Positivity rate of PD-L1 expression and its clinical significance in vulvar cancer: a systematic review and meta-analysis
File(s)
Published version
OA Location
Author(s)
Flindris, Stefanos
Margioula-Siarkou, Crysoula
Chalitsios, Christos V
Margioula-Siarkou, Georgia
Almperi, Emmanouela-Aliki
Type
Journal Article
Abstract
The prevalence and prognostic value of programmed death ligand 1 (PD-L1) expression, as a potential biomarker in vulvar squamous cell carcinomas (VSCCs), remain underexplored. We searched the PubMed, Scopus, Embase, and Cochrane Library databases until July 2024 for articles examining PD-L1 expression in VSCCs. Random-effects meta-analyses summarized PD-L1 expression overall and in subgroups by immunohistochemistry antibody type, positivity cutoff, tumor stage, and HPV positivity. Additionally, random-effects meta-analyses summarized the association between PD-L1 positivity and cancer prognosis. We included 26 studies comprising 1912 VSCC cases. The summary PD-L1 positivity rate in tumor cells was 59.9% (95% confidence interval [CI]: 47.7–71.4%; I2 = 96%, n = 26), influenced by the different cutoff thresholds utilized to define PD-L1 positivity. Compared to tumor cells, positivity rates were higher in intratumoral immune cells (75.6%; 95%CI: 52.9–92.5; I2 = 95.4%, n = 6) and peritumoral cells (78.9%; 95%CI: 54.4–95.5%; I2 = 91%, n = 3) but with overlapping 95%CIs. No heterogeneity was observed in the rates by tumor stage or HPV status. Positive PD-L1 expression was associated with worse overall (hazard ratio [HR] = 1.43; 95%CI: 1.06–1.93; I2 = 28.9%, n = 7) and progression-free survival (HR = 1.57; 95%CI: 1.07–2.3; I2 = 38.3%, n = 5). The PD-L1 expression rate in VSCC tumor cells varied across studies, was influenced by differences in immunohistochemical evaluation, and was identified as an unfavorable prognostic factor. Large, prospective, multicenter studies with standardized protocols are crucial to further elucidate the clinical significance of PD-L1 expression in VSCCs.
Date Issued
2025-05-11
Date Acceptance
2025-05-05
Citation
International Journal of Molecular Sciences, 2025, 26 (10), pp.4594-4594
ISSN
1422-0067
Publisher
MDPI AG
Start Page
4594
End Page
4594
Journal / Book Title
International Journal of Molecular Sciences
Volume
26
Issue
10
Copyright Statement
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
10.3390/ijms26104594
Subjects
Flindris, S.
Margioula-Siarkou, C.
Chalitsios, C.V.
Margioula-Siarkou, G.
Almperi, E.-A.
Almperis, A.
Styliara, E.
Flindris, K.
Paschopoulos, M.
Navrozoglou, I.
PD-L1
positivity rate
detection rate
vulvar cancer
overall survival
progression-free survival
Publication Status
Published
Date Publish Online
2025-05-11