J Cancer 2017; 8(19):4075-4082. doi:10.7150/jca.21415
Programmed cell death ligand 1 protein levels predicted survival of non-small cell lung cancer
1. Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
2. Asia & Emerging Markets, iMed, AstraZeneca, Shanghai, China
3. R&D, MedImmune, AstraZeneca, Gaithersburg, MD, USA
*Shaohua Cui and Xinying Su contributed equally to this study.
Cui S, Su X, Dong L, Qian J, Ye L, Zhang T, Fu H, Han H, Huang J, Yao Y, Gu Y, Jiang L. Programmed cell death ligand 1 protein levels predicted survival of non-small cell lung cancer. J Cancer 2017; 8(19):4075-4082. doi:10.7150/jca.21415. Available from http://www.jcancer.org/v08p4075.htm
Objective: To investigate the relationship between programmed death ligand 1 (PD-L1) expression using 5%, 25%, 50% cutoffs in tumor cells (TC) and postsurgical survival in non-small-cell lung cancer (NSCLC) patients. For samples with tumor infiltrating lymphocytes (TIL), correlation between PD-L1 expression in TIL using 1% cutoff and postsurgical survival was also evaluated.
Methods: Primary NSCLC tumor surgical samples staging I to IIIA of 126 patients who underwent surgical procedures from September 2009 to August 2012 in Shanghai Chest Hospital, Shanghai Jiao Tong University were retrospectively included. PD-L1 protein expression was detected by immunohistochemistry (IHC) assays. A rabbit anti-human PD-L1 (E1L3N) monoclonal antibody (1:300, CST#13684, Cell Signaling Technology) was used for PD-L1 IHC staining. PD-L1 expression was evaluated both on TC and TIL. Univariate and multivariate analyses for postsurgical survival were done using Kaplan-Meier and Cox regression model, respectively.
Results: The median postsurgical survival for all patients was 44.1 months [95% confidence interval (CI): 33.9-70.0 months). The median postsurgical survival for PD-L1 expression percentage 0, 1-50% and ≥50% were 51.9 months (95%CI: 33.9-70.0 months), 33.2 months (95%CI: 20.8-45.6 months) and 14.7 months (95%CI: 1.9-27.6 months), respectively (P = 0.002). Clinical stage and PD-L1 expression in TC (25% cutoff or 50% cutoff values) were found to be independent predictors for longer postsurgical survival in all cohort. Ninety (71.4%) of the 126 samples were identified to concurrent TIL. The median postsurgical survival time was 39.6 months (95% CI: 31.8-47.4 months) in patients with TIL. PD-L1 expression in TC (25% cutoff or 50% cutoff values) was found to be the independent predictor for longer postsurgical survival time in patients with TIL.
Conclusion: PD-L1 negative expression in TC at 25% or 50% cutoff values was the independent predictor for longer postsurgical survival time in both NSCLC samples and NSCLC samples with TIL. For patients with PD-L1 high expression at 25% or 50% cutoff values, PD-L1 blocking may be considered.
Keywords: Programmed death ligand 1 (PD-L1), non-small-cell lung cancer (NSCLC), tumor cells (TC), tumor infiltrating lymphocytes (TIL), survival