IMBDX

コア技術

がんの早期発見

論文

게시물 목록
番号 年度 題名 雑誌 リンクを見る
28 2025

Clinical utility and predictive value of cerebrospinal fluid cell-free DNA profiling in non-small cell lung cancer patients with leptomeningeal metastasis

Abstract   Leptomeningeal metastasis (LM) is a challenging complication of non-small cell lung cancer (NSCLC). Cerebrospinal fluid (CSF) cell-free DNA (cfDNA) analysis using next-generation sequencing (NGS) offers insights into resistance mechanisms and potential treatment strategies. We conducted a study fr|om February 2022 to April 2023 involving patients fr|om five hospitals in Taiwan who had recurrent or advanced NSCLC with LM. These patients underwent CSF cfDNA analysis using a 118-gene targeted panel for NGS, with comprehensive clinical data collected. Among 25 enrolled patients, 22 (88.0 %) had EGFR mutations, while three (12.0 %) had EML4-ALK fusion, KIF5B-RET fusion, and ERBB2 A775_G776insSVMA. CSF cfDNA sequencing of 27 samples (fr|om 25 patients) all confirmed their original driver mutations. Of total cohort, 18 patients (72.0 %) underwent intrathecal pemetrexed (ITP), with a median survival time of 7.4 months (95.0 % confidence interval, 3.3–11.6) fr|om the initiation of ITP to death. Among them, ten individuals (55.6 %) survived beyond 6 months. Notably, MET copy number gain (CNG) correlated significantly with survival time exceeding 6 months after ITP (p = 0.007). The coexistence of EGFR T790M and EGFR-independent resistance alterations was associated with shorter survival times after ITP, with a median survival time of 1.9 months compared to 9.9 months for those without EGFR T790M (p = 0.010). Our results highlight CSF cfDNA NGS's potential in LM resistance understanding and ITP efficacy prediction. MET CNG positively impacts survival for ITP recipients, whereas the coexistence of EGFR T790M and EGFR-independent resistance mechanisms leads to poor outcomes.

Neoplasia

リンクを見る

27 2025

Enhanced Detection of Actionable Mutations in NSCLC Through Pleural Effusion Cell-Free DNA Sequencing: A Prospective Study

Abstract   Background: Inadequate tumour samples often hinder molecular testing in non-small cell lung cancer (NSCLC). Plasma-based cell-free DNA (cfDNA) sequencing has shown promise in bypassing these tissue limitations. Nevertheless, pleural effusion (PE) samples may offer a richer cfDNA source for mutation detection in patients with malignant PE.   Methods: This prospective study enrolled newly diagnosed advanced NSCLC patients with malignant PE. PE samples were collected for cfDNA NGS analysis. Meanwhile, PE cell pellet RNA was extracted for reverse transcription polymerase chain reaction (RT-PCR) for clinically relevant actionable mutations and then confirmed by Sanger sequencing. The concordance between PE cell pellet RT-PCR and PE cfDNA NGS analyses was analysed.   Results: Fifty patients were enrolled. The median age was 68.5 years, and the female-to-male ratio was 29:21. Most patients (74%) were non-smokers. Notably, 45/50 patients (90%) had actionable mutations, including EGFR exon 19 deletions (24%), EGFR L858R mutations (36%), HER2 exon20 insertions (10%), ROS1 rearrangements (4%), EGFR exon20 insertions (2%), ALK rearrangements (4%), RET rearrangements (2%), KRAS G12C mutations (2%), and CD74-NRG1 fusions (2%). Among the 50 enrolled patients, actionable mutations were detected in 44 (88%) by PE cfDNA NGS, 39 (78%) by PE cell pellet Sanger sequencing, and 33 (66%) by clinical tissue genetic testing (P=0.031). The detection of actionable mutations fr|om PE cfDNA NGS remained consistently high across M1a to M1c stages.   Conclusions: PE cfDNA genotyping has clinical applicability for NSCLC patients and can serve as an additional source for molecular testing. Incorporating PE NGS cfDNA analysis into genetic testing enhances diagnostic yield and aids in identifying actionable mutations in clinical practice.

European Journal of Cancer

リンクを見る

26 2024

Personalized circulating tumor DNA assay precisely predicts the response of neoadjuvant chemotherapy in breast cancer patients

Abstract   Introduction Circulating tumor DNA (ctDNA), which is detected in the blood as cell free DNA fragment fr|om tumor cells, could indicates genomic landscape, tumor burden and treatment response during chemotherapy as a non-invasive method. Especially, personized ctDNA assay by next-generation sequencing(NGS) is able to detect a trace amount of ctDNA and precisely figure out the change of the amount of ctDNA during NAC and follow up period after curative surgery. Here, we performed serial ctDNA evaluations in EBC patients who diagnosed as TNBC or HER2-positive BC and received NAC followed by curative surgery. We aimed to predict NAC response and detect minimal residual disease (MRD) using personalized ctDNA assay.   Methods CtDNA was detected by AlphaLiquid®Detect, a tumor-informed personalized MRD detection assay exploring most of the mutations in tumor. Whole exome sequencing (WES) of tumor tissue and peripheral blood mononuclear cells (PBMCs) was performed. Patient-specific somatic mutations were selected using a proprietary algorithm. In brief, clonal variants were prioritized using integrated information including variant allele frequency, population allele frequency databases, somatic variant databases, variant pathogenicity, and genomic context. Up to 100 variants were selected for patient monitoring. A hybridization capture panel consisting of a pool of 4 patients’ selected variants was synthesized. These bespoke panels (BSPs) were used for ctDNA detection. Patients with more than 2 tumor-derived mutations detected in plasma were considered as ctDNA positive. Inclusion criteria included patient who diagnosed as stage IIA-IIIC BC planned to NAC followed by curative surgery. Among BC subtypes, TNBC and HER2-positive BC were allowed. Collection of specimens and associated clinical data used in this study was approved by the Institutional Review Board of Samsung Medical Center (IRB File No.2021-02-033), and we received informed consents for this study.   Results fr|om May 2021 to Sep 2022, 158 patients has been enrolled. Archival tissues were not available in 47 patients and tissue WES had failed in six patients. Therefore, 105 patients were enrolled and analyzed their ctDNA at diagnosis based on tissue WES data. Of 105 patients, Median age of BC patients was 49.3 years of age (range: 26.1, 67.8). Thirty-six patients (34.3%) were post-menopausal status and others (65.7%) were pre-menopausal status. In BC pathology at diagnosis, 56 (53.3%) were TNBC and other 49 (46.7%) were HER2-positive BC. Among HER2-positive BC, hormone receptor (HR)-positive were in 21 (20.0%). In clinical stage at diagnosis, stage II were 46 (43.8%) and stage III in 59 (56.2%). In 105 patients, median number of somatic mutations was 60 (interquartile range [IQR]: 38.5, 91). CtDNA detection rate at BC diagnosis was 90.5% and all of BC which not be detected ctDNA was HER2-positive BC with clinical stage II. Median amount of ctDNA at diagnosis was 20 (IQR: 6, 44). In the number of somatic mutations, there was no difference according to BC subtypes (P=0.121) and clinical stage (P=0.700) but the amounts of ctDNA at diagnosis was different. CtDNA was much more detected in TNBC compared to HER2-positive BC (Median: 34.5 vs. 15.9; P<0.001) and clinical stage III compared to clinical stage II (Median 33.2 vs. 19.5; P=0.002). After NAC, ctDNA at curative surgery was tested in 70 patients. In 70 patients, pathologic complete response(pCR) was observed in 44 patients. CtDNA was detected in ten patients (14.3%) and eight did not achieve pCR and two with pCR (Specificity of assay: 95.5%, positive predictive value: 0.80, P=0.032).    Conclusions Personalized ctDNA assay can precisely detected ctDNA at diagnosis and their detection rate was associated with BC subtypes and clinical stage. In addition, ctDNA at curative surgery also can predict NAC response in EBC patients. Long term ctDNA follow up of MRD would be warranted.    

Cancer Research

リンクを見る

25 2024

High circulating tumor DNA (ctDNA) concentration was associated with shorter progression free survival in patients with metastatic breast cancer

Abstract   Background Metastatic breast cancer can be classified into different subtypes depending on hormone receptor (HR) and HER2 status. The subtype can change during tumor progression, and repeated biopsy is needed to deliver the most appropriate treatment every time a new lesion is found. It is not always possible to get a new biopsy fr|om metastatic sites, and therefore liquid biopsy using circulating tumor DNA (ctDNA) is suggested as an alternative method to replace conventional biopsy.   Methods We performed a prospective serial collection of 65 ctDNA samples fr|om 17 patients with metastatic breast cancer (mBC) at Seoul National University Hospital fr|om October 2020 to March 2022. We used IMBdx AlphaLiquid®100 method to detect the genetic changes and analyzed the correlation with clinical outcomes.   Results Median age was 45 (range 32 – 62). Fifteen patients (88.2%) were relapsed mBC and most of the patients (14/17: 82.4%) were HR-positive and HER2-negative. Most of the patients had their ctDNA examined at baseline and at the time of maximal response and/or at progression. Fifteen patients (88.2%) received systemic therapy including hormone therapy, anti-HER2 therapy, and cytotoxic chemotherapy. Eight patients (47.1%) were on the first-line treatment for mBC, and 7 patients (41.2%) were on the second or later lines for mBC at the time of baseline sampling. The concentration of ctDNA and the sum of mutated allelic frequency was calculated for each sample. The ctDNA concentration ranged fr|om 0.71 to 1386.00 ng/mL, and the median value was 5.37 ng/mL. We dichotomized these samples into two groups, with ctDNA concentration either higher or lower than the median value. Then we analyzed progression free survival (PFS) of each group. Patients with higher ctDNA concentration showed shorter PFS (7 mo. vs. not reached, p< 0.001). The sum of mutated allelic frequency ranged fr|om 0.00% to 223.46% and the median value was 6.36%. Patients with higher mutated allelic frequency showed shorter PFS (6 mo. vs. 22 mo., p< 0.001). In addition, the PFS was significantly worse in patients who had mutated PIK3CA (5 mo vs. 22 mo, p< 0.001). The patients with mutated TP53 also showed shorter PFS (6 mo vs. 17 mo, p< 0.001) in univariate analysis. High estrogen receptor positivity in immunohistochemistry was correlated with lower mutated allelic frequency in ctDNA (p=0.003) but had no impact on the concentration of ctDNA (p=0.165). The concentration of ctDNA differed by metastatic sites. Patients with metastases to bones (p=0.007), liver (p< 0.001), soft tissue or lymph nodes (p=0.002) were more likely to have higher concentrations of ctDNA, while patients with brain metastases had significantly lower ctDNA concentration (p=0.006). When the sum of mutated allelic frequency of ctDNA and metastatic sites was analyzed, bone (p=0.001), liver (p< 0.001), and soft tissue or lymph node (p< 0.001) metastases had a positive correlation, while brain had negative correlation (p=0.017). Lung or pleural metastases had no significant correlation with ctDNA, neither concentration (p=0.271) nor mutated allelic frequency (p=0.965).   Conclusion Patients with mBC with higher concentrations of ctDNA or higher mutated allelic frequency of ctDNA at baseline showed significantly shorter PFS. PIK3CAmt and TP53mt detected by liquid biopsy could be used as a poor prognostic biomarkers for mBC patients.

AACR
24 2024

Assessing the clinical value of ctDNA sequencing for initial tumor profiling in metastatic colorectal cancer patients with sufficient tumor tissue

Abstract   Introduction Tumor profiling including RAS, BRAF, HER2, and MSI/MMR status, is required to determine the treatment for patients with metastatic colorectal cancer (mCRC) at the time of diagnosis. While comprehensive tumor profiling using tissue-based next-generation sequencing (NGS) is increasingly adopted for initial profiling in mCRC, the role of circulating tumor DNA (ctDNA) NGS as initial testing in patients with sufficient tumor tissue is not clearly understood. We assessed the clinical value of ctDNA sequencing compared to tumor NGS in patients with newly diagnosed mCRC who have sufficient tumor specimens.   Methods We prospectively enrolled consecutive patients with newly diagnosed mCRC at the National Cancer Center Korea. As per the institutional protocol for mCRC, initial tumor profiling was performed on primary tumor tissue using an in-house NGS panel (NCC PCP ver.3), which included 525 genes. For ctDNA sequencing, patients were evaluated using the AlphaLiquid®100 comprehensive cancer panel (IMBdx, Inc.), which included 118 genes, before the initiation of chemotherapy. Additionally, immunohistochemical (IHC) testing for HER2 and polymerase chain reaction (PCR)/IHC testing for MSI and/or MMR were performed to assess the accuracy of HER2 and MSI/MMR status.   Results A total of 188 patients were enrolled. In 139 eligible patients, 275 potentially actionable mutations were found in 12 selected CRC-related genes (APC, TP53, KRAS, NRAS, BRAF, FBXW7, PIK3CA, ERBB2, SMAD4, NF1, EGFR, MET). Of these, 32% were found both in ctDNA and tissue; 54% were found in ctDNA only; 12% in tissue only, and 2% were discordant. For RAS/BRAF mutations, which are required for anti-EGFR treatment decisions, the concordance rate between ctDNA and tissue NGS was 83.1%, and the concordance was higher in patients with higher ctDNA concentrations. For 9 patients with potentially actionable copy number variations (CNV) in EGFR, HER2, MET, and FGFR1, 3 cases were found by both assays; 4 were found by ctDNA only, and 2 were found by tissue only. ctDNA NGS correctly predicted MSI/MMR status in 2 out of 4 patients with MSI-H/dMMR; in the 2 other patients, the MSI and MMR statuses were different, suggesting potential false positivity. In addition, the fold changes in ctDNA dynamics during treatment significantly correlated with changes in tumor size and CEA levels, as well as with droplet digital PCR copy number fold changes. In a patient with MET amplification, ctDNA NGS identified MET Y1230H as a potential acquired resistance mutation after crizotinib treatment, which responded to cabozantinib but not to capmatinib.   Conclusions Initial tumor profiling using ctDNA NGS yielded outcomes comparable to those of tumor tissue NGS in guiding treatment for patients with newly diagnosed mCRC, thereby suggesting its utility as an initial profiling method in mCRC.  

AACR