied by severe swelling of the hypopharynx, which limited laryngeal elevation and subsequently led to decreased bolus clearance and impaired airway protection. Laboratory studies revealed a 61% increase in eosinophil count. An endoscopic biopsy of the esophagus confirmed the diagnosis of eosinophilic esophagitis. The patient was administered intravenous dexamethasone at a total dosage of 45 mg/day for 7 days. The eosinophil count dropped to the normal range, correlating with the improvement in dysphagia and aspiration. Eosinophilic esophagitis often presents in children and rarely involves the oropharyngeal structures. Due to its specific involvement of the esophagus, it seldom leads to aspiration. By contrast, the extension of eosinophilic inflammation from the esophagus to the oropharynx in this case resulted in atypical symptoms such as odynophagia and aspiration. The therapeutic approach can be challenging due to the difficulty in administering topical steroids, which are often the treatment of choice. However, the condition showed an excellent response to intravenous steroid therapy.
9.Guidelines for Manufacturing and Application of Organoids: Heart
Hyang-Ae LEE ; Dong-Hun WOO ; Do-Sun LIM ; Jisun OH ; C-Yoon KIM ; Ok-Nam BAE ; Sun-Ju AHN
International Journal of Stem Cells 2024;17(2):130-140
Cardiac organoids have emerged as invaluable tools for assessing the impact of diverse substances on heart function.This report introduces guidelines for general requirements for manufacturing cardiac organoids and conducting cardiac organoid-based assays, encompassing protocols, analytical methodologies, and ethical considerations. In the quest to employ recently developed three-dimensional cardiac organoid models as substitutes for animal testing, it becomes imperative to establish robust criteria for evaluating organoid quality and conducting toxicity assessments. This guideline addresses this need, catering to regulatory requirements, and describes common standards for organoid quality and toxicity assessment methodologies, commensurate with current technological capabilities. While acknowledging the dynamic nature of technological progress and the potential for future comparative studies, this guideline serves as a foundational framework. It offers a comprehensive approach to standardized cardiac organoid testing, ensuring scientific rigor, reproducibility, and ethical integrity in investigations of cardiotoxicity, particularly through the utilization of human pluripotent stem cell-derived cardiac organoids.
10.Mortality Burden Due to Short-term Exposure to Fine Particulate Matter in Korea
Jongmin OH ; Youn-Hee LIM ; Changwoo HAN ; Dong-Wook LEE ; Jisun MYUNG ; Yun-Chul HONG ; Soontae KIM ; Hyun-Joo BAE
Journal of Preventive Medicine and Public Health 2024;57(2):185-196
Objectives:
Excess mortality associated with long-term exposure to fine particulate matter (PM2.5) has been documented. However, research on the disease burden following short-term exposure is scarce. We investigated the cause-specific mortality burden of short-term exposure to PM2.5 by considering the potential non-linear concentration–response relationship in Korea.
Methods:
Daily cause-specific mortality rates and PM2.5 exposure levels from 2010 to 2019 were collected for 8 Korean cities and 9 provinces. A generalized additive mixed model was employed to estimate the non-linear relationship between PM2.5 exposure and cause-specific mortality levels. We assumed no detrimental health effects of PM2.5 concentrations below 15 μg/m3. Overall deaths attributable to short-term PM2.5 exposure were estimated by summing the daily numbers of excess deaths associated with ambient PM2.5 exposure.
Results:
Of the 2 749 704 recorded deaths, 2 453 686 (89.2%) were non-accidental, 591 267 (21.5%) were cardiovascular, and 141 066 (5.1%) were respiratory in nature. A non-linear relationship was observed between all-cause mortality and exposure to PM2.5 at lag0, whereas linear associations were evident for cause-specific mortalities. Overall, 10 814 all-cause, 7855 non-accidental, 1642 cardiovascular, and 708 respiratory deaths were attributed to short-term exposure to PM2.5. The estimated number of all-cause excess deaths due to short-term PM2.5 exposure in 2019 was 1039 (95% confidence interval, 604 to 1472).
Conclusions
Our findings indicate an association between short-term PM2.5 exposure and various mortality rates (all-cause, non-accidental, cardiovascular, and respiratory) in Korea over the period from 2010 to 2019. Consequently, action plans should be developed to reduce deaths attributable to short-term exposure to PM2.5.

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