COVID-19 and Breast Cancer Cross-Talk: Exploring the Role of Tumor-Associated Macrophages

This study aimed to assess the prognostic significance of CD163+ tumor-
associated macrophages (TAMs) density and distribution in breast cancer (BC)
patients during the COVID-19 pandemic compared to pre-pandemic periods. A
retrospective evaluation was conducted on two groups of BC patients: the study
group (during the COVID-19 pandemic, n = 80) and the control group (pre-
pandemic, n = 80). Immunohistochemistry was performed for CD163+. The
density of CD163+ TAMs was evaluated in intra-tumoral and peri-tumoral
areas. A significant association was observed between adverse clinicopathologic
parameters and COVID-19-positive patients with poor survival rates. A
statistically significant correlation was detected between most unfavorable
clinicopathological characteristics and a high density of CD163+ TAMs,
particularly intra-tumoral density. Additionally, a high density of intra-tumoral
CD163+ TAMs was identified as an independent predictor of shortened overall
survival in multivariate analysis (p = 0.014). This study suggested that
alterations in the tumor microenvironment of BC may be linked to COVID-19
infection. Moreover, an increased density of TAMs, particularly in intra-tumoral
areas, may contribute to tumor burden by promoting tumor progression. These
findings underscore the need to consider both the histologic location and
infiltration density of TAMs in BC as predictive biomarkers.