• Ocular Pathology/Oncology, Oculoplastics/Orbit

    Researchers evaluated the expression level of programmed death receptor ligand 1 (PD-L1) in patients with eyelid sebaceous carcinoma.

    Study design

    This is a retrospective, comparative case series of 41 patients with eyelid sebaceous carcinomas; 20 were primary, 11 were recurrent and 10 were lymph node metastatic. Researchers assessed the clinical characteristics of the cohort and performed immunohistochemical staining to evaluate PD-L1 expression.

    Clinical significance

    Overall, 48.8% of tumors were moderately graded and the remaining 51.2% were poorly graded. Immunohistochemical staining revealed PD-L1 expression in 20 (48.8%) cases, located on the tumor cell membrane.

    Investigators observed a higher expression of PD-L1 with metastatic cases when compared with primary cases, as well as higher expression in the poorly differentiated group compared with the moderately graded group.

    Limitations

    This study is based on a homogeneous population in China. It is uncertain if results from this study is consistent with what would be found in other populations.

    Clinical significance

    Treatment of metastatic and recurrent sebaceous carcinoma of the eyelid is very difficult. Recently, PD-1 inhibitors have been found to be effective in the treatment of melanoma, advanced squamous cell carcinoma and other tumors. Expression of PD-L1 in tumor cells supports the use of PD-1 inhibitors in the treatment of these cancers. The finding of PD-L1 expression in sebaceous carcinoma is an exciting development, and may lead to effective treatment of this cancer.