Prognostic factors for pleomorphic dermal sarcoma: analysis of 1911 cases from the SEER database.

Prognostic factors for pleomorphic dermal sarcoma, a rare undifferentiated neoplasm of the skin, are poorly defined, and typical staging systems do not appear to be appropriate for these neoplasms. We; therefore, sought to identify prognostic factors for disease-specific survival and predictors of metastasis.Pleomorphic dermal sarcomas were identified in the Surveillance, Epidemiology and End Results database (N=1911). Multiple imputation was used to overcome inherent limitations in this dataset to assess prognostic factors using multivariable Cox proportional hazard stratified by (neo)adjuvant radiotherapy and logistic regression for presentation with metastasis.Age, tumour size and metastasis were independent prognostic factors for cutaneous sarcoma-specific survival. Only tumour size was associated with increased odds of presentation with metastasis, with tumours >4 cm at highest risk. Metastasis is the most important factor in determining outcomes, with age and size as lesser factors. Only tumour size is predictive of metastasis, with larger tumours at highest risk.