Effectiveness of aromatase inhibitors in the treatment of advanced endometrial adenocarcinoma

Targeting the NRF2/KEAP1 pathway in cervical and endometrial cancers

Cervical and endometrial cancers are among the most dangerous gynaecological malignancies, with high fatality and recurrence rates due to frequent diagnosis at an advanced stage and chemoresistance onset. The NRF2/KEAP1 signalling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. NRF2, activated by ROS, induces the expression of antioxidant enzymes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase which neutralize ROS, protecting cells against oxidative stress damage. However, activation of NRF2/KEAP1 signalling in cancer cells results in chemoresistance, inactivating drug-mediated oxidative stress and protecting cancer cells from drug-induced cell death. We review the literature on the role of the NRF2/KEAP1 pathway in cervical and endometrial cancers, with a focus on the expression of its components and downstream genes. We also examine the role of the NRF2/KEAP1 pathway in chemotherapy resistance and how this pathway can be modulated by natural and synthetic modulators.

Contemporary Use of Hormonal Therapy in Endometrial Cancer: a Literature Review

OPINION STATEMENT

Most endometrial cancers are estrogen receptor and progesterone receptor positive. Hormonal therapy in endometrial cancer is best used in patients with low-grade disease and hormone receptor positivity. Though not standard of care, hormonal treatment can be considered in endometrial cancer treatment in both the early-stage upfront setting for patients who are not surgical candidates and in advanced and recurrent endometrial cancer. In patients who desire fertility preservation or who are not surgical candidates, levonorgestrel intrauterine device and oral progesterone are preferred treatment options. In patients with advanced and metastatic disease, there is no standard-of-care second-line treatment, and hormonal treatment is a widely accepted option for low-grade disease. Beyond progesterone, selective estrogen receptor modulators, aromatase inhibitors, gonadotropin-releasing hormone agonists, and fulvestrant are hormonal treatment options. New therapies, such as MTOR inhibitors and CDK 4/6 inhibitors, have been extensively studied in breast cancer and are shown to be useful in conjunction with hormonal therapies particularly when there is suspected resistance to anti-estrogen treatment. Hormonal therapies also tend to be better tolerated than chemotherapy agents, making them a desirable option particularly in patients with lower performance status. Results from ongoing clinical trials will hopefully help shed light on the use of combination treatment in patients with hormone receptor-positive, low-grade metastatic, and recurrent endometrial cancer.

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.

Phase 2 study of anastrozole in recurrent estrogen (ER)/progesterone (PR) positive endometrial cancer: The PARAGON trial - ANZGOG 0903

BACKGROUND

The clinical benefit rate with aromatase inhibitors and the impact of treatment on quality of life (QOL) in endometrial cancer is unclear. We report the results of a phase 2 trial of anastrozole in endometrial cancer.

METHODS

Investigator initiated single-arm, open label trial of anastrozole, 1 mg/d in patients with ER and/or PR positive hormonal therapy naive metastatic endometrial cancer. Patients were treated until progressive disease (PD) or unacceptable toxicity. The primary end-point was clinical benefit (response + stable disease) at 3 months. Secondary endpoints include progression-free survival (PFS), quality of life (QOL) and toxicity.

RESULTS

Clinical benefit rate in 82 evaluable patients at 3 months was 44% (95% CI: 34-55%) with a best response by RECIST of partial response in 6 pts. (7%; 95% CI: 3-15%). The median PFS was 3.2 months (95% CI: 2.8-5.4). Median duration of clinical benefit was 5.6 months (95% CI: 3.0-13.7). Treatment was well tolerated. Patients who had clinical benefit at 3 months reported clinically significant improvements in several QOL domains compared to those with PD; this was evident by 2 months including improvements in: emotional functioning (39 vs 6%: p = 0.002), cognitive functioning (45 vs 19%: p = 0.021), fatigue (47 vs 19%: p = 0.015) and global health status (42 vs 9%: p = 0.003).

CONCLUSION

Although the objective response rate to anastrozole was relatively low, clinical benefit was observed in 44% of patients with ER/PR positive metastatic endometrial cancer and associated with an improvement in QOL.

Anti-estrogen Treatment in Endometrial Cancer: A Systematic Review

Introduction: Hormonal therapy in endometrial cancer (EC) is used for patients who wish to preserve fertility and for patients with advanced or recurrent disease in a palliative setting. First line hormonal therapy consists of treatment with progestins, which has a response rate of 25% in an unselected population. Treatment with anti-estrogens is an alternative hormonal therapy option, but there is limited data on the effect and side-effects of anti-estrogens in EC. Therefore, we performed a systematic review to investigate the response rate and toxicity of anti-estrogenic therapy in patients with endometrial cancer.

Methods: A systematic search in electronic databases was performed to identify studies on selective estrogen receptor modulators (SERM) and down-regulators (SERD) and aromatase inhibitors that reported on response rates (RR) among EC patients. Outcome in estrogen receptor (ER) positive and negative disease was assessed independently.

Results: Sixteen studies on advanced stage and recurrent EC were included. Ten studies investigated anti-estrogen monotherapy and seven investigated a combination of anti-estrogenic drugs with either progestin or targeted treatment. Due to heterogeneity in patient population, no meta-analysis was performed. The median age of the patients in the included studies ranged from 61 to 71 years and the proportion of low grade tumors ranged from 38 to 80%. The RR for tamoxifen ranged from 10 to 53%, for other SERMs and SERDs 9–31%, for aromatase inhibitors from 8 to 9%, for combined tamoxifen/progestin treatment 19–58%, for combined chemo- and hormonal therapy 43% and for combination of anti-estrogenic treatment with mammalian target of rapamycin (mTOR) inhibitors 14–31%. Toxicity consisted mainly of nausea and thrombotic events and was higher in combination therapy of chemotherapy and hormonal therapy and hormonal therapy and mTOR inhibitors compared to other therapies.

Conclusion: Tamoxifen or a combination of tamoxifen and progestin should be the preferred choice when selecting second line hormonal treatment because the RRs are similar to first line progestin treatment and the toxicity is low. The response can be optimized by selecting patients with endometrioid tumors and positive estrogen receptor status, which should be based on a pretreatment biopsy.

SULFATION PATHWAYS: Insights into steroid sulfation and desulfation pathways

Sulfation and desulfation pathways represent highly dynamic ways of shuttling, repressing and re-activating steroid hormones, thus controlling their immense biological potency at the very heart of endocrinology. This theme currently experiences growing research interest from various sides, including, but not limited to, novel insights about phospho-adenosine-5'-phosphosulfate synthase and sulfotransferase function and regulation, novel analytics for steroid conjugate detection and quantification. Within this review, we will also define how sulfation pathways are ripe for drug development strategies, which have translational potential to treat a number of conditions, including chronic inflammatory diseases and steroid-dependent cancers.

Pir2/Rnf144b is a potential endometrial cancer biomarker that promotes cell proliferation

Endometrial cancer is one of the most common gynaecological cancers in developed countries. Its incidence has increased 20% over the last decade and the death rate has increased >100% over the past two decades. Current models for prediction of prognosis and treatment response are suboptimal, and as such biomarkers to support clinical decision-making and contribute to individualised treatment are needed. In this study, we show that the E3-ubiquitin ligase PIR2/RNF144B is a potential targetable biomarker in endometrial cancer. At transcript level, it is expressed both in normal endometrium and tumour samples, but at protein level, it is expressed in tumours only. By using endometrial cancer cell lines, we demonstrated that PIR2/RNF144B is stabilised via phosphorylation downstream of GSK3β and this is necessary for the proliferation of endometrial cancer cells, in the absence of oestrogenic growth stimuli. Here, inactivation of GSK3β activity is associated with loss of PIR2/RNF144B protein and consequent inhibition of cell proliferation. Our results, therefore, substantiate PIR2/RNF144B as a novel candidate for targeted therapy in 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.

The Importance of Steroid Uptake and Intracrine Action in Endometrial and Ovarian Cancers

Endometrial and ovarian cancers predominately affect women after menopause, and are more frequently observed in developed countries. These are considered to be hormone-dependent cancers, as steroid hormones, and estrogens in particular, have roles in their onset and progression. After the production of estrogens in the ovary has ceased, estrogen synthesis occurs in peripheral tissues. This depends on the cellular uptake of estrone-sulfate and dehydroepiandrosterone-sulfate, as the most important steroid precursors in the plasma of postmenopausal women. The uptake through transporter proteins, such as those of the organic anion-transporting polypeptide (OATP) and organic anion-transporter (OAT) families, is followed by the synthesis and action of estradiol E2. Here, we provide an overview of the current understanding of this intracrine action of steroid hormones, which depends on the availability of the steroid precursors and transmembrane transporters for precursor uptake, along with the enzymes for the synthesis of E2. The data is also provided relating to the selected transmembrane transporters from the OATP, OAT, SLC51, and ABC-transporter families, and the enzymes involved in the E2-generating pathways in cancers of the endometrium and ovary. Finally, we discuss these transporters and enzymes as potential drug targets.

The role of fulvestrant in endometrial cancer

INTRODUCTION

Endometrial cancer is the most common malignancy of the female genital tract in industrialized countries. The traditional treatment of endometrial cancer is based on a surgical approach. In recent years, systemic endocrine therapy has demonstrated good efficacy in recurrent or metastatic setting, delaying progression, ameliorating quality of life and palliating symptoms. Areas covered: Phase I and II studies on selective estrogen receptor down-regulators used for the treatment of endometrial cancer treatment have been reviewed. The pharmacokinetic and pharmacodynamic features of selective receptor down-regulators have been also investigated. Expert opinion: Selective estrogen receptor down-regulators may exhibit clinical efficacy in the treatment of gynecological malignancies due to their pure estrogen receptor antagonist properties. However, up to now data are still limited and some unsolved questions remain. Fulvestrant has poor oral bioavailability and low pharmacodynamic characteristics. Further trials are required to examine new selective estrogen receptor down-regulator agents with better pharmacodynamic and pharmacokinetic profiles.