Confirmation of Recurrent Lung Cancer Following Resection Using Liquid Biopsy, a Proof-of-Concept Real-World Study.

Appropriate management requires timely and accurate confirmation of non-small cell lung cancer (NSCLC) recurrence in patients who have had curative-intent surgical resection. We assessed the association between circulating tumor DNA (ctDNA) identified using amplicon sequencing and evidence of recurrence on CT surveillance. A prospective cohort study of NSCLC patients with early-stage disease undergoing curative-intent resection was conducted. Surveillance was performed post-operatively at pre-defined intervals with both liquid biopsy and chest CT imaging. Amplicon panel next-generation sequencing was performed on DNA and RNA from tumor tissue and on plasma cell-free DNA for tumor-informed ctDNA detection. Resected tumors from 78 NSCLC patients were analyzed. Alterations were detected on the DNA assay for 65 tumors and only on the RNA assay for 4 tumors. Of the 65 patients with alterations detected on the tumor DNA assay, 29 completed post-operative liquid biopsy testing. Four of those 29 patients had evidence of recurrence on imaging, of whom two had biopsy confirmation of recurrence and detectable ctDNA at the 12-month follow-up. Molecular confirmation of NSCLC recurrence can be provided through amplicon sequencing of plasma cell-free DNA in cases with imaging evidence of recurrence. Invasive tissue diagnosis may be avoidable in patients with ctDNA confirmation of recurrence that is suspected based on imaging. Further study of ctDNA assessment technologies in the setting of suspected recurrence is necessary to inform post-operative lung cancer surveillance guidelines.