1.Ethnic Heterogeneity in Reproductive Risk Factors for Breast Cancer, With a Focus on Asian Populations:A Meta-analysis
Youjin HONG ; Soseul SUNG ; Woojin LIM ; Sungji MOON ; Kwang-Pil KO ; Jung Eun LEE ; Inah KIM ; Sun Ha JEE ; Sun-Seog KWEON ; Min-Ho SHIN ; Sangmin PARK ; Seung-Ho RYU ; Sun Young YANG ; Jeongseon KIM ; Sang-Wook YI ; Sue K. PARK
Journal of Cancer Prevention 2026;31(1):20-27
suggest that some reproductive factors associated with BC differ across ethnicities and time trends, perhaps due to the prevalence of reproductive factors and the baseline hazard of BC.
2.The Incidence of Occult Malignancy in Contralateral Risk Reducing Mastectomy Among Affected Breast Cancer Gene Mutation Carriers in South Korea
Cho Eun LEE ; Dong Seung SHIN ; Ki Jo KIM ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Goo-Hyun MUN ; Jai-Kyong PYON ; Byung-Joon JEON ; Kyongje WOO ; Jeong Eon LEE
Journal of Breast Cancer 2025;28(1):1-10
Purpose:
Breast cancer gene (BRCA) mutation is a well-known risk factor for breast cancer, and clinical interest in prophylactic mastectomy has increased in recent years.We investigated patients who were BRCA mutation carriers and underwent contralateral risk-reducing mastectomy (RRM), focusing on the incidence of occult malignancy after contralateral RRM.
Methods:
Prospectively collected data of patients with breast cancer treated at a single institution were retrospectively reviewed. Patients who underwent RRM with BRCA mutation who underwent RRM between January 2010 and November 2023 were included in this study.Among patients who underwent contralateral RRM, those with a primary cancer diagnosis were included, and those with occult malignancy on the contralateral RRM side were reviewed additionally. The demographics and pathologies of both primary breast cancer and occult malignancies were evaluated.
Results:
In our institution, 925 patients were identified as BRCA mutation carriers, and 320 patients underwent contralateral RRM along with primary breast cancer surgery. BRCA2 mutation occurred more frequently (54.8%) in the overall BRCA mutation cohort. Furthermore, we reviewed 320 patients diagnosed with breast cancer and detected as BRCA mutation carriers who underwent contralateral RRM; high proportion of them were BRCA1 mutation carriers.Interestingly, we found a low incidence of only seven patients (2.2%) with occult malignancy on contralateral RRM side, which is different from that reported in other nations.
Conclusion
The incidence of occult malignancy in the contralateral breast of breast cancer patients with breast cancer with BRCA mutation is significantly low, and may be influenced by several factors. Increased utilization of screening and advancements in diagnostic technologies in South Korea have reduced the chance of occult malignancy in RRM, and a variety of pathologic examination methods may affect the rate of incidence.
3.The Incidence of Occult Malignancy in Contralateral Risk Reducing Mastectomy Among Affected Breast Cancer Gene Mutation Carriers in South Korea
Cho Eun LEE ; Dong Seung SHIN ; Ki Jo KIM ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Goo-Hyun MUN ; Jai-Kyong PYON ; Byung-Joon JEON ; Kyongje WOO ; Jeong Eon LEE
Journal of Breast Cancer 2025;28(1):1-10
Purpose:
Breast cancer gene (BRCA) mutation is a well-known risk factor for breast cancer, and clinical interest in prophylactic mastectomy has increased in recent years.We investigated patients who were BRCA mutation carriers and underwent contralateral risk-reducing mastectomy (RRM), focusing on the incidence of occult malignancy after contralateral RRM.
Methods:
Prospectively collected data of patients with breast cancer treated at a single institution were retrospectively reviewed. Patients who underwent RRM with BRCA mutation who underwent RRM between January 2010 and November 2023 were included in this study.Among patients who underwent contralateral RRM, those with a primary cancer diagnosis were included, and those with occult malignancy on the contralateral RRM side were reviewed additionally. The demographics and pathologies of both primary breast cancer and occult malignancies were evaluated.
Results:
In our institution, 925 patients were identified as BRCA mutation carriers, and 320 patients underwent contralateral RRM along with primary breast cancer surgery. BRCA2 mutation occurred more frequently (54.8%) in the overall BRCA mutation cohort. Furthermore, we reviewed 320 patients diagnosed with breast cancer and detected as BRCA mutation carriers who underwent contralateral RRM; high proportion of them were BRCA1 mutation carriers.Interestingly, we found a low incidence of only seven patients (2.2%) with occult malignancy on contralateral RRM side, which is different from that reported in other nations.
Conclusion
The incidence of occult malignancy in the contralateral breast of breast cancer patients with breast cancer with BRCA mutation is significantly low, and may be influenced by several factors. Increased utilization of screening and advancements in diagnostic technologies in South Korea have reduced the chance of occult malignancy in RRM, and a variety of pathologic examination methods may affect the rate of incidence.
4.The Incidence of Occult Malignancy in Contralateral Risk Reducing Mastectomy Among Affected Breast Cancer Gene Mutation Carriers in South Korea
Cho Eun LEE ; Dong Seung SHIN ; Ki Jo KIM ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Goo-Hyun MUN ; Jai-Kyong PYON ; Byung-Joon JEON ; Kyongje WOO ; Jeong Eon LEE
Journal of Breast Cancer 2025;28(1):1-10
Purpose:
Breast cancer gene (BRCA) mutation is a well-known risk factor for breast cancer, and clinical interest in prophylactic mastectomy has increased in recent years.We investigated patients who were BRCA mutation carriers and underwent contralateral risk-reducing mastectomy (RRM), focusing on the incidence of occult malignancy after contralateral RRM.
Methods:
Prospectively collected data of patients with breast cancer treated at a single institution were retrospectively reviewed. Patients who underwent RRM with BRCA mutation who underwent RRM between January 2010 and November 2023 were included in this study.Among patients who underwent contralateral RRM, those with a primary cancer diagnosis were included, and those with occult malignancy on the contralateral RRM side were reviewed additionally. The demographics and pathologies of both primary breast cancer and occult malignancies were evaluated.
Results:
In our institution, 925 patients were identified as BRCA mutation carriers, and 320 patients underwent contralateral RRM along with primary breast cancer surgery. BRCA2 mutation occurred more frequently (54.8%) in the overall BRCA mutation cohort. Furthermore, we reviewed 320 patients diagnosed with breast cancer and detected as BRCA mutation carriers who underwent contralateral RRM; high proportion of them were BRCA1 mutation carriers.Interestingly, we found a low incidence of only seven patients (2.2%) with occult malignancy on contralateral RRM side, which is different from that reported in other nations.
Conclusion
The incidence of occult malignancy in the contralateral breast of breast cancer patients with breast cancer with BRCA mutation is significantly low, and may be influenced by several factors. Increased utilization of screening and advancements in diagnostic technologies in South Korea have reduced the chance of occult malignancy in RRM, and a variety of pathologic examination methods may affect the rate of incidence.
5.Identification of Poor Prognostic Markers in Triple-Negative Breast Cancer Using Whole Exome Sequencing
Seungju LEE ; Hyun Yul KIM ; Youn Joo JUNG ; Seok-Kyung KANG ; Miri RYU ; Meehyun LEE ; Sun Min LEE ; Seung Hwan OH ; Jieon LEE ; Seongdo JEONG ; Junho KANG ; Jee Yeon KIM
Journal of Breast Cancer 2025;28(6):406-418
Purpose:
Triple-negative breast cancer (TNBC) is a heterogeneous and aggressive subtype of breast cancer associated with poor clinical outcomes. Although programmed death ligand 1 (PD-L1) expression has emerged as both a prognostic and predictive biomarker, its utility remains limited, especially in PD-L1-negative tumors. The identification of additional molecular markers is crucial for improving prognostic stratification and guiding treatment strategies.
Methods:
Formalin-fixed, paraffin-embedded tumor tissues from 38 patients with TNBC were analyzed. PD-L1 expression was assessed using immunohistochemistry and categorized as positive or negative. Whole-exome sequencing was performed, and somatic variants were analyzed using Maftools. Mutational signatures were compared with the Catalogue Of Somatic Mutations In Cancer reference profiles. Survival analyses were performed to evaluate the prognostic significance of the identified variants.
Results:
Mutational landscape analysis revealed that C>T and G>A transitions were the most frequent base substitutions. PD-L1-negative tumors exhibited a predominance of single-base substitution (SBS) 5, whereas PD-L1-positive tumors resembled SBS6, reflecting potential differences in the underlying mutational processes. Comparative analysis identified 12 PD-L1-negative-specific and seven PD-L1-positive-specific variants. Among PD-L1-negative tumors, mutations in ANGPTL5 and KIAA1549L were significantly associated with worse overall survival.
Conclusion
Our findings highlight distinct mutational profiles and prognostic variants according to PD-L1 status in TNBC. ANGPTL5 and KIAA1549L variants may serve as potential prognostic markers for PD-L1-negative tumors. These results underscore the value of incorporating genomic information to refine the prognostic stratification of TNBC.
6.Impact of emergency room occupancy on the timing of antibiotic administration in patients with septic shock who visited the emergency room
Taek Kyu NAM ; Ji Ho RYU ; Mun ki MIN ; Daesup LEE ; Mose CHUN ; Seung Woo SON ; Yang Wook TAE ; Minjee LEE
Journal of the Korean Society of Emergency Medicine 2024;35(3):212-222
Objective:
The emergency department (ED) serves as the initial point of contact for many sepsis patients, but crowding can affect the timely delivery of essential interventions, such as antibiotics. This paper explores the relationship between antibiotics administration and ED crowding in the context of sepsis management.
Methods:
This single-center study at a tertiary care hospital included adult patients aged 18 and above who visited the emergency department from January 2018 to December 2022. Patients showing signs of septic shock upon arrival were selected as the study population. This study examined factors such as emergency department occupancy, antibiotic administration time, and their correlation with timely antibiotic treatment.
Results:
This study of 839 adult patients with septic shock found a weak correlation (P=0.107) between the time to antibiotic administration and department occupancy. Delayed antibiotic administration was observed when the occupancy exceeded 100%. On the other hand, there was no significant correlation between antibiotic administration within one hour and department occupancy.
Conclusion
Various factors, such as ED bed occupancy, medical staffing, resource allocation, and patient acuity, must be considered when comprehensively evaluating the impact of ED overcrowding on treating septic shock and other conditions.
7.Antigenicity evaluation of lac color and exploratory study for identifying potential biomarkers of anaphylaxis
Hyun‑Jin LIM ; Kang Min HAN ; Seung‑Hyun KIM ; Soo‑Kyung RYU ; Ji‑Ran YOU ; Jung‑Hee YOON ; Euna KWON ; Ji‑Eun KIM ; Byeong‑Cheol KANG
Laboratory Animal Research 2024;40(4):461-475
Background:
Lac color, a natural red dye derived from the larvae of laccifer lacca kerr, is one of the most commonly used substances in food. To date, no studies have reported on the antigenicity of lac color and the other biomarkers that can determine anaphylactic reactions. To address this, we evaluated the antigenicity of lac color through active systemic anaphylaxis (ASA) in addition to identifying potential biomarkers performing exploratory studies. For ASA test, Guinea pigs (n = 5) were sensitized with 0(negative control), 4 mg/kg of lac color, 4 mg/kg of lac color + FCA, and 5 mg/kg of ovalbumin + FCA (positive control) 3 times a week for three weeks. Fourteen days after the last sensi‑ tization, animals were challenged intravenously weekly for two weeks. Hematological and histopathological analyses were performed and compared to control groups.
Results:
In the ASA test, all lac color groups showed mild symptoms such as nose rubbing, urination, and evacuation, which are insufficient indicators of anaphylaxis. Exploratory studies identified several biomarkers: decreased platelet count, and increased basophil count; distention in the lung, and redness on the inner wall of trachea; mononuclear inflammatory cell infiltration (MICI) in the ear, and heart hemorrhage. When these biomarkers were applied to the ASA test of lac color, in comparison to the negative control group, the positive control group (ovalbumin + FCA) showed a significant over 60-fold reduction in platelet count and nearly threefold higher basophil count compared to other groups. Furthermore, only positive control group exhibited full lung distention and severe redness on the inner wall of the trachea. Mononuclear inflammatory cell infiltration (MICI) in the ear was about three times higher, and heart hemorrhage was only present in the positive control group compared to others. None of the lac color groups were different from the negative control group (p > 0.05), whereas the positive control group was significantly different (p < 0.05).
Conclusions
Our study concludes that lac color, at the tested concentrations, does not induce antigenicity in the guinea pig model, providing valuable safety data. Furthermore, the biomarkers identified in this study offer a supportive approach to evaluating the immunogenicity of substances in future research.
8.Helicobacter pylori Isolation and Antibiotic Susceptibility Testing Using Rapidly Frozen Biopsy Samples
Kee Don CHOI ; Jung Mogg KIM ; Gwang Ho BAIK ; Jun Chul PARK ; Hye-Kyung JUNG ; Han Seung RYU ; Soo-Jeong CHO ; Cheol Min SHIN ; Hwoon-Yong JUNG ;
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2024;24(4):360-364
Objectives:
To involve institutions without the ability to perform susceptibility testing, long-term storage of tissue sample is critical to isolate the bacteria in a central laboratory. The aim of the study was to investigate the feasibility of H. pylori isolation and antibiotic susceptibility testing using rapidly frozen biopsy specimens collected from various institutions.
Methods:
Eight institutions located in various regions of Korea participated in the study. Patients requiring upper endoscopy and H. pylori testing were screened. Two biopsy samples were taken from the stomach. One was placed in a sterile Eppendorf tube and then immediately placed in a vacuum bottle containing dry ice, which was stored at -80°C. The other was used in a rapid urease test. Collected samples were delivered to a central laboratory. The bacteria were isolated from the frozen samples under microaerophilic conditions. The agar dilution method was used to determine the minimum inhibitory concentration (MIC) of amoxicillin, clarithromycin, metronidazole, tetracycline, ciprofloxacin, and levofloxacin for each H. pylori isolate.
Results:
Patients with a positive rapid urease test result (n=113) were enrolled. The mean age was 56.6±12.3 years. The male:female ratio was 64:49. The overall culture success rate was 77.0% (87/113). MIC values were determined using isolated 87 H. pylori strains. Rates of resistance to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, and ciprofloxacin were 23.0%, 25.3%, 28.7%, 1.1%, 33.3%, and 34.5%, respectively.
Conclusions
It is feasible to perform H. pylori isolation and antimicrobial susceptibility testing using rapidly frozen and transported biopsy specimens.
9.Perioperative nutritional practice of surgeons in Korea: a survey study
Ji-Hyeon PARK ; Mi Ran JUNG ; Sang Hyun KIM ; Hongbeom KIM ; Gyeongsil LEE ; Jae-Seok MIN ; Heung-Kwon OH ; Jung Hoon BAE ; Yoona CHUNG ; Dong-Seok HAN ; Seung Wan RYU ;
Annals of Clinical Nutrition and Metabolism 2024;16(3):134-148
Purpose:
Enhanced recovery after surgery (ERAS) protocols advocate reduced fasting and early nutrition to improve recovery in surgical patients. However, data on ERAS implementation among Korean surgeons performing major abdominal surgeries remain sparse.
Methods:
A survey conducted by the External Relation Committee of the Korean Society of Surgical Metabolism and Nutrition assessed perioperative nutritional practices among 389 Korean general surgeons from February to September 2023. The survey covered preoperative fasting, carbohydrate drinks, nasogastric tube use, postoperative dietary progression, parenteral nutrition (PN), and oral supplements, yielding 551 responses stratified by specialty.
Results:
More than 80% of respondents practiced “midnight NPO (Nil Per Os)” fasting, often at the anesthesiology department’s request, while 70%–80% reported no use of preoperative carbohydrate drinks. Most surgeons began dietary progression with water on postoperative day one, advancing to a liquid or soft diet by day two. PN was routinely prescribed by 49% of respondents, with a common dosage of 1,000–1,500 kcal/d. Oral supplements were selectively provided, with 21% of surgeons prescribing them universally.
Conclusion
The results reveal significant variability in perioperative nutrition practices across Korean surgical specialties, with many adhering to traditional practices despite ERAS guidelines. These findings highlight a need for standardized guidelines in Korea to optimize perioperative nutritional support and improve patient recovery outcomes following major abdominal surgeries.
10.Perioperative nutritional practice of surgeons in Korea: a survey study
Ji-Hyeon PARK ; Mi Ran JUNG ; Sang Hyun KIM ; Hongbeom KIM ; Gyeongsil LEE ; Jae-Seok MIN ; Heung-Kwon OH ; Jung Hoon BAE ; Yoona CHUNG ; Dong-Seok HAN ; Seung Wan RYU ;
Annals of Clinical Nutrition and Metabolism 2024;16(3):134-148
Purpose:
Enhanced recovery after surgery (ERAS) protocols advocate reduced fasting and early nutrition to improve recovery in surgical patients. However, data on ERAS implementation among Korean surgeons performing major abdominal surgeries remain sparse.
Methods:
A survey conducted by the External Relation Committee of the Korean Society of Surgical Metabolism and Nutrition assessed perioperative nutritional practices among 389 Korean general surgeons from February to September 2023. The survey covered preoperative fasting, carbohydrate drinks, nasogastric tube use, postoperative dietary progression, parenteral nutrition (PN), and oral supplements, yielding 551 responses stratified by specialty.
Results:
More than 80% of respondents practiced “midnight NPO (Nil Per Os)” fasting, often at the anesthesiology department’s request, while 70%–80% reported no use of preoperative carbohydrate drinks. Most surgeons began dietary progression with water on postoperative day one, advancing to a liquid or soft diet by day two. PN was routinely prescribed by 49% of respondents, with a common dosage of 1,000–1,500 kcal/d. Oral supplements were selectively provided, with 21% of surgeons prescribing them universally.
Conclusion
The results reveal significant variability in perioperative nutrition practices across Korean surgical specialties, with many adhering to traditional practices despite ERAS guidelines. These findings highlight a need for standardized guidelines in Korea to optimize perioperative nutritional support and improve patient recovery outcomes following major abdominal surgeries.

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