Liquid Biopsy and Immuno-Oncology for Advanced Nonsmall Cell Lung Cancer

Background In the last decade, immune checkpoint inhibitors have revolutionized the treatment of metastatic nonsmall cell lung cancer without oncogenic addiction. Currently, programmed death ligand 1 (PD-L1) status, assessed in tissue biopsy samples, is the only test for guiding the prescription of these therapies in clinical practice. However, obtaining tumor tissue from patients with lung cancer is not always feasible and PD-L1 positivity is not a guarantee of immunotherapy efficacy. In this context, liquid biopsy, represented by several circulating biomarkers that reflect the tumor characteristics, is emerging as an interesting alternative approach. Content We describe the main blood biomarkers evaluated in patients with metastatic nonsmall cell lung cancer before/during immune checkpoint inhibitor treatment, with a focus on circulating cell-free DNA, circulating tumor DNA (ctDNA), blood tumor mutational burden, and circulating tumor cells (CTCs). Monitoring of ctDNA and CTCs during immunotherapy may be a promising tool to help clinicians in therapeutic decision-making.

Automated summary

This study discusses the application of immune checkpoint inhibitors in the treatment of metastatic nonsmall cell lung cancer and focuses on the evaluation of blood biomarkers such as circulating cell-free DNA, circulating tumor DNA, blood tumor mutational burden, and circulating tumor cells. Monitoring these biomarkers during immunotherapy may assist clinicians in making therapeutic decisions.