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Genomic sequencing is necessary for first-line advanced non-small cell lung cancer (aNSCLC) treatment decision-making. Tissue next generation sequencing (NGS) is standard but tissue quantity, quality, and time-to-results remains problematic. Here, we compare upfront cell-free-DNA (cfDNA) NGS clinical utility against routine tissue testing in patients with aNSCLC.cfDNA-NGS was performed in consecutive, newly identified aNSCLC patients between December 2019-October 2021 alongside routine tissue genotyping. Variants were interpreted using AMP/ASCO/CAP guidelines. The primary endpoint was tier-1 variants detected on cfDNA-NGS. cfDNA-NGS results were compared to tissue results.Of 311 patients, 282 (91%) had an informative cfDNA-NGS test; 118 (38%) patients had a tier-1 variant identified by cfDNA-NGS. Of 243 patients with paired tissue-cfDNA tests, 122 (50%) tissue tests were informative; 85 (35%) tissue tests identified a tier-1 variant. cfDNA-NGS detected 39 additional tier-1 variants compared to tissue alone, increasing the tier-1 detection rate by 46% (from 85 to 124). The sensitivity of cfDNA-NGS relative to tissue was 75% (25% tissue tier-1 variants were not detected on cfDNA-NGS); 33% of cfDNA tier-1 variants were not identified on tissue tests. Median time from request-to-report was shorter for cfDNA-NGS versus tissue (8 versus 22 days; p 0.0001). A total of 245 (79%) patients received first-line systemic-therapy: 49 (20%) with cfDNA-NGS results alone. Median time from sampling-to-commencement of first-line treatment was shorter for cfDNA-NGS blood draw versus first tissue biopsy (16 versus 35 days; p 0.0001).cfDNA-NGS increased the tier-1 variant detection rate with high concordance with tissue, and halves time-to-treatment. 'Plasma-first' upfront cfDNA-NGS use should be considered routinely for aNSCLC.

The diagnostic pathway for lung cancer can be long. Availability of front-line targeted therapies for NSCLC demands access to good quality tissue for genomic sequencing and rapid reporting of results. Diagnosis of lung cancer and availability of tissue was delayed during the COVID-19 pandemic.A pilot study assessing Guardant360™ cfDNA-NGS in patients with radiological-suspected advanced-stage lung cancer was performed at an academic cancer centre during COVID-19. Variants were tiered using AMP/ASCO/CAP guidelines and discussed at a tumour molecular board. The primary endpoint was the proportion of patients who commenced targeted treatment based on cfDNA-NGS results without tissue molecular results, predicted to be ≥ 10%.Between April 2020-May 2021, 51 patients were enrolled; 49 were evaluable. The median age was 71 years, 43% were never-smokers, 86% had stage IV disease. 80% of evaluable cfDNA-NGS were informative (tumour-derived cfDNA detected). cfDNA-NGS detected 30 (61%) AMP/ASCO/CAP tier 1 variants, including 20 additional tier 1 variants compared to tissue testing. Three patients with non-informative cfDNA-NGS had tier 1 variants identified on tissue testing. Eleven (22%; 95%CI 12%-27%) patients commenced targeted therapy based on cfDNA-NGS results without tissue molecular results, meeting the primary endpoint. Median time to results was shorter for cfDNA-NGS compared to standard-of-care tissue tests (9 versus 25 days, P 0.0001).Blood-first cfDNA-NGS in NSCLC patients increased the breadth and rapidity of detection of actionable variants with high tissue concordance and led to timely treatment decisions. A blood-first approach should be considered to improve the speed and accuracy of therapeutic decision-making.