Frequent PD-L1 expression in testicular germ cell tumors.

Abstract

BACKGROUND:

Many testicular germ cell cancers are curable despite metastatic disease, but about 10-15% of patients fail cisplatin-based first-line treatment. Immunotherapy is considered as additional treatment approach for these patients. Inhibition of the interaction between Programmed Death Receptor 1 (PD-1) and Programmed Death Receptor Ligand 1 (PD-L1) enhances T-cell responses in vitro and mediates clinical antitumour activity. We analysed the expression of PD-L1 in testicular germ cell tumours to evaluate its potential as target for immunotherapeutic strategies.

METHODS:

Immunohistochemistry was performed in 479 formalin-fixed paraffin-embedded specimens using a rabbit monoclonal antibody (E1L3N). The tissue microarray consisted of 208 pure seminomas, 121 non-seminomas, 20 intratubular germ cell neoplasia unclassified (IGCNU) and 20 specimens of non-neoplastic testicular tissue.

RESULTS:

Programmed Death Receptor Ligand-1 expression was found in 73% of all seminomas and in 64% of all non-seminomas. None of 20 IGCNU and none of 20 normal tissue specimens exhibited PD-L1 expression. PD-L1 positive stromal cells were only detected in seminomas, but not in non-seminomas. The anti PD-L1 antibody showed a pre-dominantly membranous staining pattern in testicular tumour cells, as well as expression in stromal cells.

CONCLUSIONS:

This frequent expression of PD-L1 in human testicular germ cell tumours suggests that patients with testicular germ cell tumours could profit from immunotherapeutic strategies using anti-PD1 and anti-PDL1 antibodies.

• Authors: C D Fankhauser, A Curioni-Fontecedro, V Allmann, J Beyer, V Tischler, T Sulser, H Moch, P K Bode
• Journal: British journal of cancer (Br J Cancer) Vol. 113 Issue 3 Pg. 411-3 (Jul 28 2015) ISSN: 1532-1827 [Electronic] England
• PMID: 26171934 (Publication Type: Journal Article)

Chemical References

• B7-H1 Antigen
• CD274 protein, human

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• B7-H1 Antigen (metabolism)
• Humans
• Immunohistochemistry
• Male
• Middle Aged
• Neoplasms, Germ Cell and Embryonal (epidemiology, metabolism, pathology)
• Seminoma (epidemiology, metabolism, pathology)
• Testicular Neoplasms (epidemiology, metabolism, pathology)
• Testis (metabolism, pathology)
• Tissue Array Analysis
• Young Adult