Biological Rationale for Peripheral Blood Cell–Derived Inflammatory Indices and Related Prognostic Scores in Patients with Advanced Non-Small-Cell Lung Cancer

Purpose of review: To describe the biological rationale of peripheral blood cells (PBC)–derived inflammatory indexes and assess the related prognostic scores for patients with advanced non-small cell lung cancer (aNSCLC) treated with immune-checkpoint inhibitors (ICI). Recent findings: Inflammatory indexes based on PBC may indicate a pro-inflammatory condition affecting the immune response to cancer. The lung immune prognostic index (LIPI), consisting of derived neutrophils-to-lymphocyte ratio (NLR) and lactate dehydrogenase, is a validated prognostic tool, especially for pretreated aNSCLC patients, where the combination of NLR and PD-L1 tumour expression might also be predictive of immunotherapy benefit. In untreated high-PD-L1 aNSCLC patients, the Lung-Immune-Prognostic score (LIPS), including NLR, ECOG PS and concomitant steroids, is prognostic, and its modified version might indicate patients with favourable outcomes despite an ECOG PS of 2. NLR times platelets (i.e., SII), included in the NHS-Lung score, might improve the prognostication for combined chemoimmunotherapy. Summary: PBC-derived inflammatory indexes and related scores represent accurate, reproducible and non-expensive prognostic tools with clinical and research utility.