Chronic Lymphocytic Thyroiditis with Oncocytic Metaplasia Influences PD-L1 Expression in Papillary Thyroid Carcinoma

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• PD-L1 expression is a recognized predictor of immunotherapy response in many cancers.
• Its role and prognostic significance in thyroid cancer are not well understood.

Purpose of the Study:

• To analyze PD-L1 expression in papillary thyroid carcinoma (PTC).
• To investigate the correlation between PD-L1 expression and clinicopathological variables in PTC.

Main Methods:

• Immunohistochemistry (IHC) was used to assess PD-L1 expression.
• 121 primary PTC cases were analyzed.
• Correlations with clinicopathological variables were examined.

Main Results:

• PD-L1 expression was found in 33.1% of PTC cases, mostly weak to moderate.
• No significant correlation was observed between PD-L1 expression and clinicopathological variables.
• Chronic lymphocytic thyroiditis with oncocytic metaplasia was the sole independent predictor of PD-L1 expression (P=0.014).

Conclusions:

• A link exists between chronic lymphocytic thyroiditis with oncocytic metaplasia and PD-L1 expression in PTC.
• This suggests potential for anti-PD-1/PD-L1 therapies in refractory PTC.
• Understanding tumor microenvironment is key for effective thyroid cancer immunotherapy.