Building an Adequate ROS1 Workup With RNA-Based Sequencing

Wade Iams, MD, says adding RNA-based next-generation sequencing (NGS) to DNA-based NGS identifies about 15% more patients with actionable fusions, and urges clinicians to confirm whether the panel they ordered includes RNA at all, since the report rarely makes that obvious. He notes most major vendors now run both, but says it is worth verifying. Martin Dietrich, MD, PhD, says liquid biopsy reliably detects small DNA alterations but leaves roughly a 40% gap in fusion detection, because fusions are intron events poorly captured in blood and RNA recovered from blood remains investigational. He describes an automatic order prompt at his institution that pairs liquid and tissue testing with RNA-inclusive vendors, which he says has closed the testing gap there. Ticiana Leal, MD, adds that a positive liquid result is immediately actionable but a negative one still requires waiting for tissue.