CD68 positive and/or CD163 positive tumor-associated macrophages and PD-L1 expression in breast phyllodes tumor

Eunah Shin ¹, Hye Min Kim ¹, Ja Seung Koo ²

⁰Department of Pathology, Yonsei University College of Medicine, Seoul, South Korea.

Breast Cancer Research and Treatment +

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September 6, 2024

View abstract on PubMed

Summary

Tumor-associated macrophages (TAMs) and PD-L1 expression increase with phyllodes tumor (PT) grade. Higher PD-L1 levels correlate with poorer survival, indicating their prognostic significance in PT.

Area Of Science

Oncology
Immunology
Pathology

Background

Limited research exists on PD-L1 expression and TAM status in phyllodes tumors (PT).
Understanding these factors is crucial for assessing PT behavior and potential therapeutic targets.

Purpose Of The Study

To investigate PD-L1 expression and TAM status in breast PT.
To examine the correlation between PD-L1, TAMs, and clinicopathological parameters in PT.
To evaluate the prognostic implications of PD-L1 and TAMs in PT.

Main Methods

Tissue microarrays of 181 PT samples were analyzed using immunohistochemistry.
PD-L1 antibodies (SP142, SP263, 22C3) and TAM markers (CD68, CD163) were employed.
Staining results were correlated with clinicopathological parameters and survival data.

Main Results

TAMs (CD68+/CD163+) increased with PT grade and showed hybrid histiocyte/myofibroblast characteristics.
PD-L1 expression (SP263, 22C3) was highest in malignant PTs and correlated with TAM presence.
PD-L1 SP263 immune cell expression and PD-L1 22C3 tumor cell expression were linked to shorter disease-free and overall survival, respectively.

Conclusions

TAMs in PT exhibit hybrid features and their numbers escalate with tumor grade.
PD-L1 expression, particularly in immune cells and tumor cells, is associated with PT grade and adverse survival outcomes.
PD-L1 and TAMs represent potential prognostic biomarkers in phyllodes tumors.

Keywords:

PD-L1 Phyllodes tumor Tumor-associated macrophages