P02.21 The Impact of Inflammatory Serum Biomarkers in Non-Small Cell Lung Cancer Patients Treated With Immune Checkpoint Inhibitors

Abstract

The inflammatory serum biomarkers, that are easily accessed in clinical practice, were studied in various types of cancer in patients treated with immune checkpoint inhibitors (ICIs). The ICIs changed how we manage non-small cell lung cancer (NSCLC) in the last years, as in 1st line or as subsequent lines, with an improvement in progression-free survival (PFS), overall survival (OS) and quality of life. Biomarkers for ICIs that have been most explored are PD-L1 expression and tumor mutational burden, nevertheless, there isn’t an ideal biomarker. The objective of the study is to evaluate the predictive and prognostic impact of the following inflammatory serum biomarkers: neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), prognostic nutritional index (PNI) and advanced lung cancer inflammation index (ALI) in advanced NSCLC patients treated with the ICIs (pembrolizumab, nivolumab, atezolizumab). A retrospective study including 52 patients with stage IV NSCLC that started treatment with ICIs between March 2016 and May 2020. The inflammatory serum scores were calculated as following: NLR=total neutrophil count/total lymphocyte count; PLR=total platelet count/total lymphocyte count; PNI=albumin (g/L)+0.005xtotal lymphocyte count/μL; ALI=BMI(Kg/m2)xalbumin(g/dL)/NLR. The cut-offs 5, 200, 50 e 18 were respectively considered. The survival analysis was performed using the Kaplan-Meier method with Log Rank test and Cox regression, with a statistical significance of 5%. Forty-two patients (n=42, 80.8%) were male, 47 (90.4%) had an ECOG performance status between 0-1, and 19 (36.5%) were treated with ICIs as 1st line. The NLR was ≥5 in 34.6% (n=18); PLR was ≥200 in 38.5% (n=20); PNI was <50 in 53.8% (n=28) and ALI was <18 in 59.6% (n=31). The median follow-up period was 15.9 months. The median PFS was 4.97 months (95%CI 3.49-6.44) and the median OS was 10.80 months (95%CI 3.21-18.39). The median PFS was inferior in patients with PLR≥200: 2.13 months versus 6.60 months, HR 2.04 (95%CI 1.03-4.06), p=0.038, and in patients with PNI<50: 2.30 months versus 8.97 months, HR 3.01 (95%CI 1.47-6.20), p=0.002. There were no differences in PFS regarding the NLR and (p=0.077) and the ALI (p=0.150) scores. The median OS was lower in patients with NLR≥5: 1.83 months versus 16.5 months, HR 2.46 (95%CI 1.17-5.16), p=0.014; in patients with PLR≥200: median OS was 4.97 months versus 16.80 months, HR 2.73 (95%CI 1.31-5.72), p=0.005; and in patients with PNI<50: 6.17 months versus 19.87 months, HR 2.86 (95%CI 1.38-5.95), p=0.003. There weren’t differences in OS taking account of the ALI (p=0.083). The PLR≥200 and the PNI<50 were markers of a poorer PFS in our population. The NLR≥5, PLR≥200, and PNI<50 were markers of a worse prognosis in our NSCLC population treated with ICIs. The identification of inflammatory serum biomarkers that are easily accessed in daily practice might be important in the future in the identification and orientation of these patients. Nevertheless, these biomarkers should be prospectively studied in further studies in order to validate these results.