The Perceived Value of Liquid Biopsy: Results From a Canadian Validation Study of Circulating Tumor DNA

Introduction: Liquid biopsy is recommended to diagnose molecular resistance to targeted therapy in patients with lung cancer. Nevertheless, not all jurisdictions provide funding and patient access. We report patients' perceived value of liquid biopsy in targeted therapy resistance. Methods: Canadian patients participating in a national EGFR T790M liquid biopsy validation study completed structured interviews measuring perceived value and willingness-to-pay for plasma circulating tumor DNA testing as an alternative to tumor biopsy using open-ended and iterative bidding approaches. Results: A total of 60 patients with advanced lung cancer participated with a median age of 64 years (range: 31-87 y); 69% were Asian and 45% female. All had received prior EGFR tyrosine kinase inhibitor; 17% also received chemotherapy. All patients preferred to have plasma testing over repeat tumor biopsy. In the context of the Canadian publicly funded system, patients estimated that a median of 300 (interquartile range: 150-800) Canadian dollars was a reasonable price to pay for liquid biopsy. Patients were personally willing to pay a median 100 (interquartile range: 33-350) Canadian dollars. Conclusions: In a system that covers the cost of standard diagnostic tests, patients with lung cancer indicated high willingness-to-pay out-of-pocket for liquid biopsy in the setting of acquired targeted therapy resistance. Patients have high perceived value of plasma genotyping and prefer it to repeat tumor biopsy.