Ultra-Sensitive ctDNA Assay Significantly Improves Detection Rates for Early-Stage Lung Cancer

By LabMedica International staff writers
Posted on 27 Oct 2023

Image: The Personalis NeXT Personal cancer assay is designed to detect and monitor residual and recurrent disease (Photo courtesy of 123RF)

The existing method for confirming a recurrence of non-small cell lung cancer (NSCLC), the most frequent form of lung cancer, largely relies on imaging techniques like CT scans, which have known limitations in terms of sensitivity. Now, initial findings from a groundbreaking lung cancer study mark a significant advancement in lung cancer circulating tumor DNA (ctDNA) detection and management.

Personalis, Inc. (Menlo Park, CA, USA) has developed the NeXT Personal cancer assay for identifying and monitoring minimal residual and recurrent disease (MRD). The assay has demonstrated considerably higher detection rates for early-stage lung cancer, including lung adenocarcinoma (LUAD), a subtype of NSCLC that is notably challenging to identify in blood tests. The NeXT Personal technology employs whole genome sequencing and advanced noise suppression technology called NeXT SENSE to isolate a distinct genetic signature from a patient's tumor. This signature, based on around 1,800 variants, is then monitored over time in the patient's blood to identify any recurring or residual cancer. The technology boasts an industry-leading sensitivity level that goes down to about 1 PPM, which opens up the possibility for earlier risk assessment, early detection, more accurate monitoring, and thus, a significant improvement in lung cancer management.

For the current analysis, NeXT Personal was used to identify and track MRD in over 170 patients who were part of the TRACERx lung cancer study group. The assay displayed significantly higher sensitivity in detecting early-stage NSCLC compared to findings reported in two earlier studies focused on the TRACERx cohort. Before surgical intervention, NeXT Personal demonstrated a 100% sensitivity rate for ctDNA in non-LUAD samples and an 81% sensitivity rate for LUAD. This represents up to a fourfold increase in pre-surgical sensitivity for early-stage LUAD compared to prior research, significantly enhancing the assay's ability to effectively monitor lung cancer.

The study also revealed that NeXT Personal could classify patients into groups with lower or higher risks of cancer recurrence based on pre-surgical ctDNA levels. This ultra-sensitive ctDNA detection capability was pivotal in assessing patient recurrence risk. For instance, patients with LUAD who had no detectable ctDNA before surgery showed an impressive 100% overall five-year survival rate and a 94% relapse-free survival rate. In contrast, those with detectable ctDNA faced a high risk of cancer recurrence over a five-year period.

Moreover, NeXT Personal allowed for earlier detection of residual or recurring lung cancer post-surgery. The data indicate a median lead time of around 6 to 11 months for ctDNA detection ahead of conventional imaging methods, and substantially longer than previous findings from the TRACERx study. This earlier detection can potentially facilitate quicker treatment interventions for patients at higher risk. Overall, the findings from the TRACERx study underscore the potential utility of NeXT Personal in guiding patient management from the pre-surgery phase through to post-operative care and long-term monitoring.

"Existing tests for lung cancer patients often fall short in detecting residual or recurrent cancer early,” said Richard Chen, MD, MS, Chief Medical Officer and Executive Vice President, R&D of Personalis. “Our NeXT Personal test is designed to change that by being significantly more sensitive. We are thrilled that the TRACERx results presented at ESMO demonstrated higher sensitivity for the most common types of early-stage lung cancer, including the most challenging subtypes. That sensitivity translated into a better understanding of recurrence risk for patients, and earlier detection of recurrence. We hope that earlier detection can ultimately be life-saving, offering patients a greater chance at successful treatment."

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