Liquid Biopsy Can Help Predict Patient Response to Immunotherapy, Study Suggests

Monitoring changes in blood levels of the protein PD-L1, which acts as a protumorigenic factor in cancer cells, can help predict non-small cell lung cancer (NSCLC) patients' responses to immunotherapy, according to a study appearing this week in JCO Precision Oncology. Immune checkpoint inhibitors (ICIs) of programmed death 1 and its ligand PD-L1 have proven highly effective for NSCLC patients ineligible for molecularly targeted therapies, including patients whose tumor biopsies showed low pretreatment levels of PD-L1. Hypothesizing that tracking changes in PD-L1 levels during treatment may give more insights than a baseline level from an initial biopsy, a Rutgers University- and the Fox Chase Cancer Center-led team examined PD-L1 levels in tumor-derived blood cells of 82 patients with recurrent or metastatic NSCLC, finding that patients whose PD-L1 levels increased during treatment in response to chemotherapy or radiotherapy and were treated with ICIs have significantly better outcomes versus similar patients who did not receive immunotherapy. "These data suggest that biological changes of PD-L1 in [tumor-associated cells] can be assessed in real time, and a liquid biopsy assay may provide a noninvasive method to sequentially monitor cancer-associated cells in circulation and possibly predict patient outcomes," the study's authors write.