Article Text
Abstract
Introduction/Background We investigated the relationship of programmed death-ligand 1(PD-L1) expression with clinicopathologic characteristics, to identify clinical significance of PD-1/PD-L1 immunotherapy in endometrial cancer.
Methodology Total 232 patients with endometrial cancer were selected who underwent medical or surgical treatment in Seoul National University Bundang Hospital from May 2003 to March 2022. Paraffin-embedded tissues were immunohistochemically stained with PD-L1 antibody, p53 antibody and antibodies against MMR proteins. We regarded PD-L1 positivity as a 1 or more of Combined Positive Score (CPS). The correlation of PD-L1 expression, clinicopathologic factors and survival outcomes were statistically analyzed with SPSS ver.25.0.
Results In comparison of clinicopathologic factors, PD-L1 positivity was related to deep invasion depth (24.4% vs. 35.6%), high grade (19.1% vs. 37.0%) and LVSI positive (25.6% vs. 39.7%) between PD-L1 negative and PD-L1 positive group. With MSI test, MSI-H was correlated with PD-L1 positivity (44.0% vs. 85.7%, p value=0.005). When two MMR minor proteins (MSH6 and PMS2) are proficient, PD-L1 tends to be positive (p value= 0.006/0.002). PD-L1 expression was detected in 31.5% of all patients. Median follow-up duration was 13.5 months (range: 0.3 to 92.5 months). 31(13.4%) patients’ recurrence and 5 (2.2%) patients’ death were noted. PD-L1 was related to low recurrence rate (p value=0.005). In addition, PD-L1 negative group shows better progression free survival (PFS) than PD-L1 positive group (5 yr-PFS, 94.1% vs 86.3%, p value=0.139). However, neither PFS nor Overall survival (OS) (p value=0.596) was statistically significant. Even though PD-L1 showed no solid statistical significance, PD-L1 was significantly correlated to poor prognosis. In addition, histologically other than endometrioid type group (p=0.008) and lymphovascular invasion (LVSI) positive groups (p=0.023) are poor prognostic factors for survival also.
Conclusion PD-L1 is an independent poor prognostic factor in endometrial cancer recurrence. Patients with higher grade and LVSI positive could be rational candidates for anti PD-1/PD-L1 immunotherapy in endometrial cancer.