Comparison of immunosuppressive and cytotoxic cells in angiosarcoma: development of a possible supportive therapy for angiosarcoma.

An imbalance of immunosuppressive and cytotoxic cells plays an important role in inhibiting the anti-tumor immune response of the tumor-bearing host. The purpose of this study was to elucidate the involvement of immunosuppressive cells, such as regulatory T cells and CD163+ M2 macrophages as well as cytotoxic cells, such as granulysin-bearing cells and TIA-1+ cells in cutaneous angiosarcoma (AS) by immunohistochemical staining. In addition we evaluated the potencies of bisphosphonate, which was previously reported to suppress the expression of matrix metalloproteinase 9 (MMP-9), as a supportive therapy for AS together with docetaxel in 6 cases of cutaneous AS. These findings suggest that a high number of immunosuppressive cells might be related to the prognosis of AS, and that a combination of docetaxel with bisphosphonate risedronate sodium might be effective for MMP-9-expressing AS.