Clinical Utility Of Liquid Biopsy Research Articles

Abstract 7490: Clinical utility of liquid biopsy in early stage lung cancer: A single institution experience

Abstract INTRODUCTION: Liquid biopsy (LB) proved its clinical utility in advanced non-small cell lung cancer, but its role in early-stage disease is less clear. Here, we investigated the clinical utility of LB for molecular diagnosis in early-stage lung cancer and its correlation with cancer relapse. METHODS: This retrospective, monocentric study collected results from LB performed in patients (pts) with an early-stage lung cancer between January 2021 and May 2023, within the prospective STING study (NCT04932525). LBs were executed at different time points (before, after curative treatment, or under treatment), by using the Foundation One Liquid Dx panel. All patients had tissue molecular testing for at least EGFR, ALK and KRAS alterations. LB was considered positive (ctDNA+) if ≥ 1cancer-related alteration was identified and negative (ctDNA-) in the absence of somatic alterations or the presence of clonal hematopoiesis (CH) only. Disease-free survival (DFS) was calculated from diagnosis to cancer relapse or last follow-up, and correlated with LB results. RESULTS: A total of 52 pts were included and 52 LBs were conducted. Pts had a median age of 63 years, 40% (25/52) were females, and 84% (43/51) had a smoking history with a median pack-years of 37.5 [4-100]. Adenocarcinoma was the most common histology (48% 25/52), followed by squamous carcinoma (23% 12/52), undifferentiated (20% 10/52) and other hystologies (9% 5/52). Patients had stage I disease in 10% (5/52), stage II in 11% (6/52) and stage III in 79% (41/52). LB was performed before curative treatment in 35/52 (67%), after curative treatment in 6/52 (11.5%) and during curative treatment in 12/52 (23%). Overall, LB was positive in 57% (30/52) of cases: 63% (26/41) in stage III and 36% (4/11) in stage I/II. Major driver mutations identified in tissue were then found in 61.5% (8/13) of LBs. The concordance between LB and tissue findings was 100% in pts with ctDNA+ (7 KRAS, 4 EGFR, 1 ALK, 1 HER2 ampl). CH was present in 66.7% (20/30) of ctDNA+ LB and 47.8% (11/23) of ctDNA- LB. Median tumor mutational burden (TMB) in ctDNA+ LB was 5.5 mut/Mb, with 4 cases of TMB >16. Median follow-up was 12.6 months (mo). In pts with ctDNA+ versus ctDNA- LB, mDFS was 12.9 mo (95% 6.3-18.6) versus 27.7 mo (95%CI 12.7- NR), p=0.07, in the overall population and 12.9 mo (95%CI 7.8-19.2) versus 27.2 mo (12.7-NR) respectively, p=0.19, in pts with stage III disease. CONCLUSIONS: LB has informal results for molecular diagnosis in nearly half of pts with an early-stage lung cancer. The high frequency of CH may lead to LB misinterpretation as false positive and requires caution. The potential association of positive LB with earlier relapse requires further investigation in larger cohorts with a longer follow-up. Results will be updated by the time of meeting. Citation Format: Kristi Beshiri, Arianna Marinello, Damien Vasseur, Lodovica Zullo, Maria Virginia Sanchez Becerra, Arianna Pagliaro, Massimiliano Cani, Claudia Parisi, Pernelle Lavaud, Maxime Frelaut, Pamela Abdayem, Anas Gazzah, Angela Botticella, Antonin Levy, Cecile Le Pechoux, Olaf Mercier, Santiago Ponce, Fabrice Barlesi, David Planchard, Antonio Italiano, Benjamin Besse, Jordie Remon, Mihaela Aldea. Clinical utility of liquid biopsy in early stage lung cancer: A single institution experience [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7490.

Epigenetic modifications of cfDNA in liquid biopsy for the cancer care continuum

This review provides a comprehensive overview of the latest advancements in the clinical utility of liquid biopsy, with a particular focus on epigenetic approaches aimed at overcoming challenges in cancer diagnosis and treatment. It begins by elucidating key epigenetic terms, including methylomics, fragmentomics, and nucleosomics. The review progresses to discuss methods for analyzing circulating cell-free DNA (cfDNA) and highlights recent studies showcasing the clinical relevance of epigenetic modifications in areas such as diagnosis, drug treatment response, minimal residual disease (MRD) detection, and prognosis prediction. While acknowledging hurdles like the complexity of interpreting epigenetic data and the absence of standardization, the review charts a path forward. It advocates for the integration of multi-omic data through machine learning algorithms to refine predictive models and stresses the importance of collaboration among clinicians, researchers, and data scientists. Such cooperative efforts are essential to fully leverage the potential of epigenetic features in clinical practice.

Real-world testing, treatment patterns, and outcomes following liquid biopsy in advanced cholangiocarcinoma.

455 Background: Cholangiocarcinoma (CCA) is an aggressive cancer with a poor prognosis. Given failure rates of up to 27% of CCA tissue biopsies, liquid biopsy has become an important tool to identify actionable molecular alterations. It is estimated tissue-based testing identifies IDH1 mutations and FGFR2 fusions in 12% and 9% of patients with advanced CCA (aCCA), respectively. Here we examined the rate of molecular alteration detection using circulating tumor DNA (ctDNA) testing, treatment patterns in aCCA, and outcomes for patients receiving ivosidenib following ctDNA-detected IDH1 mutations. Methods: Real-world data was sourced from GuardantINFORM, which comprises aggregated commercial payer health claims and de-identified records from >330,000 patients with clinical ctDNA testing via Guardant360 (G360), from 2014 to 2023. Patients with aCCA and >1 treatment claim after G360 results were included (N=1726). Patient outcomes were assessed via real-world time to treatment discontinuation (rwTTD), real-world time to next treatment (rwTTNT), and real-world overall survival (rwOS), all assessed in months. Log rank test was used to compare Kaplan-Meier survival curves. Results: Of 1495 patients with >1 ctDNA alteration detected, a guideline-recommended biomarker was identified in 18% of patients. In patients with intrahepatic CCA (n=403), 11% had an IDH1 mutation, 9% an FGFR2 fusion, 1% MSI-H detected, 1% BRAF V600E mutation, <1% ERBB2 amplification and <1% RET fusion. Testing was performed prior to first-line therapy, after first-line therapy and after second-line therapy in 34%, 46% and 21% of patients respectively. Gemcitabine and cisplatin represented the most common first-line therapy (48%). FOLFOX (21%), gemcitabine and cisplatin (13%), and capecitabine (11%) were the most common second-line therapies. Among ivosidenib-naïve patients with an IDH1 mutation, 58 (20%) started therapy within 90 days of ctDNA test: 36% received ivosidenib, 57% received chemotherapy, 7% received other therapy. Patients with IDH1 mutations treated with ivosidenib (n=21) had numerically improved rwTTD and rwTTNT compared to those receiving chemotherapy (n=33) [rwTTD: 4.6 (95% CI:2.6-8.6) vs 2.8 (95% CI:2.0-6.3), p=0.1011; rwTTNT 11.0 (95% CI:5.7-NE) vs 5.2 (95% CI:3.3-NE); p=0.2559]. There was no difference in rwOS between patients receiving ivosidenib vs not. However, sample size was small. Conclusions: The rate of actionable molecular alterations detected via ctDNA is 18%, comparable to reports from tissue-based testing. Patients with aCCA are often tested before starting first or second LOT. Patients with ctDNA-detected IDH1 mutations treated with ivosidenib and had a trend toward improved rwTTD and rwTTNT, although it did not reach statistical significance. This data supports the clinical utility of liquid biopsy to identify aCCA patients who may benefit from targeted therapy.

Clinical Utility of Liquid Biopsy in the Diagnosis and Monitoring of Patients Affected by PROS Syndromes

Clinical Utility of Liquid Biopsy in the Diagnosis and Monitoring of Patients Affected by PROS Syndromes

1425P Clinical utility of liquid biopsy for the early diagnosis of EGFR mutant advanced lung cancer in real-life setting (CLEAR)

1425P Clinical utility of liquid biopsy for the early diagnosis of EGFR mutant advanced lung cancer in real-life setting (CLEAR)

Moving liquid biopsies to the Front-line of lung cancer treatment decisions

Liquid biopsies have evolved as a promising non-invasive technology for cancer diagnosis and treatment, as they provide a comprehensive analysis of tumor-derived biomarkers. Prospective multicenter studies have shown the efficacy of liquid biopsies, including circulating tumoral DNA (ctDNA) and more recently cfRNA analysis, in identifying biomarkers for targeted therapies in patients with non-small cell lung cancer (NSCLC). In addition, studies have demonstrated a reduced time to treatment initiation when liquid biopsies are used in conjunction with or in lieu of tissue genotyping. Although liquid biopsies hold excellent potential, there are several obstacles to overcome, including technical limitations, standardization of methodologies, and cost-effectiveness. However, ongoing research and technological advances are conquering these obstacles, resulting in enhanced performance and dependability of liquid biopsy assays. To maximize the clinical utility of liquid biopsies, it is necessary to continue research, validation studies, and standardization initiatives. The incorporation of liquid biopsies into standard clinical practice has the potential to revolutionize the diagnosis and treatment of cancer. These noninvasive tests not only are a great tool for diagnosis but also allow real-time monitoring, guide treatment decisions, and enhance patient outcomes. As the costs of next-generation sequencing (NGS) declines, global access to liquid biopsies is anticipated to increase. Liquid biopsies arrived in the clinical practice after we were familiar with the analysis of genetic aberrations in tissue by next generation sequencing (NGS) that is considered the standard of care in new patients with the diagnosis of metastatic non-small cell lung cancer (NSCLC) and sometimes are used now as complement of tissue analysis or only when there is not enough tissue available. We already have done enough studies that show the non-inferiority and equivalence of liquid biopsies with molecular tissue testing. This article explores recent studies that demonstrate the clinical utility and potential of liquid biopsies in oncology including the possibility to use them at the same time of tissue analysis and the comparison of both with the advantage for the patient to get an earlier result due to the shorter turnaround time of liquid biopsies.

Clinical utility of liquid biopsy in canine oral malignant melanoma using cell-free DNA.

Cell-free DNA (cfDNA), an extracellular free DNA released into the bloodstream by cells, is a potentially useful noninvasive marker to detect human malignancies and monitor response to treatment. In the present study, we evaluated the utility of circulating cfDNA in canine patients with oral malignant melanoma (OMM) in assessing therapeutic response and clinical outcomes. Plasma samples were collected from 12 dogs with OMM and 9 healthy controls. cfDNA concentration was quantified by real-time PCR resulting in short (99bp) and long (218bp) fragments of long interspersed nuclear element-1 (LINE-1), and the DNA integrity index (DII) was then calculated (218/99). A follow-up study was conducted on 6 dogs with OMM, and the plasma cfDNA and DII were quantified throughout disease progression. Although cfDNA levels obtained from dogs with OMM were not significantly different compared to those obtained from healthy controls, the DII was significantly lower in dogs with OMM than in healthy controls. The DII tended to decrease as the disease stage progressed. Moreover, changes in cfDNA concentration and DII along the clinical course were observed when major changes, such as metastasis or apparent tumor progression, were observed. The results of our study suggest that measurements of serum cfDNA and DII using LINE-1 might be valuable new biomarkers for monitoring OMM progression in dogs. This preliminary study demonstrated the potential clinical utility of monitoring plasma cfDNA in canine patients with OMM.

Clinical utility of liquid-based comprehensive genomic profiling (CGP) in gastrointestinal stromal tumors (GIST).

11541 Background: GIST is the most common mesenchymal cancer of the digestive tract. Beyond surgery, treatment for GIST focuses largely on tyrosine kinase inhibitors (TKI), whose selection and potential resistance depend on select mutations. We present the molecular landscape of GIST utilizing tissue and liquid biopsies with emphasis on the clinical utility of liquid biopsy in advanced GIST. Methods: Liquid (FoundationOne Liquid CDx [F1LCDx]) and tissue (FoundationOne CDx) CGP was performed by hybrid capture, targeted NGS at Foundation Medicine Inc. Tissue and liquid samples from 2,198 and 147 patients, respectively, were analyzed. A cohort of 27 paired tissue and liquid samples were also evaluated. The levels of circulating tumor DNA (ctDNA) in liquid biopsies was quantified by tumor fraction (TF), with a TF algorithm incorporating aneuploidy, variant allele frequency, and canonical alterations detected on F1LCDx. Results: Tissue CGP (n = 2,198) revealed the following prevalence of primary driver alterations: KIT (77%), PDGFRA (8%), NF1 (6%), SDHA/B/C/D (SDHx, 3%) and BRAF (1%). Rates of molecular markers previously associated with worse prognosis included: CDKN2A (29%), RB1 (9%), TP53 (6%) and SETD2 (4%). 7% of cases had no reportable known pathogenic alterations in canonical GIST genes (wild-type GIST), while 2% of cases had a mutation in more than one driver. In a cohort of 147 liquid biopsies, TF was < 1% in 68.0%, 1-10% in 18.4%, > 10% in 13.6% of samples. In samples with elevated TF ( > 10%), the prevalence of targetable driver alterations in KIT (89%), PDGFRA (4%) , NF1 (4%) and BRAF (4%) was comparable to the tissue prevalence. In liquid, 58% (39/67) of samples with a KIT-driver mutation had a co-occurring imatinib-resistant KIT alteration. In addition, 4/147 patients (3%) were predicted to harbor a germline KIT mutation, including one patient (0.6%) with a potential imatinib-resistant KIT D820G germline mutation and another with clinical suspicion of germline KIT L576P mutation due to the presence of multiple primary GISTs, hyperplasia of myenteric plexus and dysplastic skin nevi. In paired tissue/liquid samples, liquid detected 2/2 driver mutations found in tissue when liquid TF was > 10%, and 5/6 in specimens with TF > 1%. In the overall cohort, the relative prevalence of KIT exon 9 and 11 driver alterations was comparable in tissue vs liquid, while imatinib-resistance KIT exon 13 and 17 mutations were enriched in liquid samples. Conclusions: Known driver and TKI-resistant mutations of both somatic and potential germline origin are identified in peripheral blood ctDNA of GIST patients. Liquid biopsy shows high concordance to tissue in identifying driver mutations in the presence of elevated TF and may exhibit TKI-resistant specific alterations. This study indicates that liquid biopsy may be useful in the molecular classification of GIST during the medical management of advanced GIST patients.

Practical Utility of Liquid Biopsies for Evaluating Genomic Alterations in Castration-Resistant Prostate Cancer.

Traditional tissue-based assessments of genomic alterations in castration-resistant prostate cancer (CRPC) can be challenging. To evaluate the real-world clinical utility of liquid biopsies for the evaluation of genomic alterations in CRPC, we preemptively collected available plasma samples and archival tissue samples from patients that were being treated for clinically confirmed CRPC. The cell-free DNA (cfDNA) and tumor tissue DNA were analyzed using the AlphaLiquid®100-HRR panel. Plasma samples from a total of 87 patients were included in this study. Somatic mutations from cfDNA were detected in 78 (89.7%) patients, regardless of the presence of overt metastasis or concomitant treatment given at the time of plasma sample collection. Twenty-three patients were found to have known deleterious somatic or germline mutations in HRR genes from their cfDNA. Archival tissue samples from 33 (37.9%) patients were available for comparative analysis. Tissue sequencing was able to yield an NGS result in only 51.5% of the tissue samples. The general sensitivity of cfDNA for detecting somatic mutations in tissues was 71.8%, but important somatic/germline mutations in HRR genes were found to have a higher concordance (100%). Liquid biopsies can be a reasonable substitute for tissue biopsies in CRPC patients when evaluating genomic alterations.

Liquid Biopsy in Early-Stage Lung Cancer: Current and Future Clinical Applications.

Lung cancer remains the leading cause of cancer death worldwide, with the majority of cases diagnosed in an advanced stage. Early-stage disease non-small cell lung cancer (NSCLC) has a better outcome, nevertheless the 5-year survival rates drop from 60% for stage IIA to 36% for stage IIIA disease. Early detection and optimized perioperative systemic treatment are frontrunner strategies to reduce this burden. The rapid advancements in molecular diagnostics as well as the growing availability of targeted therapies call for the most efficient detection of actionable biomarkers. Liquid biopsies have already proven their added value in the management of advanced NSCLC but can also optimize patient care in early-stage NSCLC. In addition to having known diagnostic benefits of speed, accessibility, and enhanced biomarker detection compared to tissue biopsy, liquid biopsy could be implemented for screening, diagnostic, and prognostic purposes. Furthermore, liquid biopsy can optimize therapeutic management by overcoming the issue of tumor heterogeneity, monitoring tumor burden, and detecting minimal residual disease (MRD), i.e., the presence of tumor-specific ctDNA, post-operatively. The latter is strongly prognostic and is likely to become a guidance in the postsurgical management. In this review, we present the current evidence on the clinical utility of liquid biopsy in early-stage lung cancer, discuss a selection of key trials, and suggest future applications.

Abstract 2315: Temporal changes in circulating tumor cells and circulating tumor DNA in patients with resectable pancreatic ductal adenocarcinoma

Abstract Background: Circulating tumor cells (CTCs), circulating cell-free DNA (cfDNA), and circulating tumor DNA (ctDNA) are minimally invasive biomarkers that carry vital tumor onset, progression, and metastasis information, which is crucial for cancer diagnosis, prognosis, and management. We report here our longitudinal study of these circulating biomarkers in resectable pancreatic ductal adenocarcinoma (PDAC) patients. Although the overall 5-year survival rate of PDAC is low (~6%), truly resectable patients are expected to have better outcomes than non-resectable PDAC patients, especially if liquid biopsy can help guide anticancer treatment selection. Method: We evaluated temporal changes in CTCs, cfDNA, and ctDNA in peripheral blood samples in a cohort of patients with resectable PDAC treated with pre-operative chemotherapy and surgical excision. Five PDAC survivors in complete remission for three years without evidence of disease served as negative controls. Samples of peripheral blood were collected prior to the start of treatment and every two weeks while patients underwent neoadjuvant chemotherapy, followed by surgical excision of the pancreatic tumor. CTCs were enumerated using a previously reported microfluidic device [1] that integrates immunoaffinity-based isolation with size-based filtration, while cfDNA and ctDNA were measured using quantitative polymerase chain reaction (qPCR) and droplet digital PCR (ddPCR). Results: Among the initial seven patients who have completed the treatment sequences [2], CTCs were detectable in all patients (100%) at some points during treatment, but only 50% of patients had detectable CTCs before the start of chemotherapy. Median cfDNA concentrations were comparable to those negative controls throughout treatment. Using ddPCR to analyze peripheral blood samples, KRAS mutations were detected in in 71% of patients during anticancer therapy, but only in 29% patients prior to treatment. Overall, the majority of circulating biomarkers (81% for CTCs and 91% for ctDNA) were detected in blood samples collected after the start of neoadjuvant therapy and before surgery. Conclusion: This study suggests that a longitudinal study of circulating biomarkers provides additional data compared to single-point liquid biopsy, and that biologic “release” of biomarkers due to therapy can increase detectability. -Further study is needed to determine the clinical utility of liquid biopsy for resectable PDAC patients. [1] Chen, et al., Angew. Chem. Int. Ed., 58, 2019, 7606-7610. [2] Dopico, et al., Biosensors, 12, 2022, 206. Citation Format: Yang Zhang, Pablo J. Dopico, Minh-Chau N. Le, Zhijie Yang, Youxiang Wang, Sherise C. Rogers, Thomas J. George, Hugh Z. Fan. Temporal changes in circulating tumor cells and circulating tumor DNA in patients with resectable pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2315.

Abstract 1034: Clinical utility of liquid biopsy for molecular characterization and resistance detection in patients with advanced NSCLC and ALK, ROS1 or RET fusions

Abstract Introduction Liquid biopsy (LB) is increasingly used in non-small cell lung cancer (NSCLC) for molecular diagnosis or resistance detection. Due to its non-invasive nature, it is often preferred over tissue biopsies, especially when sequential biopsies are warranted. Here, we report the clinical utility of liquid biopsy in patients with advanced NSCLC and ALK, ROS1 or RET fusions and its relevance to detect resistance after targeted therapy. Methods Between December 2020 and June 2022, 597 patients with advanced lung cancer had at least one liquid biopsy assessed by Foundation One CDx Liquid (panel of 324 genes) in a single institution. Plasma collection was performed in treatment-naïve patients and/or at time of progression. Clinical and molecular data were collected from patients with known fusions (ALK, ROS1, RET). LB were defined as “positive” if the fusion or resistance mutations were identified and “negative” in the absence of circulating-tumor DNA. The clinical utility of LB was evaluated as the proportion of positive results. The clinical relevance for resistance detection was defined as the proportion of LB that identified a putative resistance mechanism after targeted therapy. Results A total of 68 patients (29 ALK+, 22 RET+ and 17 ROS1+) with 83 LB were included. Patients were females in 50% of cases, had no smoking history in 58% of cases and had adenocarcinoma in 91% of cases. LB was positive in 55/83 (66%) cases overall, in 14/15 (93%) treatment-naïve patients and in 39/66 (59%) pre-treated patients. Factors significantly associated with a negative LB were limited disease progression (brain- or thoracic-only, p<0.001) and ongoing treatment at time of LB collection (p<0.05). Out of 47 LB performed at progression after targeted therapies, 7 (15%) found on-target resistance, 10 (21%) by-pass resistance, 10 (21%) no explainable resistance and 20 (43%) were negative. By-pass alterations included KRAS p.G12C/A mutations (N=2, ALK+), PIK3CA p.E545K/Q (N=3, ALK+), PTEN splice-site mutation (N=1, RET+), MYC amplifications (N=3, ALK+/RET+) and MET amplification (N=1, ROS1+). Conclusion LB was able to detect resistance mechanisms in one third of NSCLC patients with ALK, RET or ROS1 fusions. However, LB frequently failed to detect circulating-tumor DNA especially in patients with limited disease progression or with ongoing treatment at time of sample collection. Citation Format: Mihaela Aldea, Arianna Marinello, Marco Tagliamento, Filippo Dall'Olio, Damien Vasseur, Arnaud Bayle, Anas Gazzah, Miruna Grecea, Claudio Nicotra, Ludovic Lacroix, Santiago Ponce, Luc Friboulet, Fabrice Barlesi, Fabrice Andre, David Planchard, Etienne Rouleau, Antoine Italiano, Benjamin Besse. Clinical utility of liquid biopsy for molecular characterization and resistance detection in patients with advanced NSCLC and ALK, ROS1 or RET fusions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1034.

Exosome-Based Liquid Biopsy Approaches in Bone and Soft Tissue Sarcomas: Review of the Literature, Prospectives, and Hopes for Clinical Application.

The knowledge of exosome impact on sarcoma development and progression has been implemented in preclinical studies thanks to technological advances in exosome isolation. Moreover, the clinical relevance of liquid biopsy is well established in early diagnosis, prognosis prediction, tumor burden assessment, therapeutic responsiveness, and recurrence monitoring of tumors. In this review, we aimed to comprehensively summarize the existing literature pointing out the clinical relevance of detecting exosomes in liquid biopsy from sarcoma patients. Presently, the clinical utility of liquid biopsy based on exosomes in patients affected by sarcoma is under debate. The present manuscript collects evidence on the clinical impact of exosome detection in circulation of sarcoma patients. The majority of these data are not conclusive and the relevance of liquid biopsy-based approaches in some types of sarcoma is still insufficient. Nevertheless, the utility of circulating exosomes in precision medicine clearly emerged and further validation in larger and homogeneous cohorts of sarcoma patients is clearly needed, requiring collaborative projects between clinicians and translational researchers for these rare cancers.

Clinical utility of liquid biopsy and integrative genomic profiling in early-stage and oligometastatic cancer patients treated with radiotherapy

BackgroundLiquid biopsy and Integrative Genomic Profiling (IGP) are yet to be implemented into routine Radiation Oncology. Here we assess the utility of germline, tumour and circulating cell-free DNA-based genomic analyses for the clinical management of early-stage and oligometastatic cancer patients treated by precision radiotherapy.MethodsWe performed germline, tissue- and liquid biopsy NGS panels on 50 early-stage/oligometastatic cancer patients undergoing radiotherapy. We also monitored ctDNA variants in serial liquid biopsies collected during radiotherapy and follow-up and evaluated the clinical utility of such comprehensive approach.ResultsThe integration of different genomic studies revealed that only 1/3 of the liquid biopsy variants are of tumour origin. Altogether, 55 tumour variants (affecting 3/4 of the patients) were considered potentially actionable (for treatment and prognosis), whereas potential follow-up biomarkers were identified in all cases. Germline cancer-predisposing variants were present in three patients, which would have not been eligible for hereditary cancer testing according to clinical guidelines. The presence of detectable ctDNA variants before radiotherapy was associated with progression-free survival both in oligometastatic patients and in those with early-stage.ConclusionsIGP provides both valuable and actionable information for personalised decision-making in Radiation Oncology.

Potential clinical utility of liquid biopsy in early-stage non-small cell lung cancer

BackgroundLiquid biopsy has been widely researched for early diagnosis, prognostication and disease monitoring in lung cancer, but there is a need to investigate its clinical utility for early-stage non-small cell lung cancer (NSCLC).MethodsWe performed a meta-analysis and systematic review to evaluate diagnostic and prognostic values of liquid biopsy for early-stage NSCLC, regarding the common biomarkers, circulating tumor cells, circulating tumor DNA (ctDNA), methylation signatures, and microRNAs. Cochrane Library, PubMed, EMBASE databases, ClinicalTrials.gov, and reference lists were searched for eligible studies since inception to 17 May 2022. Sensitivity, specificity and area under the curve (AUC) were assessed for diagnostic values. Hazard ratio (HR) with a 95% confidence interval (CI) was extracted from the recurrence-free survival (RFS) and overall survival (OS) plots for prognostic analysis. Also, potential predictive values and treatment response evaluation were further investigated.ResultsIn this meta-analysis, there were 34 studies eligible for diagnostic assessment and 21 for prognostic analysis. The estimated diagnostic values of biomarkers for early-stage NSCLC with AUCs ranged from 0.84 to 0.87. The factors TNM stage I, T1 stage, N0 stage, adenocarcinoma, young age, and nonsmoking contributed to a lower tumor burden, with a median cell-free DNA concentration of 8.64 ng/ml. For prognostic analysis, the presence of molecular residual disease (MRD) detection was a strong predictor of disease relapse (RFS, HR, 4.95; 95% CI, 3.06–8.02; p < 0.001) and inferior OS (HR, 3.93; 95% CI, 1.97–7.83; p < 0.001), with average lead time of 179 ± 74 days between molecular recurrence and radiographic progression. Predictive values analysis showed adjuvant therapy significantly benefited the RFS of MRD + patients (HR, 0.27; p < 0.001), while an opposite tendency was detected for MRD − patients (HR, 1.51; p = 0.19). For treatment response evaluation, a strong correlation between pathological response and ctDNA clearance was detected, and both were associated with longer survival after neoadjuvant therapy.ConclusionsIn conclusion, our study indicated liquid biopsy could reliably facilitate more precision and effective management of early-stage NSCLC. Improvement of liquid biopsy techniques and detection approaches and platforms is still needed, and higher-quality trials are required to provide more rigorous evidence prior to their routine clinical application.

EP08.02-035 Clinical Utility of Liquid Biopsy After Progression to First and Second-Generation TKIs in Advanced EGFR Mutant NSCLC Patients

Liquid biopsy (LB) has increased its usefulness in selecting precise therapy during different treatment phases in advanced EGFR-mutant (EGFRm) non-small cell lung cancer (NSCLC). In addition, it has played a prognostic and predictive role in EGFRm patients. Detection of main oncogenic driver alteration on LB has been associated with worse oncological outcomes and increased disease burden. This study aims to assess survival and clinical characteristics associated with LB findings at first EGFR-TKI progression.

Clinical Utility of Liquid Biopsy to Detect BRAF and NRAS Mutations in Stage III/IV Melanoma Patients by Using Real-Time PCR

Simple SummaryLiquid biopsy is an increasingly used tool for melanoma diagnosis and molecular characterization, but also for monitoring of response to anticancer drugs. The aim of our work is to assess the clinical utility of a real-time quantitative PCR (qPCR)-based platform with a very short turnaround time and identify the best setting for clinical investigation. We investigated the concordance of this technique with tissue analysis in stage III–IV melanoma patients; moreover, we correlated results to clinicopathologic characteristics and outcomes. We found a higher tissue–plasma concordance in melanoma patients with high burden of disease (sum of diameters ≥30 mm, ≥2 metastatic sites, elevated LDH levels), constituting a clinical subgroup worthy of future prospective evaluation; however, the low sensitivity of this technique seems to be not sufficient for predicting relapses in radically resected patients.Background: Liquid biopsy is a potentially useful tool for melanoma patients, also for detecting BRAS/NRAS mutations, even if the tissue analysis remains the current standard. Methods: In this work, we tested ctDNA on plasma samples from 56 BRAF-V600/NRAS mutant stage III/IV melanoma patients using a real-time quantitative PCR (qPCR)-based platform. The study population was divided into two cohorts: the first including 26 patients who had undergone radical resection (resected cohort) and the second including 30 patients who had unresected measurable disease (advanced cohort). Moreover, for 10 patients in the advanced cohort, ctDNA assessment was repeated at specified timepoints after baseline testing. Data were analyzed and correlated to the clinicopathologic characteristics and outcomes. Results: In the baseline cohort, a higher tissue–plasma concordance was seen in patients with high burden of disease (sum of diameters ≥30 mm, ≥2 metastatic sites, elevated LDH levels); furthermore, monitoring of these patients through ctDNA analysis was informative for therapeutic responses. On the other hand, the low sensitivity of this technique did not allow for clinically valuable prediction of relapses in radically resected stage III/IV patients. Conclusions: Overall, our data suggest that qPCR-based ctDNA analysis could be informative in a subset of locally advanced and metastatic melanoma patients with specific clinical–radiological characteristics, supporting further investigations in this setting.

Coupling gamified continuing education with confidence-based assessment to address knowledge gaps and assess attitudes towards liquid biopsy for cancer screening among primary care providers.

11012 Background: Blood-based liquid biopsy assays offer a simplified approach to detect cancer early, guide clinical decision making, and predict treatment success. Given their novelty, primary care providers need education to improve knowledge and confidence regarding their use. The use of gamification in continuing medical education (CME) has been shown to increase engagement and knowledge transfer, and confidence-based learning can improve the educational experience by identified areas in which learners lack comfort. Methods: We provided a gamified CME activity based on the principles of confidence-based learning designed to educate primary care providers (PCPs) on the latest advances regarding the use of liquid biopsy for cancer screening. The game coupled knowledge questions with self-assessment of confidence to gage awareness of these topics. Pre- and post-test was used to quantify the impact of the education. The CE activity was available for credit from March 31, 2021 to March 31, 2022. Results: As of January 2022, 389 PCPs have participated. Overall, participants scored an average 76% on gaming questions related to the rationale behind the use of cell free DNA (cfDNA) for cancer screening and the benefits of liquid biopsy over tissue biopsy, demonstrating relatively high baseline knowledge on these topics. Self-reported confidence among those who answered correctly, however, was only 3.4 out of 5.0, suggesting a lack of comfort with the concepts despite answering correctly. On topics related to specific studies that demonstrated the clinical utility of liquid biopsy, participants scored only 59% and confidence scored averaged 3.17 out of 5.0, demonstrating a lack of knowledge and comfort on these topics. Across all topics, providers scored a 61% on a pre-test. Post-learning, providers scored 89%, highlighting the impact of the education on knowledge gaps. Moreover, while 52% of participants had never ordered a liquid biopsy for cancer screening prior to the education, 69% report being likely or extremely likely to do so because of the education provided. Conclusions: Integration of gamified and confidence-based learning into CE activities is an impactful way to identify and address knowledge gaps while also informing the need for future education. In this study, while self-report of confidence generally correlated with knowledge scores, confidence scores were only average even among those who answered correctly, demonstrating the need for skills-based learning that may improve comfort with liquid biopsy in the clinical setting.

Clinical Utility of Liquid Biopsy (Cell-free DNA) Based EGFR Mutation Detection Post treatment Initiation as a Disease Monitoring Tool in Patients With Advanced EGFR-mutant NSCLC

IntroductionPlasma cfDNA-based mutation analysis has shown disease-monitoring potential in various cancers. We assessed the potential of cfDNA-based EGFR mutation testing as a monitoring tool in patients with NSCLC. Patients and MethodsPatients with NSCLC harboring EGFR mutations receiving first-line treatment as per institutional protocol were enrolled. EGFR mutation status was determined using plasma samples at baseline and post treatment initiation. Patients in whom EGFR mutation was detected or persisted after treatment initiation were considered circulating tumor DNA (ctDNA)-positive. Progression-free survival (PFS) and overall survival (OS) for ctDNA-positive and negative patients post treatment initiation were the primary endpoints; concordance for baseline EGFR status between tissue and plasma and proportion of patients who were ctDNA-positive post treatment initiation were the secondary endpoints. ResultsWe enrolled 158 patients; 76 received gefitinib, and 82 received gefitinib plus chemotherapy. Median follow-up duration was 42 months. About 25% of patients were ctDNA-positive post treatment initiation. Median PFS for ctDNA-negative patients post treatment initiation was 14 (95% confidence interval [CI], 12.0-17.0) months, while that for ctDNA-positive patients was 8 (95% CI, 6.0-10.0) months. Median OS for ctDNA-negative patients post treatment initiation was 27 (95% CI, 24.0-32.0) months, while that for ctDNA-positive patients was 15 (95% CI, 11.0-19.0) months. Concordance at baseline between tissue and plasma samples was 75.4%. ConclusionPlasma-based EGFR mutation detection post treatment initiation can be used as a predictive marker for outcome in patients with EGFR-mutant NSCLC receiving first-line treatment.

Clinical utility of liquid biopsy in breast cancer: A systematic review.

Advancements in genetic sequencing techniques along with the identification of specific mutations and structural changes in multiple cancer genes, make it possible to identify circulating tumor cells and cell free nucleic acids as blood-based biomarkers, serving as a liquid biopsy (LB) with great utility for the diagnosis, treatment and follow-up of patients with neoplasms. This systematic review focuses on the clinical utility of LB in patients with breast cancer (BC). Articles published between 1990 and 2021 were included. Databases searched: Trip Database, WoS, EMBASE, PubMed, SCOPUS, and Clinical Keys. Variables studied: Publication year, country, number of cases, primary study design, LB detection methods, genes found, overall survival, disease-free survival, stage, response to treatment, clinical utility, BC molecular type, systemic treatment and methodological quality of primary studies. Of 2619 articles, 74 were retained representing 12 658 patients, mainly cohort studies (66.2%), the majority were from China (15%) and Japan (12.2%). All primary studies described clinical stage and type of systemic treatment used. Most used biomarker detection method: DNA (52.7%) and type of analysis: quantification of total cfDNA (35.1%). PIK3CA mutation was most frequent (62.9%). Evidence suggests clinically useful applications of BC. Though heterogeneous, publications suggest that LB will constitute part of the standard diagnostic-therapeutic process of BC.