Figure 1.

Sorafenib results in decrease in tumor size and cellularity in superficial fibromatosis. (A) Response of 5 patients with plantar (n = 4) and/or palmar (n = 2) fibromatosis to sorafenib (starting dose 200-400 mg orally daily); 4 of which have recurrent disease after surgical resection and 3 of which have multifocal disease. Response is measured as percent change from baseline tumor size (WHO criteria) and tumor cellularity (MRI T2 fat-saturated signal intensity) in the single tumor with the best response. Tumor cellularity is a measure of tumor collagenization, and therefore, a surrogate marker of tumor growth potential.⁶ Change in tumor size of the lesion with the best response from baseline (black bars; best lesion: 33%-68%; mean of all lesions: 26%-64%). Change in tumor cellularity of the lesion with the best response from baseline (blue bars; best lesion: 0%-100%; mean of all lesions: 0%-62%). (B) Representative MRI T2 fat-saturated images of baseline and best response lesion from patient 4. (C) Representative images of PDGFRβ immunohistochemistry in superficial fibromatoses demonstrates patchy positivity.