PD-L1 Expression in Pituitary Neuroendocrine Tumors/Pituitary Adenomas

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Pituitary neuroendocrine tumors (PitNETs) can exhibit aggressive behavior, necessitating predictive factors.
• Programmed cell death ligand 1 (PD-L1) is implicated in aggressive solid tumors, but its role in PitNETs is unclear.

Purpose of the Study:

• To investigate Programmed cell death ligand 1 (PD-L1) expression in PitNETs.
• To correlate PD-L1 expression with radiological invasion, pathological findings, and recurrence rates.

Main Methods:

• Retrospective analysis of 86 PitNET surgical cases.
• Immunohistochemical evaluation of PD-L1 expression using tumor proportion score (TPS).
• Assessment of associations with cavernous sinus invasion, Trouillas' classification, p53, proliferation markers, hormonal expression, tumor size, and recurrence.

Main Results:

• PD-L1 expression was significantly higher in
• proliferative
• PitNETs (OR: 5.78) and associated with p53 expression.
• Positive association between PD-L1 and GH expression (OR: 5.44); inverse association with FSH/LH expression (OR: 0.27).
• No association found between PD-L1 expression and cavernous sinus invasion, tumor size, or recurrence.

Conclusions:

• PD-L1 expression correlates with proliferative PitNET subtypes and p53 expression.
• Somatotroph tumors show higher PD-L1 expression.
• Larger studies are required to fully elucidate the relationship between PD-L1 and PitNET aggressiveness.