Abstract 2833
Background
Circulating tumor DNA (ctDNA) is a promising, non-invasive biomarker for preclinical detection and monitoring of various cancers. The utility of ctDNA assessment in renal cell carcinoma (RCC) in not well established. Here, we evaluate the potential of a bespoke, multiplex PCR, whole exome sequencing (WES)-based approach for ctDNA detection.
Methods
The cohort consisted of 42 patients with stage Ib-IV RCC who underwent complete surgical resection. ctDNA was measured in plasma samples drawn pre-surgery (n = 34; baseline) and at post-operative time points (n = 41) using the bespoke assay targeting patient-specific tumor variants.
Results
A median of 11.7 ng (1.4-175 ng) of cfDNA was extracted from a median plasma volume of 3.2 mL (1.2-3.8 mL). ctDNA was detected with a mean mutant molecules/mL of 5.3 (0.22-62). Baseline ctDNA was detected in 41% (14/34) of patients. Presence of ctDNA was significantly associated with increased tumor size (mean 9.7 vs 7.1cm, p < 0.05), advanced tumor stage (stage III-IV vs I-II, p < 0.05) and poorly differentiated tumors (grade III-IV vs II, p < 0.0001). In the postoperative setting, 8/8 ctDNA-positive patients relapsed (positive predictive value (PPV=100%), while 16/33 ctDNA-negative patients relapsed (NPV=52%). Positive ctDNA status was associated with reduced relapse-free survival at post-surgical timepoints (HR: 2.8; 95% CI:1.2-6.6). None of the post-surgical samples from a control cohort of 17 non-relapsing patients were ctDNA-positive (specificity of 100%; median follow up of 64 months).
Conclusions
Presence of presurgical ctDNA strongly correlates with advanced stage RCC. Despite low plasma volumes, the bespoke assay detected ctDNA in 41% of baseline samples. Postoperative ctDNA presence is correlated with clinical relapse. However, absence of ctDNA does not preclude recurrence as RCC is known to shed limited amounts of ctDNA. Higher sample volumes and multiregion tumor biopsies could enhance detection rates. This personalized approach has the potential to be used for ctDNA-based detection of relapse in patients with advanced stage RCC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Natera, Inc.; Fox Chase Cancer Center.
Funding
Natera, Inc.; Fox Chase Cancer Center.
Disclosure
M. Balcioglu: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. H. Wu: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. S. Dashner: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. S. Shchegrova: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. E. Kalashnikova: Full / Part-time employment: Natera, Inc. H. Pawar: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. R.G. Uzzo: Advisory / Consultancy: Janssen; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Novartis; Advisory / Consultancy: Argos. A. Aleshin: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. H. Sethi: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. R. Salari: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. M. Louie: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. B. Zimmermann: Shareholder / Stockholder / Stock options, Full / Part-time employment, I am an employee of Natera and own stock/options to stock.: Natera, Inc. P. Abbosh: Advisory / Consultancy, Advisory: Janssen; Advisory / Consultancy, Advisory: AstraZeneca. All other authors have declared no conflicts of interest.
Resources from the same session
4097 - Targeting NRG1-fusions in multiple tumour types: Afatinib as a novel potential treatment option
Presenter: Stephen V Liu
Session: Poster Display session 3
Resources:
Abstract
1129 - Aspirin and Ticagrelor for the prevention of tumour cell induced platelet aggregation
Presenter: Meera Chauhan
Session: Poster Display session 3
Resources:
Abstract
4514 - Pharmacokinetic/ pharmacodynamic (PK/PD) exposure-response characterization of GSK3359609 (GSK609) from INDUCE-1, a phase I open-label study
Presenter: Michele Maio
Session: Poster Display session 3
Resources:
Abstract
5169 - In vitro functional interrogation of viable Circulating Tumor Associated Cells (C-TACs) for evaluating Platin resistance.
Presenter: Stefan Schuster
Session: Poster Display session 3
Resources:
Abstract
5827 - Targeting ARG2 as a novel therapeutic approach for cancer
Presenter: Marcin Grzybowski
Session: Poster Display session 3
Resources:
Abstract
3129 - MPS1 and PLK1 as new therapy targets in TP53 mutated solid tumors
Presenter: Balazs Gyorffy
Session: Poster Display session 3
Resources:
Abstract
2129 - The Tumor Static Exposure (TSE) concept & utility: application to combination treatment of radiation and radiosensitizing agent in tumor xenograft experiments
Presenter: Samer El Bawab
Session: Poster Display session 3
Resources:
Abstract
1814 - General Methodology to Optimize Tumor Treating Fields Delivery Utilizing Numerical Simulations
Presenter: Noa Urman
Session: Poster Display session 3
Resources:
Abstract
3010 - The Australian Exceptional Responders Program: a National collaboration
Presenter: Megan Barnet
Session: Poster Display session 3
Resources:
Abstract
4489 - A Window of Opportunity Trial of Atorvastatin Targeting p53 Mutant Malignancies
Presenter: Joaquina Baranda
Session: Poster Display session 3
Resources:
Abstract