Immune checkpoint blockade strategies have gained attention in the treatment/prognosis of cancers via targeting the PD-1/PD-L1 pathway or in combination with the CTLA-4 blockade and are currently in clinical trials. The present study investigated the expression of PD-1, PD-L1, CTLA-4, CD4 and CD8 proteins and their prognostic value in the tumor microenvironment of sebaceous gland carcinoma patients (SGC).
Stromal and tumor cells expressing PD-1, PD-L1, CTLA-4, CD4 and CD8 protein were assessed in 52 cases of sebaceous gland carcinoma by Immunohistochemistry and their mRNA expression was measured by quantitative Reverse-Transcriptase PCR (qRT-PCR). Kaplan–Meier curves and Cox proportional hazard models, analyzed the correlation of proteins with clinicopathological parameters and disease-free survival.
Pagetoid spread was the frequent histopathological high-risk factor in our study. Expression of PD-L1 was found to be more common in tumor cells than stromal cells. In univariate analysis, patients expressing PD-1 and PD-L1 in tumor cells were associated with reduced disease-free survival, whereas stromal-PD-L1 showed an increased survival of the patients (p < 0.05). However, in multivariate analysis, expression of PD-1 in tumor cells was found to be an independent prognostic factor for poor survival.
This is the first report describing the association of clinicopathological features and outcomes of immune checkpoint expression along with T-Lymphocytes in sebaceous gland carcinoma. These results support the consideration that PD-1/PD-L1 pathway might play an important role in tumor microenvironment for mediating immune response in the pathogenesis of sebaceous gland carcinoma patients.
Clinical trial identification
Legal entity responsible for the study
Has not received any funding.
All authors have declared no conflicts of interest.