Tumour microenvironment and PD-L1 expression in endometrial carcinoma

Abstract

Introduction. Immunotherapy has emerged as a potent strategy for treating advanced cancer. This generated new and exciting research, especially regarding tumour microenvironment (TME), including the immune checkpoint system, to further stratify endometrial carcinoma (EC) patients and improve targeted therapy. The objective of the study was to evaluate the TME and PD-L1 impact on various molecular groups. Material and methods. 50 cases of formerly diagnosed ECs were tested for CD4, CD8, CD68 and PD-L1. Results. PD-L1 testing in our group revealed 60% of cases showing <1% cell positivity, 34% of cases showing 1-49% cell positivity, and 6% of cases showing ≥50% cell positivity. The statistical analysis revealed the following significant correlations with clinical and pathological parameters: pT (p=0.012), FIGO stage (p=0.028), myometrial invasion (p=0.037) and ESMO risk stratification (p=0.017). PD-L1 expression in the three different molecular subgroups showed significant correlation with the MSI-H subgroup (p=0.014). The analysis between TME and PD-L1 expression revealed significance with stromal CD4+ cells (p=0.037), tumour and stromal CD8+ cells (p=0.011, p=0.028), and stromal CD68+ cells (p=0.012). Conclusions. Molecular classification, TME evaluation and PD-L1 expression are key ancillary tools in elaborating comprehensive EC pathology reports. Combined evaluation of these features allows a more precise prognostic stratification of EC patients and provides significant implications for incorporating immunotherapy in current therapeutic strategies for EC.

Keywords

• endometrial carcinoma
• molecular
• prognosis
• tumour microenvironment
• immunotherapy
• pd-l1