Utilization Trends and Factors Associated With ROS1 Testing Among Patients With Advanced Non–small-cell Lung Cancer in US Community Practices

William Wong, Ning Wu, Ravindra Gupta, Aaron Scott Mansfield

Research output: Contribution to journalArticlepeer-review


Background: Targeted therapy for patients with non–small-cell lung cancer (NSCLC) harboring ROS proto-oncogene 1 (ROS1) rearrangements was approved in 2016. However, little is known about real-world ROS1 testing practices in United States community practice. We aimed to characterize ROS1 testing rates and identify potential barriers to ROS1 testing. Patients and Methods: Flatiron Health's de-identified electronic health record-derived database was used to identify patients diagnosed with advanced NSCLC from July 2016 through December 2018 who received systemic treatment in a community practice setting. ROS1 and other biomarker testing was recorded. Regression analysis identified demographic and clinical characteristics associated with occurrence of ROS1 testing, longer time (≥ 25 days) from diagnosis to ROS1 result, and initiation of therapy prior to ROS1 result. Results: Among 11,409 patients, documented ROS1 testing rates increased during the study period in squamous (from 30% to 48%) and nonsquamous (63% to 78%) histologies. Patients who were older, male, black, or with squamous histology, higher Eastern Cooperative Oncology Group score, recurrent disease, or history of smoking were significantly less likely to be tested. Among patients not tested for ROS1, 63% were tested for other biomarkers. Use of next-generation sequencing, older age, Hispanic/Latino ethnicity, squamous histology, de novo disease, and smoking history predicted longer time to test result post-diagnosis. Patients with delayed results were 9.7 times more likely to receive treatment prior to ROS1 test result. Conclusion: In real-world practice, some patient subgroups may be less likely to receive timely ROS1 testing and to be identified for potential targeted therapy.

Original languageEnglish (US)
Pages (from-to)e470-e480
JournalClinical lung cancer
Issue number3
StatePublished - May 2021


  • Biomarker
  • ROS proto-oncogene 1 (ROS1)
  • ROS1 protein, human
  • Targeted therapy

ASJC Scopus subject areas

  • Oncology
  • Pulmonary and Respiratory Medicine
  • Cancer Research


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