The expression of PD-L1 in salivary gland carcinomas

Sci Rep. 2019 Sep 4;9(1):12724. doi: 10.1038/s41598-019-49215-9.

Abstract

Objective was to analyze the role of PD-L1 and its relation to demographic, patho-clinical and outcome parameters in salivary gland carcinoma (SGC) patients. Patients treated for salivary gland carcinomas between 1994 and 2010 were included. A retrospective chart review for baseline characteristics, pathohistological, clinical and outcome data was performed. Immunohistochemistry for PD-L1 was performed using tissue microarrays. PD-L1 expression was assessed in tumor cells and tumor-infiltrating immune cells (TIIC) and statistical analysis with regard to baseline and outcome data was performed. Expression of PD-L1 (by means ≥1% of the cells with PD-L1 positivity) was present in the salivary gland carcinoma cells of 17%, in the TIIC of 20% and in both tumor cells and TIIC of 10% the patients. PD-L1 expression in tumor cells and both tumor cells and TIIC was related to tumor grading (p = 0.035 and p = 0.031, respectively). A trend towards higher grading was also seen for PD-L1 expression in TIICs (p = 0.058). Patients with salivary duct carcinomas and PD-L1 expressing TIICs showed a significantly worse DFS and OS (p = 0.022 and p = 0.003, respectively), those with both tumor cells and TIIC expressing PD-L1 a significantly worse DFS (p = 0.030). PD-L1 expression is present in 17% and 20% of salivary gland carcinoma cells and TIIC. Ten percent of the patient showed a PD-L1 positivity in both tumor cells and TIIC. This is related to high tumor grading and therefore might be a negative prognostic factor.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • B7-H1 Antigen / genetics*
  • B7-H1 Antigen / immunology
  • Biomarkers, Tumor
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Male
  • Middle Aged
  • Prognosis
  • Retrospective Studies
  • Salivary Gland Neoplasms / genetics*
  • Salivary Gland Neoplasms / immunology
  • Salivary Gland Neoplasms / mortality
  • Tumor Microenvironment / genetics
  • Tumor Microenvironment / immunology

Substances

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