Clinical significance of PD-L1 (CD274) enhanced expression in cervical squamous cell carcinoma

Programmed death ligand 1 (PD-L1) is a trans-membrane protein that can reduce the immune response in both infectious diseases and cancers and is commonly expressed in various solid tumors. Despite the success of immunotherapy directed at inhibiting of PD-L1/PD-1 signaling, it is not established that whether PD-L1 expression correlates with the clinical response and outcome in cervical squamous cell carcinoma. To investigate the clinical significance of PD-L1 expression in cervical cancer, we analyzed the expression of PD-L1 in 219 cervical squamous cell cancers and 30 healthy controls,characterized the expression level of PDL-1 in tumor-infiltrating lymphocytes (TILs), and assessed the relationship between them and prognosis of cervical cancers. The expression of PD-L1 was observed in 32.4% (71/219) cervical carcinomas and 10.0% (22/219) in partial TILs. However, there was no expression of PD-L1 in normal cervical epithelium. Statistical analysis showed that increased PD-L1 expression was significantly associated with high TNM stage, reduced number of TILs, and worse prognosis in cervical carcinomas, but there was no significant statistic difference in age, tumor size, HPV infection and other clinicopathology features. PD-L1 expression in TILs was found significantly associated with the TILs amount. Furthermore, the presence of prominent lymphocytic infiltrates was also significantly associated with a clear trend towards longer survival. In conclusion, these data suggested that PD-L1 could act as a significant biomarker in the worse prognosis and adverse clinicopathologic features of cervical cancer. Anti-PD-L1 therapy may have a role in the treatment of cervical squamous cell carcinoma.