Effects of metformin on endometrial cancer: Systematic review and meta-analysis

Associated Trends in Obesity and Endometrioid Endometrial Cancer in the United States

OBJECTIVE

To evaluate the correlation in temporal trends in obesity and endometrioid endometrial cancer incidence in the United States using two comprehensive national databases.

METHODS

This is a cohort study in which data on endometrioid endometrial cancer were obtained from the U.S. Cancer Statistics from 2001 to 2018 and corrected for hysterectomy and pregnancy. Data on obesity were collected from the NHANES (National Health and Nutrition Examination Survey) database from 1988 to 2018. Average annual percentage changes (AAPCs) were used to describe trends. Pearson correlation coefficients ( r ) were calculated to examine the relationship between trends. SEER*Stat 8.3.9.2 and joinpoint regression program 5.2.0 were used for statistical analysis.

RESULTS

From U.S. Cancer Statistics data, 586,742 cases of endometrioid cancer were identified from 2001 to 2018. The average annual increase in endometrioid cancer was as follows: Hispanic 1.37% (95% CI, 1.14-1.60, P <.001), Black 1.30% (95% CI, 1.04-1.57, P <.001), and White -0.17 (95% CI, -0.91 to 0.58, P =.656). Women aged 20-29 years had a 4.48% annual increase (95% CI, 3.72-5.25, P <.001) and women aged 30-39 years had a 3.00% annual increase in rates (95% CI, 2.65-3.36, P <.001). According to the NHANES data, the prevalence of obesity in 2018 in adult women was as follows: Black 56.80%, Hispanic 44.10%, and White 40.90%. An examination of trends by age showed that women aged 20-29 years had the highest annual rise in obesity compared with other age groups (AAPC 7.36%, 95% CI, 4.0-10.8, P <.05). Strong and statistically significant correlations between endometrioid cancer and obesity trends were noted for Black ( r =0.78, P =.01) and Hispanic ( r =0.91, P <.001) women, as well as women aged 20-29 years ( r =0.72, P =.03) and 30-39 years ( r =0.88, P =.001).

CONCLUSION

The current data demonstrate a temporal association between the increasing incidence of obesity and endometrioid endometrial cancer, and this effect disproportionately affects younger women and Black and Hispanic women.

Fertility-preserving treatment for stage IA endometrial cancer: a systematic review and meta-analysis

OBJECTIVE

The increasing use of fertility-preserving treatments in reproductive-aged patients with early-stage endometrial cancer necessitates robust evidence on the effectiveness of oral progestins and levonorgestrel-releasing intrauterine device. We conducted a systematic review and meta-analysis to examine the outcomes following these 2 primary progestin-based therapies in reproductive-aged patients with early-stage endometrial cancer.

DATA SOURCES

We conducted a systematic review of observational studies and randomized controlled trials following the Cochrane Handbook guidance. We conducted a literature search of 5 databases and 1 trial registry from inception of the study to April 16, 2024.

STUDY ELIGIBILITY CRITERIA

Studies reporting complete response within 1 year in reproductive-aged patients with clinical stage IA endometrioid cancer undergoing progestin therapy treatment were included. We used data from both observational and randomized controlled studies.

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary exposure assessed was the type of progestational treatment (oral progestins or LNG-IUD). The primary outcome was the pooled proportion of the best complete response (CR) within 1 year of primary progestational treatment. We performed a proportional meta-analysis to estimate the treatment response. Sensitivity analyses were performed by removing studies with extreme effect sizes or removing grade 2 tumors. The risk of bias was assessed in each study using the Joanna Briggs Institute critical appraisal checklist.

RESULTS

Our analysis involved 754 reproductive-aged patients diagnosed with endometrial cancer, with 490 receiving oral progestin and 264 receiving levonorgestrel-releasing intrauterine device as their primary progestational treatment. The pooled proportion of the best complete response within 12 months of oral progestin and levonorgestrel-releasing intrauterine device treatment were 66% (95% CI, 55-76) and 86% (95% CI, 69-95), respectively. After removing outlier studies, the pooled proportion was 66% (95% CI, 57-73) for the oral progestin group and 89% (95% CI, 75-96) for the levonorgestrel-releasing intrauterine device group, showing reduced heterogeneity. Specifically, among studies including grade 1 tumors, the pooled proportions were 66% (95% CI, 54-77) for the oral progestin group and 83% (95% CI, 50-96) for the levonorgestrel-releasing intrauterine device group. The pooled pregnancy rate was 58% (95% CI, 37-76) after oral progestin treatment and 44% (95% CI, 6-90) after levonorgestrel-releasing intrauterine device treatment.

CONCLUSION

This meta-analysis provides valuable insights into the effectiveness of oral progestins and levonorgestrel-releasing intrauterine device treatment within a 12-month timeframe for patients with early-stage endometrial cancer who desire to preserve fertility. These findings have the potential to assist in personalized treatment decision-making for patients.

Weight-Loss and Metformin-Use Improve the Reversal Rate in Patients with Endometrial Hyperplasia

Objective

To evaluate the therapeutic outcomes of weight loss and metformin use in patients with endometrial hyperplasia (EH), and to identify the factors influencing treatment efficacy.

Methods

This study included data from patients diagnosed with either EH or endometrial atypical hyperplasia (EAH). Patients selected a progestin treatment regimen based on their diagnosis. Those with concurrent obesity or insulin resistance received additional weight management support and metformin therapy. Follow-up assessments were conducted every 3-6 months.

Results

A total of 202 patients were included. The metformin group exhibited significantly greater improvement in abnormal uterine bleeding (91.5% vs 57.1%, p < 0.001) and in ultrasound findings (91.5% vs 66.7%, p < 0.001) than the non-metformin group. Patients who achieved >3% weight loss and those using metformin showed a significantly higher rate of disease reversal than those with ≤3% weight loss (91.2% vs 77.6%, p = 0.034) and the non-metformin group (93.2% vs 52.4%, p < 0.001). At follow-up durations exceeding 12 months, metformin use was associated with a significantly higher disease reversal rate (82.1% vs 42.9%, p = 0.048) and a lower recurrence rate (12.8% vs 28.6%, p = 0.048). Weight loss of >3% (odds ratio: 0.041, 95% confidence interval: 0.004-0.437, p = 0.008) and metformin use (odds ratio: 0.059, 95% confidence interval: 0.011-0.311, p = 0.001) were both independently associated with improved reversal rates in patients with EH/EAH.

Conclusion

Combining progestin therapy with weight loss and metformin is more effective in reversing EH than progestin alone. Regular metformin use, alongside weight loss, serves as a protective factor in EH management, with the protective effect of metformin increasing with longer use.

Efficacy of drugs treatment in patients with endometrial hyperplasia with or without atypia: A systematic review and network meta-analysis

BACKGROUND

Endometrial hyperplasia (EH) is a hyperplastic endometrial lesion with irregular gland size, increased glands, and increased glandular interstitial ratio. During follow-up, some EH progressed further to endometrial cancer. It is crucial to provide timely treatment for EH and improve the overall prognosis of EH patients.

METHODS

We searched the PubMed, ClinicalTrials.gov., and Embase databases for studies published from their inception to March 31, 2023. The methodological quality of each study was evaluated in accordance with the Cochrane Collaboration's tool for assessing the risk of bias. The RevMan5.3 software provided by the Cochrane Collaboration was used for direct meta-analysis statistical analysis; and the relative risk and 95% confidence interval along with the mean difference and 95% confidence interval, were used as evaluation indexes.

RESULTS

We included 21 randomized controlled trials involving a total of 2276 women with EH, 6 studies were of high quality, and 15 were of moderate quality. The blinding of subjects and intervention providers was identified as the main source of potential bias. Six interventions were addressed in the network meta-analysis: medroxyprogesterone acetate (MPA), plus metformin, norethisterone (NET), levonorgestrel-releasing intrauterine system (LNG-IUD), megestrol acetate, and other drugs. In the direct meta-analysis, we found the probability of endometrial complete regression (CR) in the LNG-IUD group to be significantly higher than those in the NET. In the network meta-analysis, we found the probability of CR in the NET group to be significantly lower than those in the MPA and plus metformin groups, the probability of CR in the LNG-IUD group to be significantly higher than those in the NET, the probability of CR in the other drugs group to be significantly higher than those in the LNG-IUD. The NET group had the lowest incidences of endometrial complete regression, plus metformin could have a better outcome.

CONCLUSION

According to the 21 randomized controlled trials included in this study, MPA is the most effective for EH endometrial outcome when applied as a single agent, while the combination of metformin can achieve a more significant effect.

Transcriptomic Analysis of Metformin's Effect on Bovine Viral Diarrhea Virus Infection

(1) Background: Bovine viral diarrhea virus (BVDV) causes calf diarrhea, bovine respiratory syndrome, and cow abortion, resulting in substantial economic losses in the cattle industry. Owing to its persistent infection mechanism, BVDV is a major challenge in the treatment of cattle. (2) Methods: To determine how metformin (Met) inhibits the interaction between BVDV and host cells, we treated BVDV-infected cells with Met. We then performed an RNA sequencing (RNA-seq) analysis of Met-treated cells infected with BVDV to identify differentially expressed genes (DEGs). Consequently, the RNA-seq results were validated through real-time quantitative PCR (qPCR). (3) Results: Our analysis revealed 3169 DEGs in the Met-treated cells (Met group) vs. the negative controls (NC group) and 2510 DEGs in the BVDV-infected cells after pretreatment with Met (MetBVDV group) vs. the BVDV-infected cells (BVDV group). The DEGs were involved in MDBK interactions during BVDV infection, as indicated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The potential interactions of the DEGs were confirmed via a protein-protein interaction (PPI) network. Met treatment induced autophagy signaling activity and the expression of the autophagy-related genes ATG2A, ATG4B, ATG10, and ATG12 in BVDV-infected Met-pretreated cells. (4) Conclusions: We found that the host transcriptomic profile was affected by BVDV infection and Met pretreatment. These findings offer valuable new insights and provide support for future studies on the inhibition of BVDV replication by Met.

Diagnostic significance and predictive efficiency of metabolic risk score for fertility-sparing treatment in patients with atypical endometrial hyperplasia and early endometrial carcinoma

OBJECTIVE

This study aims to assess the impact of the metabolic risk score (MRS) on time to achieve complete remission (CR) of fertility-sparing treatments for atypical endometrial hyperplasia (AEH) and early endometrial cancer (EC) patients.

METHODS

Univariate and multivariate cox analyses were employed to identify independent risk factors affecting the time to CR with patients at our center. These factors were subsequently incorporated into receiver operator characteristic curve analysis and decision curve analysis to assess the predictive accuracy of time to CR. Additionally, Kaplan-Meier analysis was utilized to determine the cumulative CR rate for patients.

RESULTS

The 173 patients who achieved CR following fertility preservation treatment (FPT) were categorized into three subgroups based on their time to CR (<6, 6-9, >9 months). Body mass index (hazard ratio [HR]=0.20; 95% confidence interval [CI]=0.03, 0.38; p=0.026), MRS (HR=0.31; 95% CI=0.09, 0.52; p=0.005), insulin resistance (HR=1.83; 95% CI=0.05, 3.60; p=0.045), menstruation regularity (HR=3.77; 95% CI=1.91, 5.64; p=0.001), polycystic ovary syndrome (HR=-2.16; 95% CI=-4.03, -0.28; p=0.025), and histological type (HR=0.36; 95% CI=0.10, 0.62; p=0.005) were identified as risk factors for time to CR, with MRS being the independent risk factor (HR=0.29; 95% CI=0.02, 0.56; p=0.021). The inclusion of MRS significantly enhanced the predictive accuracy of time to CR (area under the curve [AUC]=0.789 for Model 1, AUC=0.862 for Model 2, p=0.032). Kaplan-Meier survival curves revealed significant differences in the cumulative CR rate among different risk groups.

CONCLUSION

MRS emerges as a novel evaluation system that substantially enhances the predictive accuracy for the time to achieve CR in AEH and early EC patients seeking fertility preservation.

Small molecule targeted therapies for endometrial cancer: progress, challenges, and opportunities

Endometrial cancer (EC) is a common malignancy among women worldwide, and its recurrence makes it a common cause of cancer-related death. Surgery and external radiation, chemotherapy, or a combination of strategies are the cornerstone of therapy for EC patients. However, adjuvant treatment strategies face certain drawbacks, such as resistance to chemotherapeutic drugs; therefore, it is imperative to explore innovative therapeutic strategies to improve the prognosis of EC. With the development of pathology and pathophysiology, several biological targets associated with EC have been identified, including PI3K/Akt/mTOR, PARP, GSK-3β, STAT-3, and VEGF. In this review, we summarize the progress of small molecule targeted therapies in terms of both basic research and clinical trials and provide cases of small molecules combined with fluorescence properties in the clinical applications of integrated diagnosis and treatment. We hope that this review will facilitate the further understanding of the regulatory mechanism governing the dysregulation of oncogenic signaling in EC and provide insights into the possible future directions of targeted therapeutic regimens for EC treatment by developing new agents with fluorescence properties for the clinical applications of integrated diagnosis and treatment.

Metformin and progestins in women with atypical hyperplasia or endometrial cancer: systematic review and meta-analysis

PURPOSE

To assess metformin's effectiveness in adding it to progestin-based hormone therapy for treating atypical endometrial hyperplasia (AEH) and early endometrial cancer (EEC).

METHODS

We conducted a systematic review and meta-analysis following PRISMA guidelines (registration number CRD42023399094). We searched databases for studies up to March 2023, including randomized and non-randomized clinical trials in English.

RESULTS

Out of 280 studies, 9 studies (1104 patients) were eligible. A total of 408 patients were allocated to receive metformin, and 696 patients entered the control group. Primary analysis focused on evaluating the CR showed a significant difference in patients with AEH treated with metformin (RR = 1.10, 95% CI 1.02-1.20, p = 0.02). Relapse rate (RR = 0.62, 95% CI 0.33-1.17, p = 0.14) was also evaluated. Secondary analysis indicated higher pregnancy rates (RR = 1.28, 95% CI 1.04-1.57, p = 0.02) with no significant difference in live birth rates (RR = 0.56, 95% CI 0.29-1.10, p = 0.09).

CONCLUSION

Combined therapy is effective. Metformin shows superiority to the standard regimen in achieving better CR rate in patients with AEH and benefits pregnancy rates but not recurrence or live birth rates. Therefore, the ideal fertility-sparing treatment for EC has not yet been determined and further clinical trials are needed.

Levonorgestrel-releasing intrauterine device therapy vs oral progestin treatment for reproductive-aged patients with endometrial intraepithelial neoplasia: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to examine outcomes of patients with endometrial intraepithelial neoplasia treated with oral progestins or a levonorgestrel-releasing intrauterine device (IUD).

METHODS

We conducted a systematic review across 5 databases to examine outcomes of progestational treatment (oral progestins or levonorgestrel-releasing IUD) for patients with endometrial intraepithelial neoplasia. The primary outcome was the best complete response rate within 12 months of primary progestational treatment. Sensitivity analyses were performed by removing studies with extreme effect sizes. Secondary outcomes included the pooled pregnancy rate.

RESULTS

We identified 21 eligible studies, including 824 premenopausal patients with endometrial intraepithelial neoplasia, for our meta-analysis. Among these, 459 patients received oral progestin, and 365 patients received levonorgestrel-releasing IUD as a primary progestational treatment. The pooled best complete response proportion within 12 months was 82% (95% confidence interval [CI] = 69% to 91%) following oral progestin treatment and 95% (95% CI = 81% to 99%) following levonorgestrel-releasing IUD treatment. After removing outlier studies, the pooled proportion was 86% (95% CI = 75% to 92%) for the oral progestin group and 96% (95% CI = 91% to 99%) for the levonorgestrel-releasing IUD group, with reduced heterogeneity. The pooled pregnancy rate was 50% (95% CI = 35% to 65%) after oral progestin and 35% (95% CI = 23% to 49%) after levonorgestrel-releasing IUD treatment.

CONCLUSIONS

This meta-analysis provides data on the effectiveness of oral progestins and levonorgestrel-releasing IUD treatment within 12 months of treatment among premenopausal patients with endometrial intraepithelial neoplasia. Although based on small numbers, the rate of pregnancy after treatment is modest. These data may be beneficial for selecting progestational therapies that allow fertility preservation for patients with endometrial intraepithelial neoplasia.

Glycometabolism and lipid metabolism related genes predict the prognosis of endometrial carcinoma and their effects on tumor cells

BACKGROUND

Glycometabolism and lipid metabolism are critical in cancer metabolic reprogramming. The primary aim of this study was to develop a prognostic model incorporating glycometabolism and lipid metabolism-related genes (GLRGs) for accurate prognosis assessment in patients with endometrial carcinoma (EC).

METHODS

Data on gene expression and clinical details were obtained from publicly accessible databases. GLRGs were obtained from the Genecards database. Through nonnegative matrix factorization (NMF) clustering, molecular groupings with various GLRG expression patterns were identified. LASSO Cox regression analysis was employed to create a prognostic model. Use rich algorithms such as GSEA, GSVA, xCELL ssGSEA, EPIC,CIBERSORT, MCPcounter, ESTIMATE, TIMER, TIDE, and Oncoppredict to analyze functional pathway characteristics of the forecast signal, immune status, anti-tumor therapy, etc. The expression was assessed using Western blot and quantitative real-time PCR techniques. A total of 113 algorithm combinations were combined to screen out the most significant GLRGs in the signature for in vitro experimental verification, such as colony formation, EdU cell proliferation, wound healing, apoptosis, and Transwell assays.

RESULTS

A total of 714 GLRGs were found, and 227 of them were identified as prognostic-related genes. And ten GLRGs (AUP1, ESR1, ERLIN2, ASS1, OGDH, BCKDHB, SLC16A1, HK2, LPCAT1 and PGR-AS1) were identified to construct the prognostic model of patients with EC. Based on GLRGs, the risk model's prognosis and independent prognostic value were established. The signature of GLRGs exhibited a robust correlation with the infiltration of immune cells and the sensitivity to drugs. In cytological experiments, we selected HK2 as candidate gene to verify its value in the occurrence and development of EC. Western blot and qRT-PCR revealed that HK2 was substantially expressed in EC cells. According to in vitro experiments, HK2 knockdown can increase EC cell apoptosis while suppressing EC cell migration, invasion, and proliferation.

CONCLUSION

The GLRGs signature constructed in this study demonstrated significant prognostic value for patients with endometrial carcinoma, thereby providing valuable guidance for treatment decisions.

Associations of metformin therapy treatment with endometrial cancer risk and prognosis: A systematic review and meta-analysis

BACKGROUND

Several abstract studies have demonstrated that metformin may be beneficial for preventing and treating endometrial cancer (EC), while the results have been inconsistent and inconclusive. This systematic review and meta-analysis aimed to investigate the association between metformin use and the incidence and mortality of endometrial cancer in diabetic patients.

METHODS

A systematic literature search was performed in Pubmed, EMBASE, Web of Science, Cochrane Library, SinoMed, CNKI, Wanfang Data, and VIP from inception to November 2022. The outcome measures were hazard ratios (HRs) comparing the EC incidence and mortality in patients with type 2 diabetes mellitus (T2DM) on metformin and non-metformin. A random or fixed-effects model was applied for data analysis, and subgroup analysis was performed to look for factors of heterogeneity. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessed the evidence's certainty.

RESULTS

Eleven studies reported data on EC incidence. The pooled results suggested that the use of metformin was associated with a significantly higher incidence of EC (HR = 1.17, 95% CI 1.09-1.26, P < 0.0001). Further, seventeen studies were included for survival analysis. The pooled data showed that metformin could significantly decrease all-cause mortality (HR = 0.62, 95% CI 0.52-0.74, P < 0.00001) and endometrial cancer-specific mortality (HR = 0.95, 95% CI 0.90, 1.00, P = 0.03). Finally, we noted that metformin was associated with significantly improving the progression-free survival (PFS) of EC patients with T2DM (HR = 0.55, 95% CI 0.44, 0.68, P < 0.00001).

CONCLUSIONS

This meta-analysis did not prove that metformin was beneficial for preventing EC. However, metformin could reduce their mortality risk and prolong the progression-free survival time of EC patients with T2DM.

Recent advances in the management of postmenopausal women with non-atypical endometrial hyperplasia

Non-atypical endometrial hyperplasia is a benign disease without significant somatic genetic changes. Postmenopausal women with non-atypical endometrial hyperplasia have a significant risk of progression to endometrial cancer and persistent endometrial hyperplasia. Most cases of atypical endometrial hyperplasia in postmenopausal women are treated surgically, including hysterectomy. At present, the treatment of postmenopausal women with non-atypical endometrial hyperplasia is still controversial. Correct and timely diagnosis and treatment are of great significance to prevent progression of the lesion. This study mainly provides an updated synthesis of the literature that investigates the etiology, diagnosis and treatment of postmenopausal women with non-atypical endometrial hyperplasia. As of December 2022, a literature search related to postmenopausal non-atypical endometrial hyperplasia was conducted on the PubMed database. For most postmenopausal patients with non-atypical endometrial hyperplasia, regular re-examination should be performed during conservative treatment. For postmenopausal patients with endometrial cancer risk factors, persistent non-atypical endometrial hyperplasia or progesterone contraindications, hysterectomy and bilateral salpingo-oophorectomy should be the first choice.

Proteogenomic insights suggest druggable pathways in endometrial carcinoma

We characterized a prospective endometrial carcinoma (EC) cohort containing 138 tumors and 20 enriched normal tissues using 10 different omics platforms. Targeted quantitation of two peptides can predict antigen processing and presentation machinery activity, and may inform patient selection for immunotherapy. Association analysis between MYC activity and metformin treatment in both patients and cell lines suggests a potential role for metformin treatment in non-diabetic patients with elevated MYC activity. PIK3R1 in-frame indels are associated with elevated AKT phosphorylation and increased sensitivity to AKT inhibitors. CTNNB1 hotspot mutations are concentrated near phosphorylation sites mediating pS45-induced degradation of β-catenin, which may render Wnt-FZD antagonists ineffective. Deep learning accurately predicts EC subtypes and mutations from histopathology images, which may be useful for rapid diagnosis. Overall, this study identified molecular and imaging markers that can be further investigated to guide patient stratification for more precise treatment of EC.

Metformin: A Review of Potential Mechanism and Therapeutic Utility Beyond Diabetes

Metformin has been designated as one of the most crucial first-line therapeutic agents in the management of type 2 diabetes mellitus. Primarily being an antihyperglycemic agent, metformin also has a plethora of pleiotropic effects on various systems and processes. It acts majorly by activating AMPK (Adenosine Monophosphate-Activated Protein Kinase) in the cells and reducing glucose output from the liver. It also decreases advanced glycation end products and reactive oxygen species production in the endothelium apart from regulating the glucose and lipid metabolism in the cardiomyocytes, hence minimizing the cardiovascular risks. Its anticancer, antiproliferative and apoptosis-inducing effects on malignant cells might prove instrumental in the malignancy of organs like the breast, kidney, brain, ovary, lung, and endometrium. Preclinical studies have also shown some evidence of metformin's neuroprotective role in Parkinson's disease, Alzheimer's disease, multiple sclerosis and Huntington's disease. Metformin exerts its pleiotropic effects through varied pathways of intracellular signalling and exact mechanism in the majority of them remains yet to be clearly defined. This article has extensively reviewed the therapeutic benefits of metformin and the details of its mechanism for a molecule of boon in various conditions like diabetes, prediabetes, obesity, polycystic ovarian disease, metabolic derangement in HIV, various cancers and aging.

Progestin plus metformin improves outcomes in patients with endometrial hyperplasia and early endometrial cancer more than progestin alone: a meta-analysis

Objective

Progestin based therapy is the preferred option for fertility-sparing treatment of reproductive-age women with preserved fertility in endometrial hyperplasia (EH) or early endometrial cancer (EEC). Our objective was to investigate whether metformin could enhance the efficacy of progestin-based therapies by meta-analysis.

Methods

We conducted a meta-analysis of randomized or non-randomized controlled trials by searching of PubMed, Embase, Web of science, and Cochrane database from inception to November 8, 2022. The results of enrolled studies were pooled using meta-analysis to estimate the effect of progestin plus metformin on remission, recurrence, pregnancy rate and live birth rate.

Results

In the analysis of progestin administered systemically or locally, complete response (CR) was significantly higher in progestin plus metformin versus progestin alone in the EH group (pooled OR 2.08, 95% CI 1.29 to 3.34, P=0.003), in the EEC group (pooled OR 1.86, 95% CI 1.13 to 3.05, P=0.01), but not in EEC and EH group (pooled OR 1.46, 95% CI 0.97 to 2.21, P=0.07). In the analysis of progestin administered systemically, complete response was improved in progestin plus metformin versus progestin alone, in the EH group (pooled OR 2.47, 95% CI 1.45 to 4.21, P=0.0009), in the EEC group (pooled OR 2.09, 95% CI 1.18 to 3.71, P=0.01), and in the EEC and EH group (pooled OR 2.03, 95% CI 1.16 to 3.54, P=0.01). The relapse rates of patients with EEC and EH were not different (pooled OR 0.54, 95% CI 0.24 to 1.20, P=0.13). For obstetric outcomes, the addition of metformin improved pregnancy rate (pooled OR 1.55, 95% CI 0.99 to 2.42, P=0.05), but not live birth rate (pooled OR 0.95, 95% CI 0.45 to 2.01, P=0.89).

Conclusion

For fertility-sparing management, compared to progestin alone, the outcomes of patients with endometrial hyperplasia and early endometrial cancer were more improved with progestin plus metformin because progestin plus metformin increases the rate of remission and pregnancy.

Changes in the expression of cancer- and metastasis-related genes and proteins after metformin treatment under different metabolic conditions in endometrial cancer cells

Research question

Hyperinsulinemia and elevated estrogen levels are known risk factors for endometrial cancer (EC) development and are associated with obesity, type 2 diabetes mellitus (T2DM), insulin resistance, among others. Metformin, an insulin-sensitizing drug, displays anti-tumor effects in cancer patients, including EC, but the mechanism of action is still not completely understood. In the present study, the effects of metformin on gene and protein expression were investigated in pre- and postmenopausal EC in vitro models in order to identify candidates that are potentially involved in the drug's anti-cancer mechanism.

Design

After treating the cells with metformin (0.1 and 1.0 mmol/L), changes in the expression of >160 cancer- and metastasis-related gene transcripts were evaluated with RNA arrays. A total of 19 genes and 7 proteins were selected for a follow-up expression analysis, including further treatment conditions, in order to evaluate the influence of hyperinsulinemia and hyperglycemia on metformin-induced effects.

Results

Changes in the expression of BCL2L11, CDH1, CDKN1A, COL1A1, PTEN, MMP9 and TIMP2 were analyzed on gene and protein level. The consequences resulting from the detected expression changes as well as the influence of varying environmental influences are discussed in detail. With the presented data, we contribute to a better understanding of the direct anti-cancer activity of metformin as well as its underlying mechanism of action in EC cells.

Conclusions

Although further research will be necessary to confirm the data, the influence of different environmental settings on metformin-induced effects could be highlighted with the presented data. Additionally, gene and protein regulation were not similar in the pre- and postmenopausal in vitro models.

Clinical and metabolic characteristics of endometrial lesions in polycystic ovary syndrome at reproductive age

BACKGROUND

We aimed to explore the clinical and metabolic characteristics in polycystic ovary syndrome (PCOS) patients with different endometrial lesions.

METHODS

234 PCOS patients who underwent hysteroscopy and endometrial biopsy were categorized into four groups: (1) normal endometrium (control group, n = 98), (2) endometrial polyp (EP group, n = 92), (3) endometrial hyperplasia (EH group, n = 33), (4) endometrial cancer (EC group, n = 11). Serum sex hormone levels, 75 g oral glucose tolerance test, insulin release test, fasting plasma lipid, complete blood count and coagulation parameters were measured and analyzed.

RESULTS

Body mass index and triglyceride level of the EH group were higher while average menstrual cycle length was longer in comparison with the control and EP group. Sex hormone-binding globulin (SHBG) and high density lipoprotein were lower in the EH group than that in the control group. 36% of the patients in the EH group suggested obesity, higher than the other three groups. Using multivariant regression analysis, patients with free androgen index > 5 had higher risk of EH (OR 5.70; 95% CI 1.05-31.01), while metformin appeared to be a protective factor for EH (OR 0.12; 95% CI 0.02-0.80). Metformin and hormones (oral contraceptives or progestogen) were shown to be protective factors for EP (OR 0.09; 95% CI 0.02-0.42; OR 0.10; 95% CI 0.02-0.56). Hormones therapy appeared to be a protective factor for EC (OR 0.05; 95% CI 0.01-0.39).

CONCLUSION

Obesity, prolonged menstrual cycle, decreased SHBG, and dyslipidemia are risk factors for EH in patients with PCOS. Oral contraceptives, progestogen and metformin are recommended for prevention and treatment of endometrial lesions in PCOS patients.

Glucose metabolic reprogramming and its therapeutic potential in obesity-associated endometrial cancer

Endometrial cancer (EC) is a common gynecological cancer that endangers women health. Although substantial progresses of EC management have been achieved in recent years, the incidence of EC still remains high. Obesity has been a common phenomenon worldwide that increases the risk of EC. However, the mechanism associating obesity and EC has not been fully understood. Metabolic reprogramming as a remarkable characteristic of EC is currently emerging. As the primary factor of metabolic syndrome, obesity promotes insulin resistance, hyperinsulinemia and hyperglycaemia. This metabolic disorder remodels systemic status, which increases EC risk and is related with poor prognosis. Glucose metabolism in EC cells is complex and mediated by glycolysis and mitochondria to ensure energy requirement. Factors that affect glucose metabolism may have an impact on EC initiation and progression. In this study, we review the glucose metabolic reprogramming of EC not only systemic metabolism but also inherent tumor cell metabolism. In particular, the role of glucose metabolic regulation in malignant properties of EC will be focused. Understanding of metabolic profile and glucose metabolism-associated regulation mechanism in EC may provide novel perspective for treatment.

GRADE Use in Evidence Syntheses Published in High-Impact-Factor Gynecology and Obstetrics Journals: A Methodological Survey

Objective: To identify and describe the certainty of evidence of gynecology and obstetrics systematic reviews (SRs) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Method: Database searches of SRs using GRADE, published between 1 January 2016 to 31 December 2020, in the 10 "gynecology and obstetrics" journals with the highest impact factor, according to the Journal Citation Report 2019. Selected studies included those SRs using the GRADE approach, used to determine the certainty of evidence. Results: Out of 952 SRs, ninety-six SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Sixty-seven SRs (7.04%) rated the certainty of evidence for specific outcomes. In total, we identified 946 certainty of evidence outcome ratings (n = 614 RCT ratings), ranging from very-low (42.28%) to low (28.44%), moderate (17.65%), and high (11.63%). High and very low certainty of evidence ratings accounted for 2.16% and 71.60% in the SRs of NRSs, respectively, compared with 16.78% and 26.55% in the SRs of RCTs. In the SRs of RCTs and NRSs, certainty of evidence was mainly downgraded due to imprecision and bias risks. Conclusions: More attention needs to be paid to strengthening GRADE acceptance and building knowledge of GRADE methods in gynecology and obstetrics evidence synthesis.

Endometrial Hyperplasia

The objectives of this Clinical Expert Series on endometrial hyperplasia are to review the etiology and risk factors, histologic classification and subtypes, malignant progression risks, prevention options, and to outline both surgical and nonsurgical treatment options. Abnormal uterine and postmenopausal bleeding remain the hallmark of endometrial pathology, and up to 10-20% of postmenopausal bleeding will be either hyperplasia or cancer; thus, immediate evaluation of any abnormal bleeding with either tissue procurement for pathology or imaging should be undertaken. Although anyone with a uterus may develop atypical hyperplasia, also known as endometrial intraepithelial neoplasia (EIN), genetic predispositions (eg, Lynch syndrome), obesity, chronic anovulation, and polycystic ovarian syndrome all markedly increase these risks, whereas use of oral contraceptive pills or progesterone-containing intrauterine devices will decrease the risk. An EIN diagnosis carries a high risk of concomitant endometrial cancer or eventual progression to cancer in the absence of treatment. The definitive and curative treatment for EIN remains hysterectomy; however, the obesity epidemic, the potential desire for fertility-sparing treatments, the recognition of varying rates of malignant transformation, medical comorbidities, and an aging population all may factor into decisions to employ nonsurgical treatment modalities.

Levonorgestrel-releasing intrauterine device plus metformin, or megestrol acetate plus metformin for fertility-sparing treatment of atypical endometrial hyperplasia and early endometrial carcinoma: a prospective, randomized, blind-endpoint design trial protocol

Background

Endometrial adenocarcinoma (EC) is the fifth most common cancer in women worldwide, standard treatment for EC includes hysterectomy, but it results in the loss of reproductive function. Thus, conservative treatment for these patients is strongly demanded, progestin therapy is widely accepted as the main fertility-sparing treatment for young women with endometrial hyperplasia with atypia (EHA) and well-differentiated endometrioid endometrial cancer. This trial will investigate the effectiveness of conservative treatment for obese women with early-stage EC.

Method and design

This will be an open-label, 2-armed, randomized, phase-II single-center trial of LNG-IUD plus metformin or megestrol acetate (MA) plus metformin. A total of 88 participants will be randomly assigned into 2 treatment arms in a 1:1 ratio. Clinical, laboratory, ultrasound and radiology data, will be collected at baseline, and then at 3, 6, 9, 12, 18, and 24 months. EC biomarkers will be collected at baseline. The primary aim is to determine the efficacy of a levonorgestrel-releasing intrauterine device (LNG-IUD) plus metformin, or megestrol acetate (MA) plus metformin in achieving pathological complete response (pCR) at 12 months, as well as post-treatment pregnancy outcomes and recurrence rate. The secondary aims are to predict the response to an LNG-IUD plus metformin and MA plus metformin via clinical, blood, and tissue predictive biomarkers.

Conclusions

Prospective evidence for conservative treatment of EC is limited. New methods to achieve better CR rates with fewer side effects are needed. This trial will investigate the effectiveness of LNG-IUD plus metformin, and MA plus metformin, in obese women with early-stage EC, providing a non-surgical treatment option for these patients.

Trial registration ChiCTR2200055624. The trial was registered at http://www.chictr.org.cn/listbycreater.aspx on January 15, 2022

Endometrial adenocarcinoma (EC) is the fifth most common cancer in women worldwide, and up to 90% of EC patients are obese. Standard treatment for EC includes hysterectomy, but it leads to loss of reproductive function. This trial will investigate the effectiveness of non-surgical treatment for obese women with early-stage EC. There is limited prospective evidence for the conservative treatment of EC. New methods to achieve better CR rates with fewer side effects are needed. In this trial, patients with early-stage EC will be randomly assigned in a 1:1 ratio to receive treatment with a levonorgestrel-releasing intrauterine device (LNG-IUD) plus metformin, or megestrol acetate (MA) plus metformin. The primary aims are to determine the effectiveness of the 2 treatments to achieve a pathological complete response (pCR) at 12 months, pregnancy outcomes, and recurrence rate. The secondary aims are to predict the response to the 2 treatments using clinical data and blood and tissue predictive biomarkers. If the trial results indicate the treatments are effective, they may significantly reduce the incidence of adverse events in obese EC patients receiving current treatments, and preserve fertility; thereby improving patients’ quality of life and reducing healthcare costs.

Glucose transporters: Important regulators of endometrial cancer therapy sensitivity

Glucose is of great importance in cancer cellular metabolism. Working together with several glucose transporters (GLUTs), it provides enough energy for biological growth. The main glucose transporters in endometrial cancer (EC) are Class 1 (GLUTs 1-4) and Class 3 (GLUTs 6 and 8), and the overexpression of these GLUTs has been observed. Apart from providing abundant glucose uptake, these highly expressed GLUTs also participate in the activation of many crucial signaling pathways concerning the proliferation, angiogenesis, and metastasis of EC. In addition, overexpressed GLUTs may also cause endometrial cancer cells (ECCs) to be insensitive to hormone therapy or even resistant to radiotherapy and chemoradiotherapy. Therefore, GLUT inhibitors may hopefully become a sensitizer for EC precision-targeted therapies. This review aims to summarize the expression regulation, function, and therapy sensitivity of GLUTs in ECCs, aiming to provide a new clue for better diagnosis and treatment of EC.

Metformin in Combination with Progesterone Improves the Pregnancy Rate for Patients with Early Endometrial Cancer

Objective. To study the therapeutic effects of metformin in combination with medroxyprogesterone in the early endometrial cancer patients with fertility requirements. A total of 120 patients with early endometrial cancer admitted to and treated in our hospital were enrolled and evenly assigned into two groups according to different therapeutic regimens, namely, metformin group (metformin combined with medroxyprogesterone acetate) and control group (medroxyprogesterone acetate alone). The objective response rate (ORR) and disease control rate (DCR) were 71.7% (43/60) and 90.0% (54/60) in the metformin group and 53.3% (32/60) and 78.3% (47/60) in the control group, respectively. Adverse reactions such as gastrointestinal reaction, headache, and insomnia were mainly observed in patients. The body mass index (BMI) declined from (34.43 ± 4.34) kg/m² to (24.77 ± 2.39) kg/m² in the metformin group and from (33.37 ± 4.49) kg/m² to (31.28 ± 3.55) kg/m² in the control group after treatment. After treatment, serum levels of vascular endothelial growth factor (VEGF), angiotensin-2 (Ang-2), carbohydrate antigen 125 (CA125), and CA19-9 in the metformin group were significantly lower than those in the control group (P = 0.005, P < 0.001, P = 0.002, and P < 0.001). During follow-up, the pregnancy rate was 81.7% (49/60) in the metformin group and 61.7% (37/60) in the control group, and the former was prominently higher than the latter (P = 0.025). Metformin in combination with progesterone is effective in treating early endometrial cancer patients with fertility requirements, which significantly reduced the BMI of patients and increased the pregnancy rate after treatment.

Metabolic dysfunction and obesity-related cancer: Beyond obesity and metabolic syndrome

OBJECTIVES

The metabolic dysfunction driven by obesity, including hyperglycemia and dyslipidemia, increases risk for developing at least 13 cancer types. The concept of "metabolic dysfunction" is often defined by meeting various combinations of criteria for metabolic syndrome. However, the lack of a unified definition of metabolic dysfunction makes it difficult to compare findings across studies. This review summarizes 129 studies that evaluated variable definitions of metabolic dysfunction in relation to obesity-related cancer risk and mortality after a cancer diagnosis. Strategies for metabolic dysfunction management are also discussed.

METHODS

A comprehensive search of relevant publications in MEDLINE (PubMed) and Google Scholar with review of references was conducted.

RESULTS

Metabolic dysfunction, defined as metabolic syndrome diagnosis or any number of metabolic syndrome criteria out of clinical range, inflammatory biomarkers, or markers of metabolic organ function, has been associated with risk for, and mortality from, colorectal, pancreatic, postmenopausal breast, and bladder cancers. Metabolic dysfunction associations with breast and colorectal cancer risk have been observed independently of BMI, with increased risk in individuals with metabolically unhealthy normal weight or overweight/obesity compared with metabolically healthy normal weight.

CONCLUSION

Metabolic dysfunction is a key risk factor for obesity-related cancer, regardless of obesity status. Nonetheless, a harmonized definition of metabolic dysfunction will further clarify the magnitude of the relationship across cancer types, enable better comparisons across studies, and further guide criteria for obesity-related cancer risk stratification.

Metformin and survival: Is there benefit in a cohort limited to diabetic women with endometrial, breast, or ovarian cancer?

OBJECTIVE

Evaluate the association between metformin and survival in women with Type 2 diabetes (T2DM) and breast, endometrial and ovarian cancer- 3 hormonally mediated cancers.

METHODS

We evaluated outcomes in a cohort of 6225 women with T2DM with a new diagnosis of ovarian, breast or endometrial cancer from 2010 to 2019. We classified glycemic medications at time of first cancer diagnosis into 3 tiers in accordance with ADA guidelines. Approaches compared: (i) metformin (tier 1) vs. no glycemic medication, (ii) metformin vs tier 2 medications (sulfonylureas, thiazolidinediones, SGLT2-inhibitors, DPP4-inhibitors, alpha glucosidase-inhibitors, GLP-1 agonists), (iii) metformin vs tier 3 medications (insulins, amylinomimetics), and (iv) tier 2 vs tier 3 medications. Analyses included Cox proportional-hazards models, Kaplan-Meier curves, and conditional logistic regression in a risk set-sampled nested case-control matched on T2DM duration- all modeling survival. Models were adjusted for demographics, cancer type, A1C, T2DM duration, and number of office visits and hospitalizations.

RESULTS

Metformin was the most used medication (n = 3232) and consistently demonstrated survival benefit compared with tier 2 and 3 medications, across all methods. Tier 3-users demonstrated highest risk of death when compared to metformin rather than tier 2 [adjHR = 1.83 (95% CI: 1.58, 2.13) vs. adjHR = 1.32 (95% CI: 1.11, 1.57)], despite similar baseline profiles between tier 1 and 2 users.

CONCLUSIONS

Metformin users experienced increased survival even after accounting for surrogates of diabetes progression. Benefit extended beyond that seen in tier 2-users. Our findings, consistent with prior studies, indicate metformin use improves survival in women with T2DM and hormonally mediated women's cancers.

Proteomic Analysis of Endometrial Cancer Tissues from Patients with Type 2 Diabetes Mellitus

Endometrial cancer (EC) is the most common form of gynecological cancer. Type 2 diabetes mellitus is associated with an increased risk of EC. Currently, no proteomic studies have investigated the role of diabetes in endometrial cancers from clinical samples. The present study aims to elucidate the molecular link between diabetes and EC using a proteomic approach. Endometrial tissue samples were obtained from age-matched patients (EC Diabetic and EC Non-Diabetic) during surgery. Untargeted proteomic analysis of the endometrial tissues was carried out using a two-dimensional difference in gel electrophoresis (2D-DIGE) coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF). A total of 53 proteins were identified, with a significant difference in abundance (analysis of variance (ANOVA) test, p ≤ 0.05; fold-change ≥ 1.5) between the two groups, among which 30 were upregulated and 23 downregulated in the EC Diabetic group compared to EC Non-Diabetic. The significantly upregulated proteins included peroxiredoxin-1, vinculin, endoplasmin, annexin A5, calreticulin, and serotransferrin. The significantly downregulated proteins were myosin regulatory light polypeptide 9, Retinol dehydrogenase 12, protein WWC3, intraflagellar transport protein 88 homolog, superoxide dismutase [Cu-Zn], and retinal dehydrogenase 1. The network pathway was related to connective tissue disorder, developmental disorder, and hereditary disorder, with the identified proteins centered around dysregulation of ERK1/2 and F Actin signaling pathways. Cancer-associated protein alterations such as upregulation of peroxiredoxin-1, annexin 5, and iNOS, and downregulation of RDH12, retinaldehyde dehydrogenase 1, SOD1, and MYL 9, were found in the EC tissues of the diabetic group. Differential expression of proteins linked to cancer metastasis, such as the upregulation of vinculin and endoplasmin and downregulation of WWC3 and IFT88, was seen in the patients with diabetes. Calreticulin and alpha-enolase, which might have a role in the interplay between diabetes and EC, need further investigation.

Metformin Intervention—A Panacea for Cancer Treatment?

The molecular mechanism of action and the individual influence of various metabolic pathways related to metformin intervention are under current investigation. The available data suggest that metformin provides many advantages, exhibiting anti-inflammatory, anti-cancer, hepatoprotective, cardioprotective, otoprotective, radioprotective, and radio-sensitizing properties depending on cellular context. This literature review was undertaken to provide novel evidence concerning metformin intervention, with a particular emphasis on cancer treatment and prevention. Undoubtedly, the pleiotropic actions associated with metformin include inhibiting inflammatory processes, increasing antioxidant capacity, and improving glycemic and lipid metabolism. Consequently, these characteristics make metformin an attractive medicament to translate to human trials, the promising results of which were also summarized in this review.

Targeting Cancer Metabolism Plasticity with JX06 Nanoparticles via Inhibiting PDK1 Combined with Metformin for Endometrial Cancer Patients with Diabetes

Diabetes is closely related to the occurrence of endometrial cancer (EC) and its poor prognosis. However, there is no effective clinical treatment for EC patients with diabetes (patient^EC+/dia+ ). To explore new therapeutic targets, Ishikawa is cultured with high glucose (Ishikawa^HG ) mimicking hyperglycemia in patient^EC+/dia+ . Subsequently, it is discovered that Ishikawa^HG exhibits glucose metabolic reprogramming characterized by increased glycolysis and decreased oxidative phosphorylation. Further, pyruvate dehydrogenase kinase 1 (PDK1) is identified to promote glycolysis of Ishikawa^HG by proteomics. Most importantly, JX06, a novel PDK1 inhibitor combined metformin (Met) significantly inhibits Ishikawa^HG proliferation though Ishikawa^HG is resistant to Met. Furthermore, a reduction-sensitive biodegradable polymer is adopted to encapsulate JX06 to form nanoparticles (JX06-NPs) for drug delivery. It is found that in vitro JX06-NPs have better inhibitory effect on the growth of Ishikawa^HG as well as patient-derived EC cells (PDC) than JX06. Additionally, it is found that JX06-NPs can accumulate to the tumor of EC-bearing mouse with diabetes (mice^EC+/dia+ ) after intravenous injection, and JX06-NPs combined Met can significantly inhibit tumor growth of mice^EC+/dia+ . Taken together, the study demonstrates that the combination of JX06-NPs and Met can target the cancer metabolism plasticity, which significantly inhibits the growth of EC, thereby provides a new adjuvant therapy for patients^EC+/dia+ .

Biomolecular and Genetic Prognostic Factors That Can Facilitate Fertility-Sparing Treatment (FST) Decision Making in Early Stage Endometrial Cancer (ES-EC): A Systematic Review

Endometrial cancer occurs in up to 29% of women before 40 years of age. Seventy percent of these patients are nulliparous at the time. Decision making regarding fertility preservation in early stage endometrial cancer (ES-EC) is, therefore, a big challenge since the decision between the risk of cancer progression and a chance to parenthood needs to be made. Sixty-two percent of women with complete remission of ES-EC after fertility-sparing treatment (FST) report to have a pregnancy wish which, if not for FST, they would not be able to fulfil. The aim of this review was to identify and summarise the currently established biomolecular and genetic prognostic factors that can facilitate decision making for FST in ES-EC. A comprehensive search strategy was carried out across four databases; Cochrane, Embase, MEDLINE, and PubMed; they were searched between March 1946 and 22nd December 2022. Thirty-four studies were included in this study which was conducted in line with the PRISMA criteria checklist. The final 34 articles encompassed 9165 patients. The studies were assessed using the Critical Appraisal Skills Program (CASP). PTEN and POLE alterations we found to be good prognostic factors of ES-EC, favouring FST. MSI, CTNNB1, and K-RAS alterations were found to be fair prognostic factors of ES-EC, favouring FST but carrying a risk of recurrence. PIK3CA, HER2, ARID1A, P53, L1CAM, and FGFR2 were found to be poor prognostic factors of ES-EC and therefore do not favour FST. Clinical trials with bigger cohorts are needed to further validate the fair genetic prognostic factors. Using the aforementioned good and poor genetic prognostic factors, we can make more confident decisions on FST in ES-EC.

Fertility-Sparing Approaches in Atypical Endometrial Hyperplasia and Endometrial Cancer Patients: Current Evidence and Future Directions

Endometrial cancer (EC) is the fourth most common cancer in women in developed countries. Although it is usually diagnosed in postmenopausal women, its incidence has increased in young women, as well in recent decades, with an estimated rate of 4% in those under 40 years of age. Factors involved in this increase, particularly in resource-rich countries, include delayed childbearing and the rise in obesity. The new molecular classification of EC should help to personalize treatment, through appropriate candidate selection. With the currently available evidence, the use of oral progestin either alone or in combination with other drugs such as metformin, levonorgestrel-releasing intrauterine devices and hysteroscopic resection, seems to be feasible and safe in women with early-stage EC limited to the endometrium. However, there is a lack of high-quality evidence of the efficacy and safety of conservative management in EC. Randomized clinical trials in younger women and obese patients are currently underway.

Metformin Alleviates Endometriosis and Potentiates Endometrial Receptivity via Decreasing VEGF and MMP9 and Increasing Leukemia Inhibitor Factor and HOXA10

Background: Endometriosis affects endometrial receptivity, a key factor for successful embryo implantation. Metformin treatment is associated with alleviating the symptoms of endometriosis; however the mechanism of metformin action is unclear. Neoangiogenesis plays an important role in the development and recurrence of endometriosis. In addition, the leukemia inhibitor factor (LIF) and HOXA10 genes are also distinguishing markers of endometriosis (decrease) and endometrial receptivity (increase). This study investigated the therapeutic potentials of metformin and the underlying mechanism using an in vivo rat endometriosis model. Methods: Female Wistar albino mature rats with experimentally induced endometriosis were used in this study. Metformin was administered at doses of 100 mg/kg/d and 200 mg/kg/d. The volume of endometriotic implants was assessed. The protein and mRNA expression of the vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), the endometrial receptivity markers, LIF and HOXA10, were measured in the endometrium of rats with endometriosis. Results: Metformin treatment significantly suppressed the growth of endometriotic implants. Further, the expression of VEGF and MMP-9 protein and mRNA in endometriotic implants were significantly reduced. Metformin also significantly upregulated LIF and HOXA10 expression in endometrium from rats with endometriosis. The inhibitory effect of metformin on the growth of endometriotic implants, VEGF and MMP-9, and upregulating effect on LIF and HOXA10, was optimal at a dose of 100 mg/kg/d. Conclusion: Our in vivo data demonstrates that metformin treatment alleviates endometriosis and potentiates endometrial receptivity. The underlying mechanisms are associated with decreased expression of VEGF and MMP-9 genes and upregulation of the LIF and HOXA10 genes. The effect of metformin was optimal at 100 mg/kg/d. These findings provide a potential alternative for women with endometriosis with the potential to increase fertility. Metformin is an approved drug by FDA for diabetes and this study may add another potential clinical use for metformin.

Uterine sparing management in patients with endometrial cancer: a narrative literature review

Endometrial cancer is the most common malignancy of the female genital tract. Approximately 25% of cases occur in premenopausal women, and up to 5% of cases occur in women who are younger than 40 years old. The survival rate in these cases is 99%; therefore, uterine-sparing management could be considered under strict criteria selection and the strong desire of the woman to preserve uterus and fertility. Diagnosis should be performed after a hysteroscopic biopsy instead of dilatation and curettage. The highest remission rate was achieved after combining a hysteroscopic resection with hormonal therapy compared to single hormonal treatment. The most common regiments are the following progestins: megestrol acetate (MA) and medroxyprogesterone acetate (MPA) taken orally with a daily dosage of 160 mg-320 mg for MA and 250 mg-600 mg for MP. Evaluations at three and six months could be performed by office endometrial biopsy and/or hysteroscopic directed biopsy especially in the presence of levonorgestrel intrauterine system, and in cases of remission, either a pregnancy attempt or maintenance therapy should be considered. After childbearing, hysterectomy with bilateral salpingo-oophorectomy is recommended, whereas ovarian preservation could be considered depending on the patient's age and whether they fulfil the strict criteria selection.

A Prospective Cohort Study of Metformin as an Adjuvant Therapy for Infertile Women With Endometrial Complex Hyperplasia/Complex Atypical Hyperplasia and Their Subsequent Assisted Reproductive Technology Outcomes

OBJECTIVE

To investigate the adjuvant efficacy of metformin treatment to achieve pathological complete response (CR) in patients with endometrial complex hyperplasia (CH) and complex atypical hyperplasia (CAH), and secondarily, to evaluate their pregnancy outcomes after following assisted reproductive technology (ART).

STUDY DESIGN

This prospective cohort study analyzed 219 patients diagnosed with infertility and CH/CAH from January 2016 to December 2020. Among these patients, 138 were assigned to the control group (progesterone alone) and 81 were assigned to the study group (progesterone+metformin). After 8/12 weeks of therapy, the treatment responses were assessed by histological examination of curettage specimens obtained by hysteroscopy. Once the pathological results indicated CR, the patients were able to receive ART. The ART treatment and follow-up data of these patients were collected and analyzed.

RESULTS

116 patients in the control group achieved CR, compared with 76 patients in the study group. The CR rate in the control group was significantly lower than that in the study group (P=0.034). We then divided the patients into subgroups to compare the treatment responses. In the subgroup analyses, patients with body mass index (BMI) ≥25 kg/m² and patients with polycystic ovarian syndrome (PCOS) had higher CR rates in the metformin group compared with the control group (P=0.015, P=0.028 respectively). Subsequently, 68 patients in the control group and 47 patients in the study group received an ART cycle. We examined the pregnancy indications and found no significant differences in the clinical pregnancy rate and live birth rate between the two groups (P>0.05).

CONCLUSION

Regression of CH/CAH may be improved by progesterone+metformin compared with progesterone alone. The effect was particularly pronounced in patients with BMI ≥25 kg/m² and patients with PCOS. Metformin had no obvious effect on subsequent ART outcomes. The trial is registered on the publicly accessible website.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/showproj.aspx?proj=15372, identifier ChiCTR-ONR-16009078.

The present status of metformin in fertility-preserving treatment in atypical endometrial hyperplasia and endometrioid endometrial cancer

Progestin therapy is the main fertility-sparing treatment for women with endometrial cancer (EC) and atypical endometrial hyperplasia (AEH). However, still 15-25% of these women failed to achieve complete response (CR) and then lost their fertility after definitive surgery. Metformin has been demonstrated to play an anti-cancer role in multiple cancers including EC. Several studies also suggested metformin had potential benefit in improving the therapeutic outcome of fertility-preserving treatment alongside with progestin. This review has discussed existed evidence regarding the effect of metformin combined with progestin for women with AEH and EC who desire childbearing. Nevertheless, the therapeutic effect of metformin varied in different studies due to the high heterogeneity in the patient's characteristics, the inconsistency in dose and treatment duration of metformin, the combined use of hysteroscopy, the insufficient sample size and underpowered study-design. Therefore, care should be taken when interpreting the current results on this issue. Till now, there is still no strong evidence supporting the use of metformin in fertility-preserving treatment in AEH and EEC patients. Further research is needed to provide high-quality data to validate the role of metformin as adjunctive therapy alongside with progestin to preserve fertility for AEH and EEC patients.

Hysteroscopic Curettage Followed by Megestrol Acetate Plus Metformin as a Fertility-Sparing Treatment for Women with Atypical Endometrial Hyperplasia or Well-Differentiated Endometrioid Endometrial Carcinoma

Background:

In reproductive-aged women, the incidence of atypical endometrial hyperplasia (AEH) or endometrioid endometrial carcinoma (EEC) is rising globally. The study aimed to investigate the effectiveness of hysteroscopic curettage followed by megestrol acetate (MA) plus metformin as conservative treatment in AEH and early EEC.

Methods:

We retrospectively studied AEH and stage IA, grade 1 EEC patients treated with hysteroscopic curettage followed by MA (160 mg/d) plus metformin (1500 mg/d) from January 2010 to December 2020 at Fudan University Shanghai Cancer Center. Treatment outcomes were assessed by complete response (CR) rate, recurrence rate, and pregnancy outcomes. Univariate and multivariate analyses were performed via the logistic regression model.

Results:

The study included 79 patients, 31 (39.2%) with AEH and 48 (60.8%) with EEC. The medians of age (years) and follow-up time (months) were 30 and 39.5, respectively. Seventy-six patients (96.2%) finally achieved CR. The median time to CR was 3.6 (3.0-20.6) months. The CR rate after 3 months, 6 months, and 1 year was 55 (69.6%), 67 (84.8%), and 72 (91.1%), respectively. Recurrence occurred in 26 (34.2%) patients. Treatment duration ⩾9 months was associated with a lower recurrence rate after CR (P = .012). Fourteen (93.3%) of the 15 recurrent patients who received progestin re-treatment achieved CR again. Finally, 29 patients delivered live births.

Conclusions:

Hysteroscopy followed by MA plus metformin can achieve CR in short time and is overall safe. Consolidation treatment should be prolonged to decrease the recurrence rate, despite a shorter time to CR.

Antiproliferative effects of metformin in cellular models of pheochromocytoma

Pheochromocytomas (PCCs) are rare neuroendocrine tumors derived from adrenal medulla chromaffin cells. Malignancy and recurrence are rare but demand effective treatment. Metformin exerts antiproliferative effects in several cancer cell lines. We thus evaluated the effects of metformin on cell viability and proliferation, cellular respiration and AMPK-AKT-mTOR-HIFA proliferation pathway on a rat PCC cell line (PC12-Adh). We then addressed metformin's effects on the AMPK-AKT-mTOR-HIFA pathway on two human primary cultures: one from a VHL-mutant PCC and other from a sporadic PCC. Metformin (20 mM) inhibited PC12-Adh cell proliferation, and decreased oxygen consumption, ATP production and proton leak, in addition to loss of mitochondrial membrane potential. Further, metformin induced AMPK phosphorylation and impaired AMPK-PI3k-AKT-mTOR pathway activation. The mTOR pathway was also inhibited in human VHL-related PCC cells, however, in an AMPK-independent manner. Metformin-induced decrease of HIF1A levels was likely mediated by proteasomal degradation. Altogether our results suggest that metformin impairs PCC cellular proliferation.

The Role of Hypoxia in Endometrial Cancer

Endometrial cancer represents the most frequent neoplasia from the corpus uteri and comprises the 14th leading cause of death in women worldwide. Risk factors that contribute to the disease include early menarche, late menopause, nulliparity, and menopausal hormone use, as well as hypertension and obesity comorbidities. The clinical effectiveness of chemotherapy is variable, suggesting that novel molecular targeted therapies against specific cellular processes associated with the maintenance of cancer cell survival and therapy resistance ameliorate the rates of success in endometrial cancer treatment. In the course of tumor growth, cancer cells must adapt to decreased oxygen availability in the microenvironment by upregulation of hypoxia-inducible factors, which orchestrate the activation of a transcriptional program leading to cell survival. During this adaptative process, the hypoxic cancer cells may acquire invasive and metastatic properties as well as increased cell proliferation and resistance to chemotherapy, enhanced angiogenesis, vasculogenic mimicry, and maintenance of cancer cell stemness, which contribute to more aggressive cancer phenotypes. Several studies have shown that hypoxia-inducible factor 1 alpha (HIF-1α) protein is aberrantly overexpressed in many solid tumors of the breast, prostate, ovarian, bladder, colon, brain, and pancreas. Thus, it has been considered an important therapeutic target. Here, we reviewed the current knowledge of the relevant roles of cellular hypoxia mechanisms and HIF-1α functions in diverse processes associated with endometrial cancer progression. In addition, we also summarize the role of microRNAs in the posttranscriptional regulation of protein-encoding genes involved in the hypoxia response in endometrial cancer. Finally, we pointed out the need for urgent targeted therapies to impair the cellular processes activated by hypoxia in the tumor microenvironment.

Contemporary Fertility-Sparing Management Options of Early Stage Endometrioid Endometrial Cancer in Young Nulliparous Patients

Incidence of endometrial cancer (EC) has been increasing in recent years, especially in high-income countries. The disease commonly affects peri- and postmenopausal women; however, about 5% of women are diagnosed with EC in their reproductive age. Due to both the increasing incidence of EC among reproductive age women and trends to delayed childbearing, fertility-sparing treatment for young patients with EC has become extremely important for researchers and practitioners. Because the classic treatment with total hysterectomy and bilateral saplingo-oophorectomy is not an appropriate approach for young women demanding fertility preservation, several fertility-sparing options have been developed and summarized in this review. Utilization of different medications and their combination (progestagens, gonadotropin releasing hormones analogues, and metformin in different formulations) are tested and found as efficient for fertility-sparing treatment. New minimally invasive surgical techniques, combined with progestagens, are also confirmed as valuable. There are many novel conservative and surgical treatment approaches under investigation. Assuming that molecular biomarkers can be both diagnostic and prognostic to assist in prediction of response to a certain therapy, prognostic risk groups' stratification along with specific biomarkers' identification will ensure low recurrence and decrease mortality rates in young women with EC.

Metformin for Cardiovascular Protection, Inflammatory Bowel Disease, Osteoporosis, Periodontitis, Polycystic Ovarian Syndrome, Neurodegeneration, Cancer, Inflammation and Senescence: What Is Next?

Diabetes is accompanied by several complications. Higher prevalence of cancers, cardiovascular diseases, chronic kidney disease (CKD), obesity, osteoporosis, and neurodegenerative diseases has been reported among patients with diabetes. Metformin is the oldest oral antidiabetic drug and can improve coexisting complications of diabetes. Clinical trials and observational studies uncovered that metformin can remarkably prevent or alleviate cardiovascular diseases, obesity, polycystic ovarian syndrome (PCOS), osteoporosis, cancer, periodontitis, neuronal damage and neurodegenerative diseases, inflammation, inflammatory bowel disease (IBD), tuberculosis, and COVID-19. In addition, metformin has been proposed as an antiaging agent. Numerous mechanisms were shown to be involved in the protective effects of metformin. Metformin activates the LKB1/AMPK pathway to interact with several intracellular signaling pathways and molecular mechanisms. The drug modifies the biologic function of NF-κB, PI3K/AKT/mTOR, SIRT1/PGC-1α, NLRP3, ERK, P38 MAPK, Wnt/β-catenin, Nrf2, JNK, and other major molecules in the intracellular signaling network. It also regulates the expression of noncoding RNAs. Thereby, metformin can regulate metabolism, growth, proliferation, inflammation, tumorigenesis, and senescence. Additionally, metformin modulates immune response, autophagy, mitophagy, endoplasmic reticulum (ER) stress, and apoptosis and exerts epigenetic effects. Furthermore, metformin protects against oxidative stress and genomic instability, preserves telomere length, and prevents stem cell exhaustion. In this review, the protective effects of metformin on each disease will be discussed using the results of recent meta-analyses, clinical trials, and observational studies. Thereafter, it will be meticulously explained how metformin reprograms intracellular signaling pathways and alters molecular and cellular interactions to modify the clinical presentations of several diseases.

Perspectives of metformin use in endometrial cancer and other gynaecological malignancies

Insulin resistance and hyperinsulinemia play a key role in type 1 endometrial cancer pathogenesis. Most of these cancers develop on a background of overweight or type 2 diabetes mellitus (T2DM). One of the medications widely used in the treatment of T2DM is biguanide derivative, metformin, which exerts promising anticancer properties principally through activation of adenosine monophosphate kinase (AMPK) and inhibition of mammalian target of rapamycin (mTOR) pathways. Many epidemiological studies on diabetic patients show potential preventative role of metformin in endometrial cancer patients, but data regarding its therapeutic role is still limited. So far, most of attention has been paid to the concept of metformin use in fertility sparing treatment of early-stage cancer. Another investigated alternative is its application in patients with primary advanced or recurrent disease. In this review we present the latest data on clinical use of metformin in endometrial cancer patients and potential underlying mechanisms of its activity. Finally, we present some most important clinical information regarding metformin efficacy in other gynaecological malignancies, mainly breast and ovarian cancer.

Statistical Meta-Analysis of Risk Factors for Endometrial Cancer and Development of a Risk Prediction Model Using an Artificial Neural Network Algorithm

Simple Summary

A robust and comprehensive meta-analysis, for the first time, identified definitely that BMI is by far the most influential risk factor in endometrial cancer. Risk factors were previously only studied individually and or in smaller meta-analysis studies which grouped some factors together. BMI was shown to be an important risk factor with other factors less so, but no rank order was established. This work also offers, for the first time, a neural network computer model to predict the overall increase or decreased risk of cancer for individual patients, which is 98.6% accurate. This prediction can be used as a tool to determine if a patient should be considered for testing and to predict diagnosis, as well as to suggest prevention measures to patients.

Abstract

Objectives: In this study we wished to determine the rank order of risk factors for endometrial cancer and calculate a pooled risk and percentage risk for each factor using a statistical meta-analysis approach. The next step was to design a neural network computer model to predict the overall increase or decreased risk of cancer for individual patients. This would help to determine whether this prediction could be used as a tool to decide if a patient should be considered for testing and to predict diagnosis, as well as to suggest prevention measures to patients. Design: A meta-analysis of existing data was carried out to calculate relative risk, followed by design and implementation of a risk prediction computational model based on a neural network algorithm. Setting: Meta-analysis data were collated from various settings from around the world. Primary data to test the model were collected from a hospital clinic setting. Participants: Data from 40 patients notes currently suspected of having endometrial cancer and undergoing investigations and treatment were collected to test the software with their cancer diagnosis not revealed to the software developers. Main outcome measures: The forest plots allowed an overall relative risk and percentage risk to be calculated from all the risk data gathered from the studies. A neural network computational model to determine percentage risk for individual patients was developed, implemented, and evaluated. Results: The results show that the greatest percentage increased risk was due to BMI being above 25, with the risk increasing as BMI increases. A BMI of 25 or over gave an increased risk of 2.01%, a BMI of 30 or over gave an increase of 5.24%, and a BMI of 40 or over led to an increase of 6.9%. PCOS was the second highest increased risk at 4.2%. Diabetes, which is incidentally also linked to an increased BMI, gave a significant increased risk along with null parity and noncontinuous HRT of 1.54%, 1.2%, and 0.56% respectively. Decreased risk due to contraception was greatest with IUD (intrauterine device) and IUPD (intrauterine progesterone device) at −1.34% compared to −0.9% with oral. Continuous HRT at −0.75% and parity at −0.9% also decreased the risk. Using open-source patient data to test our computational model to determine risk, our results showed that the model is 98.6% accurate with an algorithm sensitivity 75% on average. Conclusions: In this study, we successfully determined the rank order of risk factors for endometrial cancer and calculated a pooled risk and risk percentage for each factor using a statistical meta-analysis approach. Then, using a computer neural network model system, we were able to model the overall increase or decreased risk of cancer and predict the cancer diagnosis for particular patients to an accuracy of over 98%. The neural network model developed in this study was shown to be a potentially useful tool in determining the percentage risk and predicting the possibility of a given patient developing endometrial cancer. As such, it could be a useful tool for clinicians to use in conjunction with other biomarkers in determining which patients warrant further preventative interventions to avert progressing to endometrial cancer. This result would allow for a reduction in the number of unnecessary invasive tests on patients. The model may also be used to suggest interventions to decrease the risk for a particular patient. The sensitivity of the model limits it at this stage due to the small percentage of positive cases in the datasets; however, since this model utilizes a neural network machine learning algorithm, it can be further improved by providing the system with more and larger datasets to allow further refinement of the neural network.

Immunotherapy in endometrial cancer: rationale, practice and perspectives

Tumor immunotherapy has attracted more and more attention nowadays, and multiple clinical trials have confirmed its effect in a variety of solid tumors. Immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell transfer (ACT), and lymphocyte-promoting cytokines are the main immunotherapy methods. Endometrial cancer (EC) is one of the most frequent tumors in women and the prognosis of recurrent or metastatic EC is poor. Since molecular classification has been applied to EC, immunotherapy for different EC subtypes (especially POLE and MSI-H) has gradually attracted attention. In this review, we focus on the expression and molecular basis of the main biomarkers in the immunotherapy of EC firstly, as well as their clinical application significance and limitations. Blocking tumor immune checkpoints is one of the most effective strategies for cancer treatment in recent years, and has now become the focus in the field of tumor research and treatment. We summarized clinical date of planned and ongoing clinical trials and introduced other common immunotherapy methods in EC, such as cancer vaccine and ACT. Hormone aberrations, metabolic syndrome (MetS) and p53 mutant and that affect the immunotherapy of endometrial cancer will also be discussed in this review.

The evolving role of targeted metformin administration for the prevention and treatment of endometrial cancer: A systematic review and meta-analysis of randomized controlled trials

AIM

The aim of the present study was to evaluate the role of metformin in endometrial cancer (EC), focusing on its potential preventive effect in breast cancer and obese patients and its safety and efficacy when added to progesterone monotherapy in EC patients who wish to preserve their fertility.

METHODS

We reviewed the literature and then conducted a meta-analysis of the relevant parameters.

RESULTS

A total of 6 studies was included in the meta-analysis. Regarding the pre-surgical treatment with metformin versus placebo, meta-analysis of mean difference in Ki-67 after treatment among two groups, revealed no difference (MD -7.10, 95% CI -23.31 to 9.11, p = 0.39). Meta-analysis of fertility sparing EC management with a combination of megestrol acetate (MA) and metformin (500 mg three times a day) in comparison with monotherapy with 160 mg daily MA revealed no difference in either complete response or partial response rates (166 patients OR 2.94, 95% CI 0.85 to 10.15, p = 0.09 and 166 patients OR 0.76, 95% CI 0.34 to 1.66, p = 0.49, respectively). As far as breast cancer survivors under tamoxifen are concerned, metformin was associated with significantly reduced median endometrial thickness after 52 weeks of evaluation compared to women in placebo group (2.3 mm vs 3.0 mm, p = 0.05).

CONCLUSIONS

Metformin neither was found to be an anti-proliferative agent against the development of endometrial cancer nor beneficial in addition to the progesterone monotherapy for EC fertility sparing candidates. However, a protective effect of metformin was demonstrated in breast cancer survivors under tamoxifen. Clinical outcomes of the ongoing trials are warranted to evaluate the therapeutic use of metformin in EC.

Fertility-Sparing Treatment for Atypical Endometrial Hyperplasia and Endometrial Cancer: A Cochrane Systematic Review Protocol

INTRODUCTION

Endometrial cancer is the fifth most common cancer in women and atypical endometrial hyperplasia is a precancerous lesion. Obesity is an important risk factor for endometrioid endometrial adenocarcinoma and endometrial hyperplasia. Progesterone is recommended as first-line treatment in endometrial cancer or atypical endometrial hyperplasia in women who wish to preserve fertility, but optimal treatment schedules have not been defined. Metformin or bariatric surgery may also be useful in these women. The effectiveness and safety of fertility-preserving treatments being used for women with atypical endometrial hyperplasia and stage IA grade 1 endometrial cancer is unclear. Therefore, the systematic review aims to determine this point.

METHODS

We will search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trial registers, conference proceedings, abstracts, cooperative trial groups and reference lists. We will include randomised controlled trials (RCTs) that compare fertility-preserving therapy including orally administered progesterone versus a levonorgestrel-releasing intrauterine system (IUS), metformin, other pharmacological interventions or bariatric surgery, and any of these interventions with womb-removing surgery. Quasi-randomised trials, non-randomised trials and cohort studies will be included. Two review authors will independently assess study eligibility and risk of bias and extract data. The primary outcomes are complete pathologic response and live birth rate. Secondary outcomes include overall survival, progression-free survival, pregnancy rate, need for hysterectomy, adverse events, psychological symptoms and quality of life.

PLANNED OUTCOMES

This review aims to clarify the effectiveness and risks of fertility-preserving treatments, including complete pathologic response rate, live birth rates, need for surgical treatment, adverse events, psychological symptoms and quality of life. The broad scope of the review includes the use of progesterone, metformin to reverse insulin resistance, and bariatric surgery or operative hysteroscopy.

RESULTS

The results may help to determine the optimal fertility-sparing treatment in endometrial cancer and atypical endometrial hyperplasia.

SYSTEMATIC REVIEW REGISTRATION

Prospero 2019 number CRD42019145991.

Adjuvant effects of chemotherapeutics and Metformin on MFE-319 endometrial carcinoma cell line

We aimed to investigate the cytotoxicity of Metformin, Cisplatin, and Paclitaxel on MFE-319 endometrial carcinoma cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and immunocytochemistry assays. Half maximal inhibitory concentration (IC₅₀) doses of three drugs alone and in the dual combinations were applied to the cells. Immunocytochemical method was performed for the cell survival and for phosphatidylinositol 3-kinase (PI3K), phosphorylated extracellular regulated kinases (pErk)-1/2, Akt-1, phosphorylated Akt (pAkt)-1/2/3 cell growth markers and angiogenic vascular endothelial growth factor (VEGF). Immunoreactivities were evaluated using H-score and analyzed using the one-way analysis of variance (ANOVA) test for statistics. It was found that these drugs caused a decrease in the immunoreactivities of these markers. Particularly, dual combination of Paclitaxel and Cisplatin decreased the immunoreactivities of PI3K, pErk-1/2, Akt-1, and pAkt-1/2/3. Cisplatin and Paclitaxel were more effective than Metformin; on the other hand, Metformin has been shown to enhance the efficacy of these two drugs. In vitro or in vivo further studies are needed to investigate the efficacy of these three drugs via PI3K/Akt signal pathway.

Changes in protein expression due to metformin treatment and hyperinsulinemia in a human endometrial cancer cell line

The incidence of endometrial cancer (EC) has increased over the past years and mainly affects women above the age of 45 years. Metabolic diseases such as obesity and type II diabetes mellitus as well as associated conditions like polycystic ovary syndrome (PCOS), insulin resistance and hyperinsulinemia lead to elevated levels of circulating estrogens. Increased estrogen concentrations, in turn, further trigger the proliferation of endometrial cells and thus promote EC development and progression, especially in the absence of progesterone as seen in postmenopausal women. Elevated blood glucose levels in diabetic patients further contribute to the risk of EC development. Metformin is an insulin-sensitizing biguanide drug, commonly used in the treatment of type II diabetes mellitus, especially in obese patients. Besides its effects on glucose metabolism, metformin displayed anti-cancer effects in various cancer types, including EC. Direct anti-cancer effects of metformin target signaling pathways that are involved in cellular growth and proliferation, e.g. the AKT/PKB/mTOR pathway. Further proteins and pathways have been suggested as potential targets, but the underlying mechanism of action of metformin's anti-cancer activity is still not completely understood. In the present study, the effects of metformin on protein expression were investigated in the human EC cell line HEC-1A using an affinity proteomic approach. Cells were treated with 0.5 mmol/L metformin over a period of 7 days and changes in the expression pattern of 1,300 different proteins were compared to the expression in untreated control cells as well as insulin-treated cells. Insulin treatment (100 ng/mL) was incorporated into the study in order to implement a model for insulin resistance and associated hyperinsulinemia, conditions that are often observed in obese and diabetic patients. Furthermore, the culture medium was supplemented with 10 nmol/L ß-estradiol (E2) during treatments to mimic increased estrogen levels, a common risk factor for EC development. Based on the most prominent and significant changes in expression, a set of 80 proteins was selected and subjected to a more detailed analysis. The data revealed that metformin and insulin targeted similar pathways in the present study and mostly acted on proteins related to proliferation, migration and tumor immune response. These pathways may be affected in a tumor-promoting as well as a tumor-suppressing way by either metformin treatment or insulin supplementation. The consequences for the cells resulting from the detected expression changes were discussed in detail for several proteins. The presented data helps identify potential targets affected by metformin treatment in EC and allows for a better understanding of the mechanism of action of the biguanide drug's anti-cancer activity. However, further investigations are necessary to confirm the observations and conclusions drawn from the presented data after metformin administration, especially for proteins that were regulated in a favorable way, i.e. AKT3, CCND2, CD63, CD81, GFAP, IL5, IL17A, IRF4, PI3, and VTCN1. Further proteins might be of interest, where metformin counteracted unfavorable effects that have been induced by hyperinsulinemia.

The Perspectives of Fertility Preservation in Women with Endometrial Cancer

Simple Summary

Endometrial cancer is a common gynecological malignant disease. Its incidence in women of reproductive age in developed countries is increasing. The standard treatment is surgical in the form of hysterectomy and bilateral salpingo-oophorectomy, which has a significant impact on the quality of women’s lives and precludes further fertility. Conservative management to preserve reproductive function and delay final surgery can today be considered in carefully selected women. We analyze the current approaches to select appropriate candidates and current medical regimens for fertility sparing management. We elaborate on the future perspectives of management. With better characterization of the disease and implementation of molecular biomarkers, more women should be able to benefit from conservative approaches to management of endometrial cancer.

Abstract

Endometrial cancer is the most common gynecological cancer in developed countries. The disease is diagnosed with increasing frequency in younger women, commonly also in their reproductive age. The standard treatment of endometrial cancer is surgical in the form of hysterectomy and bilateral salpingo-oophorectomy, and this precludes future fertility in younger women. The current challenge is to identify the group of women with endometrial cancer and low-risk features that would benefit from more conservative treatment options. More focus in management needs to be aimed towards the preservation of quality of life, without jeopardizing oncological outcomes. In this review, we analyze the current approaches to identification of women for conservative management and evaluate the success of different medical options for treatment and surgical techniques that are fertility sparing. We also elaborate on the future perspectives, focusing on the incorporation of molecular characterization of endometrial cancer to fertility preservation algorithms. Future studies should focus specifically on identifying reliable clinical and molecular predictive markers in this group of young women. With improved knowledge and better risk assessment, the precision medicine is the path towards improved understanding of the disease and possibly widening the group of women that could benefit from treatment methods preserving their fertility.