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.A Phase II Trial of Nintedanib in Patients with Metastatic or Recurrent Head and Neck Squamous Cell Carcinoma: In-Depth Analysis of Nintedanib Arm from the KCSG HN 15-16 TRIUMPH Trial
Kyoo Hyun KIM ; Sun Min LIM ; Hee Kyung AHN ; Yun-Gyoo LEE ; Keun-Wook LEE ; Myung-Ju AHN ; Bhumsuk KEAM ; Hye Ryun KIM ; Hyun Woo LEE ; Ho Jung AN ; Jin-Soo KIM
Cancer Research and Treatment 2024;56(1):37-47
Purpose:
Precision oncology approach for recurrent and metastatic head and neck squamous cell carcinoma (HNSCC) is necessary due to its dismal prognosis. We performed a genomic profile-based umbrella trial of patients with platinum-refractory HNSCC (KCSG-TRIUMPH). Here, we present an in-depth report of the the nintedanib arm (arm 3) of the current trial.
Materials and Methods:
The TRIUMPH study was a multicenter, open-label, single-arm phase 2 trial, in which patients were assigned to treatment arms based on next-generation sequencing (NGS)–based, matching genomic profiles. Patients whose tumors harbor fibroblast growth factor receptor (FGFR) alteration were enrolled in the nintedanib arm (arm 3) as part of the TRIUMPH study. The primary endpoint was the overall response rate (ORR), and secondary endpoints included overall survival (OS), progression-free survival (PFS), safety, and biomarker analysis.
Results:
Between October 2017 and August 2020, 207 were enrolled in the TRIUMPH study, and eight were enrolled in the nintedanib arm. ORR and disease control rate were 42.9% and 57.1%, respectively. The median PFS was 5.6 months and the median duration of response was 9.1 months. Median OS was 11.1 months. One patient maintained the partial response for 36 months. Overall, the toxicity profiles were manageable.
Conclusion
Single-agent nintedanib has demonstrated significant efficacy in FGFR-mutated, recurrent or metastatic HNSCC patients, with tolerable toxicity profiles. The results from the study have provided the basis for routine NGS screening and FGFR-targeted therapy. Because of the small number of patients due to slow accrual in this study, further studies with a larger cohort are warranted for statistical power.
8.Molecular and Treatment Characteristics of SMARCB1 or SMARCA4-Deficient Undifferentiated Tumor: Retrospective Case Series
Hyeon Gyu KANG ; Jiwon KOH ; Tae Min KIM ; Doo Hee HAN ; Tae-Bin WON ; Dong-Wan KIM ; Dong-Young KIM ; Bhumsuk KEAM
Cancer Research and Treatment 2024;56(3):967-971
SMARCB1 or SMARCA4-deficient sinonasal carcinoma or thoracic undifferentiated tumor has aggressive nature with a poor prognosis. Patients with this disease were diagnosed by immunohistochemistry or next-generation sequencing. Those who were able to receive a surgery tended to be cured, while the others treated with chemotherapy, radiation therapy, or immune checkpoint inhibitor were often insensitive to these therapies. However, one having CD274 (PD-L1) amplification showed the response to immune checkpoint inhibitor and a good prognosis. We believed that this report could provide promising information for determining the optimal treatment option.
9.Analytical and Clinical Validation of a Highly Sensitive NGS-Based ctDNA Assay with Real-World Concordance in Non–Small Cell Lung Cancer
Hanbaek YI ; Jeonghwan YOUK ; Yoojoo LIM ; Hanseong ROH ; Dongsoo KYUNG ; Hwang-Phill KIM ; Duhee BANG ; Bhumsuk KEAM ; Tae-Min KIM ; Miso KIM ; Dong-Wan KIM ; Tae-You KIM
Cancer Research and Treatment 2024;56(3):765-773
Purpose:
There have been needs to improve the sensitivity of liquid biopsy. This report aims to report the analytical and clinical validation of a next-generation sequencing (NGS)–based circulating tumor DNA (ctDNA) assay.
Materials and Methods:
Analytical validation was conducted in vitro by evaluating the limit of detection (LOD), precision, and specificity for various genomic aberrations. The real-world performance in non–small cell lung cancer (NSCLC) was assessed by comparing the results of AlphaLiquid100 to the tissue-based results.
Results:
The LODs with 30 ng input DNA were 0.11%, 0.11%, 0.06%, 0.21%, and 2.13 copies for detecting single nucleotide variants, insertions, deletions, fusions, and copy number alterations (CNA), respectively. Quantitatively, single nucleotide variants/insertions and deletions, fusions, and CNAs showed a good correlation (R2=0.91, 0.40, and 0.65; y=0.95, 1.06, and 1.19) to the manufacturer’s values, and per-base specificities for all types of variants were near 100%. In real-world NSCLC (n=122), key actionable mutations in NSCLC were detected in 60.7% (74/122) with the ctDNA assay. Comparative analysis against the NGS-based tissue results for all key mutations showed positive percent agreement (PPA) of 85.3%. For individual genes, the PPA was as high as 95.7% for epidermal growth factor receptor (EGFR) mutations and 83.3% for ALK translocations. AlphaLiquid100 detected drug-sensitive EGFR mutation at a variant allele frequency as low as 0.02% and also identified an EGFR mutation in a case where tissue sample missed. Blood samples collected post-targeted therapies revealed additional acquired mutations.
Conclusion
The AlphaLiquid100 ctDNA assay demonstrates robust analytical validity, offering clinically important information for NSCLC patients.
10.Analysis of Response and Progression Patterns of Tyrosine Kinase Inhibitors in Recurrent or Metastatic Adenoid Cystic Carcinoma: A Post Hoc Analysis of Two KCSG Phase II Trials
Youjin KIM ; Bhumsuk KEAM ; Eun Joo KANG ; Jin-Soo KIM ; Hye Ryun KIM ; Keun-Wook LEE ; Jung Hye KWON ; Kyoung Eun LEE ; Yaewon YANG ; Yoon Hee CHOI ; Min Kyoung KIM ; Jun Ho JI ; Tak YUN ; Moon Young CHOI ; Ki Hyeong LEE ; Sung-Bae KIM ; Myung-Ju AHN
Cancer Research and Treatment 2024;56(4):1068-1076
Purpose:
In this study, we evaluated 66 patients diagnosed with adenoid cystic carcinoma (ACC) enrolled in two Korean Cancer Study Group trials to investigate the response and progression patterns in recurrent and/or metastatic ACC treated with vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs).
Materials and Methods:
We evaluated 66 patients diagnosed with ACC who were enrolled in the Korean Cancer Study Group trials. The tumor measurements, clinical data, treatment outcomes, and progression patterns of therapy were analyzed.
Results:
In the 66 patients (53 receiving axitinib and 13 receiving nintedanib), the disease control rate was 61%, and three patients achieved partial response. The median follow-up, median progression-free survival (PFS), overall survival, and 6-month PFS rate were 27.6%, 12.4%, and 18.1% months and 62.1%, respectively. Among 42 patients who experienced progression, 27 (64.3%) showed target lesion progression. Bone metastasis was an independent poor prognostic factor.
Conclusion
Overall, most patients demonstrated stable disease with prolonged PFS; however, prominent target lesion progression occurred in some patients. Thus, PFS may capture VEGFR-TKI efficacy better than the objective response rate.

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