Comparison of Ki-67, cyclin E, and p63 in benign and malignant human pleomorphic adenoma

Abstract

A set of cell proliferation-related molecular markers was used to detect the differences in proliferative activity between benign pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (CXPA). Seventy samples comprising 53 PAs, 10 noninvasive and 7 widely invasive (WI) CXPAs were selected. Immunohistochemical staining was used to detect Ki-67, cyclin E, and p63 expression. The average Ki-67 labeling index of WI CXPAs was higher than that of PAs and the malignant component of noninvasive CXPAs (M-noninvasive CXPA; P < .01). An increased cyclin E-positive staning was observed in M-noninvasive CXPAs and WI CXPAs compared with PAs (P = .006). The p63 expression levels were notably decreased in M-noninvasive CXPAs and WI CXPAs compared with PAs (P = .007). The data support that increased or decreased expression of Ki-67, cyclin E, and p63 may indicate the proliferative differences between PA and CXPA.