Plasma ctDNA testing reduces time to treatment in advanced lung cancer

28th July 2023

The use of plasma ctDNA testing in patients with suspected advanced lung cancer accelerates the time to treatment compared to standard tissue testing, according to the findings of a new study.

In a non-randomised clinical trial, researchers found that plasma ctDNA genotyping prior to a tissue diagnosis among patients with suspected advanced non-small cell lung cancer (NSCLC), enables faster access to treatment in comparison to patients who undergo standard tissue testing.

The findings, published in the journal JAMA Network Open, sought to understand the best way to integrate liquid biopsy (based on plasma ctDNA) into the diagnostic algorithm for patients newly diagnosed with advanced NSCLC.

The trial enrolled patients referred for investigation and diagnosis of lung cancer but only if they had radiologic evidence of advanced cancer prior to a tissue diagnosis. These individuals (referred to as the accelerate group) underwent plasma ctDNA testing with a next-generation sequencing assay before their lung cancer diagnosis.

The primary endpoint was the time to treatment, which the researchers defined as the time from diagnostic programme referral to systemic treatment initiation. This duration was then compared with a reference cohort of patients referred to the programme and who had standard tissue genotyping after tissue diagnosis.

Plasma ctDNA time to diagnosis

Among the 150 patients enrolled patients, who had a median age at diagnosis of 68 years (53% men), 60% had advanced non-squamous NSCLC.

In patients assigned to the accelerate group, the median time to treatment was significantly shorter at 39 days compared to 62 days for the reference cohort (p < 0.001). In addition, the the median turnaround time from sample collection to genotyping results was only seven days for the accelerate group but 23 days for the reference group (p < 0.001).

The researchers suggested that complementing standard tissue testing with plasma ctDNA testing before diagnosis could increase access to precision medicine and may improve patient outcomes.

Nevertheless, they cautioned that the impact of this novel approach on clinically meaningful outcomes, such as quality of life, survival and cost-effectiveness, needs to be demonstrated.