Prognostic factors of carcinoma ex pleomorphic adenoma of the salivary glands, with emphasis on the widely invasive carcinoma: a clinicopathologic analysis of 361 cases in a Chinese population.

OBJECTIVES: To analyze the clinicopathologic characteristics and prognostic factors of salivary carcinoma ex pleomorphic adenoma (Ca-ex-PA) and widely invasive Ca-ex-PA in a Chinese population. STUDY DESIGN: The clinicopathologic parameters of 361 patients with primary Ca-ex-PA from our 2001-2012 cohort were retrospectively reviewed, and the correlation between the parameters and disease-specific survival was statistically analyzed. RESULTS: Of 361 patients with Ca-ex-PA, 229 were male, 132 were female. 191 tumors were invasive carcinoma, 77 minimally invasive, and 93 noninvasive. For 334 (93%) patients, follow-up information was available, and only one of 160 patients with noninvasive or minimally invasive Ca-ex-PA died as a result of the tumor. Of 174 patients with widely invasive Ca-ex-PA, 54 (31%) died as a result of the tumor. Using the Kaplan-Meier method, age, T stage, N stage, histologic grade, and proportion of carcinoma were found to be significantly associated with disease-specific survival of widely invasive Ca-ex-PA. Cox regression analysis indicated that T stage and N stage were independent prognostic factors of disease-specific survival of widely invasive Ca-ex-PA. CONCLUSIONS: Widely invasive Ca-ex-PA had a much worse clinical outcome compared with noninvasive or minimally invasive Ca-ex-PA. T stage and N stage are the most important independent factors for predicting prognosis in Chinese patients with widely invasive Ca-ex-PA.