Change in neutrophial-to-lymphocyte ratio (NLR) in response to immune checkpoint inhibitor for advanced gastric cancer.

306 Background: We intended to evaluate the utility of neutrophil-to-lymphocyte (NLR) in advanced gastric cancer patients treated with immune checkpoint inhibitor (ICI). Methods: We examined NLR at baseline and 6 (±2) weeks later in 139 patients between August 2015 and April 2019. Landmark analysis at 6 weeks was conducted to explore the prognostic value of NLR change on progress-free survival (PFS), overall survival (OS), objective response rate (ORR), and disease control rate (DCR). Cox and logistic regression models were adjusted for tumor differention, Lauren classification, line of therapy, type of anti-PD-1/PD-L1 therapy, and baseline NLR. Results: Median duration on therapy was 6 cycles. Median NLR was 3.33 (IQR: 2.26-4.84) at baseline and 2.93 (IQR: 1.67-4.83) at week 6. Patients with a higher baseline NLR showed a trend toward lower DCR, shorter PFS, and shorter OS. Higher NLR at 6 weeks was significantly associated with inferior PFS [hazard ratios (HRs) 1.03, 95% confidence interval (CI): 1.00-1.06 ] and inferior OS (HR 1.08, 95%CI: 1.03-1.12). Relative NLR decrease by ≥ 25% from baseline to 6 weeks after ICI therapy was an independent prognostic factor for ORR (OR 8.11,95% CI:2.40-27.4), DCR (OR 20.03, 95% CI: 3.32-121), PFS (HR 0.37, 95% CI: 0.20-0.68), and OS (HR 0.26, 95% CI: 0.10-0.65). Conclusions: Early decline of NLR (and NLR at 6 weeks) were associated with improved clinical outcomes in advanced gastric cancer patients treated with ICI. [Table: see text]