1.Impact of COVID-19 on the Profitability of General Hospitals in Korea
Jun Young PARK ; Tae Hyun KIM ; Suk-Yong JANG ; Sang Gyu LEE
Journal of Preventive Medicine and Public Health 2026;59(1):46-55
Objectives:
This study was performed to quantify the impact of coronavirus disease 2019 (COVID-19) on hospital profitability in Korea by analyzing changes in the medical revenue-to-profit ratio (MRPR) and net income before reserve fund allocation (NIBR) before and after the pandemic onset. Additionally, it examined how financial outcomes varied by hospital ownership, geographic location, and type (secondary or tertiary), providing insights into the financial resilience of various hospital types during public health crises.
Methods:
We conducted a longitudinal analysis using publicly available financial disclosure data from 243 general hospitals in Korea (2016–2022). We then performed a quadrant analysis to classify hospitals based on changes in MRPR and NIBR, identifying patterns of financial impact. For inferential analysis, we employed linear mixed-effects models incorporating a difference-in-differences framework, enabling estimation of both time-varying and hospital-specific effects.
Results:
Following the onset of COVID-19, MRPR declined significantly, reaching −10.62% in 2020. NIBR initially dropped but later increased, reaching 21.09 billion Korean won per 100 beds in 2022. Quadrant analysis revealed substantial heterogeneity in financial responses, with national/public hospitals experiencing the most severe MRPR decline, whereas educational foundation and medical corporation hospitals displayed stronger financial recovery. Regression results confirmed significant interactions between outcomes after COVID-19 onset and hospital ownership type, indicating differential financial impacts across hospital categories.
Conclusions
The findings highlight the uneven financial effects of COVID-19 on Korean hospitals, emphasizing the importance of targeted government financial support. Policy measures should prioritize structural financial reforms to ensure hospital sustainability beyond short-term crisis management.
2.Differential Peripheral NLRP3 Inflammasome Expression in Patients With Parkinson’s Disease and Patients With Multiple System Atrophy
Jeongjae LEE ; Han-Joon KIM ; Huu Dat NGUYEN ; Suk Jun SONG ; Trung Nguyen THANH ; In Hee KWAK ; Hye Joung CHOI ; Hyeo-il MA ; Young Eun KIM
Journal of Movement Disorders 2026;19(1):31-38
Objective:
The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has been proposed to be a downstream mediator of neuroinflammation in individuals with Parkinson’s disease (PD). However, its involvement across disease stages and related synucleinopathies, such as multiple system atrophy (MSA), remains unclear. We aimed to analyze the peripheral mRNA expression of NLRP3-related genes and cytokines across individuals with isolated REM sleep behavior disorder (iRBD), early-stage PD, late-stage PD, and MSA.
Methods:
Peripheral blood mononuclear cells (PBMCs) were collected from 151 participants: 35 healthy controls (HCs), 31 patients with iRBD, 41 patients with early-stage PD, 21 patients with late-stage PD, and 23 patients with MSA. mRNA expression was measured using quantitative real-time polymerase chain reaction. Statistical comparisons were performed using analysis of variance (ANOVA) or Welch’s ANOVA, and associations with clinical variables were analyzed through stepwise multiple linear regression.
Results:
NLRP3 expression was significantly lower in patients with iRBD (p=0.0263) and patients with early-stage PD (p= 0.0101) than in HCs. NIMA-related kinase 7 (NEK7) expression progressively decreased across the disease spectrum (HCs vs. patients with early-stage PD, p=0.0008; vs. patients with late-stage PD, p<0.0001). In contrast, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and caspase-1 were elevated in patients with PD, especially those in the late stages. Levels of patients with MSA resembled those of HCs but differed from those of patients with PD. Interleukin (IL)-1β and IL-18 levels were not significantly different. In patients with early-stage PD, NLRP3 expression was negatively correlated with disease duration, the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale Part II score, and the cognitive score.
Conclusion
Our findings challenge the prevailing hypothesis that NLRP3 inflammasome activation directly contributes to PD pathogenesis. Instead, the observed increase in ASC and caspase-1 expression suggests the potential involvement of alternative inflammasome pathways during disease progression.
3.Delayed Bleeding With Variable Presentations in Implant-Based Breast Reconstruction During Adjuvant Ado-Trastuzumab Emtansine (Kadcyla) Therapy: Two Case Reports
Seong Jun RYU ; Young Seok KIM ; In Sik YUN ; Kyunghyun MIN ; Joon JEONG ; Tai Suk ROH
Journal of Breast Cancer 2026;29(2):192-201
Ado-trastuzumab emtansine (T-DM1) is an effective adjuvant therapy for human epidermal growth factor receptor 2-positive breast cancer; however, its surgical safety profile remains unclear. We observed delayed bleeding with variable and often subtle clinical manifestations during implant-based breast reconstruction (IBBR). Two patients who received adjuvant T-DM1 therapy after IBBR were retrospectively reviewed. The patient in Case 1 developed a recurrent seroma and liquefied hematoma requiring repeated aspirations, with platelet counts decreasing from 218 × 109 /L to 33 × 109 /L before expander removal.The patient in Case 2 experienced an acute massive hematoma on postoperative day (POD) 2, prior to T-DM1 initiation, which resolved after re-exploration; a temporally distinct delayed hemorrhagic event occurred on POD 175 during T-DM1 therapy after radiotherapy, accompanied by a platelet nadir of 34 × 109 /L. Both patients required plateletpheresis and prolonged drainage. Delayed bleeding during T-DM1 therapy may reflect a combination of hematological suppression and vascular vulnerability. Therefore, vigilant surveillance and cautious postoperative rehabilitation are warranted.
4.Germline Mutations Related to Complete Remission After Neoadjuvant Chemotherapy in Patients With Triple-negative Breast Cancer
Jee Hyun AHN ; Ji Soo PARK ; Dongju WON ; Seung-Tae LEE ; Suk Jun LEE ; Seung Hye YANG ; Jee Ye KIM ; Seho PARK ; Seung Il KIM ; Byeong-Woo PARK ; Min Hwan KIM ; Gun Min KIM ; Joohyuk SOHN ; Hyung Seok PARK
Journal of Breast Cancer 2026;29(2):118-127
Purpose:
Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing.
Methods:
A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs.
Results:
The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066).
Conclusion
Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.
5.Comparative Study of Mastectomy Using Conventional Techniques, Multiport and Single-Port Robotic Surgical Systems
Jeea LEE ; Jieon GO ; Suk Jun LEE ; Yonghan KWON ; Nam Hee KIM ; Jee Ye KIM ; Hyung Seok PARK
Cancer Research and Treatment 2026;58(2):492-500
Purpose:
Oncologic and surgical outcomes of robot-assisted nipple-sparing mastectomy (RNSM) compared to conventional nipple-sparing mastectomy (CNSM) is under investigation. This study compared the clinical outcomes of recurrence-free survival and postoperative complication after RNSM and CNSM.
Materials and Methods:
We retrospectively reviewed data of 401 patients who underwent da Vinci Si/Xi/SP-assisted RNSM or CNSM with immediate reconstruction between November 2016 and November 2020 at a single institute. Oncological outcomes were collected until March 2022. Primary endpoints were long-term outcomes, such as local recurrence, distant metastasis, disease-free survival, overall survival, and postoperative complications, while secondary endpoints were pathology results, and oncological outcomes.
Results:
Patients underwent RNSM (n=162) or CNSM (n=239). Of RNSM cases, 9 (5.6%) were performed using the da Vinci Si System, 96 (59.3%) using the da Vinci Xi System, and 57 (35.2%) using the da Vinci SP System. No significant difference in recurrence-free survival was found between the RNSM and CNSM group, and both groups had a median follow-up of 37 months. The recurrence rate in RNSM patients after a median follow-up of 24.5 months was 3.8%, compared with 5.9% in CNSM patients after a median follow-up of 42 months. No difference in recurrence was seen among RNSM patients with respect to surgical systems (multiport vs. SP, p =0.136). In addition, grade III postoperative complication rate was lower in patients with RNSM than in those with CNSM. Transfusion was only applied in 6.2% of patients.
Conclusion
Robot-assisted surgical systems can be safely used to perform nipple-sparing mastectomy in patients with early breast cancer.
6.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
7.Characteristics and outcomes of portal vein thrombosis in patients with inflammatory bowel disease in Korea
Ki Jin KIM ; Su-Bin SONG ; Jung-Bin PARK ; June Hwa BAE ; Ji Eun BAEK ; Ga Hee KIM ; Min-Jun KIM ; Seung Wook HONG ; Sung Wook HWANG ; Dong-Hoon YANG ; Byong Duk YE ; Jeong-Sik BYEON ; Seung-Jae MYUNG ; Suk-Kyun YANG ; Chang Sik YU ; Yong-Sik YOON ; Jong-Lyul LEE ; Min Hyun KIM ; Ho-Su LEE ; Sang Hyoung PARK
The Korean Journal of Internal Medicine 2025;40(2):243-250
Background/Aims:
Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea.
Methods:
This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans.
Results:
A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR.
Conclusions
Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.
8.Medical disputes involving lower gastrointestinal endoscopies: cases from the Korean Medical Dispute Mediation and Arbitration Agency
Eun Hye OH ; Jeong Eun SHIN ; Jun Yong BAE ; Yoon Suk LEE ; Yehyun PARK ; Yong Hwan KWON ; Chang Nyol PAIK ; Jun Kyu LEE ; Tae Hee LEE
The Korean Journal of Internal Medicine 2025;40(3):404-426
Background/Aims:
As the number of lower gastrointestinal endoscopies and high-risk examinees increases, the incidence of adverse events associated with these endoscopies has also increased. Medical disputes and lawsuits related to adverse events are rapidly increasing.
Methods:
Medical disputes related to lower gastrointestinal endoscopy that had been filed in Korean Medical Dispute Mediation and Arbitration Agency (K-medi) from April 2012 to August 2020 were evaluated with the corresponding medical records and written appraisal. Facilities, patients, procedures, adverse events, and outcome-related variables related to medical disputes were analyzed.
Results:
As the number of lower gastrointestinal endoscopies in Korea increases each year, the number of medical disputes related to lower gastrointestinal endoscopy appraised by K-medi has also increased yearly during the same period. Among the 121 cases analyzed, 86 (71.1%) were conciliated and 35 (28.9%) were cosigned by prosecution. Perforations accounted for the largest proportion of cases (93 cases, 76.9%). Most patients (n = 119, 98.3%) underwent non-emergent procedures, and only 10 (8.3%) underwent them for therapeutic purposes. Approximately one-fifth of the patients (n = 25, 20.7%) died.
Conclusions
The number of medical disputes related to lower gastrointestinal endoscopy are increasing. To prevent this, it is important to review the data on existing cases and establish specific response guidelines.
9.Characteristics of premenopausal breast cancer patients with a midrange 21-gene recurrence score
Jung Min PARK ; Suk Jun LEE ; Jee Hyun AHN ; Chan Seok YOON ; Seho PARK
Annals of Surgical Treatment and Research 2025;108(4):219-230
Purpose:
The results of the TAILORx trial have shown that premenopausal patients with intermediate Oncotype Dx (ODx) recurrence score of 16–25 may benefit from adjuvant chemotherapy. In addition, the clinicopathological features showed the information complementary to ODx results. However, the characteristics may vary depending on menopausal status even in the same score. This study aimed to analyze the differences in the clinical characteristics by menopausal status.
Methods:
This study conducted a retrospective analysis of 756 patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, and node-negative breast cancer who underwent the ODx test from July 2013 to December 2020 at the Severance Hospital.
Results:
Of the 756 patients, 261 patients were postmenopausal, and 495 were premenopausal. The premenopausal patients with a midrange ODx had similar clinicopathological features as compared to those with a high ODx. Conversely, the postmenopausal patients with a midrange ODx did not show significantly different clinicopathological features from those with a low ODx, whereas a difference was seen as compared to those with a high ODx.
Conclusion
In this study, unlike the postmenopausal patients, some of the clinicopathological characteristics of the premenopausal patients with a midrange ODx were closer to those with a high ODx than those with a low ODx. In the premenopausal patients with a midrange ODx, considering the baseline characteristic itself, there was a significant difference between those with a low ODx when compared with postmenopausal patients. Therefore, more aggressive treatment decisions may be helpful in premenopausal patients with a midrange ODx.
10.Characteristics and outcomes of portal vein thrombosis in patients with inflammatory bowel disease in Korea
Ki Jin KIM ; Su-Bin SONG ; Jung-Bin PARK ; June Hwa BAE ; Ji Eun BAEK ; Ga Hee KIM ; Min-Jun KIM ; Seung Wook HONG ; Sung Wook HWANG ; Dong-Hoon YANG ; Byong Duk YE ; Jeong-Sik BYEON ; Seung-Jae MYUNG ; Suk-Kyun YANG ; Chang Sik YU ; Yong-Sik YOON ; Jong-Lyul LEE ; Min Hyun KIM ; Ho-Su LEE ; Sang Hyoung PARK
The Korean Journal of Internal Medicine 2025;40(2):243-250
Background/Aims:
Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea.
Methods:
This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans.
Results:
A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR.
Conclusions
Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.

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