The therapeutic significance of aromatase inhibitors in endometrial carcinoma

Roles of estrogen receptor α in endometrial carcinoma (Review)

Endometrial carcinoma (EC) is a group of endometrial epithelial malignancies, most of which are adenocarcinomas and occur in perimenopausal and postmenopausal women. It is one of the most common carcinomas of the female reproductive system. It has been shown that the occurrence and development of EC is closely associated with the interaction between estrogen (estradiol, E2) and estrogen receptors (ERs), particularly ERα. As a key nuclear transcription factor, ERα is a carcinogenic factor in EC. Its interactions with upstream and downstream effectors and co-regulators have important implications for the proliferation, metastasis, invasion and inhibition of apoptosis of EC. In the present review, the structure of ERα and the regulation of ERα in multiple dimensions are described. In addition, the classical E2/ERα signaling pathway and the crosstalk between ERα and other EC regulators are elucidated, as well as the therapeutic targeting of ERα, which may provide a new direction for clinical applications of ERα in the future.

Cytotoxic effect of 13α-estrane derivatives on breast, endometrial and ovarian cancer cell lines

Hormone-dependent cancers such as breast, uterine, and ovarian cancers account for more than 35% of all cancers in women. Worldwide, these cancers occur in more than 2.7 million women/year and account for 22% of cancer-related deaths/year. The generally accepted mechanism for the pathophysiology of estrogen-dependent cancers is estrogen receptor-mediated cell proliferation associated with an increased number of mutations. Therefore, drugs that can interfere with either local estrogen formation or estrogen action via estrogen receptors are needed. Estrane derivatives that have low or minimal estrogenic activity can affect both pathways. In this study, we investigated the effect of 36 different estrane derivatives on the proliferation of eight breast, endometrial, and ovarian cancer cell lines and the corresponding three control cell lines. Estrane derivatives 3 and 4_2Cl showed a stronger effect on the endometrial cancer cell lines KLE and Ishikawa, respectively, compared with the control cell line HIEEC, with IC50 values of 32.6 microM and 17.9 microM, respectively. Estrane derivative 4_2Cl was most active in the ovarian cancer cell line COV362 compared to the control cell line HIO80 with an IC50 value of 3.6 microM. In addition, estrane derivative 2_4I showed a strong antiproliferative effect on endometrial and ovarian cancer cell lines, while the effect on the control cell line was slight or absent. The addition of halogen at carbon 2 and/or 4 in estrane derivatives 1 and 2 increased the selectivity for endometrial cancer cells. Overall, these results suggest that single estrane derivatives are efficient cytotoxic agents for endometrial and ovarian cancer cell lines, and thus potential lead compounds for drug development.

New Insights into Hormonal Therapies in Uterine Sarcomas

Simple Summary

Uterine sarcomas are rare mesenchymal malignant cancers, and surgery represents the mainstay of treatment for early-stage disease. In metastatic setting, uterine sarcomas’ treatment includes palliative surgery, a metastases resection, chemotherapy and targeted therapy. Hormonal therapies may also represent an effective option. Frequently, ER and PR are highly expressed in uterine sarcomas patients and they represent a favourable prognostic factor associated with improved overall survival. The scope of the present review is to report the existing evidence and future perspectives on hormonal therapy in uterine sarcomas, with a special focus on aromatase inhibitors, progestins and gonadotropin-releasing hormone analogues, in order to clarify their potential role in daily clinical practice.

Abstract

Uterine sarcoma (US) is a rare mesenchymal malignant cancer type, accounting for 3–7% of uterine malignancies. US prognosis is still poor due to high local and distant recurrence rates. As for molecular features, US may present variable oestrogen receptor (ER) and progesterone receptor (PR) expressions, mostly depending on histotype and grading. Surgery represents the mainstay of treatment for early-stage disease, while the role of adjuvant chemotherapy or local radiotherapy is still debated and defined on the basis of histotype, tumour grading and stage. In metastatic setting, uterine sarcomas’ treatment includes palliative surgery, a metastases resection, chemotherapy, hormonal therapy and targeted therapy. As for the chemotherapy regimen used, drugs that are considered most effective are doxorubicin (combined with ifosfamide or alone), gemcitabine combined with docetaxel and, more recently, trabectedin or pazopanib. Hormonal therapies, including aromatase inhibitors (AIs), progestins and gonadotropin-releasing hormone analogues (GnRH-a) may also represent an effective option, in particular for low-grade endometrial stromal sarcoma (LGESS), due to their favourable toxicity profile and patients’ compliance, while their role is still under investigation in uterine leiomyosarcoma (uLMS), high-grade endometrial stromal sarcoma (HGESS), undifferentiated uterine sarcoma (USS) and other rarer US. The present review aims to analyse the existing evidence and future perspectives on hormonal therapies in US, in order to clarify their potential role in daily clinical practice.

Spiraeoside extracted from red onion skin ameliorates apoptosis and exerts potent antitumor, antioxidant and enzyme inhibitory effects

Red onion skin waste (ROSW) was analyzed for extraction of naturally occurring 4'-O-glucoside of quercetin, spiraeoside (SPI) with promising biological activities. Reversed-phase high-performance liquid chromatography was used to determine the SPI content in three different solvent extracts of ROSW: water (12.2 mg/g), methanol (27.6 mg/g), and ethanol (32.5 mg/g). The ethanol extract and SPI showed significant radical-scavenging and anti-inflammatory activities. In addition, the anti-cancer effects of SPI on a HeLa cells was investigated. The results indicated that SPI treatment significantly inhibited cell growth, and the dose of 50 μg/mL exhibited the highest anti-cancer activity. SPI inhibited the expression of B-cell lymphoma 2 and BH3-interacting domain-death agonist and promoted apoptosis by activating caspase-9/-3 expression. Notably, SPI inhibited the expression of mu-2-related death-inducing gene, a molecule involved in death receptor-mediated apoptotic signaling. Cyclin-dependent kinase 2-cyclin-E expression was also inhibited after SPI treatment, particularly at the G₂/M checkpoint. Our findings provide novel insights into the apoptotic potential with promising anticancer and enzyme inhibitory effects of ROSW SPI.

A review on diverse heterocyclic compounds as the privileged scaffolds in non-steroidal aromatase inhibitors

Breast cancer, emerging malignancy is common among women due to overexpression of estrogen. Estrogens are biosynthesized from androgens by aromatase, a cytochrome P450 enzyme complex, and play a pivotal role in stimulating cell proliferation. Therefore, deprivation of estrogen by blocking aromatase is considered as the effective way for the inhibition and treatment of breast cancer. In recent years, various non-steroidal heterocyclic functionalities have been extensively developed and studied for their aromatase inhibition activity. This review provides information about the structural-activity relationship of heterocycles (Type II) towards aromatase. This aids the medicinal chemist around the significance of different heterocyclic moieties and helps to design potent aromatase inhibitors.

Palliative treatment of endometrial cancer: what is the role of anastrozole in elderly women?

Background

Type I endometrial cancer is the most common gynaecological tumour in developed countries and its incidence is increasing also because of population aging. The aim of this work is to test the feasibility and safety of anastrozole as palliative treatment of endometrial cancer in elderly women ineligible for standard surgical treatment.

Methods

Patients with histological diagnosis of type I endometrial cancer not suitable for surgical treatment were enrolled in this pilot study. Anastrozole was administered 1 mg daily orally after performing an accurate clinical and radiological staging. Validated questionnaire and self-reported outcomes were used to evaluate quality of life and compliance during the study period.

Results

Eight patients with a mean age of 85 (range 80–88 years) were enrolled. All patients had endometrial cancer confined to the uterus, and none progression of disease was observed during the study period. A partial response to the therapy was reported in seven patients, while one patient had stable disease. Tumour symptoms improvement such as pain, vaginal bleeding and vaginal discomfort was reported. The endometrial thickness after twelve months has showed a reduction of 9.25 ± 4.77 mm. The average follow-up time was 18.25 months. Four women died for non oncological reasons, none death related to endometrial cancer was reported. Evaluation of symptoms showed a significant reduction of appetite loss and insomnia, while a significant increase of global health status and fatigue was reported.

Conclusions

Our preliminary data suggested that the palliative use of anastrozole may be a suitable therapy for the proper management of early stages endometrial cancer in elderly women not suitable for surgical treatment with good compliance and tolerance.

Trial registration

2013000840. Date of registration: 21/09/2013. URL: trials.sanmatteo.loc.

Artesunate Suppresses the Proliferation and Development of Estrogen Receptor-α-Positive Endometrial Cancer in HAND2-Dependent Pathway

Endometrial cancer (EC) is a common leading cause of cancer-related death in women, which is associated with the increased level of estrogen in the body. Artesunate (ART), an active compound derived from Artemisia annua L., exerted antitumor properties in several cancer types. However, the role of artesunate and the molecular basis on EC remains unclear. Here, we aimed to explore the effects and mechanisms of artesunate. Our results identified that estrogen receptor-α (ER-α) was a key factor for the type I EC (ER-α-positive), which might suppress the downstream LKB1/AMPK/mTOR pathway. Besides, we found ART significantly inhibited tumor proliferation in a dose-dependent manner. Mechanistic studies identified that ART led to tumor cell apoptosis and cell cycle arrest by downregulating the ER-α expression and activating the LKB1/AMPK/mTOR pathway. In addition, we found ART could increase the expression of heart and neural crest derivatives expressed 2 (HAND2) in the ER-α-positive EC cells, which could interact with ER-α. Through the gain-and loss-function experiments, we showed that over expression of HAND2 repressed the proliferation and migration of ER-α-positive EC cells via inhibition of ER-α expression. HAND2 knockdown increased ER-α expression and alleviated the antitumor effect of ART in vitro and in vivo. Overall, our study first showed that ART could be an effective antitumor agent through modulating ER-α-mediated LKB1/AMPK/mTOR pathway in the HAND2 dependent manner. Our findings provide an effective therapeutic agent for ER-α-positive EC treatment.

Endometrial Cancer: When Upfront Surgery Is Not an Option

Background and Summary: The management of endometrial cancer, in an ever-older population with considerable comorbidity, remains a challenge for gynecological and radiation oncologists. Key Message: The present paper reviews literature data on treatment options for endometrial cancer patients unfit for surgery.

High serum Androgen and Insulin concentrations increase the tendency of Endometrial Carcinoma

Purpose: The objective of the study was to evaluate the important role played by androgen and insulin in the development of endometrial carcinoma (EC), and their combined effect on EC risk.

Methods: We enrolled 510 type I EC patients and 510 age-, time-, and nationality-matched subjects into this study. Metabolic and hormonal parameters of enrolled subjects were examined. Univariate and multivariate logistic regression analyses for EC and control subjects were performed. Type I EC risk was evaluated with respect to testosterone, androstenedione, and insulin levels based on odds ratios (ORs) using stratified data.

Results: EC risk was positively associated with C-peptide, estrone, androgen (including testosterone and androstenedione) and insulin levels, BMI, WHR, family history of cancer, nulliparity, irregular menstruation, diabetes, and hypertension. In multivariate logistic regression models, high C-peptide and testosterone levels, diabetes, and hypertension were independent risk factors after adjustment for BMI, WHR, family history of cancer, high serum insulin, and estrone levels. Increased serum total testosterone and insulin levels were positively correlated with EC risk in total, premenopausal, and postmenopausal women. Androstenedione was correlated with EC in total and postmenopausal, but not in premenopausal subjects. Compared with higher testosterone and insulin, odds ratios (ORs) for higher testosterone with lower insulin and lower testosterone with higher insulin were decreased in total, premenopausal, and postmenopausal women. Similarly, compared to both higher FAI and insulin, ORs for higher FAI with lower insulin and lower FAI with higher insulin were decreased in all three groups. Coordinately, ORs for higher androstenedione with lower insulin and lower androstenedione with higher insulin were decreased in total and postmenopausal, but not premenopausal subjects.

Conclusions: These findings suggested that androgen and insulin were risk factors of type I EC, and relatively high levels of both testosterone and insulin synergistically affected EC risk.

Aromatase Inhibitors as Adjuvant Treatment for ER/PgR Positive Stage I Endometrial Carcinoma: A Retrospective Cohort Study

OBJECTIVE

Although endometrial cancer (EC) is a hormone dependent neoplasm, there are no recommendations for the determination of steroid hormone receptors in the tumor tissue and no hormone therapy has ever been assessed in the adjuvant setting. The purpose of this study was to explore the effect of adjuvant aromatase inhibitors (AIs) on progression-free survival (PFS) and overall survival (OS) in patients with early stage and steroid receptors-positive EC.

METHODS

We retrospectively analyzed clinical and pathological factors in 73 patients with high-risk (49.3%) or low-risk (50.7%) stage I (n = 71) or II (n = 2) endometrial cancer who received by their preference after counseling either no treatment (reference group) or AI. Prognostic factors were well balanced between groups. Expression of estrogen receptor (ER), progesterone receptor (PgR), and Ki-67 index was correlated with clinical outcomes.

RESULTS

Univariate and multivariate Cox proportional regression analyses, adjusted for age, grade, stage, depth of myometrial invasion, lymphovascular space invasion, BMI, ER, PgR and Ki-67 labeling index levels, showed that PFS and OS had a trend to be longer in patients receiving AI than in the reference group HR= 0.23 (95% CI; 0.04-1.27) for PFS and HR= 0.11 (95% CI; 0.01-1.36) for OS.

CONCLUSION

Compared with no treatment, AI exhibited a trend toward a benefit on PFS and OS in patients with early stage hormone receptor-positive EC. Given the exploratory nature of our study, randomized clinical trials for ER/PgR positive EC patients are warranted to assess the clinical benefit of AI and the potential predictive role of steroid receptors and Ki-67.

Local estrogen metabolism (intracrinology) in endometrial cancer: A systematic review

Endometrial cancer (EC) is the most common malignancy of the female gynaecological tract and increased exposure to estrogens is a risk factor. EC cells are able to produce estrogens locally using precursors like, among others, adrenal steroids present in the serum. This is referred to as local estrogen metabolism (or intracrinology) and consists of a complex network of multiple enzymes. Particular relevant to the final generation of active estrogens in endometrial cells are: steroid sulfatase (STS), estrogen sulfotransferase (SULT1E1), aromatase (CYP19A1), 17β-hydroxysteroid dehydrogenase (HSD17B) type 1 and type 2. During the last decades, a plethora of studies explored the level of these enzymes in EC but contrasting data were reported, which generated vigorous debate and controversies. Several reviews attempted at clarifying some of the debated issues, but published reviews are based on investigator-defined bibliography selection and not on systematic analysis. Therefore, we performed a systematic review of the literature reporting about the level of STS, SULT1E1, CYP19A1, HSD17B1 and HSD17B2 in EC. Additional intracrine enzymes and networks (e.g., HSD17Bs other than types 1 and 2, aldo-keto reductases, progesterone and androgen metabolism) were non-systematically reviewed as well.

Hormonal therapy in uterine sarcomas

Uterine sarcomas (USs) are a group of rare but aggressive uterine malignancies, accounting for only 1% of the malignant tumors of female reproductive organs. Due to the high rate of recurrence and metastasis, the prognosis of USs is poor. Given the high mortality rate and limited clinical benefit of surgery and adjuvant chemoradiotherapy, hormonal therapy has shown good prospects in recent years. Hormonal agents include progestins, aromatase inhibitors (AIs), and gonadotropin‐releasing hormone analogue (GnRH‐a). According to the literature, hormonal therapy has been confirmed effective for recurrent, metastatic or unresectable low‐grade endometrial stromal sarcoma (LGESS) and hormone receptor positive (ER+/PR+) uterine leiomyosarcoma (uLMS) with favorable tolerance and compliance. Besides, hormonal therapy can also be used in patients with early‐staged disease who desire to preserve fertility. However, due to the rarity of USs, the rationale of hormonal therapy is generally extrapolated from data of hormone‐sensitive breast cancer, and present studies of hormonal therapy in USs were almost limited to case reports and small‐sized retrospective studies. Therefore, further systematic researches and standardized clinical trials are needed to establish the optimal hormonal therapy regimen of USs. Herein, we reviewed the existing studies related to the hormonal therapy in USs in order to provide reference for clinical management in specific settings.

A pilot study of gonadotropin-releasing hormone agonist combined with aromatase inhibitor as fertility-sparing treatment in obese patients with endometrial cancer

Objective

This study aims to evaluate the effects and pregnancy outcomes of gonadotropin-releasing hormone agonist (GnRH agonist) combined with aromatase inhibitor (AI) in preserving the fertility of obese women with grade 1 endometrial cancer (EC).

Methods

This study recruited obese EC patients who wished to preserve their fertility. The treatment regimen consisted of intramuscular GnRH agonist 3.75 mg every 4 weeks and oral AI 2.5 mg daily. The maintenance regimen was the same as the initial treatment regimen. Primary outcomes included response rate, time to complete response (CR), and time to recurrence; pregnancy outcomes included the time to pregnancy, pregnancy rate and live birth rate.

Results

Six obese patients with EC were included in this study, with the age (mean±standard deviation [SD]) of 30.5±3.3 years and body mass index (mean±SD) of 35.0±1.4 kg/m². CR rate was 100%, and time to CR was 3–6 months. None of the patients had recurrence after a median follow-up of 4.0 years (range, 1.3–7.0 years). The most common side effects were menopause-like symptoms. Among these patients, no weight gain was observed during treatment. The pregnancy rate and live birth rate was 50.0% and 75.0%, respectively, with a median time to pregnancy of 2.4 years (range, 1.0–5.5 years).

Conclusion

The combination of GnRH agonist and AI demonstrated promising long-term effect in young obese EC patients who wished to preserve their fertility. No weight gain side effects were observed. Further studies with a larger sample size are needed to fully evaluate this novel treatment regimen.

Efp promotes in vitro and in vivo growth of endometrial cancer cells along with the activation of nuclear factor-κB signaling

Endometrial cancer is common among postmenopausal women and its incidence is increasing in developed countries. Considering that >80% of endometrial cancers are assumed to be estrogen-related, higher estrogen exposure will be relevant to tumorigenesis. Therefore, the roles of estrogen target genes will be important to understand the pathophysiological mechanisms. We previously revealed that estrogen-responsive RING finger protein Efp contributes to breast cancer progression through the protein degradation of cell cycle checkpoint 14-3-3σ. We and others also proposed that Efp has tumor-promoting activities in estrogen receptor (ER)-negative cancer cells. In addition, Efp plays a role in type I interferon production by activating antiviral signaling, which provokes nuclear factor-κB (NF-κB) signaling. In the present study, we investigate whether Efp plays a critical role in endometrial cancer biology. We show that siRNA-mediated Efp knockdown represses the proliferation and migration of endometrial cancer ER-positive Ishikawa and ER-negative HEC-1A cells. Efp knockdown increases 14-3-3σ protein levels and decreases the rates proliferative stage cells. Efp siRNA significantly inhibits the in vivo tumor growth of endometrial cancer cells in both subcutaneous and orthotopic xenograft models. Intriguingly, Efp knockdown represses NF-κB-dependent transactivation and transcription of target genes, such as IL6ST and IL18, in endometrial cancer cells. Overall, Efp would exert a tumor-promoting role through modulating NF-κB pathway and 14-3-3σ protein degradation in endometrial cancer regardless of its estrogen receptor status. Our results indicate that Efp could be a potential diagnostic and therapeutic target for endometrial cancer.

Preliminary clinical application of an aromatase inhibitor and a gonadotropin-releasing hormone agonist combination for inoperable endometrial cancer patients with comorbidities: case report and literature review

Background: Endometrial cancer (EC) occurs most commonly after menopause. A proportion of patients present with advanced age and comorbidities, and become ineligible for surgery. The optimal treatment strategy of these patients remains a clinical challenge. Aromatase inhibitor (AI) combined with Gonadotropin-releasing hormone agonist (GnRH-a) possesses profound effect in suppressing the estrogen level, has become a valid treatment in the breast cancer. However, the combined use of an AI and a GnRH-a in EC has rarely been studied. Case presentation: Herein, we report the combination of an AI and a GnRH-a in the treatment of three patients with advanced age or comorbidities who were ineligible for surgery. The disease remained stable for two years in patients who received the combination treatment as an initial approach without any adverse effects. Moreover, an AI combined with a GnRH-a also effective as salvage treatment of recurrent patients. Further, we provide a brief review of the literature. Conclusion: The combination of an AI and a GnRH-a presents satisfactory therapeutic effect and provides an optimal option for inoperable EC patients.

A Phase 2, Randomized, Open-Label Study of Irosustat Versus Megestrol Acetate in Advanced Endometrial Cancer

OBJECTIVE

Advanced/metastatic or recurrent endometrial cancer has a poor prognosis. Malignant endometrial tissue has high steroid sulphatase (STS) activity. The aim of this study was to evaluate STS as a therapeutic target in patients with endometrial cancer.

METHODS

This was a phase 2, multicenter, international, open-label, randomized (1:1), 2-arm study of the STS inhibitor oral irosustat 40 mg/d versus oral megestrol acetate 160 mg/d in women with advanced/metastatic or recurrent estrogen receptor-positive endometrial cancer. The primary end point was the proportion of patients without progression or death 6 months after start of treatment. Secondary end points included progression-free survival, time to progression, overall survival, and safety.

RESULTS

Seventy-one patients were treated (36 with irosustat, 35 with megestrol acetate). The study was prematurely stopped after futility analysis. Overall, 36.1% and 54.1% of patients receiving irosustat or megestrol acetate had not progressed or died at 6 months, respectively. There were no statistically significant differences between irosustat and megestrol acetate in response and overall survival rates. Irosustat patients had a median progression-free survival of 16 weeks (90% confidence interval, 9.0-31.4) versus 40 weeks (90% confidence interval, 16.3-64.0) in megestrol acetate patients. Treatment-related adverse events occurred in 20 (55.6%) and 13 (37.1%) patients receiving irosustat or megestrol, respectively. Most adverse events in both groups were grade 1 or 2.

CONCLUSIONS

Although irosustat monotherapy did not attain a level of activity sufficient for further development in patients with advanced/recurrent endometrial cancer, this study confirms the activity of hormonal treatment (megestrol acetate) for this indication.

Endometrial cancer risk in postmenopausal breast cancer patients treated with tamoxifen or aromatase inhibitors

INTRODUCTION

The gynaecological toxicity profile of tamoxifen presents a significant burden to the patients and oncologist as tamoxifen-related side effects result in additional investigations, procedures and referrals. Aromatase inhibitor have been shown to result in significant reduction in gynaecological problems, possibly including endometrial cancer. Areas covered: We reviewed the main breast cancer trials, observation or cohort studies investigating tamoxifen or an aromatase inhibitor to report on endometrial adverse events and cancer. Expert commentary: Evidence for an increase in endometrial cancers with tamoxifen in breast cancer treated patients is now very clear. Aromatase inhibitors have shown to have a beneficial effect on the endometrium. There is an important need for further studies to clearly determine the influence of aromatase inhibitors on the endometrial in tamoxifen-naïve women. The effect of aromatase inhibitors on gynaecological problems may have potentially a very important impact in clinical practice.

Testosterone Aromatization to Estradiol in Course of Ovarian Functioning Brenner Tumor Associated With Endometrial Carcinoma and Endometriosis (Roncati-Manenti Triad)

OBJECTIVE

Aromatization is the biochemical process in which aromatase catalyzes the conversion of testosterone into estradiol, the fundamental pathway for the synthesis of estrogens. When enhanced, it can lead to hyperestrogenism, a well-known risk factor for gynecological cancers.

METHODS

The surgical specimens, coming from 2 postmenopausal women with hyperestrogenism on pap smear and bioptic diagnosis of endometrial endometrioid carcinoma, were fixed in 10% neutral buffered formalin, paraffin embedded, and then submitted for routine hematoxylin/eosin staining and immunohistochemical characterization for antiestrogen, antiprogesterone, antitesterone, anti-MLH1, anti-PMS2, anti-MSH2, and anti-MSH6.

RESULTS

The presence of an undescribed triad represented by ovarian functioning Brenner tumor, endometrial carcinoma, and pelvic endometriosis has been ascertained. The immunohistochemical investigation proved a normal expression of the DNA mismatch repair proteins and revealed a bimodal hormonal status in the pathological tissues, that is, the Brenner tumor cells showed a high expression of testosterone, contrariwise endometrioid carcinoma and endometriosis a high estrogen and progesterone immunolabeling.

CONCLUSIONS

This synchronous triad underlines the importance of aromatization and hyperestrogenism in the development of gynecological malignancies in which the immunohistochemical detection of an active source of hormone production - to always keep in consideration during synchronous diseases - can guide subsequent antihormone chemotherapy based on aromatase inhibitors.

Effectiveness of aromatase inhibitors in the treatment of advanced endometrial adenocarcinoma

PURPOSE

Type I endometrial cancer is a common tumor of the female genital tract. Since in post-menopausal women aromatase enzyme can stimulate the endometrial tissue neoplastic growth, the use of aromatase inhibitors may have a therapeutic effect, especially in patients not eligible for surgery.

METHODS

A systematic review has been performed, with a very specific scope, i.e., the use of aromatase inhibitors in the treatment of advanced or recurrent endometrial cancer, as a single agent or in combination with others drugs.

RESULTS

On the basis of the 117 records retrieved from the bibliographic search, the rationale for the use of aromatase inhibitors in endometrial cancer therapy is discussed. Six papers fall within the scope of our systematic review and their results are thoroughly analyzed. Moreover, we report our experience on the clinical effectiveness of anastrozole in the post-chemotherapy treatment of a patient affected by advanced-stage endometrial cancer.

CONCLUSION

In general, aromatase inhibitors seem to have limited clinical benefit in the treatment of advanced and recurrent endometrial cancer, although further clinical trials are necessary to investigate more in depth their role. In our case, we experienced a positive feedback in terms of control of an advanced-stage disease.

Functional investigation on aromatase in endometrial hyperplasia in polycystic ovary syndrome cases

OBJECTIVE

To explore the possible significance of aromatase P450 in endometrial hyperplasia with a background of polycystic ovary syndrome (PCOS).

METHODS

Immunohistochemistry was used to determine the expression of aromatase P450 in endometrium of PCOS patients. Semiquantitative analysis of aromatase P450 expression of mRNA and protein level wasalso carried out by real-time quantitative RT-PCR method. After endometrial cells were stimulated by testosterone and letrozole in vitro, the estradiol (E2) level was determined, and the expression of cell aromatase P450 mRNA was assessed.

RESULTS

The aromatase P450 mRNA level was increased in endometria of PCOS patients. When endometrial cells were cultured with 10-6 M testosterone, the E2 level in the culture medium increased. An inhibitory effect on E2 generation and expression of aromatase P450 mRNA was observed when the endometrial cells were treated with 10(-5) M letrozole.

CONCLUSIONS

There is an increased expression of aromatase P450 in PCOS patient endometrium. Androgen stimulation could enhance the synthesis of aromatase P450 mRNA and the production of E2 in endometrial cells in vitro while letrozole could do the reverse.

Pharmacological blockade of the aromatase enzyme, but not the androgen receptor, reverses androstenedione-induced cognitive impairments in young surgically menopausal rats

Androstenedione, the main circulating ovarian hormone present after menopause, has been shown to positively correlate with poor spatial memory in an ovary-intact rodent model of follicular depletion, and to impair spatial memory when administered exogenously to surgically menopausal ovariectomized rats. Androstenedione can be converted directly to estrone via the aromatase enzyme, or to testosterone. The current study investigated the hormonal mechanism underlying androstenedione-induced cognitive impairments. Young adult ovariectomized rats were given either androstenedione, androstenedione plus the aromatase inhibitor anastrozole to block conversion to estrone, androstenedione plus the androgen receptor blocker flutamide to block androgen receptor activity, or vehicle treatment, and were then administered a battery of learning and memory maze tasks. Since we have previously shown that estrone administration to ovariectomized rats impaired cognition, we hypothesized that androstenedione's conversion to estrone underlies, in part, its negative cognitive impact. Here, androstenedione administration impaired spatial reference and working memory. Further, androstenedione did not induce memory deficits when co-administered with the aromatase inhibitor, anastrozole, whereas pharmacological blockade of the androgen receptor failed to block the cognitive impairing effects of androstenedione. Anastrozole alone did not impact performance on any cognitive measure. The current data support the tenet that androstenedione impairs memory through its conversion to estrone, rather than via actions on the androgen receptor. Studying the effects of aromatase and estrogen metabolism is critical to elucidating how hormones impact women's health across the lifespan, and results hold important implications for understanding and optimizing the hormone milieu from the many endogenous and exogenous hormone exposures across the lifetime.

Aromatase inhibitors, tamoxifen, and endometrial cancer in breast cancer survivors

BACKGROUND

The risks of both endometrial cancer and postmenopausal breast cancer are increased by obesity and higher endogenous estrogen levels. Although aromatase inhibitors reduce breast cancer incidence, their influence on endometrial cancer is uncertain.

METHODS

The authors investigated this issue in a cohort of 17,064 women who were diagnosed with hormone receptor-positive breast cancer in an integrated group practice health plan. Information on demographics, comorbidities, and the receipt of adjuvant endocrine therapy was available from electronic medical records and pharmacy records, respectively. Endometrial cancer information was obtained from the health plan's Surveillance, Epidemiology, and End Results-affiliated tumor registry, and rates were compared across endocrine therapy groups (aromatase inhibitor, n = 5303; tamoxifen, n = 5155; switchers: both [n = 3787] or none [n = 2819]) using multivariable adjusted Cox proportional-hazards models.

RESULTS

Endometrial cancer incidence was a statistically significant 48% lower in the aromatase inhibitor group versus the tamoxifen group (hazard ratio, 0.52; 95% confidence interval, 0.31-0.87; P = .01). Endometrial cancer incidence was 29% lower in the aromatase inhibitor group versus the no endocrine therapy group (hazard ratio, 0.71; 95% confidence interval, 0.37-1.35; P = .30) and 33% lower in the aromatase inhibitor group versus the tamoxifen group (hazard ratio, 0.67; 95% confidence interval, 0.42-1.06; P = .08), but neither difference was statistically significant. Associations were stronger among those with good drug adherence.

CONCLUSIONS

In a community-based, integrated health plan setting, endometrial cancer incidence was lower in women who were receiving an aromatase inhibitor compared with those who were receiving tamoxifen. In addition, aromatase inhibitors may mitigate the incidence of tamoxifen-associated endometrial cancer. Although there were somewhat fewer endometrial cancers in the aromatase inhibitor group versus the no endocrine therapy group, further studies are needed for the definitive assessment of this potential association.