Prognostic Factors, Treatment, and Survival in Dermatofibrosarcoma Protuberans

There is limited information regarding the influence of patient demographics, tumor characteristics, and treatment type on the survival of patients with dermatofibrosarcoma protuberans (DFSP).

To assess prognostic factors and to evaluate the influence of treatment modality on overall survival of patients with DFSP.

We examined DFSP using data for 3686 patients with histologically confirmed cases of DFSP diagnosed between 1972 and 2012 from the 18 US regional registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program, with linkage to demographic data from the US Census Bureau for median household income (MHI). The analysis was performed in February 2016.

The primary outcome measures were tumor characteristics, prognostic factors, and overall survival in months.

There were 3686 cases of DFSP examined. Older age (hazard ratio [HR], 1.08; 95% CI, 1.06-1.10; P < .001), male sex (HR, 1.97; 95% CI, 1.09-3.55; P = .03), and tumor size (HR, 1.09; 95% CI, 1.01-1.18; P = .04) were significantly associated with poorer overall survival in a controlled analysis. Older age (odds ratio [OR], 1.01; 95% CI, 1.00-1.02; P = .01), male sex (OR, 1.95; 95% CI, 1.57-2.42; P < .001), and black race (OR, 1.78; 95% CI, 1.37-2.32; P < .001) were associated with larger (≥3.0 cm) tumors at presentation. Treatment modality did not influence overall survival; however, differences in patient characteristics affected the treatment received. Older age at presentation (OR, 1.02; 95% CI, 1.01-1.03; P =.01), black race (OR, 1.82; 95% CI, 1.13-2.92; P = .01), large tumor size (OR, 1.15; 95% CI, 1.09-1.21; P < .001), and head or neck location (OR, 4.63; 95% CI, 2.66-8.07; P <.001) increased the likelihood of a patient receiving surgery and radiation over surgery alone. In addition, white patients (OR, 0.51; 95% CI, 0.30-0.87; P=.01), women (OR, 0.53; 95% CI, 0.36-0.78; P <.001), and patients with a higher MHI (OR, 1.27; 95% CI, 1.11-1.46; P <.001) were more likely to receive Mohs micrographic surgery (MMS) over excision.

Age at diagnosis, male sex, and DFSP tumor size appear to be important prognostic factors. Treatment modality did not significantly influence survival; however, patient and tumor characteristics influence treatment modality.