Dermatofibrosarcoma protuberans (DFSP) is cutaneous soft tissue sarcoma affecting mainly young adults and characterized by an indolent slow dermal growth leading to late diagnosis when large tumours cause important aesthetics and functional impairments. Local relapses due to insufficient excision are common. Therefore, complete excision of the primary tumour with free margins is the cornerstone therapeutic option with subsequent potential mutilations decreasing the quality of life patients.
The genetic landmark of DFSP is a unique chromosomal translocation displacing the promoter of the collagen type1 α1 next to the platelet-derived growth factor (PDGF) gene. This leads to an unregulated production of PDGF activating the tumour growth after binding on its dedicated receptors. Based on the pathogenesis of this lesion, the option of treating DFSP patients with imatinib mesylate, a tyrosine kinase inhibiting this loop, has raised.
We have treated consecutively four patients affected by a dermatofibrosarcoma with imabinib mesylate in order to downsize the tumour before surgery. All of them responded and curative surgery was thereafter performed. No relapse was observed after a median follow up of 32 months. Therefore, our results assess the value of using Imatinib as neoadjuvant treatment of DFSP and we put into perspectives with the existing literature observations.