Login to Access Video or Poster Abstract: MP80-06
Sources of Funding: none

Introduction

Inhibition of the Programmed Death Receptor 1 (PD-1) and Programmed Death Receptor Ligand 1 (PD-L1) pathway is a promising treatment alterative and improves survival in a number of different cancers, including melanoma and kidney cancer. Recent data showed that evaluation of PD-1 and PD-L1 expression in various tumors could be used for the prognostic value of anti-PD-1 or anti-PD-L1 treatments. We aimed to analyze the expressions of PD-1, PD-L1 and PD-L2 in the testicular germ cell tumors (TGCTs) and evaluate their potential as immunotherapeutic target.

Methods

Formalin-fixed paraffin-embedded tumor specimens of 60 patients diagnosed with TGCTs were evaluated, where there are 24 pure seminomas and 36 mixed germ cell tumors. Immunohistochemistry was performed to evaluate expression of PD-1 (EH33 antibody), PD-L1 (E1L3N antibody), PD-L2 (D7U8C antibody), CD8 (4B11 antibody) and CD4 (368) using monoclonal antibodies mentioned in the brackets.

Results

None of seminoma specimens exhibited PD-L1 expression, where PD-L1 expression was found in 19.4% of mixed germ cell tumors. None of seminomas and nonseminomas expressed PD-L2. In mixed germ cell tumors PD-1 negativity or poor expression of PD-1 in both stromal and intra-tumoral lymphocytes was associated with statistically lower overall survival (figure) and high progression and mortality rates.

Conclusions

The PD-1 expression profiles in mixed germ cell tumors could help to identify patients with poor prognosis potential and those patients could benefit from early therapeutic interventions and immunotherapeutic strategies using anti-PD1 and anti-PDL1 antibodies.

Funding

none