PD-L1 Expression in Endometrial Serous Carcinoma and Its Prognostic Significance

Tao Zhang; Qin Liu; Yingfan Zhu; Songfa Zhang; Qiaohua Peng; Amanda Louise Strickland; Wenxin Zheng; Feng Zhou

doi:10.2147/CMAR.S337271

PD-L1 Expression in Endometrial Serous Carcinoma and Its Prognostic Significance

Cancer Manag Res. 2021 Dec 14:13:9157-9165. doi: 10.2147/CMAR.S337271. eCollection 2021.

Authors

Tao Zhang^#¹, Qin Liu^#², Yingfan Zhu¹, Songfa Zhang³, Qiaohua Peng³, Amanda Louise Strickland⁴, Wenxin Zheng^{4

5}, Feng Zhou²

Affiliations

¹ Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
² Department of Pathology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
³ Department of Oncology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
⁴ Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
⁵ Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.

^# Contributed equally.

Abstract

Purpose: Programmed death-ligand 1 (PD-L1) has been widely used as a prognostic biomarker and an immunotherapeutic target in numerous cancers, but information on the clinical significance of its expression in endometrial serous carcinoma (ESC) is largely lacking. Here, we evaluate the predictive value of PD-L1 expression in ESC.

Materials and methods: A total of 79 cases of ESC accessioned between January 2003 and September 2015 were selected for further analysis. PD-L1 expression was evaluated in whole tissue sections of these cases by using the tumor proportion score (TPS, cut-off 1%) and combined positive score (CPS, cut-off 1) scoring methods.

Results: Overall, there was a heterogeneous expression of PD-L1, focal or patchy, in ESCs. PD-L1 positivity was observed in 43.0% of ESCs by TPS and 73.4% of ESCs by CPS. Kaplan-Meier survival analysis showed that patients with PD-L1-positive tumors suffered significantly worse OS and PFS, when compared with PD-L1 negative tumors (log-rank p = 0.037 and p = 0.003, respectively). In contrast, PD-L1 positivity by CPS within the ESC cases showed no statistical significance for OS and PFS (log-rank p = 0.720 and p = 0.928, respectively). Multivariate Cox analysis showed that PD-L1 positivity by TPS was significantly associated with PFS (HR = 1.921, p = 0.039) but not OS (HR = 1.229, p = 0.631).

Conclusion: PD-L1 expression is frequently found in ESC, suggesting a potential role of the PD-1/PD-L1 pathway as a potential therapeutic target for these tumors. PD-L1 expression by TPS also serves as a negative prognostic marker in ESC and implies an unfavorable outcome.

Keywords: PD-L1; endometrial cancer; endometrial serous carcinoma; immune therapy.

Grants and funding

This work was supported by the Scientific Research Fund of Zhejiang Provincial Education Department (No. Y202045491) and the Medicine and Health of Zhejiang Provincial Technology Plan Project (No. 2021KY766).