George Kapetsis

Mr. George Kapetsis


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2019 in Plant Science
Verified
Journal Article
Closed access
CVChrysanthi Valassakis
Chrysanthi Valassakis
IDIrene Dervisi
Irene Dervisi
AAAdamantia Agalou
Adamantia Agalou
NPNikos Papandreou
Nikos Papandreou
GKGeorge Kapetsis
George Kapetsis
ARAndreas Roussis
Andreas Roussis

15 September 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
ATAikaterini Tsantikidi
Aikaterini Tsantikidi
EPEirini Papadopoulou
Eirini Papadopoulou
VMVasiliki Metaxa-Mariatou
Vasiliki Metaxa-Mariatou
GKGeorge Kapetsis
George Kapetsis
GTGeorgios N Tsaousis
Georgios N Tsaousis
GNGeorge Nasioulas
George Nasioulas
Several tumor types have been efficiently treated with PARP inhibitors (PARPis), which are now approved for the treatment of ovarian, breast, prostate, and pancreatic cancers. The BRCA1/2 genes and mutations in many additional genes involved in the HR pathway may be responsible for the HRD phenomenon. The aim of the present study was to investigate the association between genomic loss of heterozygosity (gLOH) and alterations in 513 genes with targeted and immuno-oncology therapies in 406 samples using an NGS assay. In addition, the %gLOHs of 24 samples were calculated using the Affymetrix technology in order to compare the results obtained via the two methodologies. HR variations occurred in 20.93% of the malignancies, while BRCA1/2 gene alterations occurred in 5.17% of the malignancies. The %LOH was highly correlated with alterations in the BRCA1/2 genes, since 76.19% (16/21) of the BRCA1/2 positive tumors had a high %LOH value (p = 0.007). Moreover, the LOH status was highly correlated with the TP53 and KRAS statuses, but there was no association with the TMB value. Lin’s concordance correlation coefficient for the 24 samples simultaneously examined via both assays was 0.87, indicating a nearly perfect agreement. In conclusion, the addition of gLOH analysis could assist in the detection of additional patients eligible for treatment with PARPis.

Verified
Journal Article
Open access
PDF file
AMAngeliki Meintani
Angeliki Meintani
MOMustafa Ozdogan
Mustafa Ozdogan
NTNikolaos Touroutoglou
Nikolaos Touroutoglou
KPKonstantinos Papazisis
Konstantinos Papazisis
IBIoannis Boukovinas
Ioannis Boukovinas
GNGeorge Nasioulas
George Nasioulas
In the era of precision oncology, comprehensive molecular profiling is critical for guiding targeted and immunotherapy strategies. This study presents the analytical and clinical validation of a 1021-gene next-generation sequencing (NGS) panel, designed for use with both formalin-fixed paraffin-embedded (FFPE) tissue- and liquid-biopsy specimens. Analytical validation confirmed the assay’s high sensitivity and specificity across variant types—including SNVs (Single Nucleotide Variations), indels, CNVs (Copy Number Variations), and fusions—down to a 0.5% variant allele frequency. The assay also accurately identified microsatellite instability (MSI) and tumor mutational burden (TMB), essential biomarkers for immunotherapy. Clinical validation was performed on over 1300 solid tumor samples from diverse histologies, revealing actionable alterations in over 50% of cases. The panel detected on-label treatment biomarkers in 12.57% of patients, increasing to 20.15% when immunotherapy markers were included. Additionally, the assay demonstrated strong concordance with orthogonal methods and was effective in detecting variants in plasma-derived circulating tumor DNA in 70% of evaluable cases. These findings support the robust performance and broad clinical applicability of the 1021-gene panel for comprehensive genomic profiling in both tissue and liquid biopsies, offering a valuable tool for personalized cancer treatment.

19 December 2023 in Cancers
Verified
Journal Article
Open access
PDF file
DZDimitrios C Ziogas
Dimitrios C Ziogas
EPEirini Papadopoulou
Eirini Papadopoulou
HGHelen Gogas
Helen Gogas
SSStratigoula Sakellariou
Stratigoula Sakellariou
EFEVANGELOS FELEKOURAS
EVANGELOS FELEKOURAS
GNGeorge Nasioulas
George Nasioulas
Despite ongoing oncological advances, pancreatic ductal adenocarcinoma (PDAC) continues to have an extremely poor prognosis with limited targeted and immunotherapeutic options. Its genomic background has not been fully characterized yet in large-scale populations all over the world. Methods: Replicating a recent study from China, we collected tissue samples from consecutive Greek patients with pathologically-confirmed metastatic/unresectable PDAC and retrospectively investigated their genomic landscape using next generation sequencing (NGS). Findings: From a cohort of 409 patients, NGS analysis was successfully achieved in 400 cases (56.50% males, median age: 61.8 years). Consistent with a previous study, KRAS was the most frequently mutated gene in 81.50% of tested samples, followed by TP53 (50.75%), CDKN2 (8%), and SMAD4 (7.50%). BRCA1/2 variants with on-label indications were detected in 2%, and 87.50% carried a variant associated with off-label treatment (KRAS, ERBB2, STK11, or HRR-genes), while 3.5% of the alterations had unknown/preliminary-studied actionability (TP53/CDKN2A). Most of HRR-alterations were in intermediate- and low-risk genes (CHEK2, RAD50, RAD51, ATM, FANCA, FANCL, FANCC, BAP1), with controversial actionability: 8% harbored a somatic non-BRCA1/2 alteration, 6 cases had a high-risk alteration (PALB2, RAD51C), and one co-presented a PALB2/BRCA2 alteration. Elevated LOH was associated with HRR-mutated status and TP53 mutations while lowered LOH was associated with KRAS alterations. Including TMB/MSI data, the potential benefit from an NGS-oriented treatment was increased from 1.91% to 13.74% (high-MSI: 0.3%, TMB > 10 muts/MB: 12.78%). TMB was slightly increased in females (4.75 vs. 4.46 muts/MB) and in individuals with age > 60 (4.77 vs. 4.40 muts/MB). About 28.41% showed PD-L1 > 1% either in tumor or immune cells, 15.75% expressed PD-L1 ≥ 10%, and only 1.18% had PD-L1 ≥ 50%. This is the largest depiction of real-world genomic characteristics of European patients with PDAC, which offers some useful clinical and research insights.

12 July 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
ATAikaterini Tsantikidi
Aikaterini Tsantikidi
EPEirini Papadopoulou
Eirini Papadopoulou
GTGeorgios N Tsaousis
Georgios N Tsaousis
VMVasiliki Metaxa-Mariatou
Vasiliki Metaxa-Mariatou
GKGeorge Kapetsis
George Kapetsis
GNGeorge Nasioulas
George Nasioulas
Several tumor types have been efficiently treated with PARPis, which are now approved for the treatment of ovarian, breast, prostate, and pancreatic cancer. The BRCA1/2 genes and mutations in many additional genes involved in the HR pathway may be responsible for the HRD phenomenon. In the present study, an NGS assay was used to analyze 513 genes associated with targeted and immuno-oncology therapies in 406 samples. In addition, the %gLOH values of 24 samples were also calculated using the Affymetrix technology to compare the results obtained by the two methodologies. HR variations occurred in 20.93% of the malignancies, while BRCA1/2 gene alterations in 5.17%. %LOH was highly correlated with alterations in the BRCA1/2 genes since 76.19% (16/21) of the BRCA1/2 positive tumors had a high %LOH value (p=0.007). Moreover, the LOH status was highly correlated with the TP53 and KRAS statuses, but there was no association with the TMB value. Lin's Concordance Correlation Coefficient for the 24 evaluable samples simultaneously examined by both assays was 0.87, indicating a nearly perfect agreement. In conclusion, the addition of gLOH analysis could assist the detection of additional patients eligible for PARPis

1 January 2025 in Journal of Young Women’s Breast Cancer and Health
Verified
Journal Article
Open access
RIRodoniki Iosifidou
Rodoniki Iosifidou
GKGeorge Kapetsis
George Kapetsis
SGSpiridon Giannoulakis
Spiridon Giannoulakis
NTNikolaos Tsoulos
Nikolaos Tsoulos
GXGrigorios Xepapadakis
Grigorios Xepapadakis
VVVasileios Venizelos
Vasileios Venizelos
Background: Multigene assays have become a key component in risk stratification of patients with HR+/human epidermal growth factor receptor 2-breast cancer. Among these, the Oncotype DX is a validated tool that predicts the risk of distant recurrence and the potential absolute benefit of adding chemotherapy to adjuvant endocrine therapy. Although breast cancer is less common in younger women, it is often associated with biologically more aggressive features and a worse prognosis. Moreover, this age group has been historically underrepresented in large, randomized clinical trials of Oncotype DX. Hence, younger women are less frequently evaluated with Oncotype DX, and even when testing is performed, the decision to administer chemotherapy is not always aligned with the recurrence score result. Methods: In this retrospective analysis, a total of 358 young patients were stratified into three genomic risk groups (low, intermediate, and high) according to their Oncotype DX Recurrence Score (RS). A subsequent subgroup analysis focused on identifying individuals within the low genomic risk category who were eligible for treatment with the cyclin-dependent kinase 4 and 6 inhibitor ribociclib. Results: Among the patients, 41% were classified as low genomic risk, 44% as intermediate, and 15% as high. Notably, 35% of the pT2 patients with low genomic risk were clinically high risk as per the NATALEE trial criteria. Conclusion: Despite the poorer prognosis in younger women, 41% had a low genomic risk and could potentially be treated effectively with endocrine therapy alone. Among those node-negative patients with tumor size 2–5 cm, one out of three (35%) were classified as clinically high-risk and could benefit from the addition of ribociclib.