Abstract 3149: Prognostic impact of PD-L1 expression in correlation with neutrophil-to-lymphocyte ratio in squamous cell carcinoma of the lung

Abstract

Abstract Aim: To investigate the prognostic impact of programmed death-ligand 1 (PD-L1) expression on tumor cells in correlation with neutrophil-to-lymphocyte ratio (NLR) in early-stage squamous cell carcinoma of the lung, as PD-L1 is a potent regulator of cancer immunity and NLR is a potential surrogate of immune status. Patients and methods: Eighty-three patients with completely resected pathologic stage I lung squamous cell carcinoma were retrospectively reviewed. Tumoral PD-L1 expression was evaluated with immunohistochemistry, and its prognostic impact was analyzed in correlation with NLR. Results: Forty-three patients (51.8%) had tumor with positive PD-L1 expression (percentage of tumor cells expressing PD-L1, ≥1%). There was no significant correlation between PD-L1 expression and NLR. PD-L1-positivity failed to provide a significant prognostic impact (overall survival [OS] rate at 5 years, 70.1% in PD-L1-negative patients versus 53.0% in PD-L1-positive patients; P=0.117). Among NLR-low (<2.2) patients, however, PD-L1-positivity was significantly correlated with a poor prognosis (OS rate at 5 years, 86.0% in PD-L1-negative patients versus 46.1% in PD-L1-positive patients; P=0.020). In contrast, among NLR-high (≥2.2) patients, PD-L1-positivity provided no prognostic impact (P=0.680). When NLR status and tumoral PD-L1 status were combined, “NLR-low and tumoral PD-L1-negative” was a significant and independent factor to predict a favorable recurrence-free survival (hazard ratio, 0.237 [95% confidence interval, 0.083 to 0.674]; P=0.007) and OS (hazard ratio, 0.260 [95% confidence interval, 0.091 to 0.745]; P=0.012). Conclusions: The prognostic impact of PD-L1 expression on tumor cells was distinct according to NLR. “NLR-low and tumoral PD-L1-negative” patients showed a favorable prognosis. Citation Format: Kazue Yoneda, Taiji Kuwata, Masataka Mori, Masatoshi Kanayama, Ayako Hirai, Yuko Tashima, Naoko Imanishi, Koji Kuroda, Yoshinobu Ichiki, Fumihiro Tanaka. Prognostic impact of PD-L1 expression in correlation with neutrophil-to-lymphocyte ratio in squamous cell carcinoma of the lung [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3149.