Immunotherapy in non-small-cell lung cancer: potential predictors of response and new strategies to assess activity.

The treatment algorithm of advanced non-small-cell lung cancer is rapidly evolving. This result is mostly related to the availability in clinical practice of checkpoint inhibitors targeting the programmed death-1 (PD-1) and its ligands (PD-Ls) immunosuppressive pathway. Although patient's selection in the first-line setting relies essentially on high levels of PD-L1 tumor expression, treatment choice in pretreated patients is more challenging and, although clinical and biological characteristics might be of help, there is an urgent need for novel tools to better identify sensitive and resistant patients. In this context, the integration of molecular markers and immune-PET imaging might represent a potentially effective strategy to refine patient selection.