High grade breast ductal carcinomas have high density of tumor-associated macrophages.

Background: The role of tumor-associated macrophages (TAMs) is double-natured and still controversial. Depending on different settings, macrophages may suppress or promote tumor growth. TAM density may be one of the predictive factors of treatment outcome in cancer patients.

Aim: To evaluate the density of tumor-associated macrophages in breast cancer and its relationship with various histopathologic findings.

Materials and methods: 55 patients with invasive ductal carcinoma of breast who underwent mastectomy were enrolled. Sections of tumor samples were stained and the density of CD68⁺ cells was evaluated.

Results: There was an association between estrogen receptor (ER) expression and CD68 density (p = 0.010) as the higher densities of CD68 were seen in ER negative tumors. Moreover, there was a significant relationship between histological grade and CD68 density (p = 0.006).

Conclusion: The higher TAM density is associated with higher tumor grade and negative ER expression in breast cancer tissues. These findings revealed that inflammation could have an important role in malignancies.