Investigator

Jun Kang

Catholic University of Korea School of Medicine, Hospital Pathology

JKJun Kang
Papers(6)
Prediction of homolog…Prognostic Significan…Roles of Cancer Histo…Improved Prognostic S…Prediction of homolog…HPV ctDNA as a Biomar…
Collaborators(6)
Ahwon LeeKeun Ho LeeKidong KimSohyun HwangHyojin KimJae Hong No
Institutions(3)
Catholic University O…Seoul National Univer…Cha University Bundan…

Papers

Prediction of homologous recombination deficiency from Oncomine Comprehensive Assay Plus correlating with SOPHiA DDM HRD Solution

Objective Poly(ADP-ribose) polymerase (PARP) inhibitors are used for targeted therapy for ovarian cancer with homologous recombination deficiency (HRD). In this study, we aimed to develop a homologous recombination deficiency prediction model to predict the genomic integrity (GI) index of the SOPHiA DDM HRD Solution from the Oncomine Comprehensive Assay (OCA) Plus. We also tried to a find cut-off value of the genomic instability metric (GIM) of the OCA Plus that correlates with the GI index of the SOPHiA DDM HRD Solution. Methods We included 87 cases with high-grade ovarian serous carcinoma from five tertiary referral hospitals in Republic of Korea. We developed an HRD prediction model to predict the GI index of the SOPHiA DDM HRD Solution. As predictor variables in the model, we used the HRD score, which included percent loss of heterozygosity (%LOH), percent telomeric allelic imbalance (%TAI), percent large-scale state transitions (%LST), and the genomic instability metric (GIM). To build the model, we employed a penalized logistic regression technique. Results The final model equation is -21.77 + 0.200 × GIM + 0.102 × %LOH + 0.037 × %TAI + 0.261 × %LST. To improve the performance of the prediction model, we added a borderline result category to the GI results. The accuracy of our HRD status prediction model was 0.958 for the test set. The accuracy of HRD status using GIM with a cut-off value of 16 was 0.911. Conclusion The Oncomine Comprehensive Assay Plus provides a reliable biomarker for homologous recombination deficiency.

Prognostic Significance of the Immune Microenvironment in Endometrial Cancer

This study used artificial intelligence (AI)-based analysis to investigate the immune microenvironment in endometrial cancer (EC). We aimed to evaluate the potential of AI-based immune metrics as prognostic biomarkers. In total, 296 cases with EC were classified into 4 molecular subtypes: polymerase epsilon ultramutated (POLEmut), mismatch repair deficiency (MMRd), p53 abnormal (p53abn), and no specific molecular profile (NSMP). AI-based methods were used to evaluate the following immune metrics: total tumor-infiltrating lymphocytes (TIL), intratumoral TIL, stromal TIL, and tumor cells using Lunit SCOPE IO, as well as CD4+, CD8+, and FOXP3+ T cells using immunohistochemistry (IHC) by QuPath. These 7 immune metrics were used to perform unsupervised clustering. PD-L1 22C3 IHC expression was also evaluated. Clustering analysis demonstrated 3 distinct immune microenvironment groups: immune active, immune desert, and tumor dominant. The immune-active group was highly prevalent in POLEmut, and it was also seen in other molecular subtypes. Although the immune-desert group was more frequent in NSMP and p53mut, it was also detected in MMRd and POLEmut. POLEmut showed the highest levels of CD4+ and CD8+ T cells, total TIL, intratumoral TIL, and stromal TIL with the lowest levels of FOXP3+/CD8+ ratio. In contrast, p53abn in the immune-active group showed higher FOXP3+/CD4+ and FOXP3+/CD8+ ratios. The immune-active group was associated with favorable overall survival and recurrence-free survival. In the NSMP subtype, a significant association was observed between immune active and better recurrence-free survival. The PD-L1 22C3 combined positive score (CPS) showed significant differences among the 3 groups, with the immune-active group having the highest median CPS and frequency of CPS ≥ 1%. The immune microenvironment of EC was variable within molecular subtypes. Within the same immune microenvironment group, significant differences in immune metrics and T cell composition were observed according to molecular subtype. AI-based immune microenvironment groups served as prognostic markers in ECs, with the immune-active group associated with favorable outcomes.

Roles of Cancer Histology Type and HPV Genotype in HPV ctDNA Detection at Baseline in Cervical Cancer: Implications for Tumor Burden Assessment

Introduction: Human papillomavirus circulating tumor DNA (HPV ctDNA) is a promising biomarker for monitoring cervical cancer. HPV ctDNA level at baseline (before treatment) reflects tumor burden. However, reported HPV ctDNA detection rates at baseline have shown variations across studies, suggesting the existence of other potential contributing factors. This study aimed to identify additional factors that might influence HPV ctDNA detection at baseline, focusing on histology type and HPV genotypes (high-risk genotypes HPV16 and HPV18). Methods: We retrospectively analyzed blood samples at baseline prior to treatment from 92 patients diagnosed with HPV16- or HPV18-associated cervical cancer (FIGO IA2–IIIC2) between 2013 and 2020. HPV ctDNA was evaluated using digital droplet PCR. Results: HPV ctDNA was detected at baseline in 41.3% of cases. Locally advanced cervical cancers had a higher (p = 0.028) detection rate at baseline than early stage cervical cancers. HPV ctDNA positivity was significantly (p = 0.048) higher for HPV18 (60%) than for HPV16 (34.3%). Adenocarcinoma/adenosquamous carcinoma had a higher HPV ctDNA detection rate at baseline (54.2%) than squamous cell carcinoma (36.8%) but not significantly (p = 0.212) higher. Conclusion: This study found the impact of histology and HPV genotype on HPV ctDNA at baseline in cervical cancer. HPV18 and adenocarcinoma were associated with a higher baseline HPV ctDNA detection rate. These results suggest the need for different HPV ctDNA approaches for analyzing tumor burden. This finding may also serve as a useful reference for posttreatment surveillance studies.

Improved Prognostic Stratification With 2023 International Federation of Gynecology and Obstetrics Staging in Endometrial Cancer Reflecting Poor Prognosis of Aggressive Histological Types and p53 Abnormality

This study compares the distribution and prognostic impact of the 2009 and 2023 International Federation of Gynecology and Obstetrics (FIGO) staging systems for endometrial cancer and their impact on the 2022 European Society for Medical Oncology (ESMO) risk classification. Patients were restaged according to the 2009 FIGO staging system, the 2023 FIGO staging system, and the 2023 FIGO staging system with molecular classification. Risk groups were assigned according to the 2022 ESMO guidelines using each staging system. Among 679 patients, 139 (20.5%) experienced stage migration when transitioning from the 2009 FIGO staging system to the 2023 FIGO staging system with molecular classification, with 121 (17.8%) upstaged and 18 (2.7%) downstaged. Most changes were from FIGO stage I to stage II, primarily due to p53 abnormality, aggressive histological type, or extensive/substantial lymphovascular space invasion. Hazard ratios for overall survival, disease-free survival, and event-free survival increased with advancing stage groups in all systems, showing the greatest differences when the 2023 FIGO staging system with molecular classification was used. The newly introduced FIGO stages IC, IIC (both representing aggressive histological types), and IICmp53abn (associated with p53 abnormality) in the 2023 FIGO staging system were associated with worse outcomes, similar to FIGO stage III. The prognostic predictability of the 2022 ESMO risk group was minimally affected by the transition from the 2009 FIGO to the 2023 FIGO staging system, as the factors introduced in the new FIGO system were already incorporated into the 2022 ESMO risk classification. Only 17 (2.5%) patients experienced a change in their assigned risk group. The 2023 FIGO staging system showed improved prognostic stratification over the 2009 FIGO staging system, particularly by reflecting the poor prognosis of aggressive histological types and p53 abnormality.

23Works
6Papers
6Collaborators
NeoplasmsBiomarkers, TumorOvarian NeoplasmsBreast NeoplasmsTumor Suppressor Protein p53Lymphocytes, Tumor-InfiltratingAdenocarcinoma

Positions

Researcher

Catholic University of Korea School of Medicine · Hospital Pathology

2014–

Clinical Assistant Professor

Incheon St. Mary's Hospital · Pathology

2013–

Assistant Professor

Inje University Haeundae Paik Hospital · Pathology

Education

2012

Ph.D.

University of Ulsan College of Medicine · Pathology

2006

B.S

University of Ulsan College of Medicine · Pathology

2003

M.D.

University of Ulsan College of Medicine · Pathology

Country

KR

Keywords
PathologyBioinformatics