Premenopausal Circulating Androgens and Risk of Endometrial Cancer: results of a Prospective Study

The association of endogenous sex hormones with endometrial cancer risk: A systematic review and meta-analysis

OBJECTIVES

The role of endogenous sex hormones in the risk of endometrial cancer (EC) remains contradictory across the studies. This meta-analysis was carried out to investigate the relation of circulating concentrations of sex hormones and sex hormone-binding globulin (SHBG) to EC risk.

METHODS

A search of the PubMed, Web of Science, and Scopus databases was conducted to include relevant studies. We used odds ratios (OR) with 95% confidence intervals (CI) to pool effect sizes using a random effects model.

RESULTS

The analysis included 16 studies with 292,695 participants. SHBG levels showed an inverse relationship with EC (OR: 0.67). In contrast, higher circulating levels of total testosterone (OR: 1.70), free testosterone (OR: 1.75), dehydroepiandrosterone sulfate (OR: 1.39), and androstenedione (OR: 1.58) were positively associated with EC risk. Estrogens also demonstrated significant associations, so that estrone (OR: 1.55), unconjugated estrone (OR: 1.86), estradiol (OR: 1.38), unconjugated estradiol (OR: 2.14), estriol (OR: 1.75), and unconjugated estriol (OR: 1.99) were linked to increased EC risk, while conjugated estrogens showed no significant associations. A non-linear dose-response relationship was found for SHBG, estrone, estradiol, and total testosterone. The results were significantly affected by age, cancer type, geographic region, menopausal status, study type, and the level of adjustments for covariates. For all hormones, the significant associations were found only for postmenopausal women.

CONCLUSIONS

This study found an inverse association between SHBG and EC, while identified a direct relationship between sex hormones, except for conjugated estrogens, and EC risk only in postmenopausal women.

RNA modification regulator DDC in endometrial cancer affects the tumor microenvironment and patient prognosis

Uterine corpus endometrial carcinoma (UCEC) is infiltrated by immune cells, which are involved in the growth and proliferation of malignant tumors and resistance to immunotherapy. This study suggested that RNA modification regulators played an important role in the development and prognosis of UCEC. Many studies confirmed that RNA modification played an essential role in tumor immune regulation, and abnormal RNA modification contributed to tumorigenesis and cancer progression. Based on the RNA modification regulatory factors, the UCEC samples from TCGA (The Cancer Genome Atlas) were classified into two clusters, namely Cluster A and Cluster B, using unsupervised consensus clustering. We obtained DEG (differentially expressed genes) between the two clusters, and constructed a risk model of RNA modification-related genes using DEGs. Cluster A had lower RNA modification regulatory factors, richer immune cell infiltration, and better prognosis. The differentially expressed genes between the two clusters were obtained, and these genes were used for modeling. This model divided patients with UCEC into two groups. The low-risk group had better immune infiltration, and the ROC (receiver operating characteristic) curve showed that this model had good predictive efficacy. The low-risk group had a better response to immunotherapy by immune checkpoint prediction. We obtained the key gene L-dopa decarboxylase (DDC) through the intersection of LASSO model genes and GEO dataset GSE17025. We evaluated the potential biological functions of DDC. The differences in the expression of DDC were verified by immunohistochemistry. We evaluated the relationship between DDC and immune cell infiltration and verified this difference using immunofluorescence. Cluster A with low expression of RNA modification regulators has better prognosis and richer immune cell infiltration, therefore, we believed that RNA modification regulators in UCEC were closely related to the tumor microenvironment. Also, the risk score could well predict the prognosis of patients and guide immunotherapy, which might benefit patients with UCEC.

Androgens in endometrial carcinoma: the killer or helper?

PURPOSE

The aim of this review is to discuss the role of androgens in the progression of endometrial carcinoma (EC) with particular focus on the different kinds of androgenic hormones, androgen receptor (AR) and intracrine androgen metabolism.

METHODS

A comprehensive literature search within PubMed was performed. Selected publications related to androgens and EC were reviewed.

RESULTS

There are different kinds of androgenic hormones, and different kinds of androgens may have different effects. Elevated androgens (especially testosterone) have been associated with an increased EC risk in postmenopausal women. 5α-reductases (5α-Reds) and 17β-hydroxysteroid dehydrogenase type 2 (17βHSD2) pathway may inhibit the progression of EC mediated by dihydrotestosterone (DHT), but aromatases stimulate further progression of EC. The most of studies accessing the prognostic value of AR have found that AR expression may be a favorable prognostic indicator.

CONCLUSION

Androgens may have both oncogenic and tumor suppressive roles. Androgen-specific biases in metabolism and the expression of AR may contribute to the different prognosis of patients with EC.

What Role do Androgens Play in Endometrial Cancer?

The role of estrogens and progesterone in the development and progression of endometrial cancer is well-established, but there are very little data about the role of androgens. There are five different androgens produced in women: dehydroepiandrosterone sulphate (DHEAS), dehydroepiandrosterone (DHEA), androstenedione (A₄), testosterone (T) and dihydrotestosterone (DHT). The most potent hormones are T and DHT, the latter being mainly produced from T in peripheral tissues, including endometrium. Although they are considered to exert antiproliferative effects in many settings and the expression of their receptors is more often associated with a good prognosis in EC, it is still unknown in which specific settings androgens have carcinogenic or protective effects in EC.

Neighborhood walkability and sex steroid hormone levels in women

BACKGROUND

Neighborhood walkability (NW) has been linked to increased physical activity, which in turn is associated with lower concentrations of sex hormones and higher concentration of SHBG in women. However, no study has directly examined the association of NW with female sex hormone levels.

OBJECTIVE

We conducted a cross-sectional study to evaluate the association between NW and circulating levels of sex hormones and SHBG in pre- and post-menopausal women.

METHODS

We included 797 premenopausal and 618 postmenopausal women from the New York University Women's Health Study (NYUWHS) who were healthy controls in previous nested case-control studies in which sex hormones (androstenedione, testosterone, DHEAS, estradiol and estrone) and SHBG had been measured in serum at enrollment. Baseline residential addresses were geo-coded and the Built Environment and Health Neighborhood Walkability Index (BEH-NWI) was calculated. Generalized Estimating Equations were used to assess the association between BEH-NWI and sex hormone and SHBG concentrations adjusting for individual- and neighborhood-level factors.

RESULTS

In premenopausal women, a one standard deviation (SD) increment in BEH-NWI was associated with a 3.5% (95% CI 0.9%-6.1%) lower DHEAS concentration. In postmenopausal women, a one SD increment in BEH-NWI was related to an 8.5% (95% CI 5.4%-11.5%) lower level of DHEAS, a 3.7% (95% CI 0.5%-6.8%) lower level of testosterone, a 1.8% (95% CI 0.5%-3.0%) lower level of estrone, and a 4.2% (95% CI 2.7%-5.7%) higher level of SHBG. However, the associations with respect to DHEAS and estrone became apparent only after adjusting for neighborhood-level variables. Sensitivity analyses using fixed effects meta-analysis and inverse probability weighting accounting for potential selection bias yielded similar results.

CONCLUSION

Our findings suggest that NW is associated with lower concentrations of androgens and estrone, and increased SHBG, in postmenopausal women, and lower levels of DHEAS in premenopausal women.

Quantitative analysis of specific androgens in serum and urine samples from male, pre, and postmenopausal subjects using LC-MRM-MS

Androgens are endogenous hormones that play a crucial role in the paracrine and intracrine hormone system to perform and maintain vital physiological functions. Altered levels of androgens are implicated in many diseases such as sexual dysregulation, breast cancer, prostate cancer, and heart diseases etc. In this manuscript we describe a liquid chromatography-mass spectrometry (LC-MS) method using multiple reaction monitoring (MRM) for quantitatively measuring specific androgens such as dehydroepiandrosterone, testosterone, androsterone sulphate, androstenedione, and dihydrotestosterone in serum and urine samples. Serum acquired from nine different subjects (three pre-menopausal women, three postmenopausal women, and three healthy males) were used to evaluate the developed methods. In the sample preparation methods for serum either protein precipitation or liquid-liquid extraction (LLE) was used while the analysis of urinary androgens used LLE. The extracted androgens were quantitatively measured using LC-MRM-MS to which known amounts of stable isotope labeled standards were added. This manuscript also presents a LC-MRM-MS method mode for the analysis of oxime derivatized androgens potentially to enhance the sensitivity of the assay if required, from urine and venous-drawn serum samples.

Integration of androgen hormones in endometrial cancer biology

Endometrial cancer (EC) is a gynecological pathology that affects the uterine inner lining. In recent years, genomic studies revealed continually evolving mutational landscapes of endometrial tumors that hold great potential for tailoring therapeutic strategies. This review aims to broaden our knowledge of EC biology by focusing on the role of androgen hormones. First, we discuss epidemiological evidence implicating androgens with EC pathogenesis and cover their biosynthesis and metabolism to bioactive 11-oxyandrogens. Next, we explore the endometrial tumor tissue and the altered microbiota as alternative sources of androgens and their 11-oxymetabolites in EC patients. Finally, we discuss the biological significance of androgens' genomic and nongenomic signaling as part of a medley of pathways ultimately deciding the fate of cells.

Review of Mendelian Randomization Studies on Endometrial Cancer

Endometrial cancer (EC) is a common gynecological cancer. In some parts of the world, the incidence and mortality of EC are on the rise. Understanding the risk factors of EC is necessary to prevent the occurrence of this disease. Observational studies have revealed the association between certain modifiable environmental risk factors and EC risk. However, due to unmeasured confounding, measurement errors, and reverse causality, observational studies sometimes have limited ability to judge robust causal inferences. In recent years, Mendelian randomization (MR) analysis has received extensive attention, providing valuable insights for cancer-related research, and is expected to identify potential therapeutic interventions. In MR analysis, genetic variation (alleles are randomly assigned during meiosis and are usually independent of environmental or lifestyle factors) is used instead of modifiable exposure to study the relationship between risk factors and disease. Therefore, MR analysis can make causal inference about exposure and disease risk. This review briefly describes the key principles and assumptions of MR analysis; summarizes published MR studies on EC; focuses on the correlation between different risk factors and EC risks; and discusses the application of MR methods in EC research. The results of MR studies on EC showed that type 2 diabetes, uterine fibroids, higher body mass index, higher plasminogen activator inhibitor-1 (PAI-1), higher fasting insulin, early insulin secretion, longer telomere length, higher testosterone and higher plasma cortisol levels are associated with increased risk of EC. In contrast, later age of menarche, higher circulatory tumor necrosis factor, higher low-density lipoprotein cholesterol, and higher sex hormone-binding globulin levels are associated with reduced risk of EC. In general, despite some limitations, MR analysis still provides an effective way to explore the causal relationship between different risk factors and EC.

Testosterone, sex hormone-binding globulin, insulin-like growth factor-1 and endometrial cancer risk: observational and Mendelian randomization analyses

BACKGROUND

Dysregulation of endocrine pathways related to steroid and growth hormones may modify endometrial cancer risk; however, prospective data on testosterone, sex hormone-binding globulin (SHBG) and insulin-like growth factor (IGF)-1 are limited. To elucidate the role of these hormones in endometrial cancer risk we conducted complementary observational and Mendelian randomization (MR) analyses.

METHODS

The observational analyses included 159,702 women (80% postmenopausal) enrolled in the UK Biobank. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. For MR analyses, genetic variants associated with hormone levels were identified and their association with endometrial cancer (12,906 cases/108,979 controls) was examined using two-sample MR.

RESULTS

In the observational analysis, higher circulating concentrations of total (HR per unit inverse normal scale = 1.38, 95% CI = 1.22-1.57) and free testosterone (HR per unit log scale = 2.07, 95% CI = 1.66-2.58) were associated with higher endometrial cancer risk. An inverse association was found for SHBG (HR per unit inverse normal scale = 0.76, 95% CI = 0.67-0.86). Results for testosterone and SHBG were supported by the MR analyses. No association was found between genetically predicted IGF-1 concentration and endometrial cancer risk.

CONCLUSIONS

Our results support probable causal associations between circulating concentrations of testosterone and SHBG with endometrial cancer risk.

Clinical needs for transgender men in the gynecologic oncology setting

Transgender men remain at risk for gynecologic malignancies, but are an underserved population. Members of the transgender community experience discrimination and have experiences that contribute to health disparities, including in gynecology and oncology. While efforts have been made within the United States to reduce inequalities experienced by members of this community, many needs in the clinical setting remain. Increased education and training among providers and healthcare professionals, and general improvements towards understanding barriers to health screening and health resource uptake may reduce some disparities. Additional research towards screening and cancer surveillance among this community will be necessary to understand any potential additional risks and survival disparities experienced by transgender men. This review focuses on barriers and clinical needs for transgender men in the gynecologic oncology setting, and suggestions for moving forward to improve care for this patient population.

Case-control study of endogenous sex steroid hormones and risk of endometrial cancer

BACKGROUND

Epidemiologic evidence regarding the role of endogenous sex hormones in endometrial cancer etiology remains inconsistent. The objective of this study was to investigate if circulating levels of endogenous estrone, estradiol, sex hormone binding globulin (SHBG), testosterone, and androstenedione are associated with endometrial cancer risk.

METHODS

We conducted a population-based case-control study of 522 incident endometrial cancer cases and 976 population controls, in Alberta, Canada from 2002 to 2006. Study participants completed in-person interviews and provided fasting blood samples. Sex hormone levels were determined by enzyme-linked immunosorbent assays.

RESULTS

Higher levels of androstenedione were associated with increased endometrial cancer risk (OR 1.44, 95% CI 1.04-2.02). Endometrial cancer risk in pre- and peri-menopausal women was reduced for the highest versus lowest quartiles of estrone (OR 0.44, 95% CI 0.22-0.88) and estradiol (OR 0.30, 95% CI 0.14-0.65), but in post-menopausal women, the endometrial cancer risk was increased for the highest versus lowest quartile of androstenedione (OR 1.82, 95% CI 1.25-2.65). In addition, endometrial cancer risk in normal/underweight women was decreased for the highest versus lowest quartile of serum SHBG (OR 0.39, 95% CI 0.19-0.84).

CONCLUSIONS

Overall, positive associations were found for androstenedione concentrations, while sub-group analyses revealed = inverse associations with estrogens and SHBG. Results of this study provide empirical evidence for the role of circulating sex hormones in endometrial cancer etiology and highlight the importance of modifiable factors that contribute to changes in sex hormone concentration levels.

Dihydrotestosterone and cancer risk

PURPOSE OF REVIEW

Androgens have been implicated in prostate growth; however, the role of androgens in prostate cancer development is not clear. Furthermore, studies suggest a role for androgens in female-hormone-dependent cancers and common nonhormone dependent cancers. This study aims to review key studies and more recent studies of dihydrotestosterone (DHT) and cancer risk.

RECENT FINDINGS

Epidemiological studies are reassuring as they have not associated endogenous androgens with prostate cancer risk. Intraprostatic regulation of DHT is becoming recognized as an important area of research to clarify the role of DHT in prostate cancer development. In females, further understanding of intracrine regulation of sex hormones and interactions between androgens and estrogens in influencing breast and endometrial cancer risk are required. Studies show a signal for DHT in modulating lung and colorectal cancer growth; however, research in this area is relatively scarce and further studies are required to clarify these associations.

SUMMARY

Although concerns of prostate cancer risk remain, there is also potential for androgens to modulate the growth and development of other common cancers. Further research is required as this may have clinical implications.

Anti-Mullerian hormone and endometrial cancer: a multi-cohort study

BACKGROUND

The Mullerian ducts are the embryological precursors of the female reproductive tract, including the uterus; anti-Mullerian hormone (AMH) has a key role in the regulation of foetal sexual differentiation. Anti-Mullerian hormone inhibits endometrial tumour growth in experimental models by stimulating apoptosis and cell cycle arrest. To date, there are no prospective epidemiologic data on circulating AMH and endometrial cancer risk.

METHODS

We investigated this association among women premenopausal at blood collection in a multicohort study including participants from eight studies located in the United States, Europe, and China. We identified 329 endometrial cancer cases and 339 matched controls. Anti-Mullerian hormone concentrations in blood were quantified using an enzyme-linked immunosorbent assay. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) across tertiles and for a doubling of AMH concentrations (ORlog2). Subgroup analyses were performed by ages at blood donation and diagnosis, oral contraceptive use, and tumour characteristics.

RESULTS

Anti-Mullerian hormone was not associated with the risk of endometrial cancer overall (ORlog2: 1.07 (0.99-1.17)), or with any of the examined subgroups.

CONCLUSIONS

Although experimental models implicate AMH in endometrial cancer growth inhibition, our findings do not support a role for circulating AMH in the aetiology of endometrial cancer.

Androgens Are Differentially Associated with Ovarian Cancer Subtypes in the Ovarian Cancer Cohort Consortium

Invasive epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. The etiology of EOC remains elusive; however, experimental and epidemiologic data suggest a role for hormone-related exposures in ovarian carcinogenesis and risk factor differences by histologic phenotypes and developmental pathways. Research on prediagnosis androgen concentrations and EOC risk has yielded inconclusive results, and analyses incorporating EOC subtypes are sparse. We conducted a pooled analysis of 7 nested case-control studies in the Ovarian Cancer Cohort Consortium to investigate the association between pre-diagnosis circulating androgens [testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS)], sex hormone binding globulin (SHBG), and EOC risk by tumor characteristics (i.e., histology, grade, and stage). The final study population included 1,331 EOC cases and 3,017 matched controls. Multivariable conditional logistic regression was used to assess risk associations in pooled individual data. Testosterone was positively associated with EOC risk (all subtypes combined, ORlog2 = 1.12; 95% confidence interval 1.02-1.24); other endogenous androgens and SHBG were not associated with overall risk. Higher concentrations of testosterone and androstenedione associated with an increased risk in endometrioid and mucinous tumors [e.g., testosterone, endometrioid tumors, ORlog2 = 1.40 (1.03-1.91)], but not serous or clear cell. An inverse association was observed between androstenedione and high grade serous tumors [ORlog2 = 0.76 (0.60-0.96)]. Our analyses provide further evidence for a role of hormone-related pathways in EOC risk, with differences in associations between androgens and histologic subtypes of EOC. Cancer Res; 77(14); 3951-60. ©2017 AACR.

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.

Demographic, lifestyle, and other factors in relation to antimüllerian hormone levels in mostly late premenopausal women

OBJECTIVE

To identify reproductive, lifestyle, hormonal, and other correlates of circulating antimüllerian hormone (AMH) concentrations in mostly late premenopausal women.

DESIGN

Cross-sectional study.

SETTING

Not applicable.

PATIENT(S)

A total of 671 premenopausal women not known to have cancer.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Concentrations of AMH were measured in a single laboratory using the picoAMH ELISA. Multivariable-adjusted median (and interquartile range) AMH concentrations were calculated using quantile regression for several potential correlates.

RESULT(S)

Older women had significantly lower AMH concentrations (≥40 [n = 444] vs. <35 years [n = 64], multivariable-adjusted median 0.73 ng/mL vs. 2.52 ng/mL). Concentrations of AMH were also significantly lower among women with earlier age at menarche (<12 [n = 96] vs. ≥14 years [n = 200]: 0.90 ng/mL vs. 1.12 ng/mL) and among current users of oral contraceptives (n = 27) compared with never or former users (n = 468) (0.36 ng/mL vs. 1.15 ng/mL). Race, body mass index, education, height, smoking status, parity, and menstrual cycle phase were not significantly associated with AMH concentrations. There were no significant associations between AMH concentrations and androgen or sex hormone-binding globulin concentrations or with factors related to blood collection (e.g., sample type, time, season, and year of blood collection).

CONCLUSION(S)

Among premenopausal women, lower AMH concentrations are associated with older age, a younger age at menarche, and currently using oral contraceptives, suggesting these factors are related to a lower number or decreased secretory activity of ovarian follicles.

In situ androgen and estrogen biosynthesis in endometrial cancer: focus on androgen actions and intratumoral production

In situ estrogen biosynthesis is considered to play pivotal roles in the development and progression of human endometrial carcinoma. However, the biological roles of androgen have remained virtually unknown. Various epidemiological studies have revealed that elevated serum androgen levels are generally associated with an increased risk of developing endometrial carcinoma; however, studies directly examining androgens in carcinoma tissues are relatively rare and reviews summarizing this information are scarce. Therefore, we summarized recent studies on androgens in endometrial carcinoma, especially focusing androgen actions and in situ androgen biosynthesis. Among the enzymes required for local biosynthesis of androgen, 17β-hydroxysteroid dehydrogenase type 5 (conversion from androstenedione to testosterone) and 5α-reductase (reduction of testosterone to dihydrotestosterone (DHT)) are the principal enzymes involved in the formation of biologically most potent androgen, DHT. Both enzymes and androgen receptor were expressed in endometrial carcinoma tissues, and in situ production of DHT has been reported to exist in endometrial carcinoma tissues. However, testosterone is not only a precursor of DHT production, but also a precursor of estradiol synthesis, as a substrate of the aromatase enzyme. Therefore, aromatase could be another key enzyme serving as a negative regulator for in situ production of DHT by reducing amounts of the precursor. In an in vitro study, DHT was reported to exert antiproliferative effects on endometrial carcinoma cells. Intracrine mechanisms of androgens, the downstream signals of AR, which are directly related to anticancer progression, and the clinical significance of DHT-AR pathway in the patients with endometrial carcinoma have, however, not been fully elucidated.