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
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
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
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
British journal of cancer 2015 Jul 14 [Epub]
C D Fankhauser, A Curioni-Fontecedro, V Allmann, J Beyer, V Tischler, T Sulser, H Moch, P K Bode
Department of Urology, University Hospital Zurich, Zurich, Switzerland , Department of Oncology, University Hospital Zurich, Zurich, Switzerland , Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland , Department of Oncology, University Hospital Zurich, Zurich, Switzerland , Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland , Department of Urology, University Hospital Zurich, Zurich, Switzerland , Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland , Institute of Surgical Pathology, University Hospital Zurich, Zurich, Switzerland