Quantification of p53 in epithelial ovarian cancer.

OBJECTIVE

The perceived function of wild-type p53 is suppression of cell proliferation. An alteration in the p53 tumor suppressor gene is a common defect in human malignancies. The purpose of this study was to prospectively determine whether p53 expression, as quantified by image analysis, was related to traditional prognostic indicators as well as survival in patients epithelial ovarian cancer.

METHODS

Eighty-three consecutive patients with epithelial ovarian cancer had their p53 expression studied by immunohistochemical staining and quantified by image analysis. Unless otherwise noted, p53 expression was reported as the percentage positive nuclear area staining.

RESULTS

The mean follow-up was 37 months (median, 30 months; range 24-55 months). In patients with serous carcinomas of the ovary, the mean p53 expression was 29.4%, whereas in patients with other histologies, the mean was 10.5% (P < 0.001). The tumors of patients with stage III or IV tumors stained significantly higher (mean 28. 7%) than the tumors of patients with stage I or II disease (mean 8. 36%) (P < 0.001). The tumors of patients with disease which could be optimally cytoreduced stained significantly lower (mean 23.0%) than the tumors of patients whose disease was unable to be optimally cytoreduced (mean 28.6%) (P = 0.041). Utilizing survival as the endpoint for multivariate analysis, FIGO stage (P = 0.006), p53 expression (P = 0.046), and the level of cytoreduction (P < 0.001) were independent prognostic indicators.

CONCLUSION

Image analysis allows quantitative measurements of p53 staining. p53 staining is significantly higher in advanced-stage, high-grade tumors which are unable to be cytoreduced than in early-stage, low-grade tumors which can be optimally cytoreduced. p53 expression is an independent prognostic indicator of survival in patients with epithelial ovarian carcinomas.