scholarly journals Liquid Biopsies for Molecular Biology-Based Radiotherapy

2021 ◽  
Vol 22 (20) ◽  
pp. 11267
Author(s):  
Erik S. Blomain ◽  
Everett J. Moding

Molecular alterations drive cancer initiation and evolution during development and in response to therapy. Radiotherapy is one of the most commonly employed cancer treatment modalities, but radiobiologic approaches for personalizing therapy based on tumor biology and individual risks remain to be defined. In recent years, analysis of circulating nucleic acids has emerged as a non-invasive approach to leverage tumor molecular abnormalities as biomarkers of prognosis and treatment response. Here, we evaluate the roles of circulating tumor DNA and related analyses as powerful tools for precision radiotherapy. We highlight emerging work advancing liquid biopsies beyond biomarker studies into translational research investigating tumor clonal evolution and acquired resistance.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 4096-4096 ◽  
Author(s):  
Anna M. Varghese ◽  
Juber Ahamad A Patel ◽  
Yelena Yuriy Janjigian ◽  
Fanli Meng ◽  
S Duygu Selcuklu ◽  
...  

4096 Background: FGFR2 alterations are present in 14% of cholangiocarcinomas (CCA) and are promising targets of investigational FGFR-directed therapies. Cell-free DNA profiling has emerged as a non-invasive approach to monitor disease and longitudinally characterize tumor evolution. We describe the use of circulating tumor DNA (ctDNA) among patients (pts) with FGFR2-altered CCA receiving FGFR-targeted therapy in the identification of acquired FGFR2 mutations (mut) at resistance. Methods: Serial blood samples were collected from 8 pts with FGFR-altered CCA for ctDNA isolation and next generation sequencing. Plasma ctDNA collected at baseline and resistance to FGFR-targeted therapy were sequenced using a custom ultra-deep coverage cfDNA panel, MSK-ACCESS, incorporating dual index primers and unique molecular barcodes to enable background error suppression and high-sensitivity mut detection. The assay was enhanced to include all protein-coding exons and relevant introns of FGFR2. In 5/8 pts, genomic profiling of an initial tumor biopsy was performed. Results: 8 pts with FGFR2-altered CCA (7 gene fusions, 1 amplification) were treated with FGFR-targeted therapies. 7/8 pts exhibited stable disease or partial response. 19 total acquired mut in FGFR2 were detected at resistance in 5/8 pts (between 1-9 unique mut identified in each sample). All mut were located in the kinase domain. Conclusions: Acquired mut in FGFR2 are seen in pts who have developed resistance to targeted therapy. CtDNA can be used to identify these mut at the time of acquired resistance. The multitude of FGFR2 mut observed within individual pts suggest heterogeneity and evolutionary convergence of resistance mechanisms. Our results illustrate the utility of ctDNA as a less invasive way to monitor for signs of resistance and to identify other potential targetable alterations. [Table: see text]


2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 401-401
Author(s):  
Dario Martin Villamar ◽  
Kristin Sedgwick Price ◽  
Rebecca Nagy ◽  
Scott T. Tagawa ◽  
Ana M. Molina ◽  
...  

401 Background: UC is characterized by extensive genomic heterogeneity. Access to genomic DNA from all metastatic lesions is infeasible. Next-generation sequencing (NGS) of circulating tumor DNA (ctDNA) may recapitulate heterogeneity and offer an opportunity for continuous tracking of tumor evolution. Methods: We analyzed a cohort of advanced UC patients with serial (2 time points) ctDNA NGS using Guardant360. Restaging scans were examined to determine the relationship between ctDNA dynamics and radiologic progression. We performed whole exome sequencing (WES) of a subset of the corresponding tumors to define patterns of genomic heterogeneity. Results: NGS was performed on 214 individual ctDNA samples from 78 advanced UC patients (61 M, 17 F). A minimum of 2 serial ctDNA tests per patient (range 2-8) were collected over an average 21.5 (2-108) weeks between samples. Molecular alterations (MAs) were identified in 188 (88%) of samples with a mean of 4.3 alterations (1-31) per sample. 184 (85%) samples harbored SNVs, 30 (14%) harbored indels and 36 CNVs (17%). Most commonly mutated genes were TP53 (18%), ARID1A, NF1 (4.5% each ), EGFR (3.5%), FGFR3 (3.4%), ERBB2 and PIK3CA (3.4% each ). The most frequently amplified genes were ERRB2 and CCNE1. Serial analysis of maximum variant allele frequency (mVAF) revealed a mean 7.5-fold change between 1st and 2nd and a 6-fold change between 2nd and 3rd ctDNA samples. Interestingly, the mean rate of mVAF fold change/week was stable between serial testing time points (0.35, 0.32 p = 0.7). We observed that patients with higher initial mVAF ( > 3%) experienced a significantly larger mean fold decrease compared to patients with initial mVAF below this threshold (p = 0.008). In patients with available restaging scans timed with ctDNA testing, all patients with radiologic progression exhibited increasing mVAF (mean: 8-fold). Interestingly, ctDNA identified several clinically-significant somatic MAs not present on matching tumor WES including PIK3CA (T727R, M1043I), TP53 (Q331*, P190L), RB1 (R556*, Q257*), APC (D2527H), and BRCA2 (P2804S).WES is ongoing in more patients. Conclusions: ctDNA sequencing enables dynamic monitoring of therapy-driven clonal evolution patterns of advanced UC.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e17100-e17100
Author(s):  
Zeynep Busra Zengin ◽  
Nazli Dizman ◽  
Nicholas Salgia ◽  
Jeremy Jones ◽  
Jingbo Zhang ◽  
...  

e17100 Background: Despite extensive work to characterize genomic alterations (GAs) in metastatic renal cell carcinoma (mRCC), GAs are not currently used for treatment sequencing or selection. Circulating tumor DNA (ctDNA) in both blood and urine may elucidate potential mRCC biomarkers through a minimally invasive approach. We aimed to validate previous blood-based ctDNA studies (Pal et al Eur Urol 2017) and compare detection rates of clinically relevant GAs in plasma and urine. Methods: From a single institution, patients (pts) with mRCC were recruited to provide a plasma and urine specimen. ctDNA next-generation sequencing was performed using an investigational 120-gene panel, and we limited our assessment to 7 GAs with biological relevance in RCC ( VHL, MTOR, PIK3CA, TSC2, MET, AKT1, TSC1). Further, only pathogenic alterations previously recognized in RCC and cited in the Catalogue of Somatic Mutations in Cancer (COSMIC) database were considered. Clinicopathologic variables, treatment type and response to therapy were collected from an institutional mRCC patient database. Concordance analysis was performed at the gene level between blood and urine using previously published approaches (Chae et al Oncotarget 2016). Results: 50 pts (40M:10F) were enrolled with a median age of 65. 40 pts (80%) had clear cell histology, while the remainder were papillary (12%), chromophobe (4%) or other (4%). Pts received a median of 1 line of therapy (range, 0-7). GAs were identified in 45 pts (90%) in blood and in 45 pts (90%) in urine . Applying the above criteria, the most frequently observed GAs in blood specimens were TSC2 (9%), MTOR (4%), and VHL (2%). The most frequently observed GAs in urine were VHL (4%) and MTOR (2%). The rate of concordance between blood- and urine-detected GAs was 93%. Of pts bearing mTOR pathway alterations in blood or urine, 3 received everolimus-based therapy. All 3 pts remain on therapy at 10.4, 13.8 and 14.0 months, respectively. Conclusions: Biologically relevant GAs can be detected in pts with mRCC using blood and urine. Our methodology showed high concordance between both platforms. Consistent with prior reports, ctDNA assessment of pts with pretreated mRCC shows a higher frequency of TOR pathway alterations and a lower frequency of VHL mutation.


2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 658-658
Author(s):  
Walid Labib Shaib ◽  
Ali Roberts ◽  
Mehmet Akce ◽  
Christina Wu ◽  
Olatunji B. Alese ◽  
...  

658 Background: Appendiceal cancers (AC) comprise around 0.5% of all gastrointestinal neoplasia. The genomic landscape of AC has not been well studied. The yield of circulating tumor DNA (ctDNA) from the plasma of patients with AC has not been reported. The aim of this study is to confirm the feasibility of NGS using ctDNA and characterize common alternations in the genomic profile of AC. Methods: The molecular alterations in 372 plasma samples from 303 patients with AC using clinical-grade NGS of ctDNA (Guardant 360) across multiple institutions, was evaluated. The test detects single nucleotide variants in 54 -73 genes, copy number amplifications, fusions, and indels in selected genes. Results: A total of 303 AC patients were evaluated; 169 female (56%). Median age was 56.8 (range: 25-83). ctDNA NGS testing was done on 372 plasma samples; 48 patients had testing performed twice, 9 three times, and 1 was tested four times. Genomic alterations were defined in 207 (55.6%) samples with a total of 288 alterations identified after excluding variants of uncertain significance (VUSs) and synonymous mutations. TP53 associated genes were most commonly altered (n = 96, 33.3%), followed by KRAS (n = 41, 14.2%), APC (n = 19, 6.6%), EGFR (n = 15, 5.2%), BRAF (n = 13, 4.5%), NF1 (n = 13, 4.5%), MYC (n = 9, 3.1%), GNAS (n = 8, 2.7%), PI3CA (n = 7, 2.4%), MET (n = 6, 2.08%), ATM in 6 (1.6%). Other genomic alterations of low frequency, but clinically relevant: AR (n = 4, 1.39%), TERT (n = 4, 1.39%), ERBB2 (n = 4, 1.39%), SMAD4 (n = 3, 1.04%), CDK4 (n = 2, 0.69%), NRAS (n = 2, 0.69%), FGFR1 (n = 2, 0.69%), FGFR2 (n = 2, 0.69%), PTEN (n = 2, 0.69%), RB1 (n = 2, 0.69%), and CDK6, CDKN2A, BRCA1, BRCA2, JAK2, IDH2, MAPK, NTRK1, CDH1, ARID1A, and PDGFRA were all reported once. Conclusions: Evaluation of ctDNA was feasible among individuals with AC. The frequency of genomic alterations in ctDNA testing is similar to those previously reported in tissue NGS. Liquid biopsies are non-invasive methods that can provide personalized options for targeted therapies in patients with AC.


2018 ◽  
Author(s):  
Franciele Knebel ◽  
Fabiana Bettoni ◽  
Andrea Shimada ◽  
Manoel Cruz ◽  
João Victor Alessi ◽  
...  

2016 ◽  
Vol 23 (4) ◽  
pp. R207-R217 ◽  
Author(s):  
Jamie L Van Etten ◽  
Scott M Dehm

Metastatic disease is responsible for the majority of prostate cancer deaths. The standard treatment for metastatic disease is surgical or chemical castration in the form of androgen deprivation therapy. Despite initial success and disease regression, resistance to therapy ultimately develops and the disease transitions to castration-resistant prostate cancer, which is uniformly fatal. Thus, developing an understanding of genetic evolution in metastasis and in response to therapy has been a focus of recent studies. Large-scale sequencing studies have provided an expansive catalog of the mutation events that occur in the prostate cancer genome at various stages of disease progression. Small-scale studies have interrogated the genomic composition of multiple metastatic sites within individual patients or have tracked clonal evolution longitudinally in tissues, circulating tumor cells, or circulating tumor DNA. Collectively, these efforts have provided a new conceptual framework for understanding the origin of prostate cancer, as well as the origin and evolution of metastatic disease. In this review, we highlight these recent insights into the spatiotemporal landscape of genetic evolution of prostate cancer.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Benoit Busser ◽  
Julien Lupo ◽  
Lucie Sancey ◽  
Stéphane Mouret ◽  
Patrice Faure ◽  
...  

Melanoma is a cutaneous cancer with an increasing worldwide prevalence and high mortality due to unresectable or metastatic stages. Mutations inBRAF,NRAS, orKITare present in more than 60% of melanoma cases, but a useful blood-based biomarker for the clinical monitoring of melanoma patients is still lacking. Thus, the analysis of circulating tumor cells (CTCs) and/or cell-free circulating tumor DNA (ctDNA) analysis from blood (liquid biopsies) appears to be a promising noninvasive, repeatable, and systemic sampling tool for detecting and monitoring melanoma. Here, we review the molecular biology-based strategies used for ctDNA quantification in melanoma patients, as well as their main clinical applications. Droplet digital PCR (ddPCR) and next generation sequencing (NGS) technologies appear to be two versatile and complementary strategies to study rare variant mutations for the detection and monitoring of melanoma progression. Among the different clinical uses of ctDNA, we highlight the assessment of molecular heterogeneity and the identification of genetic determinants for targeted therapy as well as the analysis of acquired resistance. Importantly, ctDNA quantification might also be a novel biomarker with a prognostic value for melanoma patients.


2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 131-131
Author(s):  
Adithya Chennamadhavuni ◽  
Pashtoon Murtaza Kasi

131 Background: For patients with metastatic RAS/RAF wild-type refractory colorectal cancer anti-EGFR therapy can be reused in subsequent lines of therapy. However, it is not entirely clear if all patients derive benefit. Increasingly it is been recognized that these patients acquire mechanisms of resistance which can be detected on circulating tumor DNA-based testing. We present a series of patients who had serial testing post EGFR therapy showing its feasibility and value. This would have implications for EGFR rechallenge. Methods: We reviewed records for patients who initially were noted to have tissue RAS/RAF Wild type who received prior anti-EGFR therapy and then subsequently had at least 1 circulating tumor DNA-based testing. Included a result of patients who had comprehensive NGS based profiling for both tissue as well as ctDNA. Results: Median duration of initial prior anti EGFR therapy was around 10 months. Table shows results of patient's tissue based genomic testing in parallel with the serial circulating tumor DNA-based testing that was done later when subsequent lines of therapy were being decided. As noted, known acquired mechanisms of resistance were noted in 100% of the cases. These included KRAS, NRAS, extracellular domain mutations in EGFR and BRAF mutations. Interestingly the levels of the sub-clones expressed as variant allele fraction percentage varied and decreased over time in relation to timing of the prior EGFR exposure. Additionally, these were noted to be polyclonal and the number of clones also varied including some disappearing over time during non-EGFR based therapy (EGFR holiday). Conclusions: Patient's post EGFR blockade may have multiple mechanisms of acquired resistance that can be easily detected on noninvasive liquid biopsies. These patients likely will not benefit from EGFR rechallenge based on the results of the recently reported CRICKET (NCT02296203) and CAVE (EudraCT number: 2017-004392-32) clinical trials. Rechecking liquid biopsy plasma RAS/RAF status is one thing that may be incorporated into practice with EGFR rechallenge only if acquired mechanisms of resistance are absent. [Table: see text]


2020 ◽  
Vol 9 (11) ◽  
pp. 3674
Author(s):  
D. Akhoundova ◽  
J. Mosquera Martinez ◽  
L. E. Musmann ◽  
C. Britschgi ◽  
C. Rütsche ◽  
...  

Liquid biopsy is a rapidly emerging tool of precision oncology enabling minimally invasive molecular diagnostics and longitudinal monitoring of treatment response. For the clinical management of advanced stage lung cancer patients, detection and quantification of circulating tumor DNA (ctDNA) is now widely adopted into clinical practice. Still, interpretation of results and validation of ctDNA-based treatment decisions remain challenging. We report here our experience implementing liquid biopsies into the clinical management of lung cancer. We discuss advantages and limitations of distinct ctDNA assay techniques and highlight our approach to the analysis of recurrent molecular alterations found in lung cancer. Moreover, we report three exemplary clinical cases illustrating the complexity of interpreting liquid biopsy results in clinical practice. These cases underscore the potential and current limitations of liquid biopsy, focusing on the difficulty of interpreting discordant findings. In our view, despite all current limitations, the analysis of ctDNA in lung cancer patients is an essential and highly versatile complementary diagnostic tool for the clinical management of lung cancer patients in the era of precision oncology.


2020 ◽  
pp. 192-201 ◽  
Author(s):  
Peter Vu ◽  
Yulian Khagi ◽  
Paul Riviere ◽  
Aaron Goodman ◽  
Razelle Kurzrock

PURPOSE Studies have demonstrated an association between quantity of circulating tumor DNA (ctDNA) and poorer survival. We investigated the relationship between percent ctDNA (%ctDNA), total number of ctDNA alterations, and overall survival (OS) in liquid biopsies. MATERIALS AND METHODS Overall, 418 patients with blood-based next-generation sequencing (54 to 73 genes) were analyzed. Eligible patients included those who had advanced/metastatic solid tumor malignancies and never received immunotherapy treatment, which may alter the survival curve in patients with high mutational burden. RESULTS Patients with a high (≥ 5%) %ctDNA had significantly shorter OS versus those with intermediate (≥ 0.4% to < 5%) or low (< 0.4%) values (median OS, 7.0 v 14.1 v not reached [NR] months, respectively; P < .0001). Patients with a high (≥ 5) total number of alterations had significantly shorter OS versus those with intermediate (≥ 1.46 to < 5), low (< 1.46), or no alterations (median OS, 4.6 v 11.7 v 21.3 v NR months, respectively; P < .0001). The total number of alterations correlated with %ctDNA (r = 0.85; 95% CI, 0.81 to 0.87; P < .0001). However, only an intermediate to high total number of alterations (≥ 1.46) was an independent predictor of worse OS (hazard ratio, 1.96; 95% CI, 1.30 to 2.96; P = .0014; multivariate analysis). CONCLUSION We demonstrate that the total number of alterations and %ctDNA have prognostic value and correlate with one another, but only the total number of alterations was independently associated with survival outcomes. Our findings suggest that the total number of alterations in plasma may be an indicator of more aggressive tumor biology and therefore poorer survival.


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