Liquid biopsy may help diagnose cancer faster than tissue biopsy: Study

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 Nir Peled, MD, a medical oncologist and Head of the Cancer Institute, Soroka Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel.

Dr. Or Sehayek, Dr. Peled and their colleagues developed a pilot study and evaluated 25 patients with treatment-naive advanced metastatic non-small cell lung cancer (NSCLC). Dr. Peled sought to compare time to report 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-based analysis was based on local standard of care, which was immunohistochemistry for ALK, ROS1, and PCR or amplicon-based NGS for EGFR mutation statuses. Each patient also was given a liquid NGS platform blood biopsy.

Turnaround-time analysis revealed that the median range (days) from the pathologic diagnosis to receipt of the tissue report on the last biomarker was 21.5 (7-45) days while the median ranges from blood draw to receiving the cfDNA findings was 10 (7-19) days.

Dr. Peled reported that actionable genes were identified in 11 tissue biopsies and in 14 by liquid biopsy. Liquid biopsy was able to identify mutations in PIK3CA and MET, as well as RET fusion, that were not tested by the local labs. 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," Peled said. In addition, he said, "I am convinced that that the practice of 'liquid first' should be even implemented before tissue biopsy is performed; if so, we may see even more dramatic outcomes."