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.