# Increased infiltration of M2-polarized tumour-associated macrophages is highly associated with advanced disease stage and high expression of PD-L1 in buccal mucosa carcinoma

## TL;DR

The study found that M2-polarized tumor-associated macrophages are more common in advanced stages of buccal mucosa carcinoma and linked to higher PD-L1 and EGFR expression.

## Contribution

This study identifies M2-polarized TAMs as a potential therapeutic target in buccal mucosa carcinoma.

## Key findings

- High infiltration of M2-polarized TAMs correlates with advanced disease stages (T3–T4, N+, III–IV).
- M2-polarized TAMs infiltration is positively linked to PD-L1 and EGFR expression in buccal mucosa carcinoma.
- CD206+ TAM infiltration is higher in patients with high EGFR expression.

## Abstract

To assess the infiltration characteristics of tumour-associated macrophages (TAMs) in buccal mucosa carcinoma (BMC) and the correlation of these features with clinicopathological factors.

Immunohistochemistry was used to detect the expression of TAM-related markers (CD68, CD163, CD206), CD8+ T cell markers, PD-L1, and epidermal growth factor receptor (EGFR) in 46 patients with mucosal cancer after radical surgery. In addition, the correlation between TAM infiltration and clinical characteristics, PD-L1 expression, and EGFR expression was analysed.

A high infiltration level of M2-polarized (CD206+) TAMs and M2-polarized (CD163+) TAMs was more common in stage T3–T4, N+, III–IV patients than in other patient groups (P < 0.05). The infiltration degree of M2-polarized (CD68+) TAMs was positively correlated with the PD-L1 TPS (P = 0.0331). The infiltration level of M2-polarized (CD206+) TAMs was higher in the EGFR high expression group than in the EGFR low expression group (P = 0.040).

High infiltration of M2-polarized TAMs is highly associated with advanced disease stage and higher expression of PD-L1 and EGFR in BMCs, suggesting that M2-polarized TAMs infiltration can serve as a potential therapeutic target.

The online version contains supplementary material available at 10.1007/s12672-024-01190-y.