PD-L1 Expression and Tumor-Infiltrating Lymphocytes in High-Risk and Metastatic Cutaneous Squamous Cell Carcinoma

Otolaryngol Head Neck Surg. 2019 Jan;160(1):93-99. doi: 10.1177/0194599818788057. Epub 2018 Jul 17.


Objective: To characterize programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocyte (TIL) positivity for locally aggressive or regionally metastatic cutaneous head and neck squamous cell carcinoma (cHNSCC).

Study design: Retrospective chart review, followed by immunohistochemical staining of archived tumor specimens.

Setting: Tertiary academic medical center.

Subjects and methods: After identification of 101 patients treated surgically for locally advanced or regionally metastatic cHNSCC, archived tissue was stained and graded for PD-L1 expression in addition to TIL presence. Cross-tabulation was performed to examine the association between either of these variables and clinicopathologic features and outcomes.

Results: A total of 101 patients met inclusion criteria, but archived tissue was available only for 83 (31 primaries, 52 metastases). The majority of primary tumors demonstrated grade 1 PD-L1 staining, while grade 2 staining was more likely for metastases. Neither high- nor low-grade PD-L1 expression correlated with any clinicopathologic variable for primary tumors. However, for metastases, high-grade staining was significantly associated with regional recurrence (15 of 19, P = .02). TILs were present for 65% of primary tumors and 90% of regional metastases but did not correlate with any clinicopathologic variables.

Conclusion: Diffuse expression of PD-L1 in this study highlights the possibility of using immunotherapy in the form of programmed death 1/PD-L1 blockade to improve treatment for this devastating disease. However, further studies are needed to clarify the significance of PD-L1 expression and TIL positivity for locally advanced or regionally metastatic cHNSCC.

Keywords: PD-1; PD-L1; cancer immunohistochemistry; cutaneous HNSCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Academic Medical Centers
  • Adult
  • Aged
  • B7-H1 Antigen / metabolism*
  • Biomarkers, Tumor / metabolism*
  • Biopsy, Needle
  • Carcinoma, Squamous Cell / blood
  • Carcinoma, Squamous Cell / mortality
  • Carcinoma, Squamous Cell / pathology*
  • Carcinoma, Squamous Cell / surgery
  • Cell Death
  • Cohort Studies
  • Disease-Free Survival
  • Female
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • Lymphocytes, Tumor-Infiltrating / metabolism*
  • Male
  • Middle Aged
  • Neoplasm Invasiveness / pathology
  • Neoplasm Staging
  • Prognosis
  • Retrospective Studies
  • Risk Assessment
  • Skin Neoplasms / blood
  • Skin Neoplasms / mortality
  • Skin Neoplasms / pathology*
  • Skin Neoplasms / surgery
  • Survival Rate


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