1.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.
2.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.
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.The importance of compression time in stapled hemorrhoidopexy: is patience a virtue?
Byung Eun YOO ; Wook Ho KANG ; Yong Teak KO ; Young Chan LEE ; Cheong Ho LIM
Annals of Coloproctology 2024;40(2):176-181
Purpose:
The aim of this study was to evaluate whether longer compression time before firing the stapler reduced the postoperative complications related to staple line formation in stapled hemorrhoidopexy.
Methods:
This retrospective case-control study was conducted at a colorectal-anal specialty hospital. Consecutive patients with grades III and IV hemorrhoids who underwent stapled hemorrhoidopexy between January 2016 and November 2019 were included. According to the compression time, patients were assigned to the long compression time group (2 minutes) or the typical compression time group (30 seconds). The primary outcome measure was incidence of staple line complications such as dehiscence, bleeding, and stenosis.
Results:
A total of 348 patients treated with stapled hemorrhoidopexy were evaluated. Seventy-three and 275 patients were included in the long compression time group and the typical compression time group, respectively. No significant differences were observed in patient characteristics between the groups. However, additional procedures were performed more frequently in the typical compression time group (78.1% vs. 92.0%, P=0.001). Bleeding occurred more frequently in the typical compression time group (1.4% vs. 8.4%, P=0.030). The rates of dehiscence and stenosis were not significantly different between the groups. Fecal urgency developed more frequently in the typical compression time group (0% vs. 5.1%, P=0.040). In logistic regression analysis, typical compression time (30 seconds) was the only risk factor for bleeding (odds ratio, 8.496; P=0.040).
Conclusion
Longer compression time was associated with a decreased incidence of postoperative bleeding after stapled hemorrhoidopexy.
5.Evaluation of safety and operative time in tumescent-free robotic nipple-sparing mastectomy: a retrospective single-center cohort study
Yung-Huyn HWANG ; Hyun Ho HAN ; Jin Sup EOM ; Tae-Kyung Robyn YOO ; Jisun KIM ; Il Yong CHUNG ; BeomSeok KO ; Hee Jeong KIM ; Jong Won LEE ; Byung Ho SON ; Sae Byul LEE
Annals of Surgical Treatment and Research 2024;107(1):8-15
Purpose:
Tumescent in nipple-sparing mastectomy (NSM) has been reported to increase the risk of necrosis by impairing blood flow to the skin flap and nipple-areolar complex. At our institution, we introduced a tumescent-free robotic NSM using the da Vinci single-port system (Intuitive Surgical, Inc.).
Methods:
We conducted a retrospective analysis of patients who underwent tumescent-free robotic NSM between October 2020 and March 2023 at Asan Medical Center (Seoul, Korea). Clinicopathological characteristics, adverse events, and operative time were evaluated.
Results:
During the study period, 118 patients underwent tumescent-free robotic NSM. Thirty-one patients (26.3%) experienced an adverse event. Five patients (4.2%) were classified as grade III based on the Clavien-Dindo classification and required surgery. The mean total operative time was 467 minutes for autologous tissue reconstruction (n = 49) and 252 minutes for implants (n = 69). No correlation was found between the cumulative number of surgical cases and the breast operative time (P = 0.30, 0.52, 0.59 for surgeons A, B, C) for the 3 surgeons. However, a significant linear relationship (P < 0.001) was observed, with the operative time increasing by 13 minutes for every 100-g increase in specimen weight.
Conclusion
Tumescent-free robotic NSM is a safe procedure with a feasible operative time and few adverse events.
6.Implementation of BRCA Test among Young Breast Cancer Patients in South Korea: A Nationwide Cohort Study
Yung-Huyn HWANG ; Tae-Kyung YOO ; Sae Byul LEE ; Jisun KIM ; Beom Seok KO ; Hee Jeong KIM ; Jong Won LEE ; Byung Ho SON ; Il Yong CHUNG
Cancer Research and Treatment 2024;56(3):802-808
Purpose:
This study aimed to investigate the frequency of BRCA testing and related factors among young breast cancer patients (age < 40 years) in South Korea.
Materials and Methods:
We conducted a nationwide retrospective cohort study using data from the Health Insurance Review and Assessment claims. Newly diagnosed breast cancer patients younger than 40 were included. Annual BRCA testing ratios (number of BRCA test recipients/the number of patients undergoing breast cancer surgery in each year) were analyzed by region and health care delivery system. We investigated the location of breast cancer diagnosis and BRCA testing.
Results:
From January 2010 to December 2020, there were 25,665 newly diagnosed young breast cancer patients, of whom 12,186 (47.5%) underwent BRCA testing. The BRCA testing ratios increased gradually from 0.084 (154/1,842) in 2010 to 0.961 (1,975/2,055) in 2020. Medical aid (vs. health insurance) and undergoing surgery in metropolitan cities or others (vs. Seoul), general hospitals, and clinics (vs. tertiary hospitals) were associated with a lower likelihood of BRCA testing. While 97.8% of the patients diagnosed in Seoul underwent BRCA testing in Seoul, 22.9% and 29.2% of patients who were diagnosed in metropolitan areas and other regions moved to Seoul and underwent BRCA testing, respectively.
Conclusion
The frequency of BRCA testing has increased over time in South Korea, with Seoul showing a particularly high rate of testing. About one-quarter of patients diagnosed with breast cancer outside of Seoul moved to Seoul and underwent BRCA testing.
7.Contemporary Statistics of Acute Ischemic Stroke and Transient Ischemic Attack in 2021: Insights From the CRCS-K-NIH Registry
Do Yeon KIM ; Tai Hwan PARK ; Yong-Jin CHO ; Jong-Moo PARK ; Kyungbok LEE ; Minwoo LEE ; Juneyoung LEE ; Sang Yoon BAE ; Da Young HONG ; Hannah JUNG ; Eunvin KO ; Hyung Seok GUK ; Beom Joon KIM ; Jun Yup KIM ; Jihoon KANG ; Moon-Ku HAN ; Sang-Soon PARK ; Keun-Sik HONG ; Hong-Kyun PARK ; Jeong-Yoon LEE ; Byung-Chul LEE ; Kyung-Ho YU ; Mi Sun OH ; Dong-Eog KIM ; Dong-Seok GWAK ; Soo Joo LEE ; Jae Guk KIM ; Jun LEE ; Doo Hyuk KWON ; Jae-Kwan CHA ; Dae-Hyun KIM ; Joon-Tae KIM ; Kang-Ho CHOI ; Hyunsoo KIM ; Jay Chol CHOI ; Joong-Goo KIM ; Chul-Hoo KANG ; Sung-il SOHN ; Jeong-Ho HONG ; Hyungjong PARK ; Sang-Hwa LEE ; Chulho KIM ; Dong-Ick SHIN ; Kyu Sun YUM ; Kyusik KANG ; Kwang-Yeol PARK ; Hae-Bong JEONG ; Chan-Young PARK ; Keon-Joo LEE ; Jee Hyun KWON ; Wook-Joo KIM ; Ji Sung LEE ; Hee-Joon BAE ;
Journal of Korean Medical Science 2024;39(34):e278-
This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively.Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques.There has been a decrease in intravenous thrombolysis rates, from 12% in 2017–2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for noncardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.
8.Waiting Time for Breast Cancer Treatment in Korea: A Nationwide Cohort Study
Young-jin LEE ; Jae Ho JEONG ; Jinhong JUNG ; Tae-Kyung YOO ; Sae Byul LEE ; Jisun KIM ; Beom Seok KO ; Hee Jeong KIM ; Jong Won LEE ; Byung Ho SON ; Il Yong CHUNG
Journal of Breast Cancer 2023;26(4):334-343
Purpose:
This study aimed to analyze the waiting time for initial treatment after breast cancer diagnosis and determine the factors influencing treatment delay in South Korea.
Methods:
This nationwide retrospective cohort study was conducted using the Health Insurance Review and Assessment data. The participants were classified according to the regions where their biopsy and treatment were performed (Seoul-Seoul, Metro-Metro, OtherOther, Metro-Seoul, Other-Seoul). Waiting time was analyzed according to regional subgroup, year of diagnosis, and type of treatment. Multivariable logistic regression models were constructed to identify the factors associated with treatment delay (after 30 days of diagnosis).
Results:
A total of 133,514 participants newly diagnosed between January 2010 and December 2017 were included in the study. The median waiting time for initial treatment in the total population increased from 8 days, in 2010, to 14 days, in 2017. In the Seoul-Seoul group, the waiting time increased from 10 days, in 2010, to 16 days, in 2017. Although the median waiting time was approximately 10 days in the Metro-Metro and Other-Other groups, it was 27 and 24 days, in the Metro-Seoul and Other-Seoul group, respectively, in 2017. The proportion of delayed upfront surgery by more than 30 days was higher in the Metro-Seoul (odds ratio [OR], 8.088; 95% confidence interval [CI], 7.357–8.893; p < 0.001) and OtherSeoul (OR, 6.210; 95% CI, 5.717–6.750; p < 0.001) groups than in the Metro-Metro (OR, 1.468; 95% CI, 1.352–1.594; p < 0.001) and Other-Other (reference) groups. Previous medical history and treatment at tertiary hospital were observed as factors related to delayed surgery.
Conclusion
Waiting times for breast cancer surgery have increased across all regions of Korea, with those traveling to Seoul experiencing particularly long wait times.
9.Fracture Liaison Service in Korea: 2022 Position Statement of the Korean Society for Bone and Mineral Research
Jae-Young LIM ; Young Yul KIM ; Jin-Woo KIM ; Seongbin HONG ; Kyunghoon MIN ; Jaewon BEOM ; Byung-Ho YOON ; Sang Yoon LEE ; Sung Hye KONG ; Jun-Il YOO ; Myung Sook PARK ; Jae-Hwi NHO ; Sangbong KO ; Min Wook JOO ; Dong Hwan KIM ; Chan Ho PARK ; Tae-Young KIM ; Seil SOHN ; So Young PARK ; A Ram HONG ; Young Joo KWON ; Sung Bae PARK ; Young-Kyun LEE ; Nam Hoon MOON ; Bo Ryun KIM ; Yongsoon PARK ; Yonghan CHA ; Yong-Chan HA
Journal of Bone Metabolism 2023;30(1):31-36
Osteoporosis and osteoporotic fractures cause socioeconomic concerns, and medical system and policies appear insufficient to prepare for these issues in Korea, where the older adult population is rapidly increasing. Many countries around the world are already responding to osteoporosis and osteoporotic fractures by adopting fracture liaison service (FLS), and such an attempt has only begun in Korea. In this article, we introduce the operation methods for institutions implementing FLS and characteristics of services, and activities of the FLS Committee for FLS implementation in the Korean Society for Bone and Mineral Research. In addition, we hope that the current position statement will contribute to the implementation of FLS in Korea and impel policy changes to enable a multidisciplinary and integrated FLS operated under the medical system.
10.Association between pralidoxime administration during cardiopulmonary resuscitation and brain tissue oxygen tension in a swine model of cardiac arrest
Sang Won KO ; Young Il MIN ; Kyung Woon JEUNG ; Hyoung Youn LEE ; Yong Hun JUNG ; Byung Kook LEE ; Dong Hun LEE ; Tag HEO
Journal of the Korean Society of Emergency Medicine 2023;34(6):498-504
Objective:
Previous studies have suggested that epinephrine reduces brain tissue O2 tension (PbtO2) after the return of spontaneous circulation (ROSC) via α1-adrenoceptor stimulation and that pralidoxime had α1-adrenoceptor inhibitory action together with non-adrenergic vasopressor action. We sought to investigate the effects of pralidoxime administered during cardiopulmonary resuscitation (CPR) as a sole vasopressor on PbtO2 after ROSC. We hypothesized that pralidoxime administration would lead to a comparable ROSC rate and a higher PbtO2 after ROSC when compared to epinephrine administration.
Methods:
After 7 minutes of ventricular fibrillation, 24 pigs randomly received either pralidoxime or epinephrine during CPR. Cerebral measurements, including PbtO2, were measured from the parietal cortices during the 60-minute postROSC period.
Results:
Coronary perfusion pressure (CPP) during CPR was significantly higher in the epinephrine group than in the pralidoxime group (P=0.012). All the animals in the epinephrine group achieved ROSC, while seven (58.3%) did so in the pralidoxime group (P=0.037). The area under the curves for PbtO2 during the post-ROSC period did not differ between the two groups.
Conclusion
Pralidoxime alone was significantly inferior to epinephrine in increasing CPP and achieving ROSC. In addition, pralidoxime administration did not improve PbtO2 during the post-resuscitation period as compared with epinephrine.

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