Endocrine therapy in epithelial ovarian cancer

The prognostic value of MEK pathway-associated estrogen receptor signaling activity for female cancers

BACKGROUND

Other than for breast cancer, endocrine therapy has not been highly effective for gynecologic cancers. Endocrine therapy resistance in estrogen receptor positive gynecologic cancers is still poorly understood. In this retrospective study, we examined the estrogen receptor (ER) signaling pathway activities of breast, ovarian, endometrial, and cervical cancers to identify those that may predict endocrine therapy responsiveness.

METHODS

Clinical and genomic data of women with breast and gynecological cancers were downloaded from cBioPortal for Cancer Genomics. Estrogen receptor alpha (ESR1) expression level and sample-level pathway enrichment scores (EERES) were calculated to classify patients into four groups (low/high ESR1 and low/high EERES). Correlation between ESR1/EERES score and survival was further validated with RNAseq data from low-grade serous ovarian cancer. Pathway analyses were performed among different ESR1/EERES groups to identify genes that correlate with endocrine resistance, which are validated using Cancer Cell Line Encyclopedia gene expression and Genomics of Drug Sensitivity in Cancer data.

RESULTS

We identified a novel combined prognostic value of ESR1 expression and the corresponding estrogen response signaling (EERES score) for breast cancer. The combined prognostic value (ESR1/EERES) may be applicable to other gynecologic cancers. More importantly, we discovered that ER signaling can cross-regulate MEK pathway activation. We identified downstream genes in the MEK pathway (EPHA2, INAVA, MALL, MPZL2, PCDH1, and TNFRSF21) that are potential endocrine therapy response biomarkers.

CONCLUSION

This study demonstrated that targeting both the ER and the ER signaling activity related MEK pathway may aid the development of endocrine therapy strategies for personalized medicine.

Glyceollins from soybean: Their pharmacological effects and biosynthetic pathways

Flavonoids are a highly abundant class of secondary metabolites present in plants. Isoflavonoids, in particular, are primarily synthesized in leguminous plants within the subfamily Papilionoideae. Numerous reports have established the favorable role of isoflavonoids in preventing a range of human diseases. Among the isoflavonoid components, glyceollins are synthesized specifically in soybean plants and have displayed promising effects in mitigating the occurrence and progression of breast and ovarian cancers as well as other diseases. Consequently, glyceollins have become a sought-after natural component for promoting women's health. In recent years, extensive research has focused on investigating the molecular mechanism underlying the preventative properties of glyceollins against various diseases. Substantial progress has also been made toward elucidating the biosynthetic pathway of glyceollins and exploring potential regulatory factors. Herein, we provide a review of the research conducted on glyceollins since their discovery five decades ago (1972-2023). We summarize their pharmacological effects, biosynthetic pathways, and advancements in chemical synthesis to enhance our understanding of the molecular mechanisms of their function and the genes involved in their biosynthetic pathway. Such knowledge may facilitate improved glyceollin synthesis and the creation of health products based on glyceollins.

Hormone Receptors and Epithelial Ovarian Cancer: Recent Advances in Biology and Treatment Options

Epithelial ovarian cancer (EOC) is a significant cause of cancer-related mortality in women. Despite advances in diagnosis and treatment, EOC remains a challenging disease to manage, and the 5-year survival rate is still poor. The role of hormone receptors (HRs) in EOC carcinogenesis and prognosis has been actively explored; however, the role of hormone therapy (HT) in the treatment of these tumors is not well established. Most available data on HT mainly come from retrospective series and small early clinical trials. Several of these studies suggest that HT may have a role in adjuvant, maintenance therapy, or in the case of recurrent disease, especially for some subtypes of EOC (e.g., low-grade serous EOC). Furthermore, HT has recently been combined with targeted therapies, but most studies evaluating these combinations are still ongoing. The main aim of this review is to provide an overview of the progress made in the last decade to characterize the biological and prognostic role of HRs for EOC and the developments in their therapeutic targeting through HT.

Low grade serous ovarian cancer - A rare disease with increasing therapeutic options

High-grade serous ovarian cancers (HGSOCs) most commonly arise from the fimbrial end of the fallopian tube and harbor TP53 gene mutations. In contrast, low-grade serous ovarian cancers (LGSOCs) appear to have different pathological, epidemiological, and clinical features and should be seen as a distinct serous epithelial ovarian cancer subtype. Our current understanding of LGSOC is limited, and treatment has generally been derived from the more common HGSOCs due to a lack of separate trial data. LGSOCs are characterized by slow tumor growth and are assumed to develop from serous borderline ovarian tumors as precursors. These cancers are often estrogen-receptor positive and show an activated mitogen-activated protein kinase pathway together with KRAS and BRAF mutations and, rarely, TP53 mutations. These characteristics are now commonly used to guide therapeutical decision making and, consequently, a substantial part of treatment consists of maintenance with endocrine treatment, thus balancing disease stabilization and mild toxicity. Additionally, new trials are ongoing that examine the role of targeted therapies such as MEK inhibitors in combination with endocrine treatments. The purpose of this work is to summarize current knowledge and present ongoing trial efforts for LGSOCs.

Hormone Receptor Expression in Primary and Recurrent High-Grade Serous Ovarian Cancer and Its Implications in Early Maintenance Treatment

Endocrine therapy is an effective treatment for low-grade serous ovarian cancer. However, the role of estrogen and progesterone receptors as biomarkers for high-grade serous ovarian cancer (HGSOC) is yet to be elucidated because not all estrogen and progesterone receptor-positive tumors benefit from anti-estrogen therapy. The degree of expression is presumed to play a vital role; however, that role is not well-defined in ovarian cancer. We aimed to determine the role of estrogen and progesterone receptor expression in primary and paired relapsed HGSOC. In this study, primary and matched relapsed tumor samples were collected from 80 patients with International Federation of Gynecology and Obstetrics Stage II-IV HGSOC. Tissue microarray was conducted and immunohistochemistry for estrogen and progesterone receptor expression was performed. Two independent pathologists performed the tissue microarray analysis with the Immunoreactive Score and Allred Total score. In the paired analysis, no significant difference in estrogen receptor expression was observed. However, progesterone receptor expression was significantly lower in patients with recurrent platinum-sensitive HGSOC. We conclude that anti-estrogen therapy targeting estrogen receptor positive HGSOC could be administered in primary and relapsed settings. The use of endocrine maintenance with an aromatase inhibitor in patients with estrogen receptor positive HGSOC needs to be further evaluated and validated in a randomized controlled trial.

Therapy for Recurrent High-Grade Epithelial Ovarian Cancer—The Current Status and Future Trends

Ovarian malignancy is the seventh most frequently diagnosed cancer among women. The most common type is epithelial ovarian cancer. Several subtypes with distinct biological and molecular properties exist, and there is inconsistency in availability of and access to different modalities of treatment. The standard first-line management is combining surgery and platinum-based chemotherapy. Most of them are diagnosed at an advanced stage due to which they have poor outcomes. The existing screening tests have a low predictive value. Even with the best available upfront treatment, high rates of recurrences are observed. As a result, there have been major advances in the treatment of recurrences with the development of anti-angiogenic agents and PARP inhibitors. It has led to the improvement in survival and quality of life among the relapsed epithelial ovarian cancers. This review is focused on the management of recurrent epithelial ovarian cancers and future directions based on current evidence. The application of a personalized and structured approach will meaningfully bring changes in the paradigm of care in these groups of patients.

Inhibition of Tumor Microenvironment Cytokine Signaling Sensitizes Ovarian Cancer Cells to Antiestrogen Therapy

Simple Summary

Antiestrogen hormonal therapy is a relatively low side effect, orally administered cancer treatment option, yet response rates have been limited in epithelial ovarian cancer despite estrogen receptor expression in many tumors. This suggests that other pathways impact estrogen response. Cytokine signaling from the tumor microenvironment promotes ovarian cancer growth, and crosstalk between cytokine signaling and estrogen signaling has been reported in other tumor types. We therefore aimed to investigate whether cytokine signaling impacts estrogen signaling in high-grade serous ovarian cancer. We demonstrated crosstalk between these two pathways in patient-derived samples, in vitro and in animal studies. We found that inhibiting interleukin-6/leukemia inhibitory factor (IL6/LIF) cytokine signaling activates estrogen signaling and blocking both pathways was synergistic in inhibiting tumor cell growth. These results suggest a potential role for combination therapy for epithelial ovarian cancer patients.

Abstract

Antiestrogen therapy (AET) is an alternative to cytotoxic chemotherapy for recurrent ovarian cancer, yet the often short duration of response suggests mechanisms of resistance. We previously demonstrated that tumor microenvironment interleukin-6/leukemia inhibitory factor (IL6/LIF) cytokines induce tumor cell JAK-STAT signaling to promote cancer growth. Crosstalk between estrogen signaling and cytokine signaling has been reported. Therefore, we sought to characterize the impact of IL6/LIF signaling on estrogen signaling in epithelial ovarian cancer and investigate the efficacy of combination therapy. We first assessed patient tumors for cytokine expression and compared it with response to AET to determine clinical relevance. In vitro, we determined the effect of IL6/LIF on estrogen receptor expression and signaling. Cell viability assays were used to determine the efficacy and potential synergy of cytokine blockade and AET. We then extended studies to animal models, incorporating patient-derived stromal cells. Our results demonstrated shorter progression-free interval on AET in patients with stromal IL6/LIF expression. In vitro, IL6/LIF increased tumor cell estrogen receptor expression and signaling, and combination cytokine blockade and AET resulted in synergistic inhibition of tumor cell growth. The anticancer effect was verified in a mouse model. In conclusion, due to crosstalk between IL6/LIF cytokine signaling and estrogen signaling, dual blockade is a potential new treatment approach for ovarian cancer.

Traditional Systemic Treatment Options in Advanced Low-Grade Serous Ovarian Cancer after Successful Cytoreduction: A Systematic Review and Meta-Analysis

Simple Summary

Low-Grade Serous Ovarian cancer (LGSOC) is considered less sensitive to traditional chemotherapy than its high-grade counterpart. Guidelines are still inconsistent around the use and value of cytotoxic and antihormonal agents in the adjuvant setting. Traditional cytotoxic or antihormonal systemic treatment option is not associated with a significant OS or PFS benefit in this Meta-analysis.

Abstract

Objective: We performed a systematic literature review and a subsequent meta-analysis to compare traditional treatment options, i.e., antihormonal and cytotoxic, in LGSOC. Methods: We conducted a systematic literature review in MEDBASE and MEDLINE between September 2000 and June 2021 for women who received cytotoxic chemotherapy and/or antihormonal treatment after primary cytoreduction due to stage II–IV LGSOC and also at relapse. PFS and OS were calculated depending on the type of their adjuvant treatment. For each endpoint in the meta-analysis, pooled HR was calculated using the random effect model with the inverse variance weighted method. Only primary patients were included in the subsequent meta-analysis due to the small number of studies in the relapsed setting. Results: Five eligible first-line studies were included. Systemic chemotherapy failed to provide a significant OS benefit when compared to no systemic treatment (pooled HR = 1.01, 95% CI [0.79, 1.29]) after successful cytoreduction. Moreover, systemic chemotherapy followed by antihormonal treatment also did not result to a significant PFS or OS benefit when compared to systemic chemotherapy alone (for PSF: pooled HR = 0.59, 95% CI [0.33, 1.04]; for OS: pooled HR = 0.83, 95% CI [0.50, 1.39]). There were insufficient data from studies in the recurrent setting to allow their inclusion in the meta-analysis. Conclusions: In this meta-analysis, we failed to identify a traditional cytotoxic or antihormonal systemic treatment option that was associated with a significant OS or PFS benefit when administered following successful cytoreduction for advanced LGSOC. Prospective randomized studies are urgently warranted to define optimal adjuvant options in this challenging disease.

Impact of estrogen receptor expression on prognosis of ovarian cancer according to antibody clone used for immunohistochemistry: a meta-analysis

Background

The prognostic value of the expression of estrogen receptor (ER) subtypes ER⍺ and ERβ in ovarian cancer has previously been evaluated by meta-analyses. However, the results are contradictory and controversial.

Methods

We conducted an updated meta-analysis with stringent inclusion criteria to ensure homogeneous studies to determine the effect of ER subtypes on ovarian cancer prognosis. Articles were retrieved by systematic search of PubMed and Web of Science for articles dated up to June 2021. Only studies with known hazard ratio (HR) and antibody clone for immunochemistry (IHC) were included. Pooled HRs with the corresponding 95% confidence intervals (CIs) were calculated for the effect of ER⍺ and ERβ expression on ovarian cancer patient progression-free survival (PFS) and overall survival (OS).

Results

A total of 17 studies were included, of which 11 and 13 studies examined the relationships between ER⍺ expression and PFS and OS, respectively, and 5 and 7 studies examined the relationships between ERβ expression and PFS and OS, respectively. Neither ER⍺ expression (random-effects model; HR = 0.99, 95% CI = 0.83–1.18) nor ERβ expression (fixed-effects model; HR = 0.94, 95% CI = 0.69–1.27) was associated with PFS. Random-effects models showed that ER⍺ expression (HR = 0.81, 95% CI = 0.64–1.02) and ERβ expression (HR = 0.75, 95% CI = 0.50–1.13) were only marginally and not significantly associated with better OS. Subgroup analysis revealed that ER⍺ expression determined using antibody clone 1D5 (HR = 0.75, 95% CI = 0.64–0.88) and ERβ expression determined using ERβ1-specific-antibody clone PPG5/10 or EMR02 (HR = 0.65, 95% CI = 0.50–0.86) were associated with significantly better OS, but ER expression determined using other antibodies was not.

Conclusions

In conclusion, a higher ER⍺ expression and ERβ expression are significantly associated with a better survival of ovarian cancer patients, but the results from previous prognostic studies are significantly dependent on the choice of specific ER antibody clones used in immunohistochemistry analysis.

Maintenance Therapy with Aromatase Inhibitor in epithelial Ovarian Cancer (MATAO): study protocol of a randomized double-blinded placebo-controlled multi-center phase III Trial

Background

A high percentage of epithelial ovarian cancers (EOC) express the estrogen receptor (ER), which is an ideal target for endocrine therapy. Letrozole is a proven, potent aromatase inhibitor, extensively tested and used in the treatment of ER positive breast cancer. In addition, it seems a potent drug for patients with heavily pre-treated OC as demonstrated in several distinctive settings. However, it has never been evaluated prospectively in a maintenance setting for ovarian cancer after standard of care. The here proposed trial aims to define a population of EOC patients, who would benefit from the effectiveness of the generic agent letrozole, with little expected toxicity and thus beneficial impact on overall quality of life (QoL).

Methods

In this international multicenter randomized, placebo-controlled phase III trial at clinical centers in Switzerland, Germany and Austria, we plan to include 540 patients with primary, newly diagnosed FIGO Stage II to IV and histologically confirmed low- or high-grade serous or endometrioid epithelial ovarian/fallopian tube/peritoneal cancer. Patients are randomized in a 1:1 ratio into two groups: receiving blinded study treatment (letrozole or placebo tablets). When assuming a HR of 0.7, a median PFS of 18 months in the control arm and a median PFS of 25.7 months in the treatment arm, a two-sided alpha level of 5%, 3.5 years recruitment and 1.5 years observation time, we expect 330 events to have occurred within these 5 years in the total cohort yielding a power of 90%. Follow-up data for the whole cohort will be collected for up to 10 years and for the low-grade cancer for up to 12 years.

Discussion

The here proposed randomized phase III trial aims to identify patients with EOC in the maintenance setting, who benefit from the effectiveness of the letrozole, by proving its efficacy whilst maintaining a high standard of QoL due to the limited toxicity expected in comparison to the current alternative drugs on the market for this treatment phase.

Trial registration

This trial is registered at clinicaltrials.gov under the identifier NCT04111978. Registered 02 October 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09555-8.

Four Types of RNA Modification Writer-Related lncRNAs Are Effective Predictors of Prognosis and Immunotherapy Response in Serous Ovarian Carcinoma

Serous ovarian carcinoma (SOC) is a gynecological malignancy with high mortality rates. Currently, there is a lack of reliable biomarkers for accurate SOC patient prognosis. Here, we analyzed SOC RNA-Seq data from The Cancer Genome Atlas (TCGA) to identify prognostic biomarkers. Through the pearson correlation analysis, univariate Cox regression analysis, and LASSO-penalized Cox regression analysis, we identified nine lncRNAs significantly associated with four types of RNA modification writers (m6A, m1A, APA, and A-I) and with the prognosis of SOC patients (P <0.05). Six writer-related lncRNAs were ultimately selected following multivariate Cox analysis. We established a risk prediction model based on these six lncRNAs and evaluated its prognostic value in multiple groups (training set, testing set, and entire set). Our risk prediction model could effectively predict the prognosis of SOC patients with different clinical characteristics and their responses to immunotherapy. Lastly, we validated the predictive reliability and sensitivity of the lncRNA-based model via a nomogram. This study explored the association between RNA modification writer-related lncRNAs and SOC prognosis, providing a potential complement for the clinical management of SOC patients.

Development and Validation of a Nomogram to Predict the Probability of Venous Thromboembolism in Patients with Epithelial Ovarian Cancer

To identify predictive factors and develop a nomogram to predict the probability of venous thromboembolism for epithelial ovarian cancer patients. Methods: Our study cohort was composed of 208 EOC patients who had received initial treatment in Sun Yat-sen Memorial Hospital from January 2016 to March 2020. Clinicopathological variables predictive of VTE were identified using univariate logistic analysis. A multivariate logistic regression model was used to select the predictive factors used for nomogram. The accuracy of nomogram was evaluated by the Concordance index (C-index), the area under the receiver–operator characteristic (ROC) curve, area under concentration-time curve (AUC) and the calibration curve. Results: Advancing age (hazard ratio [HR], 1.042; 95% confidence interval [CI], 1.000-1.085; P = .048), higher D-dimer level (HR, 1.144; 95%CI, 1.020-1.283; P = .022), lower PR immunohistochemical positive rate (HR, 0.186; 95%CI, 0.034-1.065; P = .059) and higher Ki67 immunohistochemical positive rate (HR, 4.502; 95%CI, 1.637-12.380; P = .004) were found to be independent risk factors for VTE, and were used to construct the nomogram. The C-index for VTE prediction of the nomogram was 0.75. Conclusions: We constructed and validated a nomogram able to quantify the risk of VTE for EOC patients, which can be applied in recognizing EOC patients with high risk of VTE.

Biomarkers of Central Nervous System Involvement from Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the leading cause of death among women affected by gynaecological malignancies. Most patients show advanced disease at diagnosis (FIGO stage III-IV) and, despite the introduction of new therapeutic options, most women experience relapses. In most cases, recurrence is abdominal-pelvic; however, EOC can occasionally metastasize to distant organs, including the central nervous system. The incidence of brain metastases (BMs) from EOC is low, but it has grown over time; currently, there are no follow-up strategies available. In the last decade, a few biomarkers able to predict the risk of developing BMs from OC or as potential therapeutic targets have been investigated by several authors; to date, none have entered clinical practice. The purpose of this review is to offer a summary on the role of the most relevant predictors of central nervous system (CNS) involvement (hormone receptors; BRCA; MRD1; PD-1/PD-L1) and to highlight possible therapeutic strategies for the management of metastatic brain disease in EOC.

Regorafenib or Tamoxifen for platinum-sensitive recurrent ovarian cancer with rising CA125 and no evidence of clinical or RECIST progression: A GINECO randomized phase II trial (REGOVAR)

OBJECTIVE

To evaluate the efficacy and safety of regorafenib versus tamoxifen in platinum-sensitive ovarian cancer biological recurrence, defined by CA-125 increase without radiological (RECIST criteria) or symptomatic evidence of progression.

PATIENTS AND METHODS

116 patients with platinum-sensitive ovarian cancer presenting an isolated increase of CA-125 were planned to be randomized. Regorafenib was administered orally at 160 or 120 mg daily, 3 weeks on/1 week off or tamoxifen at 40 mg daily, until disease progression or development of unacceptable toxicity. The primary endpoint was Progression-Free Survival, assessed by progression according to RECIST 1.1 or death (by any cause). Secondary endpoints included Overall Survival, Best Response and CA-125 response rate.

RESULTS

68 patients were randomized. Median age was 67 years (range: 30-87). Primary site of cancer was ovarian for most patients (92.6%). Tumors were predominantly serous / (89.7%), high grade (83.6%) and initial FIGO staging was III for 69.6% of the patients. Most (79.4%) patients were included after the first line of platinum-based treatment. After a median follow-up of 32 months, there was no difference of progression-free survival (PFS) between regorafenib and tamoxifen groups (p = 0.72), with median PFS of 5.6 months (CI 90%: 3.84-7.52) for the tamoxifen arm and 4.6 months (CI 90%: 3.65-7.33) for the regorafenib arm. There was also no difference in term of overall survival, best response or CA-125 response, delay to next therapy. Regorafenib presented a less favorable safety profile than tamoxifen, with grade 3/4 events occurring for 90.9% of the patients compared to 54.3% for tamoxifen. The most frequent were cutaneous, digestive, and biological events. Notably, hand-foot syndrome occurred in 36.4% of these patients.

CONCLUSION

Regorafenib presented an unfavorable toxicity profile compared to tamoxifen, with no superior efficacy in this population of patients.

Integrated molecular characterisation of endometrioid ovarian carcinoma identifies opportunities for stratification

Endometrioid ovarian carcinoma (EnOC) is an under-investigated ovarian cancer type. Recent studies have described disease subtypes defined by genomics and hormone receptor expression patterns; here, we determine the relationship between these subtyping layers to define the molecular landscape of EnOC with high granularity and identify therapeutic vulnerabilities in high-risk cases. Whole exome sequencing data were integrated with progesterone and oestrogen receptor (PR and ER) expression-defined subtypes in 90 EnOC cases following robust pathological assessment, revealing dominant clinical and molecular features in the resulting integrated subtypes. We demonstrate significant correlation between subtyping approaches: PR-high (PR + /ER + , PR + /ER−) cases were predominantly CTNNB1-mutant (73.2% vs 18.4%, P < 0.001), while PR-low (PR−/ER + , PR−/ER−) cases displayed higher TP53 mutation frequency (38.8% vs 7.3%, P = 0.001), greater genomic complexity (P = 0.007) and more frequent copy number alterations (P = 0.001). PR-high EnOC patients experience favourable disease-specific survival independent of clinicopathological and genomic features (HR = 0.16, 95% CI 0.04–0.71). TP53 mutation further delineates the outcome of patients with PR-low tumours (HR = 2.56, 95% CI 1.14–5.75). A simple, routinely applicable, classification algorithm utilising immunohistochemistry for PR and p53 recapitulated these subtypes and their survival profiles. The genomic profile of high-risk EnOC subtypes suggests that inhibitors of the MAPK and PI3K-AKT pathways, alongside PARP inhibitors, represent promising candidate agents for improving patient survival. Patients with PR-low TP53-mutant EnOC have the greatest unmet clinical need, while PR-high tumours—which are typically CTNNB1-mutant and TP53 wild-type—experience excellent survival and may represent candidates for trials investigating de-escalation of adjuvant chemotherapy to agents such as endocrine therapy.

MiR-200b is upregulated in plasma-derived exosomes and functions as an oncogene by promoting macrophage M2 polarization in ovarian cancer

Background

Ovarian cancer is the seventh most common cancer in women and the second most reason of gynecologic cancer-related death. Growing evidence showed that exosomal miRNA plays a crucial role in the progression of ovarian cancer.

Methods

Exosomes were identified using nanoparticle tracking analysis, transmission electron microscopy and marker proteins detection. The levels of mRNA and proteins were ensured by qRT-PCR and western blot, respectively. Immunofluorescence, flow cytometry and ELISA assay were carried out to analyze macrophages polarization. CCK-8 and Transwell assay were used to measure the cell viability and invasion of ovarian cancer cells. The interaction of miR-200b and Kruppel like factor 6 (KLF6) was ensured by using luciferase reporter assay.

Results

Here, we obtained plasma-derived exosomes successfully, and proved that miR-200b was increased in the exosomes of ovarian cancer patients. Subsequently, our data showed that increasing of miR-200b could promote macrophage M2 polarization, but inhibit M1 polarization. miR-200b-overexpressed macrophages-conditioned medium notably enhanced the cell viability and invasion of ovarian cancer cells. Moreover, increasing of miR-200b inhibited KLF6 expression, while decreasing of miR-200b promoted KLF6 expression. Overexpression of KLF6 recused miR-200b-induced macrophage polarization toward M2, and the inhibitory effect of miR-200b on M1 polarization.

Conclusions

Overall, our results demonstrated that miR-200b was highly expressed in the plasma-derived exosome of ovarian cancer patients, and promoted the proliferation and invasion of ovarian cancer cells through inducing macrophage M2 polarization by suppressing KLF6 expression. Our results suggested that miR-200b might be a novel target for ovarian cancer treatment.

Functional estrogen receptor signaling pathway activity in high-grade serous ovarian carcinoma as compared to estrogen receptor protein expression by immunohistochemistry

Purpose

Anti-estrogen therapy may be used as a palliative treatment option in high-grade serous ovarian carcinomas (HGSC). However, clinical implementation is limited as the use of estrogen receptor (ER) protein expression by immunohistochemistry remains insufficient in predicting therapy response. To determine the accuracy of ER protein expression as a marker for ER signaling pathway activity, we aimed to correlate ER protein expression to functional ER signaling pathway activity in HGSC.

Methods

Immunohistochemical ER protein expression was visually scored using total percentages of stained tumor cells and histoscores. Subsequently, mRNA was extracted, and RT-qPCR analysis was performed. Functional ER pathway activity was assessed by a computational Bayesian model inferring ER signaling pathway activity from mRNA levels of ER-specific target genes.

Results

Our analysis of 29 HGSCs shows that neither total percentage of ER protein expression, nor ER histoscores are significantly correlated to ER signaling pathway activity (respectively, p = 0.473 and p = 0.606). Classification of HGSC into three groups based on ER histoscores 0–100 (n = 6), 101–200 (n = 15) and 201–300 (n = 8) resulted in comparable mean ER signaling pathway activity among the groups (p = 0.356). Several samples in the higher ER histoscore groups had low ER signaling pathway activity, indicating that nuclear ER protein expression is not sufficient to describe transcriptional ER activation.

Conclusion

Positive immunohistochemical ER staining is not always indicative of an active ER signaling pathway and is, therefore, a poor predictor of anti-estrogen response. Further research is needed to prove the predictive value of ER signaling pathway activity regarding anti-estrogen sensitivity in HGSC patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13402-021-00600-5.

Transcription factors in epithelial ovarian cancer: histotype-specific drivers and novel therapeutic targets

Transcription factors (TFs) are major contributors to cancer risk and somatic development. In preclinical and clinical studies, direct or indirect inhibition of TF-mediated oncogenic gene expression profiles have proven to be effective in many tumor types, highlighting this group of proteins as valuable therapeutic targets. In spite of this, our understanding of TFs in epithelial ovarian cancer (EOC) is relatively limited. EOC is a heterogeneous disease composed of five major histologic subtypes; high-grade serous, low-grade serous, endometrioid, clear cell and mucinous. Each histology is associated with unique clinical etiologies, sensitivity to therapies, and molecular signatures - including diverse transcriptional regulatory programs. While some TFs are shared across EOC subtypes, a set of TFs are expressed in a histotype-specific manner and likely explain part of the histologic diversity of EOC subtypes. Targeting TFs present with unique opportunities for development of novel precision medicine strategies for ovarian cancer. This article reviews the critical TFs in EOC subtypes and highlights the potential of exploiting TFs as biomarkers and therapeutic targets.

Estrogen Signaling and Its Potential as a Target for Therapy in Ovarian Cancer

The estrogen receptor (ER) has functionality in selected ovarian cancer subtypes and represents a potential target for therapy. The majority (>80%) of high grade serous, low grade serous and endometrioid carcinomas and many granulosa cell tumors express ER-alpha (ERα), and these tumor types have demonstrated responses to endocrine therapy (tamoxifen and aromatase inhibitors) in multiple clinical studies. Biomarkers of responses to these drugs are actively being sought to help identify responsive cancers. Evidence for both pro-proliferative and pro-migratory roles for ERα has been obtained in model systems. ER-beta (ERβ) is generally considered to have a tumor suppressor role in ovarian cancer cells, being associated with the repression of cell growth and invasion. The differential expression of the specific ERβ isoforms may determine functionality within ovarian cancer cells. The more recently identified G protein-coupled receptor (GPER1; GPR30) has been shown to mediate both tumor-suppressive and tumor-promoting action in ovarian cancer cells, suggesting a more complex role. This review will summarize recent findings in this field.

Fallopian tube initiation of high grade serous ovarian cancer and ovarian metastasis: Mechanisms and therapeutic implications

Ovarian cancer is the most lethal gynecologic malignancy and the fifth leading cause of cancer-related death in women. Although outcomes have improved in recent years, there remains an unmet clinical need to understand the early pathogenesis of ovarian cancer in order to identify new diagnostic approaches and agents of chemoprevention and chemotherapy. While high grade serous ovarian cancer (HGSOC), the most abundant histotype, was initially thought to arise from the ovarian surface epithelium, there is an increasing body of evidence suggesting that HGSOC originates in the fallopian tube. With this new understanding of cell of origin, understanding of disease development requires analysis with a novel perspective. Currently, factors that drive the initiation and migration of dysplastic tubal epithelial cells from the fallopian tube to the ovary are not yet fully defined. These factors include common mutations to fallopian tube epithelial cells, as well as factors originating from both the fallopian tube and ovary which are capable of inducing transformation and dissemination in said cells. Here, we review these changes, their causative agents, and various potential means of intervention.

Ki67 expression as a predictor of chemotherapy outcome in low-grade serous ovarian cancer

OBJECTIVE

Low-grade serous ovarian cancers characterize a unique clinical pattern and lower chemotherapy responsiveness. The expression level of Ki67 is associated with differences in prognosis; however, this has not yet been evaluated in regard to predicting the outcome of therapy.

METHODS

Patients with low-grade serous ovarian cancers were identified in an institutional database. Receiver-operator characteristics (ROC) curve analysis was performed to find cut-off values of Ki67 to discriminate patients with residual tumor mass after surgery from maximal debulked patients: therapy response and therapy-free interval (TFI).

RESULTS

A total of 68 patients with low-grade serous ovarian cancer were identified. All patients underwent surgery. 61 (89.7%) patients received platinum-based first-line chemotherapy; of these 61 patients, 13 (21.3%) had residual mass (>0 mm) after primary cytoreduction and 11 (18%) received neo-adjuvant chemotherapy. Ki67 ≥3.6% was associated with higher risk of residual mass after surgery (OR 8.1, 95% CI 1.45 to 45.18; p=0.017). Patients with Ki67 <3.6% showed a therapy-free interval of ≥6 months more often (OR 13.9, 95% CI 1.62 to 118.40; p=0.016). In the multivariate analysis of TFI <6 months, including CA125, age at diagnosis, peritoneal carcinomatosis, and ascites, Ki67 <3.6% remained a significant prognostic factor (OR 18.8, 95% CI 1.77 to 199.09; p=0.015). Chemotherapy responsiveness was evaluated in 21 patients who had residual disease and/or received neo-adjuvant chemotherapy. Ki67 ≥4.0% (OR 44.1, 95%CI 2.36-825.17, p = 0.011) was related to a significantly higher response rate (complete and partial response).

CONCLUSIONS

This is the first study to show an association between Ki67 expression and chemotherapy response, duration of TFI to platinum-based chemotherapy as well as outcome of surgery in low-grade serous ovarian cancers. Further prospective trials should use Ki-67 as a stratification factor to explore the effect of chemotherapy and endocrine strategies.

The Identification and Analysis of mRNA-lncRNA-miRNA Cliques From the Integrative Network of Ovarian Cancer

Ovarian cancer is one of the leading causes of cancer mortality in women. Since little clinical symptoms were shown in the early period of ovarian cancer, most patients were found in phases III-IV or with abdominal metastasis when diagnosed. The lack of effective early diagnosis biomarkers makes ovarian cancer difficult to screen. However, in essence, the fundamental problem is we know very little about the regulatory mechanisms during tumorigenesis of ovarian cancer. There are emerging regulatory factors, such as long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), which have played important roles in cancers. Therefore, we analyzed the RNA-seq profiles of 407 ovarian cancer patients. An integrative network of 20,424 coding RNAs (mRNAs), 10,412 lncRNAs, and 742 miRNAs were construed with variance inflation factor (VIF) regression method. The mRNA-lncRNA-miRNA cliques were identified from the network and analyzed. Such promising cliques showed significant correlations with survival and stage of ovarian cancer and characterized the complex sponge regulatory mechanism, suggesting their contributions to tumorigenicity. Our results provided novel insights of the regulatory mechanisms among mRNAs, lncRNAs, and miRNAs and highlighted several promising regulators for ovarian cancer detection and treatment.

Metastases with definitive pathological diagnosis but no detectable primary tumor: A surveillance epidemiology and end results-based study

Background

This study investigates the characteristics of a special type of cancer of unknown primary site (CUP, type 2), which is a metastasis of a definite pathological diagnosis without a detectable primary site.

Patients and methods

Patients diagnosed between 2004 and 2014 were identified from the Surveillance Epidemiology and End Results (SEER) database. The characteristics of type 2 CUP from different sources were analyzed. For each source of type 2 CUP, tumors of the corresponding T_nN_0‐XM₁ stage were used as controls.

Results

A total of 8505 patients with type 2 CUP were included in this analysis. Type 2 CUP shows an increasing trend, while type 1 shows the opposite. Type 2 CUPs have significant differences with stage IV of the same pathological primary lesion. Many characteristics influenced the prognosis of type 2 CUP patients, including marital status, age, race, sex, registration time, lymph node metastasis, surgery, chemotherapy, and radiation.

Conclusion

Our study suggests that identifying the source of metastasis is the key to the selection of treatment and the determination of the prognosis for CUP.

Synthesis of New Dihydroquinopimaric Acid Analogs with Nitrile Groups as Apoptosis-Inducing Anticancer Agents

BACKGROUND

Cyan-containing compounds are of great interest as potential anticancer agents. Terpenoids can severe as a natural matrix for the development of promising derivatives with antitumor activity.

METHODS

The 2-cyanoethoxy methyl dihydroquinopimarate derivatives (5-9) were synthesized by the reaction of the intermediates (1-4) with acrylonitrile in the presence of alkali (30% KOH solution) using triethylbenzylammonium chloride. The cytotoxicity evaluation was carried out according to the National Cancer Institute (NCI) Protocol, while apoptosis was studied by flow cytometric analysis of Annexin V and 7-aminoactinomycin D staining and cell cycle was analyzed using the method of propidium iodide staining.

RESULTS

Synthesis of new dihydroquinopimaric acid derivatives with nitrile groups was carried out. The obtained cyanoethyl derivatives were converted into tetrazole, amine, oxadiazole and amidoxime analogs. The primary screening for antitumor activity showed the highest cytotoxic potency of the cyanoethyl-substituted compounds. The introduction of cyanoethyl groups at C-1, C-4 and C-1, C-4, C-20 positions of dihydroquinopimaric acid methyl ester provided antiproliferative effect towards the Jurkat, K562, U937, and HeLa tumor cell cultures (CC50=0.045-0.154µM). These nitrile derivatives are effective inducers of tumor cell apoptosis affecting the S and G2 phases of the cell cycle in a dose-dependent manner.

CONCLUSION

The cyanoethyl analogs of dihydroquinopimaric acid reported herein are apoptosis inducers and cytotoxic agents. These findings will be useful for the further design of more potent cytotoxic agents based on natural terpenes.

Pattern of endocrine treatment for epithelial ovarian cancer in the Southeast medical region of Sweden: a population-based study

AIM OF THE STUDY

Endocrine treatment (ET) is an alternative as salvage therapy in epithelial ovarian cancer (EOC) but the usage in routine care is unknown. We evaluated the treatment patterns and outcome of patients receiving ET for EOC in the Southeast medical region in Sweden.

METHOD

Patients were identified through the population-based Southeast Quality Registry for gynaecological cancer. Inclusion criteria were: age ≥18 years, histologically verified EOC diagnosed 2000-2013, ET for ≥4 weeks. Coverage compared with the Swedish National Cancer Registry was 100%. Data extracted from medical records was collected by means of a study-specific Case Report Form. Last date of follow-up was February 1st, 2018. All statistics were descriptive.

RESULTS

Altogether 248 (18%) of 1414 patients were treated with ET. Most (49%) had received only one, and 34% two previous lines of chemotherapy. Time from last chemotherapy to ET was 4 months, range 0-55months. The reason for initiating ET was tumor progression (66%), chemotherapy related toxicity (29%) and maintenance (4%). Tamoxifen was prescribed in 94% of cases. Best response was partial (< 5%) and stable disease (50%). No patient had a complete response. 194 (78%) patients received subsequent chemotherapy, of these 27% had 3-7 lines of chemotherapy. Duration of ET was a median 4 months (range 1-80 months). Median time from ET to subsequent chemotherapy was 5 months (range 0-79). The median overall survival was 45 months (range 9-173).

CONCLUSION

In the Southeast region of Sweden, endocrine treatment for EOC was prescribed inconsistently and in various settings, usually initiated by a rising CA-125 level. Poorer documentation and irregular tumor response assessment were observed for endocrine treatment compared to chemotherapy.

Interaction of ERα and NRF2 Impacts Survival in Ovarian Cancer Patients

Nuclear factor erythroid 2-related factor 2 (NRF2) regulates cytoprotective antioxidant processes. In this study, the prognostic potential of NRF2 and its interactions with the estrogen receptor α (ERα) in ovarian cancer cells was investigated. NRF2 and ERα protein expression in ovarian cancer tissue was analyzed as well as mRNA expression of NRF2 (NFE2L2) and ERα (ESR1) in four ovarian cancer and one benign cell line. NFE2L2 silencing was carried out to evaluate a potential interplay between NRF2 and ERα. Cytoplasmic NRF2 expression as inactive form had significantly higher expression in patients with low-grade histology (p = 0.03). In the serous cancer subtype, high cytoplasmic NRF2 expression (overall survival (OS), median 50.6 vs. 29.3 months; p = 0.04) and high ERα expression (OS, median 74.5 vs. 27.1 months; p = 0.002) was associated with longer overall survival as well as combined expression of both inactive cytoplasmic NRF2 and ERα in the whole cohort (median 74.5 vs. 37.7 months; p = 0.04). Cytoplasmic NRF2 expression showed a positive correlation with ERα expression (p = 0.004). NFE2L2 was found to be highly expressed in the ovarian cancer cell lines OVCAR3, UWB1.289, and TOV112D. Compared with the benign cell line HOSEpiC, ESR1 expression was reduced in all ovary cancer cell lines (all p < 0.001). Silencing of NFE2L2 induced a higher mRNA expression of ESR1 in the NFE2L2 downregulated cancer cell lines OVCAR3 (p = 0.003) and ES2 (p < 0.001), confirming genetic interactions of NRF2 and ERα. In this study, both inactive cytoplasmic NRF2 and high ERα expression were demonstrated to be associated with improved survival in ovarian cancer patients. Further understanding of interactions within the estradiol⁻ERα⁻NRF2 pathway could better predict the impact of endocrine therapy in ovarian cancer.

The role of menopausal hormone therapy in women with or at risk of ovarian and breast cancers: Misconceptions and current directions

For women who are candidates for menopausal hormone therapy (MHT), estrogen can provide relief from symptomatic menopause, decrease rates of chronic illnesses, and improve health-related quality of life. However, confusion surrounds the evidence regarding the impact of exogenous estrogen and progesterone on the breast and ovary. Available data regarding the risks of MHT (estrogen and/or progestin) related to the development of breast and ovarian cancer are often inconsistent or incomplete. Modern molecular and genetic techniques have improved our understanding of the heterogeneity of breast and ovarian cancer. This enhanced understanding of the disease has impacted our understanding of carcinogenesis. Treatment options have evolved to be more targeted toward hormonal therapy for certain subtypes of disease, whereas cytotoxic chemotherapy remains the standard for other histological and molecular subtypes. The role of MHT in the breast and ovarian cancer survivor, as well as women who are at high risk for the development of hereditary breast and ovarian cancer, remains controversial despite evidence that this treatment can improve quality of life and survival outcomes. Through this article, we examine the evidence for and against the use of MHT with a focus on women who have or are at high risk for breast and ovarian cancer.

ESR1 methylation in primary tumors and paired circulating tumor DNA of patients with high-grade serous ovarian cancer

OBJECTIVE

Estrogen receptor, coded by the ESR1 gene, is highly expressed in epithelial ovarian cancer. ESR1 gene is frequently methylated in many types of gynecological malignancies. However, only a few studies attempted to investigate the role of ESR1 methylation and its clinical significance in ovarian cancer so far. The aim of our study was to examine ESR1 methylation status in primary tumors and corresponding circulating tumor DNA of patients with high-grade serous ovarian cancer (HGSC).

METHODS

ESR1 methylation was detected by a highly specific and sensitive real-time methylation-specific PCR assay. Two groups of HGSC samples were analyzed: group A (n = 66 primary tumors) and group B (n = 53 primary tumors and 50 corresponding plasma samples).

RESULTS

ESR1 was found methylated in both groups of primary tumors: in 32/66 (48.5%) of group A and in 15/53 (28.3%) of group B. 19/50 (38.0%) corresponding plasma samples of group B were also methylated for ESR1. A significant agreement for ESR1 methylation was observed between primary tumors and paired plasma ctDNA samples (P = 0.004). Interestingly, the presence of ESR1 methylation in primary tumor samples of group B was significantly correlated with a better overall survival (P = 0.027) and progression-free survival (P = 0.041).

CONCLUSIONS

We report for the first time the presence of ESR1 methylation in plasma ctDNA of patients with HGSC. The agreement between ESR1 methylation in primary tumors and paired ctDNA is statistically significant. Our results indicate a correlation between the presence of ESR1 methylation and a better clinical outcome in HGSC 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.