Fibrosarcomatous changes and expression of CD34+ and apolipoprotein-D in dermatofibrosarcoma protuberans.

Background: Dermatofibrosarcoma protuberans (DFSP) is a relatively common soft-tissue tumor. A more aggressive appearing fibrosarcoma may arise in DFSP, changing its biological behavior. CD34 and apolipoprotein-D are highly expressed in DFSP, but their prognostic significance is uncertain.

Methods: DFSP and fibrosarcomatous-DFSP (FS-DFSP) patients referred to our institute between 1982 and 2009 were identified. Fibrosarcomatous changes, expression of CD34 and apolipoprotein-D were evaluated.

Results: 40 patients, (median age 43 years, 55% males) were identified. Tumor was located in the limbs in 60%, in the trunk in 40%. Thirty-seven patients had localized and 3 had metastatic disease. Thirteen (32%) patients were FS-DFSP. All but one underwent surgery with adequate surgical margins in 72%. 7 FS-DFSP received also radiotherapy (RT). Chemotherapy was administered to 3 patients with FS-DFSP. With a median follow-up of 49 months, the 5-OS was 90%. Local recurrence rate was 23%: 42% FS-DFSP, 15% DFSP. Metastases developed in three FS-DFSP patients. The 5-year EFS was 70% in localized patients. Histology (DFSP 75% vs. FS-DFSP 52%, p = 0.002), surgical margins (adequate 74% vs. inadequate 55%, p = 0.02), site (limb 47% vs. trunk 100%), CD34 expression (CD34 positive: 70% vs. CD34 negative: 33%, p = 0.05), and apolipoprotein-D expression (Apo-D positive: 73% vs. Apo-D negative: 33%, p = 0.02) influenced the 5-year EFS, whereas sex, use of RT or number of previous surgical treatments did not.

Conclusions: Patients with DFSP have a high survival probability. Site, adequate surgical margins, presence of the fibrosarcomatous component, lack of CD34 expression and apolipoprotein-D influence outcome.