Association between PD-L1 expression and lymph node metastasis in cutaneous squamous cell carcinoma

Asia Pac J Clin Oncol. 2020 Apr;16(2):e108-e112. doi: 10.1111/ajco.13102. Epub 2018 Nov 8.

Abstract

Aim: To clarify the relationship between programmed cell death ligand 1 (PD-L1) expression in cutaneous squamous cell carcinoma (cSCC) and clinicopathological variables.

Methods: We examined PD-L1 expression in tumor cells (TCs) and tumor infiltrating immune cells (ICs) in 46 cases of cSCC by immunohistochemistry. In each case, we employed two methods-intensity and proportion scores-to evaluate PD-L1 expression in TCs. For the evaluation of PD-L1 expression in ICs, only the proportion score was used. Association between PD-L1 expression and clinicopathological variables was analyzed using Fisher's exact test.

Results: High intensity scores in TCs were observed in 18 of the 46 cases (39.1%) and low intensity scores were observed in 28 cases (60.9%). Applying the proportions, using cut-off values of ≥1% and 50%, positive scores in TCs were observed in 36 (78.3%) and 20 cases (43.5%), respectively. PD-L1-positive ICs were observed in 29 (63%) and seven cases (15.2%), using cut-off values of ≥1% and 10%, respectively. The high intensity scores in TCs correlated with lymph node metastasis (P = 0.008) and female gender (P = 0.017), although positive proportions in TCs or ICs were not significantly related to lymph node metastasis. A multivariate analysis showed that high intensity of PD-L1 expression in TCs was an independent risk factor for lymph node metastasis.

Conclusions: The results suggested that high intensity of PD-L1 expression in TCs is associated with lymph node metastasis in cSCC.

Keywords: PD-L1; cutaneous squamous cell carcinoma; immunohistochemistry.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • B7-H1 Antigen / metabolism*
  • Carcinoma, Squamous Cell / genetics*
  • Carcinoma, Squamous Cell / pathology
  • Female
  • Humans
  • Immunohistochemistry
  • Lymphatic Metastasis / immunology*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • Skin Neoplasms / genetics*
  • Skin Neoplasms / pathology

Substances

  • B7-H1 Antigen
  • CD274 protein, human