At the Speed of Liquid (Biopsy)

The lung and thoracic oncology spotlight is increasingly shining on liquid biopsy. Genomic profiling is a pivotal tool for non-small cell lung carcinoma (NSCLC) and tissue-based analysis is the preferred method of investigation – despite being invasive and only providing a single one-place snapshot of the tumor. In recent years, the liquid biopsy has begun to challenge the standard approach, offering a minimally invasive – and spatially and temporally representative – method of investigating the tumor gene profile.

Nir Peled and colleagues explored the potential role of liquid biopsy for lung cancer patients by investigating the difference between next-generation sequencing (NGS)-based liquid biopsy and tissue-based analysis. The researchers focused on time to report and time to treat in treatment-naive NSCLC patients (1). In their pilot study, they ordered both types of biopsies for patients and found that the turnaround time for liquid biopsy results was 10 days faster than for tissue results, with actionable genes identified in 11 tissue biopsies and 14 identified by liquid biopsy.

“This is the first step to stabilizing the community’s understanding that liquid biopsy is faster than solid,” says Peled, Head of the Cancer Institute at Soroka Medical Center. “I expect to see a wider reimbursement for liquid biopsy – first in local laboratories. Having local labs perform liquid NGS is a challenge; however, it will provide a faster service, more rapid diagnosis, and shorter time to treatment – which is the main goal.”

Natasha Leighl and colleagues studied the value of liquid biopsy for tissue profiling in advanced NSCLC patients in the Canadian public healthcare system. In a collaborative effort between six Canadian hospitals, the team divided 210 patients into two groups: 150 treatment-naive patients with measurable disease who smoked fewer than 10 packets of cigarettes per year and 60 patients with known oncogenic drivers whose disease progressed on tyrosine kinase inhibitors (TKIs) (2).

They found that over 80 percent of advanced NSCLC patients had genomic alterations that could be detected in circulating free DNA. Additionally, 56 percent of treatment-naive patients and 37 percent of TKI-resistant patients had alterations that could be clinically actioned with FDA-approved drugs or clinical trials.

For patients with advanced NSCLC, liquid biopsy can speed up genomic profiling and reduce time to treatment – but pathologists who prefer tissue-based methods need not worry. “Liquid biopsy is not a replacement for tissue-based diagnosis – it is complementary,” says Peled. “Together, they can support our patients with a more comprehensive approach.”