Differential expression of PD-L1 between primary and metastatic epithelial ovarian cancer and its clinico-pathological correlation

Sandeep Kumar Parvathareddy,Ismail A Al-Badawi,Asma Tulbah,Fouad Al-Dayel,Abdul K Siraj,Khawla S Al-Kuraya

doi:10.1038/s41598-021-83276-z

Sandeep Kumar Parvathareddy, Ismail A Al-Badawi + Show 4 more

Open Access

https://doi.org/10.1038/s41598-021-83276-z

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Abstract

Ovarian cancer (OC) is one of the most common gynecologic cancer, which has the worst prognosis and highest mortality rate. The lack of curative treatment and the high relapse rate, especially in advanced OC, continues to present a clinical challenge, highlighting the need for new therapeutic strategies. This study was performed to compare the expression of PD-L1 in primary epithelial ovarian cancer (EOC) and their corresponding peritoneal metastases, as well as to evaluate its correlation with clinico-pathological parameters. In total, 194 treatment naïve paired EOC and peritoneal metastasis were analyzed by immunohistochemistry for PD-L1 expression. Clinico-pathological information was available for all patients. Significant differences in PD-L1 expression were found between primary EOC and peritoneal metastasis (p < 0.0001). We found discordant tumor cell PD-L1 expression between primary tumors and corresponding peritoneal metastasis in 34% (66/194) of cases. Furthermore, PD-L1 expression in peritoneal metastasis samples was significantly associated with adverse prognostic factors, such as high proliferative index (Ki67) (p = 0.0039) and high histologic grade (p = 0.0330). In conclusion, the discordance of PD-L1 expression between primary EOC and corresponding peritoneal metastases suggests that its assessment as a potential biomarker for predicting response to anti-PD-L1 therapy may require analysis of metastatic lesions.

Highlights

Ovarian cancer (OC) is one of the most common gynecologic cancer, which has the worst prognosis and highest mortality rate
Programmed cell death ligand 1 (PD-L1) expression was analysed in 194 treatment naïve paired primary epithelial ovarian cancer (EOC) and peritoneal metastases tissues using tissue microarray (TMA)
Of the 131 cases with negative PD-L1 expression in primary tumor, 85 had negative expression of PD-L1 in the paired peritoneal metastasis and 46 cases were positive for PD-L1 (Table 2)

Summary

Introduction

Ovarian cancer (OC) is one of the most common gynecologic cancer, which has the worst prognosis and highest mortality rate. This study was performed to compare the expression of PD-L1 in primary epithelial ovarian cancer (EOC) and their corresponding peritoneal metastases, as well as to evaluate its correlation with clinico-pathological parameters. We found discordant tumor cell PD-L1 expression between primary tumors and corresponding peritoneal metastasis in 34% (66/194) of cases. The discordance of PD-L1 expression between primary EOC and corresponding peritoneal metastases suggests that its assessment as a potential biomarker for predicting response to anti-PD-L1 therapy may require analysis of metastatic lesions. Most currently available treatments are not curative for patients with advanced disease, which could explain the low five-year survival rate of less than 30%7. The immunohistochemical expression of PD-L1 as a prognostic marker and/or predictor of curative effect of anti-PD-L1 therapy has been investigated in various malignancies including OC18–24.

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