1.Association between Tumor Size at the Time of Disease Progression and Survival Outcomes
Chi Hoon MAENG ; Bum Jun KIM ; Myung-Ju AHN ; In Sil CHOI ; Dae Young ZANG ; Bo-Hyung KIM ; Minji KWON ; Dae Seog HEO ; Bhumsuk KEAM
Cancer Research and Treatment 2025;57(2):362-368
Purpose:
This study evaluates the prognostic significance of tumor size at disease progression (PD) and depth of response (DOR) in cancer patients.
Materials and Methods:
We performed post hoc analysis using data from six prospective clinical trials conducted by the Korean Cancer Study Group. Patients with tumor size at PD was categorized into ‘Mild PD’ and ‘Significant PD’ based on the cutoff values of relative change from baseline using maximally selected rank statistics. The overall survival (OS) and progression-free survival (PFS) were compared between PD and DOR categories.
Results:
Among the 194 evaluable patients, 130 experienced PD. A 35.48% decrease from baseline in tumor size at PD was chosen for the cutoff between mild and significant PD for OS (mild PD: tumor size from the baseline ≤ −35.48%; significant PD > −35.48%). The mild PD had superior OS compared to the significant PD (25.8 vs. 12.8 months; Hazard ratio [HR] 0.47, 95% CI 0.266-0.843, p=0.009). When using an exploratory cutoff based on whether the tumor size was below vs. exceeded from the baseline (mild PD: tumor size from the baseline ≤ 0%; significant PD > 0%), OS remained significantly longer in the mild PD (17.1 vs. 11.8 months; HR 0.60, 95% CI 0.392-0.932, p=0.021). The greatest DOR was associated with the longest OS and PFS (p<0.001 for both).
Conclusion
Tumor size at PD and DOR were significant prognostic factors for progressive disease. Maintaining a sufficiently reduced tumor size even during PD was associated with better survival outcomes.
2.The Survival and Financial Benefit of Investigator-Initiated Trials Conducted by Korean Cancer Study Group
Bum Jun KIM ; Chi Hoon MAENG ; Bhumsuk KEAM ; Young-Hyuck IM ; Jungsil RO ; Kyung Hae JUNG ; Seock-Ah IM ; Tae Won KIM ; Jae Lyun LEE ; Dae Seog HEO ; Sang-We KIM ; Keunchil PARK ; Myung-Ju AHN ; Byoung Chul CHO ; Hoon-Kyo KIM ; Yoon-Koo KANG ; Jae Yong CHO ; Hwan Jung YUN ; Byung-Ho NAM ; Dae Young ZANG
Cancer Research and Treatment 2025;57(1):39-46
Purpose:
The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients.
Materials and Methods:
We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided.
Results:
From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient.
Conclusion
Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.
3.Association between Tumor Size at the Time of Disease Progression and Survival Outcomes
Chi Hoon MAENG ; Bum Jun KIM ; Myung-Ju AHN ; In Sil CHOI ; Dae Young ZANG ; Bo-Hyung KIM ; Minji KWON ; Dae Seog HEO ; Bhumsuk KEAM
Cancer Research and Treatment 2025;57(2):362-368
Purpose:
This study evaluates the prognostic significance of tumor size at disease progression (PD) and depth of response (DOR) in cancer patients.
Materials and Methods:
We performed post hoc analysis using data from six prospective clinical trials conducted by the Korean Cancer Study Group. Patients with tumor size at PD was categorized into ‘Mild PD’ and ‘Significant PD’ based on the cutoff values of relative change from baseline using maximally selected rank statistics. The overall survival (OS) and progression-free survival (PFS) were compared between PD and DOR categories.
Results:
Among the 194 evaluable patients, 130 experienced PD. A 35.48% decrease from baseline in tumor size at PD was chosen for the cutoff between mild and significant PD for OS (mild PD: tumor size from the baseline ≤ −35.48%; significant PD > −35.48%). The mild PD had superior OS compared to the significant PD (25.8 vs. 12.8 months; Hazard ratio [HR] 0.47, 95% CI 0.266-0.843, p=0.009). When using an exploratory cutoff based on whether the tumor size was below vs. exceeded from the baseline (mild PD: tumor size from the baseline ≤ 0%; significant PD > 0%), OS remained significantly longer in the mild PD (17.1 vs. 11.8 months; HR 0.60, 95% CI 0.392-0.932, p=0.021). The greatest DOR was associated with the longest OS and PFS (p<0.001 for both).
Conclusion
Tumor size at PD and DOR were significant prognostic factors for progressive disease. Maintaining a sufficiently reduced tumor size even during PD was associated with better survival outcomes.
4.The Survival and Financial Benefit of Investigator-Initiated Trials Conducted by Korean Cancer Study Group
Bum Jun KIM ; Chi Hoon MAENG ; Bhumsuk KEAM ; Young-Hyuck IM ; Jungsil RO ; Kyung Hae JUNG ; Seock-Ah IM ; Tae Won KIM ; Jae Lyun LEE ; Dae Seog HEO ; Sang-We KIM ; Keunchil PARK ; Myung-Ju AHN ; Byoung Chul CHO ; Hoon-Kyo KIM ; Yoon-Koo KANG ; Jae Yong CHO ; Hwan Jung YUN ; Byung-Ho NAM ; Dae Young ZANG
Cancer Research and Treatment 2025;57(1):39-46
Purpose:
The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients.
Materials and Methods:
We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided.
Results:
From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient.
Conclusion
Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.
5.Association between Tumor Size at the Time of Disease Progression and Survival Outcomes
Chi Hoon MAENG ; Bum Jun KIM ; Myung-Ju AHN ; In Sil CHOI ; Dae Young ZANG ; Bo-Hyung KIM ; Minji KWON ; Dae Seog HEO ; Bhumsuk KEAM
Cancer Research and Treatment 2025;57(2):362-368
Purpose:
This study evaluates the prognostic significance of tumor size at disease progression (PD) and depth of response (DOR) in cancer patients.
Materials and Methods:
We performed post hoc analysis using data from six prospective clinical trials conducted by the Korean Cancer Study Group. Patients with tumor size at PD was categorized into ‘Mild PD’ and ‘Significant PD’ based on the cutoff values of relative change from baseline using maximally selected rank statistics. The overall survival (OS) and progression-free survival (PFS) were compared between PD and DOR categories.
Results:
Among the 194 evaluable patients, 130 experienced PD. A 35.48% decrease from baseline in tumor size at PD was chosen for the cutoff between mild and significant PD for OS (mild PD: tumor size from the baseline ≤ −35.48%; significant PD > −35.48%). The mild PD had superior OS compared to the significant PD (25.8 vs. 12.8 months; Hazard ratio [HR] 0.47, 95% CI 0.266-0.843, p=0.009). When using an exploratory cutoff based on whether the tumor size was below vs. exceeded from the baseline (mild PD: tumor size from the baseline ≤ 0%; significant PD > 0%), OS remained significantly longer in the mild PD (17.1 vs. 11.8 months; HR 0.60, 95% CI 0.392-0.932, p=0.021). The greatest DOR was associated with the longest OS and PFS (p<0.001 for both).
Conclusion
Tumor size at PD and DOR were significant prognostic factors for progressive disease. Maintaining a sufficiently reduced tumor size even during PD was associated with better survival outcomes.
6.The Survival and Financial Benefit of Investigator-Initiated Trials Conducted by Korean Cancer Study Group
Bum Jun KIM ; Chi Hoon MAENG ; Bhumsuk KEAM ; Young-Hyuck IM ; Jungsil RO ; Kyung Hae JUNG ; Seock-Ah IM ; Tae Won KIM ; Jae Lyun LEE ; Dae Seog HEO ; Sang-We KIM ; Keunchil PARK ; Myung-Ju AHN ; Byoung Chul CHO ; Hoon-Kyo KIM ; Yoon-Koo KANG ; Jae Yong CHO ; Hwan Jung YUN ; Byung-Ho NAM ; Dae Young ZANG
Cancer Research and Treatment 2025;57(1):39-46
Purpose:
The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients.
Materials and Methods:
We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided.
Results:
From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient.
Conclusion
Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.
7.The Profile of Early Sedation Depth and Clinical Outcomes of Mechanically Ventilated Patients in Korea
Dong-gon HYUN ; Jee Hwan AHN ; Ha-Yeong GIL ; Chung Mo NAM ; Choa YUN ; Jae-Myeong LEE ; Jae Hun KIM ; Dong-Hyun LEE ; Ki Hoon KIM ; Dong Jung KIM ; Sang-Min LEE ; Ho-Geol RYU ; Suk-Kyung HONG ; Jae-Bum KIM ; Eun Young CHOI ; JongHyun BAEK ; Jeoungmin KIM ; Eun Jin KIM ; Tae Yun PARK ; Je Hyeong KIM ; Sunghoon PARK ; Chi-Min PARK ; Won Jai JUNG ; Nak-Jun CHOI ; Hang-Jea JANG ; Su Hwan LEE ; Young Seok LEE ; Gee Young SUH ; Woo-Sung CHOI ; Keu Sung LEE ; Hyung Won KIM ; Young-Gi MIN ; Seok Jeong LEE ; Chae-Man LIM
Journal of Korean Medical Science 2023;38(19):e141-
Background:
Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known.
Methods:
From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation–Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups.
Results:
Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence inter val [CI], 0.55– 0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% 0.56–0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79–1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65–2.17; P = 0.582).
Conclusion
In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.
8.The Effect of Pulsatile Versus Nonpulsatile Blood Flow on Viscoelasticity and Red Blood Cell Aggregation in Extracorporeal Circulation.
Chi Bum AHN ; Yang Jun KANG ; Myoung Gon KIM ; Sung YANG ; Choon Hak LIM ; Ho Sung SON ; Ji Sung KIM ; So Young LEE ; Kuk Hui SON ; Kyung SUN
The Korean Journal of Thoracic and Cardiovascular Surgery 2016;49(3):145-150
BACKGROUND: Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation. METHODS: Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was started at a pump flow rate of 80 mL/kg/min, cardiac fibrillation was induced. Blood sampling was performed before and at 1, 2, and 3 hours after ECC commencement. To eliminate bias induced by hematocrit and plasma, all blood samples were adjusted to a hematocrit of 45% using baseline plasma. Blood viscoelasticity, plasma viscosity, hematocrit, arterial blood gas analysis, central venous O2 saturation, and lactate were measured. RESULTS: The blood viscosity and aggregation index decreased abruptly 1 hour after ECC and then remained low during ECC in both groups, but blood elasticity did not change during ECC. Blood viscosity, blood elasticity, plasma viscosity, and the aggregation index were not significantly different in the groups at any time. Hematocrit decreased abruptly 1 hour after ECC in both groups due to dilution by the priming solution used. CONCLUSION: After ECC, blood viscoelasticity and RBC aggregation were not different in the pulsatile and nonpulsatile groups in the adult dog model. Furthermore, pulsatile flow did not have a more harmful effect on blood viscoelasticity or RBC aggregation than nonpulsatile flow.
Adult
;
Animals
;
Bias (Epidemiology)
;
Blood Gas Analysis
;
Blood Viscosity
;
Cardiopulmonary Bypass
;
Dogs
;
Elasticity
;
Erythrocytes*
;
Extracorporeal Circulation*
;
Hematocrit
;
Hematology
;
Humans
;
Lactic Acid
;
Plasma
;
Pulsatile Flow
;
Viscosity
9.3D Printing Technology and Its Applications for Tissue/Organ Regeneration.
Chi Bum AHN ; Kuk Hui SON ; Jin Woo LEE
The Journal of the Korean Society for Transplantation 2015;29(4):187-193
Three-dimensional (3D) printing, also known as additive manufacturing (AM), has been used frequently in regenerative or translational medicine. In addition, recent advances in 3D printing technologies have opened the door to 3D bio-printing, which uses cells, biocompatible materials, and scaffolding simultaneously to generate 3D functional tissues. Although tissue generation by bio-printing such as multilayered skin, bone, bladder, and vascular grafts has shown good results, there are still several challenges related to printing of entire organs, particularly modulation of vascular formation during organ regeneration. This article provides a background and introduction to bio-printing for creation of artificial organs and tissues.
Artificial Organs
;
Biocompatible Materials
;
Bioprinting
;
Regeneration*
;
Skin
;
Tissue Engineering
;
Tissue Scaffolds
;
Translational Medical Research
;
Transplants
;
Urinary Bladder
10.Surgical Planning by 3D Printing for Primary Cardiac Schwannoma Resection.
Kuk Hui SON ; Kun Woo KIM ; Chi Bum AHN ; Chang Hu CHOI ; Kook Yang PARK ; Chul Hyun PARK ; Jae Ik LEE ; Yang Bin JEON
Yonsei Medical Journal 2015;56(6):1735-1737
We report herein a case of benign cardiac schwannoma in the interatrial septum. A 42-year-old woman was transferred from a clinic because of cardiomegaly as determined by chest X-ray. A transthoracic echocardiography and chest computed tomography examination revealed a huge mass in the pericardium compressing the right atrium, superior vena cava (SVC), left atrium, and superior pulmonary vein. To confirm that the tumor originated from either heart or mediastinum, cine magnetic resonance imaging was performed, but the result was not conclusive. To facilitate surgical planning, we used 3D printing. Using a printed heart model, we decided that tumor resection under cardiopulmonary bypass (CPB) through sternotomy would be technically feasible. At surgery, a huge tumor in the interatrial septum was confirmed. By incision on the atrial roof between the aorta and SVC, tumor enucleation was performed successfully under CPB. Pathology revealed benign schwannoma. The patient was discharged without complication. 3D printing of the heart and tumor was found to be helpful when deciding optimal surgical approach.
Adult
;
Atrial Septum/pathology/surgery
;
Cardiomegaly/*etiology/radiography
;
*Cardiopulmonary Bypass
;
Female
;
Heart Atria/pathology
;
Heart Neoplasms/pathology/*surgery
;
Humans
;
Magnetic Resonance Imaging, Cine
;
Neurilemmoma/*pathology/surgery
;
*Printing, Three-Dimensional
;
Sternotomy
;
Treatment Outcome
;
Vena Cava, Superior/pathology

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