Serum p53 antibody as a diagnostic marker of high-risk endometrial cancer

Objective The purpose of this study was to investigate the diagnostic impact of preoperative serum p53 antibody (S-p53 Ab) in patients with endometrial cancer. Study Design A hospital-based series of 67 patients, comprising 58 endometrioid adenocarcinomas (EA) and 9 serous adenocarcinomas (SA) between 1998-2002 were included. First, preoperative pathology was compared with final pathology in terms of histologic classification and tumor grade. Second, S-p53 Ab and CA125 were measured using preoperative serum samples, and immunohistochemical staining for p53 protein was assessed using hysterectomy specimens. Results There were discrepancies between preoperative and final pathology in terms of histologic classification (7%) and tumor grade in EAs (30%); other objective tests, therefore, were needed to minimize the diagnostic problems. S-p53 Ab titers varied from 0.27-786 (mean, 124) in SAs and from 0.1-7.47 (mean, 0.46) U/mL in EAs, respectively, and were positive in 6 (67%) SAs and in 3 (6%) EAs using 1.3 U/mL as cut-off. S-p53 Ab-positive rate was significantly correlated with SA histology and grade 3 EA tumor (odds ratio, 40; P = .005; 95% confidence interval, 3.04-525.43) with higher sensitivity and higher specificity than p53 staining and CA125, respectively. Conclusion S-p53 Ab could conveniently and specifically identify high-risk endometrial cancer.