The V-domain Ig-containing suppressor of T-cell activation (VISTA) protein is a new immunological checkpoint protein with immunotherapeutic promise. However, its role in endometrial cancer is not well understood. The purpose of this study was to look at VISTA expression and its connections with clinicopathological characteristics, molecular subtypes, programmed cell death-ligand 1 (PD-L1) expression, CD8+ T-cell count, and survival in a group of 839 endometrial cancer patients.
Researchers classified endometrial malignancies into four molecular categories using direct sequencing of the polymerase epsilon (POLE) exonuclease domain and immunohistochemistry for mismatch repair (MMR) proteins and p53: POLE ultramutated, MMR-deficient, p53-mutant, and nonspecific molecular profile (NSMP). Immunohistochemistry was used to identify PD-L1, CD8, and VISTA. VISTA was found in 76.6% (643/839) of the immune cells and 6.8% (57/839) of the tumor cells.
VISTA was found in 76.6% (643/839) of the immune cells and 6.8% (57/839) of the tumor cells in the samples. Immune cell VISTA positivity was more common in tumor stages I–III, those with positive PD-L1 or high CD8+ T-cell density, and those exhibiting POLE ultramutated and MMR-deficient subtypes. Furthermore, in clear cell carcinoma samples, VISTA positive in tumor cells was more common. VISTA in immune cells was related to increased survival across the board, including endometrioid histology, stage I, PD-L1-negative, MMR-deficient, MMR-proficient, and high and low number of CD8+ T-cell-infiltration tumor groupings. Independent of molecular subtype or CD8+ T-cell density, VISTA in immune cells was a predictive factor in patients with endometrioid histology.