A significance of immunohistochemical determination of steroid receptors, cell proliferation factor Ki-67 and protein p53 in endometrial carcinoma.

OBJECTIVES

The aim of the study was to preoperatively predict the biologic behavior of the endometrial carcinoma using immunohistochemical analysis of the p53 protein and Ki-67 expression, and estrogen receptor (ER) and progesterone receptor (PR) status, in the material obtained by fractional curettage.

METHODS

One hundred and thirty-six patients with primary endometrial carcinoma were included in the study. In all 136 patients, the fractional curettage was performed before the hysterectomy, and the diagnosis of endometrial carcinoma was confirmed pathohistologically after the surgical procedure on the hysterectomy specimens. The significance of the prognostic factors was assessed using univariate and multivariate analyses. The cutoff values of the percentage of ER, PR, p53, and Ki-67 positive cells in terms of survival probability determination were obtained as the values of the highest chi-square test, using proportional-risk regression method. A multivariate Cox regression analysis was performed to estimate the influence of several clinical, pathohistologic, and immunohistochemical covariates to patients' survival. Survival curves were determined by the Kaplan-Meier product-limit method based on the most recent clinical status.

RESULTS

According to the histologic type of the tumor, fractional curettage specimens revealed 111 histologically favorable types (81.6%) and 25 unfavorable types (18.4%). The data indicate that ER, PR, Ki-67, and p53 levels of the hysterectomy specimens and those of the preoperative specimens were in fairly good agreement. The patients with the most favorable tumor grade (G I) had significantly better prognosis when the percentage of p53 positive cells was less than 15%. In the group of patients with histologic grade II, the survival was affected by ER expression (more than 30% of positive cells) and p53 levels (less than 15% of positive cells). None of the parameters was predictive in the group of patients with histologic grade III.

CONCLUSIONS

We found that determination of immunohistochemical parameters (ER, PR, and p53) on well-differentiated and moderately differentiated endometrial carcinoma of favorable histologic type obtained by curettage enables the recognition of the patients with favorable prognosis, who should not be treated by radical surgery.