Abstract: Background: Soft tissue sarcomas (STSs) are a heterogeneous group of tumors of mesenchymal origin with similar biological behavior. These tumors comprise 10-15% of solid malignant tumors in canines, and have up to 30% mortality rate. The aim of this study was to evaluate the immune make up of soft tissue sarcomas in canines and identify its correlation with tumor stage and patient outcome. We hypothesized that tumors exhibiting an immune competent landscape are more likely to be associated with less aggressive biological behavior and a better prognosis.
Methods: A retrospective study of 74 client owned dogs from a single institution with confirmed diagnosis of STSs was conducted. Patient information, clinical data and outcomes were collected and analyzed. In addition, correlated tumor samples were subjected to immunohistochemistry and nanostring analysis, to identify immune components that are associated with overall survival (OS), progression free survival (PFS), and metastatic risk (MTR).
Results: We have identified a comprehensive and significant correlation between immunosuppressive gene signatures and patient outcome. Genes such as AXL, LFNG, MCAM and TAL1 had all exhibited a significant statistical correlation with decreased OS, PFS, and MTR. Furthermore, we have identified distinct immune contextures that included tumors of high, low, or marginal immune cell infiltrations.
Conclusion: This study highlights the significance of the tumor immunity for disease progression and patient’s outcome. In addition, the detection of potential disease markers and novel targets will promote the design of future immunotherapies for dogs with soft tissue sarcomas.
