ESMO Immuno-Oncology Congress 2023

Abstract 189P

Background

Malignant tumors are sophisticated, organized ecosystems in addition to collections of cancer cells. It has long been established that the formation, recurrence, and metastasis of cancers are all tightly correlated with their immune components. However, the impact of the tumor microenvironment in soft tissue sarcoma (STS) remains mainly unclear. Studying how the immunological microenvironment affects the clinical presentation and prognosis of soft tissue sarcomas is the objective.

Methods

Retrospective research was conducted on 168 soft tissue sarcoma patients who received care at the Republican specialized Scientific and practical Medical Center of Oncology and Radiology of Uzbekistan. Through immunohistochemistry analyses of CD3, CD4, CD8, CD20, and CD68, lymphocyte subpopulations that infiltrate tumours and their subpopulations were investigated.

Results

In the immunological microenvironment, CD 68+ macrophages and CD 3+ T cells were the most prevalent cell types. There was a substantial positive correlation between CD 68 expression and the probability of local recurrence (p = 0.014) in a multivariate analysis employing the Fine & Gray risk regression model with death as a competing event, independent of age, resection margins, and the presence of B cells. Furthermore, B cell abundance was significantly lower (p = 0.013) and macrophage abundance was much higher in patients older than middle age. Regarding histological subtypes, undifferentiated pleomorphic sarcoma and myxofibrosarcoma were more frequently found to have these cells, which had a high total number of tumor-infiltrating lymphocytes in general and macrophages in particular.

Conclusions

The significant number of CD 68 macrophages in soft tissue sarcomas and their detrimental effect on the prognosis for local recurrence are both confirmed by this investigation.