Gambichler T, Gnielka M, Rüddel I, Stockfleth E, Stücker M, Schmitz L. Expression of PD-L1 in keratoacanthoma and different stages of progression in cutaneous squamous cell carcinoma.
Cancer Immunol Immunother 2017;
66:1199-1204. [PMID:
28501937 PMCID:
PMC11029236 DOI:
10.1007/s00262-017-2015-x]
[Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/06/2017] [Indexed: 12/31/2022]
Abstract
BACKGROUND
Programmed cell death 1 (PD-1) and its ligands (PD-L1) play a major role in the immune responses of a variety of cancers.
OBJECTIVES
To investigate the expression of PD-L1 in different progression forms of cutaneous squamous cell carcinoma (cSCC) and keratoacanthoma (KA).
METHODS
We performed immunohistochemical staining of 21 KA, 26 actinic keratoses (AK), 20 Bowen´s diseases (BD), and 26 high-risk cSCC. The staining patterns were assessed using the tumour proportion score and staining intensity evaluation. Immunohistology scores were statistically analysed.
RESULTS
PD-L1 expression of tumour cells as well as tumour-infiltrating cells (TILs) was significantly higher in KA and cSCC when compared to AK and BD (P = 0.00028 and P = 0.00033, respectively). We observed a very strong positive correlation between the PD-L1 protein expression of tumour cells of KA and the PD-L1 protein expression of TILs (r = 0.97; P < 0.0001). A similar correlation was also found for cSCC (r = 0.86; P < 0.0001). The percentage of PD-L1 + tumours was 33.3% for KA and 26.9% for cSCC. Similarly, the percentage of PD-L1 + TILs in KA and cSCC was 33.3 and 34.6%, respectively.
CONCLUSIONS
PD-L1 is differently expressed in cSCC and closely related non-melanoma skin cancer. cSCC exhibit PD-L1 expression in a fourth of cases, indicating that PD1/PD-L1 inhibitors might be beneficial in a proportion of patients with an inoperable or metastatic cSCC. Unlike AK and BD, TILs and tumour cells of KA and cSCC present very similar PD-L1 expression profiles indicating a common immune escape mechanism.
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