Perspective | 11 September 2020

Genotyping is recommended for all patients with metastatic non-squamous non-small-cell lung cancers (NSCLC), both to enable patients to receive targeted therapies and to avoid therapies they are unlikely to benefit from. However, obtaining tumour biopsy material for genotyping is often challenging and is unfeasible in some patients, indicating the need to incorporate liquid biopsy approaches. In this Perspective, the authors provide guidance on how analysis of ctDNA from liquid biopsy samples in patients with metastatic NSCLC prior to first-line therapy has the potential to extend the benefits of genotyping to virtually all patients.