Carcinoma ex pleomorphic adenoma: A review of incidence, demographics, risk factors, and survival.

Purpose: Identify variables that are independent predictors of survival in carcinoma ex pleomorphic adenoma (CXPA) of the major salivary glands using a population-based database and evaluate the incidence and management strategies for this rare malignancy. Materials and Methods: The Surveillance, Epidemiology, and End Results (SEER) database was queried for all cases of major salivary gland CXPA from 1973 to 2015. Results: Of the 619 patients identified, the parotid gland was the most common site of involvement (76.9%, 476/619). The reported incidence of CXPA has risen in the past decade (2005-2015, 0.24 to 0.63 per 1,000,000). The 2 -year and 5 -year disease -specific survival (DSS) rates were 90.3% and 80.4%, respectively. On univariate analysis, facial nerve sacrifice was not a statistically significant predictor of survival (HR = 1.213, 95% CI [0.588-2.058], P = 0.602). Patients with a tumor size > 4 cm, multiple positive lymph nodes, and distant metastatic disease had a 2 to 4 -fold statistically significant increase in mortality using a multivariate analysis. Statistical significance was not demonstrated in the DSS of patients who underwent partial versus total parotid ectomy procedures. Conclusions: CXPA is a rare salivary malignancy that has a reported increased incidence in the last decade. Tumor size > 4 cm, multiple positive lymph nodes, and distant metastatic disease are predictors of disease specific mortality. Further research should be conducted to improve early detection and survival strategies for this salivary cancer.