Abstract 4238
Background
We developed a tumor-only NGS assay (TruSight assay), a 523 gene panel covering 1.94 megabases (Mb), that detects small DNA variants, provides a microsatellite instability (MSI) score, and estimates tumor mutational burden (TMB) from FFPE tissue DNA. We demonstrate the assay’s ability to detect a variety of biomarkers compared to various orthogonal methods across a range of solid tumor tissues. We also demonstrate accuracy in determining TMB status, using a clinically based cutoff, in non-small cell lung cancer (NSCLC) FFPE samples compared to tumor-normal whole exome sequencing (WES).
Methods
The study used ∼400 paired tumor-normal FFPE samples from 7 tumor types, including 240 NSCLC. Tumor samples were tested using the verified assay workflow including software analysis. All tumor and normal FFPE were tested with internal WES (with an independent analysis pipeline) and most with a commercial MSI PCR kit (Promega). The TMB score threshold, in mutations (mut)/Mb, was established for the TruSight assay and WES using 119 independent NSCLC FFPE samples and correlated with an external published cutoff.
Results
Across different tumor types, there was high concordance in small DNA variant calling (>95% positive percent agreement [PPA], >99% negative percent agreement [NPA]) between the TruSight assay and WES. For MSI, >95% PPA and 100% NPA were achieved between the TruSight assay and MSI-PCR. TMB scores from the TruSight assay showed good correlation with WES TMB scores (R2 >0.95 on linear regression). Among the NSCLC samples, TMB scores (range 0 – 184.6 mut/Mb) determined by the TruSight assay correlated well with WES (R2 0.94). Using cutoffs of 12.3 and 8.3 mut/Mb (TruSight assay and WES, respectively) to assign TMB High and Low statuses, overall percent agreement (OPA) was 85%.
Conclusions
The tumor-only TruSight assay showed high accuracy in detecting biomarkers across a range of solid tumors. The assay showed a good correlation in TMB score and agreement in TMB status with tumor-normal WES in a collection of NSCLC samples.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Illumina.
Disclosure
I. Deras: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina; Shareholder / Stockholder / Stock options: Bristol-Myers Squibb. T. Du: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. C. Zhao: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. N. Haseley: Full / Part-time employment: Illumina. A. Yazdanparast: Full / Part-time employment: Illumina. T. Jiang: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina; Shareholder / Stockholder / Stock options: Bristol-Myers Squibb. A. Mentzer: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. A. Purdy: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina; Shareholder / Stockholder / Stock options: Bristol-Myers Squibb. B. Crain: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. C. Echegaray: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. D. Lee: Full / Part-time employment: Illumina. J. Lee: Full / Part-time employment: Illumina. J. Silhavy: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. K. O’Brien: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. R. Vijayaraghavan: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. R. Garcia: Full / Part-time employment: Illumina. R. Haigis: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. T. Pawlowski: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina. J. Dockter: Shareholder / Stockholder / Stock options, Full / Part-time employment: Illumina.
Resources from the same session
3524 - Cabazitaxel For Octogenarian Patients With Metastatic Castration-Resistant Prostate Cancer (MCRPC).
Presenter: Paolo Tralongo
Session: Poster Display session 3
Resources:
Abstract
5637 - External Validation of a Prognostic Score in First-Line Metastastic Castration-Resistant Prostate Cancer (mCRPC)
Presenter: David Lorente
Session: Poster Display session 3
Resources:
Abstract
3228 - Treatment outcomes of 3rd treatment in a real-world metastatic castration resistant prostate cancer (mCRPC) population: results from the Dutch CAPRI-registry
Presenter: Jessica Notohardjo
Session: Poster Display session 3
Resources:
Abstract
4695 - Pelvic lymph node dissection and its extent on survival benefit in prostate cancer patients with a risk of lymph node invasion>5%: a propensity score matching analysis from SEER database
Presenter: Junru Chen
Session: Poster Display session 3
Resources:
Abstract
4438 - Multi-institutional evaluation of therapeutic management for oligometastatic cancer prostate recurrence with choline-PET/CT
Presenter: Morgane Guibert-broudic
Session: Poster Display session 3
Resources:
Abstract
4574 - Safety of new androgen receptor inhibitors (ARi) in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC): a network meta-analysis of randomized controlled trials (RCT)
Presenter: Amelia Altavilla
Session: Poster Display session 3
Resources:
Abstract
3816 - Real-world use of radium-223 for treatment of metastatic castration resistant-prostate cancer (mCRPC): results from the Dutch CAPRI registry
Presenter: Malou Kuppen
Session: Poster Display session 3
Resources:
Abstract
5180 - A phase 2a study of radium-223 dichloride (Ra-223) alone or in combination with abiraterone acetate or enzalutamide in metastatic castration-resistant prostate cancer (mCRPC)
Presenter: Daniel Petrylak
Session: Poster Display session 3
Resources:
Abstract
1067 - Adding ADT to PSMA-PET/CT-guided SBRT for oligometastatic prostate cancer improves distant progression-free survival
Presenter: Carole Mercier
Session: Poster Display session 3
Resources:
Abstract
5529 - Safety and efficacy of Ac-225-PSMA-617 in metastatic castration resistant prostate cancer (mCRPC) after failure of Lu-177-PSMA
Presenter: Robert Tauber
Session: Poster Display session 3
Resources:
Abstract