Histiocytic sarcoma - targeted therapy: novel therapeutic options? A series of 4 cases

Histiocytic sarcoma (HS) is a rare but highly aggressive disease. The cancer-specific survival of patients with HS is short and only limited response to conventional chemotherapy or radiation therapy is seen. Some data from single case reports have suggested efficacy for high-dose chemotherapy and autologous/allogeneic stem cell transplantation.

We report on 4 cases of HS, and demonstrate that different druggable receptors are expressed on HS. Using immunohistochemistry, we detected the expression of platelet-derived growth factor receptor, vascular endothelial growth factor receptor and epidermal growth factor receptor, which are all well-known targets for novel targeted agents. Based on the marker profile, different novel targeted therapies including imatinib, sorafenib and bevacizumab were applied to the patients. We observed a varying clinical course for each patient.

In our case series, we demonstrated that different receptors, which represent potential targets for novel drugs, are expressed on HS tumor cells. For a definitive assessment of the efficacy of these agents a prospective case study of a larger number of patients should be performed.