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Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Aug 10, 2017; 8(4): 320-328
Published online Aug 10, 2017. doi: 10.5306/wjco.v8.i4.320
Use of programmed cell death protein ligand 1 assay to predict the outcomes of non-small cell lung cancer patients treated with immune checkpoint inhibitors
Carmelo Tibaldi, Alice Lunghi, Editta Baldini
Carmelo Tibaldi, Alice Lunghi, Editta Baldini, Division of Oncology, Department of Oncology, S. Luca Hospital, 55100 Lucca, Italy
Author contributions: Tibaldi C, Lunghi A and Baldini E contributed equally to this work.
Conflict-of-interest statement: None of the authors have any potential conflicts of interest associated with this research.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Carmelo Tibaldi, Division of Oncology, Department of Oncology, S. Luca Hospital, Via Guglielmo Lippi Francesconi 1, 55100 Lucca, Italy. carmelo.tibaldi@uslnordovest.toscana.it
Telephone: +39-0583-055748 Fax: +39-0583-970161
Received: February 13, 2017
Peer-review started: February 14, 2017
First decision: April 14, 2017
Revised: May 15, 2017
Accepted: May 22, 2017
Article in press: May 24, 2017
Published online: August 10, 2017
Processing time: 175 Days and 6.9 Hours
Abstract

The recent discovery of immune checkpoints inhibitors, especially anti-programmed cell death protein 1 (PD-1) and anti-programmed cell death protein ligand 1 (PD-L1) monoclonal antibodies, has opened new scenarios in the management of non-small cell lung cancer (NSCLC) and this new class of drugs has achieved a rapid development in the treatment of this disease. However, considering the costs of these drugs and the fact that only a subset of patients experience long-term disease control, the identification of predictive biomarkers for the selection of candidates suitable for treatment has become a priority. The research focused mainly on the expression of the PD-L1 receptor on both tumor cells and/or immune infiltrates determined by immunohistochemistry (IHC). However, different checkpoint inhibitors were tested, different IHC assays were used, different targets were considered (tumor cells, immune infiltrates or both) and different expression thresholds were employed in clinical trials. In some trials the assay was used prospectively to select the patients, while in other trials it was evaluated retrospectively. Some confusion emerges, which makes it difficult to easily compare the literature data and to translate them in practice management. This mini-review shows the possibilities and pitfalls of the PD-L1 expression to predict the activity and efficacy of anti PD1/PD-L1 monoclonal antibodies in the treatment of NSCLC.

Keywords: Predictive biomarkers; Immunotherapy; Checkpoint inhibitors; Programmed cell death protein ligand 1; Non-small cell lung cancer

Core tip: Use of programmed cell death protein ligand 1 (PD-L1) assay to predict the outcomes of non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors. This minireview underlines promises and pitfalls of the PD-L1 expression to predict the activity and efficacy of programmed cell death protein 1/PD-L1 inhibitors in NSCLC.