Immunotherapy involving the programmed death-1 (PD-1)/the programmed death-ligand (PD-1/PD-L) blockade is an understudied tumor therapy approach in cases of adenosarcoma. PD-L1 and PD-L2, and tumor protein p53 (p53) were examined in 20 uterine adenosarcoma cases, and tumor-infiltrating lymphocytes and tumor-associated macrophages were counted in tumor tissue using immunohistochemistry. While CPS PD-L1 positivity with 1% and 10% cut-off values was observed in 40% and 10% of tumors, respectively, CPS PD-L2 positivity with 1%, 10% and 50% cut-off values was observed in 100%, 85% and 50% of the tumors, respectively. The CPS PD-L2 positivity with a 50% cut-off value was positively correlated with tumor grade and the presence of sarcomatous overgrowth and lymphovascular invasion (LVI) (p = 0.025, p = 0.025, and p = 0.025, respectively). Nine of 11 high-grade adenosarcomas and none of the low-grade adenosarcomas showed mutant type p53 expression (p = 0.000). However, PD-L1 expression and tumor-infiltrating immune cells did not correlate with clinicopathological parameters. The CPS PD-L2 positivity with a 50% cut-off value was also positively correlated with mutant type p53 expression (p = 0.024) and tumor-associated macrophages density (p = 0.024). The CPS PD-L2 positivity with a 50% cut-off value and mutant type p53 expression were associated with shorter disease-free survival and shorter overall survival. The high density of tumor-associated macrophages and low density of tumor-infiltrating lymphocytes were also associated with shorter disease-free survival and overall survival (p < 0.05).These results suggested that the CPS PD-L2 positivity with a 50% cut-off value, p53 mutation and tumor microenvironment played an essential role in the progression of uterine adenosarcomas.
Keywords: PD-L1; PD-L2; adenosarcoma; p53; tumor microenvironment.