P21WAF1, P27KIP1, TP53 and C-MYC analysis in 204 ovarian carcinomas treated with platinum-based regimens

Abstract

The prognostic and predictive value of cell cycle regulatory proteins in ovarian cancer has not been established. We evaluated the clinical and biological significance of P21(WAF1), P27(KIP1), C-MYC, TP53 and Ki67 expressions in ovarian cancer patients. Immunohistochemical analysis was performed on 204 ovarian carcinomas of International Federation of Gynecology and Obstetrics (FIGO) stage IIB to IV treated with platinum-based chemotherapy. Multivariate analysis with Cox and logistic regression models was performed in the whole group, and in the TP53-negative and TP53-positive subgroups. High P21(WAF1) labeling index (LI) was an independent positive predictor of platinum-sensitive response (P = 0.02). Overall survival was positively influenced by P21(WAF1) LI (P = 0.02) or by P21(WAF1) plus P27(KIP1) LI (P = 0.004) in the TP53-negative group only. Ki67 LI showed borderline association with disease-free survival (P = 0.05). Growth fraction was negatively associated with P21(WAF1) and P27(KIP1) indices in the TP53-negative group (P = 0.023 and 0.008, respectively), and these associations were borderline or lost in the TP53-positive group. Endometrioid and clear cell carcinomas differed from other carcinomas by having a low incidence of TP53 accumulation, a high incidence of C-MYC overexpression (70%) and a low median Ki67 LI (all with P <0.001). We have shown an independent predictive value of P21(WAF1) LI in ovarian carcinoma patients. The prognostic value of P21(WAF1) and P21(WAF1) plus P27(KIP1) LI was determined by TP53 status. A high frequency of C-MYC overexpression in endometrioid and clear cell carcinomas may suggest its role in the development of these tumor types.