A pilot study comparing liquid biopsy with tissue-based testing showed that liquid biopsy delivered results approximately 10 days faster than tissue biopsy, according to research presented by Nir Peled, MD, PhD, and colleagues at the International Association for the Study of Lung Cancer (IASLC) 2020 Lung Cancer Hot Topic: Liquid Biopsy Virtual Conference (Abstract VP01.33).
Oncologists and pathologists prefer tissue-based analysis for patients with lung cancer, but liquid biopsy may provide a salvage approach in case of tissue exhaustion and may even be faster than tissue-based analysis, according to Dr. Peled, a medical oncologist and Head of the Cancer Institute at Soroka Medical Center, Ben Gurion University of the Negev, Beersheeba, Israel.
Nir Peled, MD, PhD
Methods
Researchers developed a pilot study and evaluated 25 treatment-naive patients with metastatic non–small cell lung cancer (NSCLC). Dr. Peled and his colleagues sought to compare time to reporting and time to treatment for next-generation sequencing (NGS)-based liquid biopsy vs tissue-based analysis.
Tissue and blood biopsies were ordered for all patients. Tissue analysis was based on local standard of care, which was immunohistochemistry for ALK, ROS1, and polymerase chain reaction or amplicon-based NGS for EGFR mutation statuses. Each patient also was given a liquid NGS platform blood biopsy.
Time to Results
Turnaround analysis revealed that the median time from pathologic diagnosis to receipt of the tissue report on the last biomarker was 21.5 days (range = 7–45 days), whereas the median time from blood draw to receiving cell-free DNA findings was 10 days (range = 7–19 days).
Dr. Peled reported that actionable genes were identified in 11 tissue biopsies and in 14 liquid biopsies. Liquid biopsy was able to identify mutations in PIK3CA and MET, as well as RET fusion, that were not tested by the local laboratories. Of note, one ALK fusion and one EGFR mutation were detected by tissue biopsy but not by liquid biopsy.
“This study suggests that NGS-based liquid biopsy improves time to report and more importantly, time to treatment, in patients with advanced NSCLC in comparison to tissue-based molecular analysis,” said Dr. Peled. In addition, he commented, “I am convinced that the practice of ‘liquid first’ should be implemented before tissue biopsy is performed; if so, we may see even more dramatic outcomes.”
