Abstract
BackgroundPD-L1 expression levels determined by immunostaining are known to be related to the survival rate and prognosis of patients with various types of cancers, as well as to the therapeutic response to immune checkpoint inhibitors. Recently, the U.S. Food and Drug Administration approved an immune checkpoint inhibitor for the treatment of non-small cell lung cancer along with the clones used for PD-L1 immunostaining to predict the resulting response. In this study, we performed PD-L1 immunostaining of tissue microarrays from ovarian epithelial cancer using SP263, an approved clone, and examined the effect of PD-L1 expression on survival rate and prognosis.MethodsTissue microarrays were constructed from ovarian epithelial cancer tissues of 248 patients and PD-L1 immunostaining was performed using the SP263 clone. PD-L1 expression levels in tumor cells, intraepithelial tumor-infiltrating lymphocytes, and stromal tumor-infiltrating lymphocytes were evaluated, and the effect of PD-L1 expression on survival and prognosis was analyzed.ResultsPD-L1 was detected in tumor cells as well as intraepithelial tumor-infiltrating lymphocytes and stromal tumor-infiltrating lymphocytes. It was most frequently expressed in stromal tumor-infiltrating lymphocytes. The Kaplan-Meier curve analysis and log rank test showed that only high stromal PD-L1 expression was associated with increased overall survival in ovarian serous carcinoma. Multivariate and univariate Cox regression analyses revealed that stromal PD-L1 expression was an independent prognostic factor, especially in ovarian serous carcinoma.ConclusionsPD-L1 immunostaining using SP263 was observed in tumor cells as well as intraepithelial and stromal tumor-infiltrating lymphocytes. PD-L1-expressing stromal tumor-infiltrating lymphocytes were associated with an increased overall survival rate and may serve as a favorable prognostic factor in ovarian cancer, particularly serous carcinoma.
Highlights
Ovarian epithelial cancer is one of the most common cancers and a leading cause of death in women [1]
Some studies have shown that tumor cells can express PD-L1 and that tumor PD-L1 can interact with PD-1 on tumor specific T cells and suppress them to avoid host immune surveillance [3, 4]
Association between PD-L1 expression and clinicopathologic factors in all types of ovarian epithelial cancers and ovarian serous carcinoma Spanning all histologic types of ovarian epithelial cancers, high PD-L1 expression in stromal tumor-infiltrating lymphocytes, tumor cells, and intraepithelial tumor-infiltrating lymphocytes was detected in 42 (16.9%), 21 (8.5%), and 26 (10.5%) patients of total 248 patients with ovarian epithelial cancers, respectively
Summary
Ovarian epithelial cancer is one of the most common cancers and a leading cause of death in women [1]. PD-L1 expression level was reported to be associated with patient survival rate and prognosis in various types of cancers, including ovarian cancer [5,6,7,8,9,10]. PD-L1 expression levels determined by immunostaining are known to be related to the survival rate and prognosis of patients with various types of cancers, as well as to the therapeutic response to immune checkpoint inhibitors. The U.S Food and Drug Administration approved an immune checkpoint inhibitor for the treatment of non-small cell lung cancer along with the clones used for PD-L1 immunostaining to predict the resulting response. We performed PD-L1 immunostaining of tissue microarrays from ovarian epithelial cancer using SP263, an approved clone, and examined the effect of PD-L1 expression on survival rate and prognosis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
