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

OBJECTIVE: 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).

STUDY DESIGN: 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.

RESULTS: 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).

CONCLUSIONS: The data support that increased or decreased expression of Ki-67, cyclin E, and p63 may indicate the proliferative differences between PA and CXPA.