Submucous and outer myometrium leiomyomas are two distinct clinical entities

Bipedalism and the dawn of uterine fibroids

The high prevalence and burden of uterine fibroids in women raises questions about the origin of these benign growths. Here, we propose that fibroids should be understood in the context of human evolution, specifically the advent of bipedal locomotion in the hominin lineage. Over the ≥7 million years since our arboreal ancestors left their trees, skeletal adaptations ensued, affecting the pelvis, limbs, hands, and feet. By 3.2 million years ago, our ancestors were fully bipedal. A key evolutionary advantage of bipedalism was the freedom to use hands to carry and prepare food and create and use tools which, in turn, led to further evolutionary changes such as brain enlargement (encephalization), including a dramatic increase in the size of the neocortex. Pelvic realignment resulted in narrowing and transformation of the birth canal from a simple cylinder to a convoluted structure with misaligned pelvic inlet, mid-pelvis, and pelvic outlet planes. Neonatal head circumference has increased, greatly complicating parturition in early and modern humans, up to and including our own species. To overcome the so-called obstetric dilemma provoked by bipedal locomotion and encephalization, various compensatory adaptations have occurred affecting human neonatal development. These include adaptations limiting neonatal size, namely altricial birth (delivery of infants at an early neurodevelopmental stage, relative to other primates) and mid-gestation skeletal growth deceleration. Another key adaptation was hyperplasia of the myometrium, specifically the neomyometrium (the outer two-thirds of the myometrium, corresponding to 90% of the uterine musculature), allowing the uterus to more forcefully push the baby through the pelvis during a lengthy parturition. We propose that this hyperplasia of smooth muscle tissue set the stage for highly prevalent uterine fibroids. These fibroids are therefore a consequence of the obstetric dilemma and, ultimately, of the evolution of bipedalism in our hominin ancestors.

Fibroids and unexplained infertility treatment with epigallocatechin gallate: a natural compound in green tea (FRIEND) - protocol for a randomised placebo-controlled US multicentre clinical trial of EGCG to improve fertility in women with uterine fibroids

INTRODUCTION

Uterine fibroids affect 30%-77% of reproductive-age women and are a significant cause of infertility. Surgical myomectomies can restore fertility, but they often have limited and temporary benefits, with postoperative complications such as adhesions negatively impacting fertility. Existing medical therapies, such as oral contraceptives, gonadotropin hormone-releasing hormone (GnRH) analogues and GnRH antagonists, can manage fibroid symptoms but are not fertility friendly. This study addresses the pressing need for non-hormonal, non-surgical treatment options for women with fibroids desiring pregnancy. Previous preclinical and clinical studies have shown that epigallocatechin gallate (EGCG) effectively reduces uterine fibroid size. We hypothesise that EGCG from green tea extract will shrink fibroids, enhance endometrial quality and increase pregnancy likelihood. To investigate this hypothesis, we initiated a National Institute of Child Health and Human Development Confirm-funded trial to assess EGCG's efficacy in treating women with fibroids and unexplained infertility.

METHODS AND ANALYSIS

This multicentre, prospective, interventional, randomised, double-blinded clinical trial aims to enrol 200 participants with fibroids and unexplained infertility undergoing intrauterine insemination (IUI). Participants will be randomly assigned in a 3:1 ratio to two groups: green tea extract (1650 mg daily) or a matched placebo, combined with clomiphene citrate-induced ovarian stimulation and timed IUI for up to four cycles. EGCG constitutes approximately 45% of the green tea extract. The primary outcome is the cumulative live birth rate, with secondary outcomes including conception rate, time to conception, miscarriage rate, change in fibroid volume and symptom severity scores and health-related quality of life questionnaire scores.

ETHICS AND DISSEMINATION

The FRIEND trial received approval from the Food and Drug adminstration (FDA) (investigational new drug number 150951), the central Institutional Review Board (IRB) at Johns Hopkins University and FRIEND-collaborative site local IRBs. The data will be disseminated at major conferences, published in peer-reviewed journals and support a large-scale clinical trial.

TRIAL REGISTRATION NUMBER

NCT05364008.

Understanding the Impact of Uterine Fibroids on Human Endometrium Function

Uterine fibroids (leiomyomas) are the most common benign gynecological tumors in women of reproductive age worldwide. They cause heavy menstrual bleeding, usually leading to severe anemia, pelvic pain/pressure, infertility, and other debilitating morbidities. Fibroids are believed to be monoclonal tumors arising from the myometrium, and recent studies have demonstrated that fibroids actively influence the endometrium globally. Studies suggest a direct relationship between the number of fibroids removed and fertility problems. In this review, our objective was to provide a complete overview of the origin of uterine fibroids and the molecular pathways and processes implicated in their development and growth, which can directly affect the function of a healthy endometrium. One of the most common characteristics of fibroids is the excessive production of extracellular matrix (ECM) components, which contributes to the stiffness and expansion of fibroids. ECM may serve as a reservoir of profibrotic growth factors such as the transforming growth factor β (TGF-β) and a modulator of their availability and actions. Fibroids also elicit mechanotransduction changes that result in decreased uterine wall contractility and increased myometrium rigidity, which affect normal biological uterine functions such as menstrual bleeding, receptivity, and implantation. Changes in the microRNA (miRNA) expression in fibroids and myometrial cells appear to modulate the TGF-β pathways and the expression of regulators of ECM production. Taken together, these findings demonstrate an interaction among the ECM components, TGF-β family signaling, miRNAs, and the endometrial vascular system. Targeting these components will be fundamental to developing novel pharmacotherapies that not only treat uterine fibroids but also restore normal endometrial function.

Impairment of Uterine Contractility Is Associated with Unexplained Infertility

The uterine junctional zone represents the juncture between endometrium and myometrium. The junctional zone is hormonally dependent and displays continuous peristaltic activity throughout the menstrual cycle in the nonpregnant state which is concerned with sperm transport and embryo implantation. Peristalsis may be observed using various invasive and noninvasive modalities, of which ultrasound is the most readily applied in the clinical setting. Women with pelvic pathology display alterations in uterine peristalsis which may contribute to infertility. Characterization of peristalsis in infertility subgroups, the development of a subjective peristalsis tool, and the application of potential therapeutics to an assisted reproductive treatment setting are the subject of ongoing investigation. Meta-analysis indicates a potential role for oxytocin antagonist in the improvement of fertility treatments.

Expression of Endometrial Receptivity Genes Increase After Myomectomy of Intramural Leiomyomas not Distorting the Endometrial Cavity

This study was designed to investigate whether endometrial receptivity genes are altered in infertile patients with intramural leiomyomas (IM) not distorting the endometrial cavity undergoing myomectomy. We measured endometrial HOXA-10, HOXA-11, LIF, ITGB3, and ITGAV messenger RNA (mRNA) expressions levels before and after myomectomy/metroplasty during mid-luteal phase in participants with IM, submucosal leiomyomas (SM), and septate uterus and fertile participants without fibroids. Initial endometrial sampling was obtained at the time of surgery, and second sampling was obtained 3 months after myomectomy/metroplasty. Expressions of each gene were evaluated using real-time reverse transcriptase polymerase chain reaction (RT-PCR). A trend toward decreased endometrial HOXA-10, HOXA-11, and ITGAV mRNA expression was detected in both SM and IM groups before myomectomy when compared to both fertile group and septate uterus. However, the differences failed to show statistical significance. After myomectomy of IM, we have detected 12.8-fold increase in endometrial HOXA-10 mRNA expression and 9.0-fold increase in endometrial HOXA-11 mRNA expression. This increase in endometrial HOXA-10 and 11 mRNA expression was significant. Accordingly, 2 patients having intramural fibroids greater than 5 cm were able to remain pregnant after myomectomy. Conversely, submucosal myomectomy did not cause any significant effect on endometrial receptivity markers. Likewise, all markers of endometrial receptivity remained unchanged after metroplasty. Myomectomy of IM have favorable effect on endometrial HOXA-10 and 11 mRNA expression.

Epidemiological and genetic clues for molecular mechanisms involved in uterine leiomyoma development and growth

BACKGROUND

Uterine leiomyomas (fibroids) are highly prevalent benign smooth muscle tumors of the uterus. In the USA, the lifetime risk for women developing uterine leiomyomas is estimated as up to 75%. Except for hysterectomy, most therapies or treatments often provide only partial or temporary relief and are not successful in every patient. There is a clear racial disparity in the disease; African-American women are estimated to be three times more likely to develop uterine leiomyomas and generally develop more severe symptoms. There is also familial clustering between first-degree relatives and twins, and multiple inherited syndromes in which fibroid development occurs. Leiomyomas have been described as clonal and hormonally regulated, but despite the healthcare burden imposed by the disease, the etiology of uterine leiomyomas remains largely unknown. The mechanisms involved in their growth are also essentially unknown, which has contributed to the slow progress in development of effective treatment options.

METHODS

A comprehensive PubMed search for and critical assessment of articles related to the epidemiological, biological and genetic clues for uterine leiomyoma development was performed. The individual functions of some of the best candidate genes are explained to provide more insight into their biological function and to interconnect and organize genes and pathways in one overarching figure that represents the current state of knowledge about uterine leiomyoma development and growth.

RESULTS

In this review, the widely recognized roles of estrogen and progesterone in uterine leiomyoma pathobiology on the basis of clinical and experimental data are presented. This is followed by fundamental aspects and concepts including the possible cellular origin of uterine fibroids. The central themes in the subsequent parts are cytogenetic aberrations in leiomyomas and the racial/ethnic disparities in uterine fibroid biology. Then, the attributes of various in vitro and in vivo, human syndrome, rodent xenograft, naturally mutant, and genetically modified models used to study possible molecular mechanisms of leiomyoma development and growth are described. Particular emphasis is placed on known links to fibrosis, hypertrophy, and hyperplasia and genes that are potentially important in these processes.

CONCLUSIONS

Menstrual cycle-related injury and repair and coinciding hormonal cycling appears to affect myometrial stem cells that, at a certain stage of fibroid development, often obtain cytogenetic aberrations and mutations of Mediator complex subunit 12 (MED12). Mammalian target of rapamycin (mTOR), a master regulator of proliferation, is activated in many of these tumors, possibly by mechanisms that are similar to some human fibrosis syndromes and/or by mutation of upstream tumor suppressor genes. Animal models of the disease support some of these dysregulated pathways in fibroid etiology or pathogenesis, but none are definitive. All of this suggests that there are likely several key mechanisms involved in the disease that, in addition to increasing the complexity of uterine fibroid pathobiology, offer possible approaches for patient-specific therapies. A final model that incorporates many of these reported mechanisms is presented with a discussion of their implications for leiomyoma clinical practice.

Selective progesterone receptor modulators: an update

INTRODUCTION

Several selective progesterone receptor modulators (SPRMs) show promise in several areas of medicine and this work has been summarized by us in 2008.

AREAS COVERED

Since the publication of our reviews, several developments have taken place in the field of reproductive medicine. The first is emergency contraception (EC). Two SPRMs are clinically utilized today: mifepristone (MFP) and ulipristal acetate (UPA). MFP is available for EC in up to 120 h following unprotected intercourse. A dose of 10 mg is significantly more effective than levonorgestrel (LNG). In a metanalysis of the use of UPA versus LNG up to 72 h after unprotected intercourse, failure rates of 1.4 versus 2.2% were reported. The second is contraception. A daily dose of 2 mg MFP can block ovulation and several MFP regimens are being tested, including a vaginal ring releasing MFP. The third is the preoperative administration in women harboring leiomyomas, where clinical testing of several SPRM has shown that they can decrease uterine leiomyomas' size and substantially reduce uterine bleeding. SPRM can induce unusual, specific endometrial appearances. Many believe that these changes should not cause concern, but the issue remains controversial.

EXPERT OPINION

SPRMs are very effective in EC and for the preoperative treatment of uterine leiomyomas.

New developments in reproductive surgery

The introduction of in-vitro fertilisation within reproductive medicine has prompted questions to be asked about the relevance of reproductive surgery. Reproductive surgery is more than a competing discipline; it is complementary to the techniques of in-vitro fertilisation. As a complementary discipline, reproductive surgery covers the field of tubal and ovarian pathology and correction of uterine alterations. In recent decades, more attention has been paid to the importance of the uterus in the process of conception and implantation. The place of reproductive surgery and the existing controversies in the treatment of uterine congenital and acquired pathology, tubal, and ovarian surgery are discussed. Continuous training and accreditation programmes for reproductive technologies and surgery are more important than ever.

AAGL practice report: practice guidelines for the diagnosis and management of submucous leiomyomas

Submucous leiomyomas or myomas are commonly encountered by gynecologists and specialists in reproductive endocrinology and infertility with patients presenting with 1 or a combination of symptoms that include heavy menstrual bleeding, infertility, and recurrent pregnancy loss. There exists a variety of interventions that include those performed under hysteroscopic, laparoscopic and laparotomic direction; an evolving spectrum of image guided procedures, and an expanding number of pharmaceutical agents, each of which has value for the appropriately selected and counseled patient. Identification of the ideal approach requires the clinician to be intimately familiar with a given patient's history, including her desires with respect to fertility, as well as an appropriately detailed evaluation of the uterus with any one or a combination of a number of imaging techniques, including hysteroscopy. This guideline has been developed following a systematic review of the evidence, to provide guidance to the clinician caring for such patients, and to assist the clinical investigator in determining potential areas of research. Where high level evidence was lacking, but where a majority of opinion or consensus could be reached, the guideline development committee provided consensus recommendations as well.

Congenital malformations of the female genital tract: the need for a new classification system

Current proposals for classifying female genital anomalies seem to be associated with limitations in effective categorization, creating the need for a new classification system that is as simple as possible, clear and accurate in its definitions, comprehensive, and correlated with patients' clinical presentation, prognosis, and treatment on an evidence-based foundation. Although creating a new classification system is not an easy task, it is feasible when taking into account the experience gained from applying the existing classification systems, mainly that of the American Fertility Society.

Differential infiltration of macrophages and prostaglandin production by different uterine leiomyomas

BACKGROUND

The association between uterine myoma and infertility is still controversial. The anatomical defect of endometrium by uterine fibroids could be a factor for reducing pregnancy rates and increasing miscarriage rates. However, pregnancy and implantation rates were found to be significantly lower in women with intramural myomas (IMMs), when there was no deformity of uterine cavity. This could be due to other biological factors such as increased accumulation of inflammatory cells within fibroid tissue and corresponding endometrium that might impair fertility. Therefore, we tried to investigate the pattern of macrophage (Mvarphi) accumulation in different uterine fibroids and the production of chemokine and prostaglandin (PG) by these tissues.

METHODS

The selection criteria of uterine fibroids were based on the classification of European Society of Hysteroscopy. Biopsy specimens were collected from respective nodules and autologous endometrium of 20 women with submucosal myoma (SMM), 29 women with IMM and 18 women with subserosal myoma (SSM). CD68 immunoreactive Mvarphis were identified in these tissues by immunohistochemistry. A fraction of corresponding tissues were homogenized, and levels of monocyte chemotactic protein-1 (MCP-1) and PGF(2alpha) were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Mvarphi infiltration in the myoma nodule and corresponding endometrium of women with SMM and IMM was significantly higher than that of women with SSM or control women (P<0.01 and P<0.05, respectively). This tissue accumulation of inflammatory cells was independent of the sizes of the myoma nodules and phases of menstrual cycle. The tissue concentration of MCP-1 corresponded to increased Mvarphi infiltration and was significantly higher in women with SMM and IMM than that in women with SSM (P<0.05 for each). A positive correlation was observed between MCP-1 concentration and accumulated Mvarphi numbers in the endometrium of women with SMM and IMM but not in women with SSM. The tissue levels of PGF2alpha were also significantly higher in the nodule and corresponding endometrium of women with SMM and IMM than that in SSM or control women (P<0.05 for each).

CONCLUSIONS

Higher production of MCP-1 could be responsible for the increased accumulation of Mvarphi in women with SMM and IMM. The augmented inflammatory reaction in endometrium and increased PGF2alpha levels might be detrimental to reproductive outcome in women with SMM or IMM.

The genetics of uterine leiomyomata: what clinicians need to know

The genetics of many complex diseases, including hypertension, diabetes, and asthma, are receiving intense investigation and beginning to have therapeutic relevance. Family medical history can be a critical source of information for providing optimal patient care. For gynecologists, knowledge of cancer susceptibility genes such as BRCA1 and BRCA2 and the genetic syndrome hereditary nonpolyposis colorectal cancer (Lynch syndrome II) affects how patients are screened for ovarian and endometrial cancers. Similarly, identification of mutations in the fumarate hydratase (FH) gene that lead to a syndrome called hereditary leiomyomatosis and renal cell carcinoma (HLRCC) will impact screening and treatment of women with uterine leiomyomas. Hereditary leiomyomatosis and renal cell carcinoma syndrome is particularly relevant to clinicians and patients because of the resulting increased risk of malignant disease for both the affected woman and her family. The goals of this article are to summarize the evolving genetic information concerning uterine leiomyomas, including hereditary leiomyomatosis and renal cell carcinoma syndrome, and to discuss the clinical importance of these findings. The current role of family medical history and future implications of genes relevant to leiomyoma biology will be reviewed.

The uterine junctional zone

Magnetic resonance imaging has revealed that the endometrio-myometrial interface constitutes a distinct, hormone-dependent uterine compartment termed the junctional zone. In the non-pregnant uterus, highly specialized contraction waves originate exclusively from the junctional zone and participate in the regulation of diverse reproductive events, such as sperm transport, embryo implantation, and menstrual shedding. Conversely, growing evidence suggests that disruption of the normal endometrio-myometrial interface plays an integral role in diverse reproductive disorders. This chapter reviews our current understanding of the mechanisms that govern the cyclic changes in the uterine junctional zone and summarizes the evidence implicating the endometrio-myometrial interface in normal uterine physiology and pathological processes.

Myomas and Assisted Reproductive Technologies: When and How to Act?

The effect of myomas on reproductive outcome has been the subject of many studies; however, a definitive answer is still missing. Therefore, the authors have tried to outline some guidelines for the management of women who have uterine myomas and desire to conceive. The location and size of the myomas are the two parameters that influence the success of a future pregnancy. Subserosal myomas seem to have little, if any,effect on reproductive outcome, especially if they are up to 5 to 7 cm in diameter. Intramural myomas that do not encroach upon the endometrium also can be considered to be relatively harmless to reproduction, if they are smaller than 4 to 5 cm in diameter. This is the ambiguous gray zone of the subject, and where research should be focused before a consensus can be established. Myomas that compress the uterine cavity with an intramural portion (submucous myoma type II) and submucous myomas significantly reduce pregnancy rates, and should be removed before assisted reproductive techniques are used. Hysteroscopic myomectomy is the gold standard for the treatment of submucous myomas. For other myomas, abdominal myomectomy, or laparoscopic myomectomy--when the experience of the surgeon and the facilities are sufficient--are the best alternatives. In most of the literature, the pregnancy rates were increased and the miscarriage rates were decreased after surgery with these two techniques. Other alternative treatment modalities, such as CUV, laparoscopic myolysis, or MRI-guided focused ultrasound, are to be monitored and evaluated thoroughly before they are applied as routine procedures.

Effect of myomectomy on the outcome of assisted reproductive technologies

OBJECTIVE

To evaluate the impact of myomectomy on in vitro fertilization-embryo transfer (IVF-ET) and oocyte donation cycle outcome.

DESIGN

Retrospective case-controlled study of consecutive fresh IVF-ET and oocyte donation patients during a 2-year interval.

SETTING

Private assisted reproductive technology (ART) center.

PATIENT(S)

Patients with submucosal leiomyomata resected hysteroscopically (group A: 15 oocyte donor recipients; group 1 = 31 IVF-ET patients) and those with intramural components or strictly intramural leiomyomata that distorted or impinged upon the endometrial cavity resected at laparotomy (group B = 26 oocyte donor recipients; group 2 = 29 IVF-ET patients).

INTERVENTION(S)

Precycle hysteroscopic or abdominal myomectomy and subsequent fresh IVF-ET or oocyte donation.

MAIN OUTCOME MEASURE(S)

Results of controlled ovarian hyperstimulation as well as ongoing pregnancy and implantation rates were evaluated in comparison with contemporaneous patient groups without such lesions (group C = 552 oocyte donor recipients; group 3: 896 IVF-ET patients).

RESULT(S)

As would be expected, the mean number and size of leiomyomata were significantly larger in patients who underwent abdominal myomectomy. However, neither ongoing pregnancy nor implantation rates were significantly different in comparison with controls among either oocyte donor recipients (group A: 86.7%, 57.8%; group B: 84.6%, 55.2%; group C 77%, 49.1%). The findings were similar for those undergoing IVF-ET in comparison with controls (group 1: 61%, 24%; group 2: 52%, 26%; group 3: 53%, 23%).

CONCLUSION(S)

Precycle resection of appropriately selected clinically significant leiomyomata results in IVF-ET or oocyte donation cycle outcomes that are similar to controls.

Effect of inner myometrium fibroid on reproductive outcome after IVF

To evaluate the influence of inner myometrium fibroids (myomas) on the outcome of IVF cycles, a retrospective agematched controlled study was performed at SISMeR Reproductive Medicine Unit. The study group included 129 IVF/intracytoplasmic sperm injection cycles in 75 patients with one or more intramural and/or submucosal fibroids, while the control group consisted of 129 cycles in 127 patients without fibroids. The two groups were similar for mean oestradiol concentration at human chorionic gonadotrophin administration (1205.16 +/- 874 versus 1395 +/- 821 pg/ml), mean number of transferred embryos (2.02 +/- 0.4 versus 2.14 +/- 0.6) and clinical pregnancy rate (34.9 versus 41.1%). Conversely, the implantation rate was significantly lower in the study group (18.0%) than in the control group (26.5%; chi(2) = 4.81, P < 0.05), whereas the rate of spontaneous abortion demonstrated an opposite trend (40 versus 18.9%; chi(2) = 4.34, P < 0.05). Further research should be aimed at classifying fibroids on the basis of their location, especially when they are positioned in the junctional zone of the myometrium. Whether this classification will be superior in predicting the impact of fibroids on the reproductive outcome should be elaborated in a large multicentric study.