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
5056 - Phase 2 study of 2 dosing regimens of cemiplimab, a human monoclonal anti–PD-1, in metastatic cutaneous squamous cell carcinoma (mCSCC)
Presenter: Danny Rischin
Session: Poster Display session 3
Resources:
Abstract
5710 - Avelumab for advanced Merkel cell carcinoma in the Netherlands; a nationwide survey
Presenter: Sonja Levy
Session: Poster Display session 3
Resources:
Abstract
3152 - Health-related quality of life in patients with metastatic Merkel cell carcinoma receiving second-line or later avelumab treatment: 36-month follow-up data
Presenter: Sandra D'Angelo
Session: Poster Display session 3
Resources:
Abstract
5715 - A Phase 2, Randomized Study of Nivolumab (NIVO) and Ipilimumab (IPI) versus NIVO, IPI and Stereotactic Body Radiation Therapy (SBRT) for Metastatic Merkel Cell Carcinoma (MCC, NCT03071406) – a preliminary report.
Presenter: Sungjune Kim
Session: Poster Display session 3
Resources:
Abstract
2854 - Real-world impact of immune checkpoint inhibitors in metastatic uveal melanoma
Presenter: Kalijn Bol
Session: Poster Display session 3
Resources:
Abstract
2928 - Immune checkpoint inhibitors in a cohort of 206 metastatic uveal melanomas patients
Presenter: Mathilde Saint-Ghislain
Session: Poster Display session 3
Resources:
Abstract
1235 - Incidence and survival of Uveal Melanoma occurring as single cancer versus its occurrence as a first or second primary neoplasm
Presenter: Ahmad Alfaar
Session: Poster Display session 3
Resources:
Abstract
3615 - Validation of a Clinicopathological and Gene Expression Profile (CP-GEP) Model for Sentinel Lymph Node Metastasis in Primary Cutaneous Melanoma
Presenter: Evalyn Mulder
Session: Poster Display session 3
Resources:
Abstract
1793 - External validation of the 8th Edition Melanoma Staging System of the American Joint Committee on Cancer (AJCC) using the Surveillance, Epidemiology and End Results (SEER) Program
Presenter: Angelina Tjokrowidjaja
Session: Poster Display session 3
Resources:
Abstract
4278 - Clinical factors and overall survival (OS) associated with patterns of metastases (mets) in melanoma patients (pts).
Presenter: Ines Pires da Silva
Session: Poster Display session 3
Resources:
Abstract