Associations between p53 overexpression and multiple measures of clinical outcome in high-risk, early stage or suboptimally-resected, advanced stage epithelial ovarian cancers: A Gynecologic Oncology Group study

Objective. The Gynecologic Oncology Group (GOG) performed a detailed analysis of p53 overexpression in previously-untreated women with invasive early or advanced stage epithelial ovarian cancer (EOC). Methods. Women were eligible for the study if they provided a tumor block for translational research and participated in either GOG-157, a randomized phase III trial of three versus (vs.) six cycles of paclitaxel+carboplatin in high-risk, early stage EOC, or GOG-111, a randomized phase III trial of cyclophosphamide+cisplatin vs. paclitaxel+cisplatin in suboptimally-resected, advanced stage EOC. The N-terminal DO-7 p53 antibody was used to examine the expression of the major normal and Mutant p53-isoforms. p53 overexpression was defined as >= 10%, tumor cells exhibiting nuclear staining. Results. p53 was overexpressed in 51% (73/143) and 66% (90/136) of cases in the GOG-157 and GOG-111 cohorts, respectively. In the GOG-157 cohort, p53 overexpression was not associated with any clinical characteristics or overall survival (OS) but was associated with worse progress ion-free survival (PFS) (logrank test: p=0.013; unadjusted Cox modeling: p=0.015). In the GOG-111 cohort, p53 overexpression was associated with GOG performance status (p=0.018) and grade (p=0.003), but not With age, stage, cell type or with tumor response and disease