36P - Expression Pattern of Immune Checkpoints Programmed Death (PD-1) and Programmed Death-Ligand (PD-L1) in Retinoblastoma and its Prognostic Significa...

Date 08 December 2017
Event ESMO Immuno-Oncology Congress 2017
Session Lunch & Poster Display session
Topics Supportive Care
Palliative and Supportive Care
Presenter Lata Singh
Citation Annals of Oncology (2017) 28 (suppl_11): xi6-xi29. 10.1093/annonc/mdx711
Authors L. Singh1, S. Kashyap2, N. Pushker3, S. Bakhshi4, S. Sen2, M.A. Rizvi1
  • 1Biosciences, JAMIA MILLIA ISLAMIA, 110025 - Delhi/IN
  • 2Ocular Pathology, All India Institute of Medical Sciences, 110029 - New Delhi/IN
  • 3Ophthalmology, All India Institute of Medical Sciences, 110029 - New Delhi/IN
  • 4Medical Oncology, All India Institute of Medical Sciences, 110029 - New Delhi/IN

Abstract

Background

Retinoblastoma (RB), malignant tumor of the sensory retina, is the most common eye cancer of childhood due to the defect of RB gene. The immune system plays an important role in controlling and eradicating cancer. Recent studies suggest that programmed death-1/programmed death ligand-1 (PD-1/PD-L1) pathway in T-cell activation plays a major role in tumor escape mechanism from host immunity. Therefore, we investigated the expression of PD-1 and PD-L1 in human retinoblastoma cancer to define their clinical significance in patient’s prognosis after enucleation.

Methods

We prospectively evaluate the expression of PD-1 and PD-L1 protein in 62 cases of primary enucleated retinoblastoma specimens by immunohistochemistry and further validated by immunoblotting. mRNA levels of PD-1 and PD-L1 genes were quantified in normal retina and tumor samples by quantitative real time PCR (qPCR). Expression of PD-1 and PD-L1 proteins were then correlated with clinicopathological parameters and patient survival by statistical analysis.

Results

Immunohistochemistry showed cytoplasmic PD-1 expression in (12/62) 19.3% cases, whereas PD-L1 expressed in 80.6% (50/62) cases. Immunostaining was found in stromal and tumor infiltrating lymphocytes. Immunoreactivity results of target protein were validated by western blotting on representative cases. Protein and mRNA level by IHC and real time qPCR was found to be closely correlated. Expression of PD-L1 showed significant correlation with poor tumour differentiation and tumor invasion (p 

Conclusions

These data suggest that PD-L1 expression may be a new therapeutic immunomarkers for patients with retinoblastoma. This study provides first data for the role of immune checkpoints in retinoblastoma patients. Further translational studies are necessary to confirm this observation and evaluate the predictive value of PD-1 and PD-L1 in retinoblastoma in the context of PD-1 inhibition.

Clinical trial identification

NIL

Legal entity responsible for the study

Department of Science and Technology (DST), India

Funding

None

Disclosure

All authors have declared no conflicts of interest.