Neoadjuvant Imatinib Therapy for Dermatofibrosarcoma Protuberans

Abstract

Background: Dermatofibrosarcoma protuberans (DFSP) is an unusual soft-tissue tumor with a propensity for subclinical extension and local recurrence. Surgical excision, even with tissue-sparing techniques, may cause significant deformity or disability because of the infiltrative nature of DFSP. In this study, we evaluate retrospective data obtained from 4 patients with locally advanced or recurrent DFSP who received neoadjuvant imatinib mesylate therapy before undergoing Mohs micrographic surgery.Observations: Patients treated with neoadjuvant imatinib therapy had an average tumor size reduction of 36.9%. This clinical response was paralleled by histopathologic changes, including decreased cellularity in 100% of the total area as well as significant hyalinization. Imatinib therapy for DFSP before Mohs micrographic surgery was associated with 100% local control at a maximum follow-up of 4 years.Conclusions: Neoadjuvant imatinib therapy is a welltolerated, novel approach to DFSP that reduces tumor burden and facilitates resection. Larger prospective studies are needed to confirm and expand on these results.

Imatinib Mesylate as a Preoperative Therapy in Dermatofibrosarcoma: Results of a Multicenter Phase II Study on 25 Patients

“…Interestingly, clinical response was correlated with a decrease in cell density, which was itself associated with the score for fibrosis. Hyalinic fibrosis induced by IM has hitherto been reported only in two isolated cases (23,26) but was observed in 19 of 25 of our patients. The replacement of tumor cells by hyalinized collagen has also been reported in gastrointestinal stromal tumors treated with IM (31).…”

“…The use of IM has also been reported in 20 isolated cases outside of clinical trials (4,5,(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Among these, seven patients had fibrosarcoma on DFSP (4,15,16,24) and six patients had metastatic sarcoma (4,5,15,16,18).…”

“…The time to initial response was 3 months or less in 15 patients for whom this information was available (4, 5, 15, 16, 18-20, 22, 24-26). Treatment exceeded 6 months for seven patients (16,17,19,20,23,24,26), reaching 14, 17, and 20 months for three patients (16,20,24). Our study was designed in 2003 when only three case reports of response in metastatic disease had been published.…”

Giant Dermatofibrosarcoma Protuberans: A Case Report of a Surgical Reconstruction and Patient Rehabilitation Challenge

“…Responses to these drugs were shown in cases of advanced or metastatic disease. 10 However, patients with a mutation other than t(17;22) may not respond to this drug, a fact that shows the importance of molecular studies before the initiation of adjuvant therapy. 3,5 This case report stimulated intensive discussion, especially because of the reconstruction.…”

Changing Pathology with Changing Drugs: Skin Cancer

“…Tumor cells are transformed into less viable hyaline fibers and thus lose vitality [186,190] . The reduction of vital cells allows a smaller safety margin for the surgical treatment thereof.…”