Positive correlation between the density of macrophages and T-cells in undifferentiated sarcoma.

Undifferentiated sarcoma (US) is a frequent soft tissue sarcoma. Although the 10-year survival rate is around 60%, advanced US is highly resistant to chemo/radiotherapy. The tumor microenvironment (TME) is closely associated with tumor progression. However, few studies of infiltrated immune cells in US have been published. In this study, we evaluated tumor-associated macrophages (TAMs) and CD8-positive cytotoxic T lymphocytes (CTLs) in 28 cases of US. Iba1, CD163, and CD204 were used as markers for TAMs. The density of CTLs was positively correlated with the density of TAMs. However, a negative correlation was seen between the density of CTLs and the percentage of CD204-positive TAMs. We found no significant association between the density of Iba1-/CD204-/CD8-positive cells and clinicopathological factors. No significant correlation between immune cell infiltration and clinical outcome was observed. Although we found no significant association between immune cells and clinicopathological factors, these findings may provide new insight into the characterization of immune cells in the TME of US.