Background: Macrophage colony stimulating factor (M-CSF) binds to colony-stimulating factor-1 receptor (CSF-1R) and thereby stimulates the proliferation, differentiation and behaviour of monocytes, macrophages and their bone marrow progenitors. Previous studies have suggested that high expression of these markers is correlated with poor prognosis.
Materials and methods: M-CSF, CSF-1R and CD68 protein expression was examined by immunohistochemistry in paraffin embedded sections of soft tissue tumor specimens from 46 patients. The proportion of positive cells and the expression intensity of M-CSF, CSF-1R and CD68 in both the tumor cell areas and the adjacent stromal areas were correlated to the histological grade.
Results: In the high grade tumors M-CSF and CSF-1R were more highly expressed than in the low grade tumors. This was seen in both the tumor cell areas and the adjacent stromal areas. No differences in CD68 expression between the high and low grade tumors were found either in the tumor cell areas or the stromal areas.
Conclusion: The expression of M-CSF and CSF-1R in tumor cell areas and adjacent stromal areas correlate with the histological grade of soft tissue tumors.