Clinical Utility of Reflex Ordered Testing for Molecular Biomarkers in Lung Adenocarcinoma

Introduction: In order to standardize and expedite molecular biomarker testing, we implemented reflex ordered testing of targeted gene alterations in newly diagnosed lung adenocarcinomas within our hospital system. Patients and Methods: Reflex ordered testing of specific molecular biomarkers at the time of pathologic diagnosis of lung adenocarcinoma was approved and adopted system-wide in our hospital during 2017. Through institutional review board approval, we retrospectively looked at cohort of patients whose specimens received a diagnosis of lung adenocarcinoma, with molecular biomarker testing performed at Houston Methodist Hospital between 2016 and 2018. We compared average turnaround time (TAT) from 2016 (prior to reflex ordered testing) to 2017 and 2018 (post reflex ordered testing). Results: Standard molecular testing performed on 39 patients in 2016 had an average TAT of 52.6 days, whereas reflex ordered molecular testing in 2017 yielded an average TAT of 26.5 days (n = 127) and 15.6 days in 2018 (n = 54). The average TAT for reporting of molecular results significantly decreased by 37 days (P = .0002) within our hospital system post adoption of reflex ordered testing for lung adenocarcinoma. Reflex ordered testing also resulted in a higher variant detection rate than standard molecular biomarker ordering practices (48.8% vs. 25.6%; P < .05). Overall, the frequencies and types of variants identified among our cohort were similar to previous reports. Conclusions: Reflex ordered testing of molecular biomarkers in lung adenocarcinoma led to significantly decreased TAT within our hospital system and higher detection rates of targeted gene alterations. Patients with metastatic lung adenocarcinoma may not be getting the correct molecular biomarker testing prior to first-line therapy. We implement reflex ordered testing for molecular biomarkers at time of pathologic diagnosis of lung adenocarcinoma. We retrospectively compared reflex ordered testing to standard molecular testing. Reflex ordered testing lead significantly shorter turnaround time and higher variant detection rate.