Prognostic significance of p27 and Ki-67 expression in mucoepidermoid carcinoma of the intraoral minor salivary gland

p27 and Ki-67, a universal cyclin-dependent kinase inhibitor and a prolifer ative cell marker, respectively, have been useful in predicting clinical ag gressiveness in various human tumors. We studied clinicopathologic signific ance of these molecules in mucoepidermoid carcinoma of the intraoral minor salivary gland. Expression of p27 and Ki-67 was assessed Immunohistochemica lly in primary mucoepidermoid carcinomas from 31 patients without distant m etastasis at surgery. Correlation each of p27 and Ki-67 expression was anal yzed with various clinicopathologic parameters including age, sex, primary tumor site, tumor size, nodal metastasis, clinical stage, and histologic gr ade. The latter was evaluated using a point-scoring scheme of Auclair et al . that consists of five histologic factors (intracystic component, neural i nvasion, necrosis, mitosis, and anaplasla). p27 expression was correlated i nversely with histologic grade (P=.007),but with none of other factors. Whe n the correlation of p27 expression was further examined with each of the h istologic factors, It was correlated significantly with intracystic compone nt, but not with neural invasion, necrosis, mitosis, or anaplasla. Ki-67 ex pression was correlated significantly with histologic grade only in the cli nicopathologic factors (P<.0001), and in the histologic factors, with necro sis, mitosis, and anaplasia. Multivariate prognostic analyses were performe d to identify independent risk factors for both disease-free and overall su rvivals. Large tumor size (P=.031, relative risk=5.5) and low p27 expressio n (P=.012, relative risk=5.2) were risk factors for worse disease-free surv ival. Low p27 expression (P=.015, relative risk=15.2) was selected as a ris k factor for worse overall survival. Other factors including age, sex, tumo r site, nodal status, clinical stage, histologic grade, and Ki-67 did not e merge as independent risk factors in either prognostic analysis. These data suggest that p27 may be useful in estimating prognosis of the patients who have mucoepidermoid carcinoma of the intraoral minor salivary gland.