Intratumoral effects of medroxy-progesterone on proliferation, apoptosis, and sex steroid receptors in endometrioid endometrial adenocarcinoma.

OBJECTIVE: The effects of progesterone on proliferation and apoptosis are studied in a scrutinized evaluation of endometrial carcinoma before, during, and after progesterone therapy. The heterogeneity of sex steroid expression as well as proliferation, indicated as Ki-67 index, is considered. METHODS: A total of 29 endometrial carcinomas were studied with in situ evaluation of Ki-67 proliferation marker, estrogen and progesterone receptors (ER and PR), and bcl-2 and p53 immunohistochemistry in the epithelial part of the tumor. In biopsy 1, before the therapy, Ki-67 ER, and PR were studied also in stroma. Apoptotic cells were morphologically identified in hematoxylin- and eosin-stained sections of the tumors and the apoptotic index (apoptotic cells per 1000 cells) was calculated. Chances in feature factors were mainly evaluated by repeated measures ANOVA. RESULTS: Proliferation (Ki-67) was decreased in grade 1 (G1) and grade 2 (G2) tumors during progesterone therapy both in overall evaluation (Ki) and particularly in the areas of maximal proliferation (Ki-max). No change was seen in G3 tumors. A decrease in PR expression in the areas of maximal expression for PR (PR-max) was also observed in G1 and G2 tumors. Apoptosis as well as bcl-2 and ER expression were unchanged during therapy and withdrawal. CONCLUSIONS: The effect of progesterone is seen only on proliferation in low-grade (G1 and G2) tumors. The coexistence of high PR expression in the foci of high proliferation may contribute to the effect in G1 and G2 tumors. No effect of progesterone is seen on apoptosis in tumors of any grade.

Apoptosis, proliferation, and hormone receptors in endometrial carcinoma: results depending on methods of analysis.

Apoptosis and proliferation were studied in 29 endometrial adenocarcinomas of the endometrioid type and characterized by the immunohisto-chemical pattern of estrogen receptor (ER) alpha and progesterone receptor (PR) expression. Intratumoral heterogeneous distribution of both ER and PR as well as of the proliferation marker Ki-67 was studied and quantified. Both density and heterogeneity of the two steroid receptors and Ki-67 varied, depending on the histological malignancy grade (grades 1-3, or G1-3); interestingly, however, the apoptotic index (Ai) was in the same range for all grades. Receptor staining was evaluated by three different methods: i) counting the percentage of stained cells (staining index), according to stereological principles; ii) the mixed method, a combination of the staining index results and ranking staining intensity; and iii) a superficial and rapid visual scoring. The three methods gave equal results. Apoptotic cells and bodies were generally scattered in the endometrial carcinoma but more frequently observed adjacent to necrotic foci. Bcl-2, known as anti-apoptotic factor, showed no correlation to apoptotic index, Ki-67 expression, ER, or PR. Overexpression of p53 was seen in two tumors of grade 3. In a detailed study of intra-tumoral microfoci performed on consecutively taken tissue sections, a higher staining index of both ER and PR was found in the areas of maximal proliferation compared with the areas of minimal proliferation in tumors of grades 1-2, but not in G3 tumors. Other covariations were also found when non-specified areas were studied. The Ki-67 index was both higher and more heterogeneous in G2-3 tumors than in G1 tumors. Our results indicate that there is an increasing discrepancy between cell death and cell proliferation with progressing tumor grade, which may contribute to the differences in tumor aggressivity.

Apoptosis, proliferation, and sex hormone receptors in superficial parts of human endometrium at the end of the secretory phase.

Apoptosis with one regulator, Bcl-2, and proliferation with the marker Ki-67 were studied in 75 endometrial biopsies representing superficial parts of endometrium from 35 regularly menstruating women premenstrually and menstrually. Hormonal withdrawal was studied in serum samples and potentiated in epithelium by the decreasing 17beta-estradiol and progesterone receptor scores 4 days premenstrually. The apoptotic index increased 2 days before the onset of menstruation and peaked on the second menstrual day. The high apoptotic index together with low proliferation in endometrial epithelium at the end of the menstrual cycle are similar to the involution process seen in other hormone-dependent organs. In stroma, the apoptotic index increased later, at the onset of menstruation, and the increase was lower than that in epithelium. The Ki-67 index increased during the last 3 days of the secretory phase, parallel with an increasing progesterone receptor score and decreasing Bcl-2 staining, and peaked at the onset of menstruation. The findings in stroma concur with high proliferation at the end of the menstrual cycle and high cell turnover during menstruation, suggesting the participation of stroma in the renewal process of endometrium.