Squamous metaplasia in endometrial cancer changing local hormonal tumor profile.

Abstract

e17621 Background: An imbalance of sex hormones in endometrial cancer (EC) towards hyperestrogenism together with progesterone deficiency is considered to stimulate proliferation and suppress endometrial apoptosis. EC with squamous metaplasia is characterized by a more severe clinical course and the lack of an adequate response to standard treatment. The purpose of this study was to analyze the local hormonal profiles of tumors with squamous metaplasia in patients with obesity. Methods: The main group included 20 EC patients with squamous metaplasia, and control group included 35 patients with endometrioid adenocarcinoma: T1-3N0-1M0, mean age 64±3.2 years. Intact endometrial tissues were obtained during surgical treatment of patients with uterine fibroids (n = 20). All patients gave their written informed consent for the study. Levels of estradiol (E2), estrone (E1), testosterone (T), progesterone (P4), estrogen receptors ERα and ERβ, progesterone receptor RP4 and androgen receptors RA were measured by ELISA in samples of tumor and peritumoral (PT) tissues. Statistical processing of results was performed using the Statistica 10. Results: Tumor tissues of patients with EC, regardless of the histological structure, showed higher levels of estrogens and androgens and their receptors, compared with the intact endometrium, without significant changes in levels of progesterone and its receptor. In the main group, compared with the control group, E1 levels in tumors were lower by 1.6 times, E2 by 1.3 times (p < 0.05), but T higher by 2.4 times, ERα by 1.7 times, ERβ by 1.5 times (p < 0.05). PT, compared with the intact endometrium, had lower levels of E1 and E2 by 2 times and 1.5 times, P4 by 5.1 times, and T was lower only in PT with squamous metaplasia by 2.8 times. Levels of all steroid hormone receptors in PT were higher, regardless of the histological type of tumors. In PT of the main group, levels of E1 were 1.3 times lower (p < 0.05) than in controls, P4 – by 2.2 times, T – by 2.8 times, RP4 – by 1.7 times and ERβ by 1.8 times (p < 0.05), but ERα was 3.2 times higher. Conclusions: Tumors with squamous metaplasia, compared with endometrioid adenocarcinoma, are characterized by an imbalance of steroid hormones towards the predominance of androgens, and ERα plays a dominant role among estrogen receptors. The tumor probably synthesizes sex steroids independently and also pumps them over from the surrounding area. At the same time, malignant endometrial tumors, regardless of their histological structure, are more saturated with estrogens, androgens and their receptors, compared with the intact endometrium.