Determinants of survival in advanced non-small cell lung cancer patients treated with anti-PD-1/PD-L1 therapy

Background: The present study aimed to investigate the determinant factors of survival in patients with pretreated advanced stage non-small cell lung cancer (NSCLC) who received anti-PD-1/PD-L1 therapy. Methods: In this observational retrospective study, the clinical profiles and laboratory parameters of patients with NSCLC treated with anti-PD-1/PD-L1 therapy were consecutively collected. Lung Immune Prognostic Index (LIPI) was calculated based on the derived neutrophil-to-lymphocyte ratio (dNLR) and lactate dehydrogenase level (LDH). Modified Glasgow Prognostic Score (mGPS) was calculated based on serum C reactive protein and albumin, and tumor mutation burden (TMB) was calculated using a targeted next-generation sequencing panel based on 422 cancer-relevant genes. The primary and secondary end points were overall survival (OS) and progression-free survival (PFS), respectively. The Cox regression model was used to identify the potential determinant factors of survival benefit. Trained oncologists at Sun Yat-sen University Cancer Center followed all of the participants through visits to doctors' offices or via telephone calls to determine their clinical status. Results: Seventy-three patients were included in our study. With a median follow up time of 637 days, there was a significant difference in PFS between patients with high TMB compared to those with low TMB (3.7 vs. 2.1 months; P=0.004), while no significant difference was found in OS (14.0 vs. 16.4 months; P=0.972). Patients with a good LIPI score had a significantly longer OS compared to patients with a poor LIPI score (19.2 vs. 12.6 months; P=0.010). The median OS in patients with a good and a poor mGPS was 16.8 and 4.3 months, respectively (P=0.029). In multivariate analysis, TMB was found to be significantly associated with PFS (HR, 0.38; 95% CI: 0.21-0.69; P=0.002), while LIPI score was found to be significantly associated with OS (HR, 0.50; 95% CI: 0.28-0.89; P=0.012). Conclusions: In the present study, LIPI score was a significant determinant of OS in patients with advanced NSCLC who received ICIs; however, TMB was only associated with PFS and not associated with OS.