P53/MDM2 overexpression in metastatic endometrial cancer: correlation with clinicopathological features and patient outcome

Abstract

Several studies have reported that p53/mdm2 distortions play a pivotal role in the development and progression of various human malignancies. However, the number of reports having evaluated simultaneously the components of the P53-pathway alterations in advanced-stage human endometrial carcinomas (EC) is low. In this study, we examined the expression of P53/MDM2 proteins in primary and metastatic ECs, and analyzed the clinicopathological characteristics as well as the survival outcome of patients in relation to P53/MDM2 overexpression. The study group comprised 36 patients with advanced EC, whose primary and metastatic tumor slides were sufficient for analysis. Immunohistochemical assessment was made by applying anti-human P53 and MDM2 antibodies and a highly sensitive EnVision(+)/HPR visualization system. Nuclear P53 overexpression was seen in 11 (31%) primary ECs and 12 (33%) metastatic tumors. There was a significant correlation between P53 overexpression (in primary cancers and metastatic tumors) and MDM2 overexpression in metastatic tumors. Nuclear MDM2 overexpression was noted in 42% (15/36) of primary carcinomas and in 47% (17/36) of metastatic tumors. A significant association existed between MDM2 overexpression and histological grading (G1 + G2 versus G3, P = 0.043). P53/MDM2 overexpression occurred simultaneously in 7 out of 36 (19%) primary ECs and in 9 out of 36 (25%) metastatic lesions. Concomitant overexpression of these proteins was reported in 7 out of 36 (19%) cases and tended to be higher in tumors showing VSI compared to neoplasms lacking vascular space invasion (P = 0.051). P53 overexpression, either in primary ECs (P < 0.0001) or metastatic lesions (P < 0.0001), was significantly associated with poor survival in univariate analysis. Moreover, the log-rank test demonstrated that simultaneous P53/MDM2 overexpression was also correlated with decreased length of survival. There was no correlation between MDM2 overexpression and patient survival. Multivariate Cox regression analysis revealed that only P53 overexpression is an independent predictor of survival. In conclusion, our data support the view that patients with P53 overexpression are significantly associated with an unfavorable outcome, whereas MDM2 overexpression is not related to decreased survival length in women operated on for advanced-stage EC.