Published in:
01-06-2019 | Cutaneous Squamous Cell Carcinoma | Original Article
Heterogeneity of PD-L1 expression and CD8 tumor-infiltrating lymphocytes among subtypes of cutaneous adnexal carcinomas
Authors:
Lucie Duverger, Amélie Osio, Bernard Cribier, Laurent Mortier, Adèle De Masson, Nicole Basset-Seguin, Céleste Lebbé, Maxime Battistella
Published in:
Cancer Immunology, Immunotherapy
|
Issue 6/2019
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Abstract
Background
Adnexal carcinomas are rare and heterogeneous skin tumors, for which no standard treatments exist for locally advanced or metastatic tumors.
Aim of the study
To evaluate the expression of PD-L1 and CD8 in adnexal carcinomas, and to study the association between PD-L1 expression, intra-tumoral T cell CD8+ infiltrate, and metastatic evolution.
Materials and methods
Eighty-three adnexal carcinomas were included. Immunohistochemistry using anti-PD-L1 monoclonal antibodies (E1L3N and 22C3) and CD8 was performed. PD-L1 expression in tumor and immune cells, and CD8+ tumor-infiltrating lymphocyte (TIL) density were analyzed semi-quantitatively.
Results
Among the 60 sweat gland, 18 sebaceous and 5 trichoblastic carcinomas, 11% expressed PD-L1 in ≥ 1% tumor cells, more frequently sweat gland carcinomas (13%, 8/60) including apocrine carcinoma (40%, 2/5) and invasive extramammary Paget disease (57%, 4/7). Immune cells expressed significantly more PD-L1 than tumor cells (p < 0.01). Dense CD8+ TILs were present in 60% trichoblastic, 43% sweat gland, and 39% sebaceous carcinomas. CD8+ TILs were associated with PD-L1 expression by tumor cells (p < 0.01). Thirteen patients out of 47 developed metastases (27%) with a median follow-up of 30.5 months (range 7–36). Expression of PD-L1 by tumor cells was associated with the development of metastasis in univariate analysis (HR 4.0, 95% CI 1.1–15, p = 0.0377) but not in multivariate analysis (HR 4.1, 95% CI 0.6–29, p = 0.15).
Conclusion
PD-L1 expression is highly heterogeneous among adnexal carcinoma subtypes, higher in apocrine carcinoma and invasive extramammary Paget disease, and associated with CD8+ TILs. Our data suggest the interest of evaluating anti-PD1 immunotherapy in advanced or metastatic cutaneous adnexal carcinoma.