High PD-L1 Expression Correlates with Metastasis and Poor Prognosis in Oral Squamous Cell Carcinoma

PLoS One. 2015 Nov 12;10(11):e0142656. doi: 10.1371/journal.pone.0142656. eCollection 2015.


PD-L1 has been widely demonstrated to contribute to failed antitumor immunity. Blockade of PD-L1 with monoclonal antibody could modulate the tumor immune environment to augment immunotherapy. PD-L1 expression is also detected in several types of cancer and is associated with poor prognosis. However, the prognostic role of PD-L1 in oral squamous cell carcinoma (OSCC) is still controversial. Our aim was to determine the role of PD-L1 in the prognosis of OSCC patients to identify its potential therapeutic relevance. PD-L1 immunoreactivity was analyzed by immunohistochemistry in 305 cancer specimens from primary OSCC patients. The medium follow-up time after surgery was 3.8 years (range from 0.1 to 11.1 years). The prognostic value of PD-L1 on overall survival was determined by Kaplan-Meier analysis and Cox proportional hazard models. Higher PD-L1 expression is more likely in tumor tissues of female than male OSCC patients (P = 0.0062). Patients with distant metastasis also had high PD-L1 expression (P = 0.0103). Multivariate analysis identified high PD-L1 expression as an independent risk factor in males and smokers (males: hazard ratio = 1.556, P = 0.0077; smokers: hazard ratio = 2.058, P = 0.0004). We suggest that PD-L1 expression, determined by IHC staining, could be an independent prognostic marker for OSCC patients who are male or who have a smoking habit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B7-H1 Antigen / biosynthesis*
  • Biomarkers, Tumor / biosynthesis*
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / surgery
  • Female
  • Follow-Up Studies
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Mouth Neoplasms / metabolism*
  • Mouth Neoplasms / pathology
  • Mouth Neoplasms / surgery
  • Multivariate Analysis
  • Neoplasm Metastasis
  • Outcome Assessment, Health Care / statistics & numerical data
  • Prognosis
  • Proportional Hazards Models
  • Risk Factors
  • Sex Factors
  • Smoking


  • B7-H1 Antigen
  • Biomarkers, Tumor
  • CD274 protein, human

Grant support

This work was jointly supported by grants from 103-CCH-IRP-091 (Dr. CJ Chen, Changhua Christian Hospital, Changhua, Taiwan) (http://www2.cch.org.tw/cch_english/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.