Programmed Death Ligand 1: A Poor Prognostic Marker in Endometrial Carcinoma

PD-L1 Immunohistochemical Expression in Endometrial Carcinoma: Egyptian Cross-Sectional Study

OBJECTIVE

Endometrial carcinoma (EC) is the most common cancer of the female genital tract. According to the recently evolved strategies of cancer immunotherapy, immune checkpoints inhibitors are one of the most crucial strategies. Programmed Death Ligand 1 (PD-L1) is an important immune checkpoint regulator. PD-L1 antibodies have shown efficacy in clinical trials of some malignancies. Some of these antibodies have been approved for clinical usage by the Food and Drug Administration (FDA).

METHODS

This retrospective study included a total of 100 ECs, collected from archived, formalin-fixed, paraffin-embedded tissue blocks of hysterectomy specimens of Egyptian females. The samples were immunohistochemically analyzed for PD-L1 expression (in both tumor cells; TCs and tumor infiltrating leucocytes; TILs) by a semiquantitative score (0 to 4), with cutoff points of (0: <1% of the cells, 1: 1% to 4%, 2: 5% to 9%, 3: 10% to 49%, and 4: ≥ 50%). Membranous staining only was considered positive.

RESULTS

PD-L1 was highly expressed in ECs (67% TCs+ and 61% TILs+), with statistically significant relationships with age, lympho-vascular space invasion (LVSI) and TILs score (P = 0.006, 0.016 and <0.005 respectively).  However, no statistically significant relationships were detected between PD-L1 expression and the following parameters: histological type, histological grade, pathological stage (pT) or FIGO stage, myometrial, cervical, adnexal/serosal, parametrial involvements and nodal metastasis, as well as ESMO risk stratification system. Moreover, statistically significant relationships were achieved when correlating TILs score with tumor grade and LVSI (P = 0.034 and 0.012 respectively). Also, comparing endometrial hyperplasia (EH) PD-L1 and TCs PDL1 median scores achieved statistically significant relationship (P = 0.001).

CONCLUSION

Our results concluded that PD-L1 expression was greater in both TCs and TILs in a subgroup of patients that have advanced age, LVSI and are TILs-rich, identifying them as potential candidates for anti-PD-1/PD-L1 immunotherapy.

Expression of PD-1 and PD-L1 in Endometrial Cancer: Molecular and Clinical Significance

The landscape of diagnosing and treating endometrial cancer is undergoing a profound transformation due to the integration of molecular analysis and innovative therapeutic approaches. For several decades, the cornerstone treatments for endometrial cancer have included surgical resection, cytotoxic chemotherapy, hormonal therapy, and radiation therapy. However, in recent years, the concept of personalised medicine has gained momentum, reshaping the way clinicians approach cancer treatment. Tailoring treatments based on specific biomarkers has evolved into a standard practice in both initial and recurrent therapy protocols. This review aims to provide an in-depth exploration of the current state of molecular analysis and treatment strategies in the context of endometrial cancer, focusing on the immunological aspect of the PD-1/PD-L1 axis. Furthermore, it seeks to shed light on emerging and innovative approaches that hold promise for the future modulation of endometrial cancer treatments. In essence, as researchers delve into the complex molecular landscape of endometrial cancer and harness the understanding of the PD-1/PD-L1 axis, we are paving the way for more targeted, effective, and personalised therapies that have the potential to significantly improve the outcomes and quality of life for patients with this challenging disease.

Expression of Programmed Cell Death Ligand-1 and Mismatch Repair Status in Endometrial Carcinomas

Background and Aims

Programmed death ligand-1 (PD-L1) is a co-regulatory molecule that suppresses local immunity, and mismatch repair (MMR) deficiency (dMMR) is reported to influence the response to anti-PD-L1-targeted therapy. This study was conducted to find the PD-L1 status, the occurrence of dMMR in endometrial carcinomas, and the association between them.

Materials and Methods

The study included 35 resected specimens of endometrial carcinomas represented on formalin-fixed paraffin-embedded sections from January 2016 to July 2020. The clinicopathologic information including patient age, tumor histologic type, grade, stage, lymphovascular invasion, the extent of myometrial invasion, and the percentage of tumor-infiltrating lymphocytes (TILs) were obtained in all cases. The expression of PD-L1 and MMR antibodies including mutS homolog 2 (MSH-2), MSH-6, mutL homolog 1 (MLH-1) and MLH-3, and postmeiotic segregation 2 were assessed using immunohistochemistry. The statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 26.

Results

PD-L1 expression was noted in 48.6% of the cases in tumor cells and 65.7% of the cases in TILs and MMR was deficient in 28.6% of endometrial carcinomas. A statistically significant relation was noted between dMMR and TILs, PD-L1 expression in tumor cells and TILs, PD-L1 expression in tumor cells, and extent of myometrial invasion. Although there was no statistically significant association between MMR status and PD-L1 expression in tumor cells or TILs, 60% of patients with dMMR were PD-L1 positive.

Conclusion

Sixty percent of dMMR cases showed PD-L1 expression in tumor cells. We conclude, ECs that are MMR deficient might get better response to anti-PD-L1 therapy. This study also revealed the prognostic use of TILs in PD-L1-expressed tumors.

Aziz NH, Md Zin RR, Tan GC, Shafiee MN. PD-L1 Expression in Endometrial Cancer and Its Association with Clinicopathological Features: A Systematic Review and Meta-Analysis

Endometrial cancer (EC) is one of the most common malignancies of the female genital tract and its current treatment mainly relies on surgical removal of the tumour bulk, followed by adjuvant radiotherapy with or without chemotherapy/hormonal therapy. However, the outcomes of these approaches are often unsatisfactory and are associated with severe toxicity and a higher recurrence rate of the disease. Thus, more clinical research exploring novel medical intervention is needed. Involvement of the immune pathway in cancer has become important and the finding of a high positive expression of programmed cell death-ligand 1 (PD-L1) in EC may offer a better targeted therapeutic approach. Numerous studies on the PD-L1 role in EC have been conducted, but the results remained inconclusive. Hence, this systematic review was conducted to provide an update and robust analysis in order to determine the pooled prevalence of PD-L1 expression in EC and evaluate its association with clinicopathological features in different focuses of tumour cells (TC) and immune cells (IC). A comprehensive literature search was conducted using the PubMed, Web of Science, and Scopus databases. Twelve articles between 2016 and 2021 with 3023 EC cases met the inclusion criteria. The effect of PD-L1 expression on the outcome parameters was estimated by the odds ratios (ORs) with 95% confidence intervals (CIs) for each study. The pooled prevalence of PD-L1 was 34.26% and 51.39% in the tumour cell and immune cell, respectively, among women with EC. The PD-L1 expression was significantly associated with Stage III/IV disease (in both TC and IC) and correlated to the presence of lympho-vascular invasion in IC. However, the PD-L1 expression in TC was not associated with the age groups, histology types, myometrial invasion, and lympho-vascular invasion. In IC, PD-L1 expression was not associated with age group, histology type, and myometrial invasion. The meta-analysis survival outcomes of PD-L1 high expression had a significant association with worse OS in IC but not in TC.