Sunitinib malate in solitary fibrous tumor (SFT).
BACKGROUND
To report on sunitinib activity in a retrospective series of 35 solitary fibrous tumor (SFT) treated at a single institution.


METHODS
From April 2008, 35 patients with progressive advanced SFT (male/female: 20/15; mean age: 58 years; meningeal/extrameningeal: 6/29; locally advanced/metastatic: 15/20; prior chemotherapy: 25) were treated, on an individual use basis, with continuous-dosing sunitinib 37.5 mg/day. Platelet-derived growth factor receptor beta (PDGFRB) and vascular endothelial growth factor receptor 2 (VEGFR2) status were assessed by immunohistochemistry and, in a subgroup of patients, by real time PCR.


RESULTS
Thirty-one patients were assessable for response by RECIST (one early death; three early interruptions). Best responses were 2 partial response (PR), 16 stable disease, 13 progressive disease. A <30% decrease in size was observed in three patients. Fourteen of 29 patients assessable by Choi criteria had a PR. Median progression-free survival by RECIST was 6 months (range 1-22). In two of six patients, resistance to sunitinib was overcome by increasing sunitinib to 50 mg/day. PDGFRB and/or VEGFR2 were positive in all cases and not predictive of response; a less aggressive morphology corresponded to an increased response rate (53% PR by Choi in the malignant SFT, 20% PR in the pleomorphic/dedifferentiated SFT).


CONCLUSIONS
Sunitinib is active in SFT. Response can be long-lasting.
Department of Cancer Medicine, Adult Sarcoma Medical Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy. Electronic address: silvia.stacchiotti@istitutotumori.mi.it.
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Stacchiotti
Department of Pathology, Experimental Molecular Pathology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Negri
Department of Cancer Medicine, Adult Sarcoma Medical Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Libertini
Department of Cancer Medicine, Adult Sarcoma Medical Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Palassini
Department of Cancer Medicine, Adult Sarcoma Medical Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Marrari
Department of Cancer Medicine, Adult Sarcoma Medical Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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De Troia
(3)Department of Surgery, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Gronchi
Department of Anatomic Pathology, General Hospital of Treviso, Treviso, Italy.
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Dei Tos
Department of Radiology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Morosi
Department of Radiology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Messina
Department of Pathology, Experimental Molecular Pathology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Pilotti
Department of Cancer Medicine, Adult Sarcoma Medical Oncology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
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Casali
D000328:Adult; D000368:Aged; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D018952:Antigens, CD34 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000627:therapeutic use; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011758:Pyrroles / Q000627:therapeutic use*; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism; D012189:Retrospective Studies; D054364:Solitary Fibrous Tumors / Q000188:drug therapy* / Q000401:mortality*; D000077210:Sunitinib; D016896:Treatment Outcome; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D018952:Antigens, CD34; D000970:Antineoplastic Agents; D007211:Indoles; D019253:Proto-Oncogene Proteins c-bcl-2; D011758:Pyrroles; D020797:Receptor, Platelet-Derived Growth Factor beta; D040301:Vascular Endothelial Growth Factor Receptor-2; D000077210:Sunitinib