Ultrarapid EGFR Testing in Non-Small Cell Lung Carcinoma Patients: Findings From a Canadian Clinical Testing Workflow

Single vs multigene molecular testing modalities for lung cancer offer distinct advantages and risks. We examined lung cancer cases with clinically requested ultrarapid EGFR testing to (1) identify clinical features of rapid tested cases and their association with EGFR mutations, (2) evaluate performance of single-gene and multigene panel testing for ultrarapid tested patients, and (3) estimate laboratory costs and clinical outcomes. We include all retrospectively identified lung cancer patients who had ultrarapid Idylla EGFR testing during the study period. Demographic data were retrieved from clinical charts, and cost estimates were obtained from the BC Cancer Genetics and Genomics Laboratory. Of the 109 ultrarapid tests, 94 (86%) were technically successful, yielding a positive or negative result. Of these, 62 tests (66%) identified an EGFR mutation. Patients with negative or failed testing were offered panel sequencing (n = 47, 43%). Ultrarapid testing had a median 1-day turnaround time and 95% sensitivity for EGFR mutation detection relative to panel sequencing. East/Southeast Asian ethnicity and female sex were significantly associated with EGFR mutation positivity in a multivariate logistic regression model (P = .0001 and .029, respectively). The mean molecular testing cost per ultrarapid tested patient, including panel sequencing for cases with negative/failed rapid tests, was $550.53 (SD: $284), slightly less than the $571 cost for panel sequencing. Single-gene testing of patients with urgent clinical need or high probability of mutation may allow a rapid time to treatment at similar testing costs.