Descriptive epidemiology of dermatofibrosarcoma protuberans in the United States, 1973 to 2002

Background: The epidemiology of dermatofibrosarcoma protuberans (DFSP) has not been studied in detail. Objective: We sought to describe patterns of DFSP incidence and survival in the United States. Methods: Data were obtained from 9 population-based cancer registries of the Surveillance, Epidemiology, and End Results Program for 1973 to 2002. Results: DFSP overall annual incidence was 4.2 per million. Incidence increased by 43% (3.1-4.4 per million per year) during the study period, but this increase was restricted to whites. Annual incidence among blacks (6.5 per million) was almost double the incidence among whites (3.9 per million; P < .005 95% confidence interval of difference 2.02-3.22). Women had higher rates of incidence than men (4.4 vs 4.2 per million per year; P = .052, 95% confidence interval of difference -0.002 to 0.60), except among the elderly. Relative 5-year Survival was 99.2% (95% confidence interval 98.3-100%). Limitations: The Surveillance, Epidemiology, and End Results Program lacks independent verification of diagnoses and case detail. Conclusions: The racial differences in the incidence of DFSP are significant, and the cause is unknown. Previous literature had suggested that men were more frequently affected, which was not true in our data. The tumor rarely results in death. Epidemiologic investigation using population-based data is important to better understand this disorder.