Tumor response to sunitinib malate observed in clear-cell sarcoma.

We report on a tumor response to sunitinib malate (SM) in a 46-year-old female patient with metastatic clear-cell sarcoma (CCS). The tumor appeared in December 2008, with two close lesions located to the soft tissues of the left knee. It was initially treated elsewhere with a marginal excision plus local–regional lymph node dissection, followed by radiation therapy on the primary tumor site. The presence of the tumor-specific EWSR1 chromosomal rearrangement was assessed by FISH analysis and confirmed the diagnosis. In June 2009, the disease relapsed at multiple sites. The patient was treated with chemotherapy with anthracycline plus ifosfamide for two cycles, with progression. Meanwhile, the analysis of a series of naive CCS preliminarily showed evidence of platelet-derived growth factor receptor beta (PDGFRB) immunohistochemical expression and biochemical expression/activation in seven of nine cases. On this basis, lacking any conventional alternative for this patient, we biopsied one of her recurrent lesions, which proved positive for PDGFRB on immunohistochemistry. Therefore, in September 2009, she was treated with SM 37.5 mg/day on a continuous dosing regimen. Treatment was provided within a compassionate use program, with the approval of the Institutional Ethics Committee. SM is a multitargeted tyrosine kinase inhibitor and antiangiogenic drug with activity against VEGFR, PDGFRA/B, KIT, FLT3, RET, and M-CSFR approved for the treatment of gastrointestinal stromal tumor and renal cancer. Evidence of activity in selected soft tissue sarcomas has been provided [1, 2]. The disease was extended to the left laterocervical nodes, soft tissues (multiple lesions to the trunk