Risk factors for clinically diagnosed uterine fibroids in women around menopause

Body Mass Index and Uterine Fibroid Development: A Prospective Study

OBJECTIVE

Fibroids are hormonally dependent uterine tumors. The literature on adiposity and fibroid prevalence is inconsistent. Previous work usually combined all those with a body mass index (BMI) ≥30 kg/m2 into a single category and relied on clinically diagnosed fibroids, which misclassifies the many women with undiagnosed fibroids. We used a prospective cohort design with periodic ultrasound screening to investigate associations between repeated measures of BMI and fibroid incidence and growth assessed at each follow-up ultrasound.

METHODS

The Study of Environment, Lifestyle & Fibroids followed 1693 Black/African American women, ages 23 to 35 years from Detroit, Michigan, with ultrasound every 20 months for 5 years. Measured height and repeated weight measures were used to calculate BMI. Fibroid incidence was modeled using Cox models among those who were fibroid free at the enrollment ultrasound. Fibroid growth was estimated for individual fibroids matched across visits as the difference in log-volume between visits and was modeled using linear mixed models. All models used time-varying BMI and adjusted for time-varying covariates.

RESULTS

Compared with BMI <25 kg/m2, those with BMI 30 to <35 kg/m2 had increased fibroid incidence (adjusted hazard ratio, 1.37; 95% CI, 0.96-1.94), those with BMI ≥40 kg/m2 had reduced incidence (adjusted hazard ratio, 0.61; 95% CI, 0.41-0.90). Fibroid growth had mostly small magnitude associations with BMI.

CONCLUSION

BMI has a nonlinear association with fibroid incidence, which could be driven by effects of BMI on inflammation and reproductive hormones. More detailed measures of visceral and subcutaneous adiposity and their effects on hormones, DNA damage, and cell death are needed.

Risk of uterine leiomyomata with menstrual and reproductive factors in premenopausal women: Korea nurses' health study

BACKGROUND

Uterine leiomyomata (UL) are benign smooth muscle tumors that may cause significant morbidity in women of reproductive age. This study aimed to investigate the relationship of menstrual and reproductive factors with the risk of UL in premenopausal women.

METHODS

This prospective study included 7,360 premenopausal women aged 22-48 years who were part of the Korea Nurses' Health Study. Information on the menstrual cycle and reproductive history was assessed between 2014 and 2016, and self-reported cases of UL were obtained through 2021. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During 32,072 person-years of follow-up, 447 incident cases of UL were reported. After adjusting for other risk factors, women with late age at menarche had a lower incidence of UL (≥ 16 vs. 12-13 years: HR 0.68; 95% CI 0.47-0.99; p for trend = 0.026). The risk of UL was inversely associated with current menstrual cycle length (≥ 40 or too irregular to estimate vs. 26-31 days: HR 0.40; 95% CI 0.24-0.66) and cycle length at ages 18-22 years (HR 0.45; 95% CI 0.31-0.67; p for trend < 0.001, each). Parous women had lower risk of UL than nulliparous women (HR 0.40; 95% CI 0.30-0.53) and women who were aged 29-30 years at first birth had a lower risk of UL than those who were aged ≤ 28 years at first birth (HR 0.58; 95% CI 0.34-0.98). There was no significant association of the number of births or breastfeeding with the risk of UL among parous women. Neither a history of infertility nor oral contraceptive use was associated with the risk of UL.

CONCLUSIONS

Our results suggest that age at menarche, menstrual cycle length, parity, and age at first birth are inversely associated with the risk of UL in premenopausal Korean women. Future studies are warranted to confirm the long-term effects of menstrual and reproductive factors on women's health.

Diagnosis and management of uterine fibroids: current trends and future strategies

Uterine fibroids (UFs), leiomyomas or myomas, are a type of malignancy that affects the smooth muscle of the uterus, and it is most commonly detected in women of reproductive age. Uterine fibroids are benign monoclonal growths that emerge from uterine smooth muscle cells (myometrium) as well as fibroblasts. Uterine fibroid symptoms include abnormal menstrual bleeding leading to anaemia, tiredness, chronic vaginal discharge, and pain during periods. Other symptoms include protrusion of the abdomen, pain during intercourse, dysfunctions of bladder/bowel leading to urinary incontinence/retention, pain, and constipation. It is also associated with reproductive issues like impaired fertility, conceiving complications, and adverse obstetric outcomes. It is the leading cause of gynaecological hospitalisation in the American subcontinent and a common reason for the hysterectomy. Twenty-five percent of the reproductive women experience the symptoms of uterine fibroids, and among them, around 25% require hospitalization due to the severity of the disease. The frequency of the disease remains underestimated as many women stay asymptomatic and symptoms appear gradually; therefore, the condition remains undiagnosed. The exact frequency of uterine fibroids varies depending on the diagnosis, and the population investigated; nonetheless, the incidence of uterine fibroids in reproductive women ranges from 5.4 percent to 77 percent. The uterine fibroid treatment included painkillers, supplementation with iron, vitamin D3, birth control, hormone therapy, gonadotropin-releasing hormone (GnRH) agonists, drugs modulating the estrogen receptors, and surgical removal of the fibroids. However, more research needed at the level of gene to get a keen insight and treat the disease efficiently.

Association between ESR1 rs2234693 single nucleotide polymorphism and uterine fibroids in Taiwanese premenopausal and postmenopausal women

BACKGROUND

Uterine fibroids (UFs) are uterine smooth muscle neoplasms that affect women, especially during the reproductive stage. Both genetic and lifestyle factors affect the onset of the disease. We examined the association between the estrogen receptor 1 (ESR1) rs2234693 variant (whose genotypes are TT, TC, and CC) and UFs in Taiwanese premenopausal and postmenopausal women.

METHODS

We linked individual-level data of 3588 participants from the Taiwan Biobank to the National Health Insurance Research Database at the Health and Welfare Data Science Center. The association of the ESR1 rs2234693 variant and other variables with UFs was determined by multiple logistic regression, and the results were presented as odds ratios and 95% confidence intervals (CIs).

RESULTS

The 3588 participants comprised 622 cases and 2966 controls. In all the participants, the ESR1 rs2234693 TC and CC genotypes compared to the reference genotype (TT) were associated with a lower risk of UFs. However, the results were significant only for the CC genotype (OR; 95% CI = 0.70; 0.52-0.93). Noteworthy, the association of TC and CC with UFs was dose-dependent (p-trend = 0.012). Based on menopausal status, both TC and CC were significantly and dose-dependently associated with a lower risk of UFs in premenopausal women (OR; 95% CI = 0.76; 0.59-0.98 for TC and 0.64; 0.43-0.95 for CC: p-trend = 0.010).

CONCLUSION

The TC and CC genotypes of the ESR1 rs2234693 variant may reduce susceptibility to UFs, especially in premenopausal women.

"I think people should be more aware:" Uterine fibroid experiences among women living in Indiana, USA

OBJECTIVE

To understand healthcare experiences among patients with uterine fibroids (fibroids) across the continuum of care, from early symptoms through diagnosis, treatment, and management, while also investigating health disparities.

METHODS

We conducted 20 semi-structured interviews with patients with fibroids. Interviews were transcribed verbatim and qualitatively analyzed using thematic analysis. Eligible participants were women aged 18 and over, residing within 75 miles of one of the two recruitment locations (Tippecanoe or Marion County) in Indiana, USA.

RESULTS

Women experienced myriad physical symptoms, which often manifested into psychological and sexual disturbances and infiltrated all aspects of daily life. Internet searches were frequently mentioned as their main information source. Fertility became a prominent factor in deciding treatment options. However, health disparities prevented some from receiving quality fibroids healthcare. Some women reported staying home during COVID-19 pandemic facilitated the management of physical symptoms. Overall, participants advocated for greater fibroids awareness and education.

CONCLUSION

Results highlight barriers and facilitators to fibroids-related decisions, behaviors, and outcomes. Translation of research to practice was guided by a combined Social-Ecological Model and social determinants of health framework for development of strategic interventions.

PRACTICE IMPLICATIONS

Interventions should aim to improve fibroids healthcare access, education and awareness, and patient-provider communication for minority, rural, and low socioeconomic status communities disproportionately impacted by fibroids.

Exploring Potential Causal Genes for Uterine Leiomyomas: A Summary Data-Based Mendelian Randomization and FUMA Analysis

Objective: To explore potential causal genetic variants and genes underlying the pathogenesis of uterine leiomyomas (ULs).

Methods: We conducted the summary data-based Mendelian randomization (SMR) analyses and performed functional mapping and annotation using FUMA to examine genetic variants and genes that are potentially involved in the pathogenies of ULs. Both analyses used summarized data of a recent genome-wide association study (GWAS) on ULs, which has a total sample size of 244,324 (20,406 cases and 223,918 controls). We performed separate SMR analysis using CAGE and GTEx eQTL data.

Results: Using the CAGE eQTL data, our SMR analysis identified 13 probes tagging 10 unique genes that were pleiotropically/potentially causally associated with ULs, with the top three probes being ILMN_1675156 (tagging CDC42, PSMR = 8.03 × 10⁻⁹), ILMN_1705330 (tagging CDC42, PSMR = 1.02 × 10⁻⁷) and ILMN_2343048 (tagging ABCB9, PSMR = 9.37 × 10⁻⁷). Using GTEx eQTL data, our SMR analysis did not identify any significant genes after correction for multiple testing. FUMA analysis identified 106 independent SNPs, 24 genomic loci and 137 genes that are potentially involved in the pathogenesis of ULs, seven of which were also identified by the SMR analysis.

Conclusions: We identified many genetic variants, genes, and genomic loci that are potentially involved in the pathogenesis of ULs. More studies are needed to explore the exact underlying mechanisms in the etiology of ULs.

Body Habitus Across the Lifespan and Risk of Pituitary Adenoma

CONTEXT

No studies have examined the association between body habitus and incidence of pituitary adenoma.

OBJECTIVE

To determine if body mass index (BMI), waist circumference, body somatotype, or height are associated with risk of pituitary adenoma.

DESIGN

Pooled analysis of 3 prospective cohort studies.

SETTING

Population-based study.

PARTICIPANTS

Participants of the Nurses' Health Study (NHS), Nurses' Health Study II (NHSII), and the Health Professionals Follow-Up Study (HPFS), totaling 284 946 American health professionals.

EXPOSURES

BMI, waist circumference, body somatotype, and height.

OUTCOME MEASURES

Self-reported incident pituitary adenoma. Multivariable (MV)-adjusted hazard ratios (HRs) of pituitary adenoma were estimated using Cox proportional hazards models.

RESULTS

During 7 350 156 person-years of follow-up, 387 incident pituitary adenomas were reported. Comparing BMI of ≥30 to <25 kg/m2, higher adult BMI was associated with higher risk of pituitary adenoma (MV HR = 1.74; 95% CI, 1.33-2.28), as was higher maximum adult BMI (MV HR = 1.76; 95% CI, 1.34-2.30), higher waist circumference (MV HR = 1.06; 95% CI, 1.04-1.09 per inch), and higher BMI during early adulthood (at age 18 to 21, MV HR = 2.65; 95% CI, 1.56-4.49). Taller adult height was associated with pituitary adenoma (MV HR = 1.05; 95% CI, 1.01-1.09 per inch). Overall findings were similar in women and men, although power was limited in men (n = 62 cases). Sensitivity analyses demonstrated that the association between adult BMI and pituitary adenoma extended to at least 14 years prior to diagnosis and that the results were not affected when analyses were restricted to participants with similar healthcare utilization.

CONCLUSION

Higher BMI and waist circumference, from early adulthood to the time of diagnosis, were associated with higher risk of pituitary adenoma.

Association between obesity and the risk of uterine fibroids: a systematic review and meta-analysis

BACKGROUND

Uterine fibroids (UFs) are the most common form of sex steroid hormone-dependent benign tumours that grow in the walls of the uterus. Several observational studies have examined the association between obesity and the risk of UFs, but findings are inconsistent. The objective of this systematic review and meta-analysis is to further examine the association of obesity with the risk/prevalence of UFs.

METHODS

A literature search was performed in three databases (PubMed, EMBASE and Web of Science) from 1 January 1992 to 30 May 2020. We used random-effect models to calculate the pooled ORs with corresponding 95% CIs. Additionally, we performed a dose-response meta-analysis to analyse the effect of body mass index (BMI), weight change since age 18, waist-to-hip ratio and waist circumference on the risk/prevalence of UFs.

RESULTS

A total of 22 articles, covering 24 studies including 325 899 participants and 19 593 cases, were selected based on our inclusion criteria. We found a positive association between obesity and the risk/prevalence of UFs (OR, 1.19; 95% CI, 1.09 to 1.29). Among participants with the highest BMI, the pooled OR was 1.19 (1.09 to 1.31) when compared to participants with normal BMI. For weight change since age 18, the pooled OR (95% CI) of UFs was 1.26 (1.12 to 1.42) among the highest change group when compared with no change. Additionally, our meta-analysis indicated the relationship of BMI with risk of UFs to be an inverse J-shaped pattern.

CONCLUSIONS

The results of this meta-analysis suggest that obesity may increase the risk/prevalence of UFs, and the association is non-linear.

Lower prevalence of non-cavity-distorting uterine fibroids in patients with polycystic ovary syndrome than in those with unexplained infertility

OBJECTIVE

To study whether there is a difference in the prevalence of non-cavity-distorting uterine fibroids between infertile patients with polycystic ovary syndrome (PCOS) and those with unexplained infertility (UI).

DESIGN

A secondary analysis of data from three randomized clinical trials.

SETTING

Academic health centers.

PATIENT(S)

A total of 2,249 patients with normal uterine cavities.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The presence or absence of non-cavity-distorting fibroids.

RESULT(S)

Compared with women with UI, those with PCOS were younger, had a higher body mass index, and were more likely to be Hispanic or African American, with a lower percentage of previous conception and live birth, a higher percentage of current smokers, a lower percentage of current alcohol users, and higher total testosterone, fasting insulin, and homeostasis-model-assessment insulin resistance. The prevalence of women with non-cavity-distorting uterine fibroids was lower in women with PCOS than in those with UI (6.7% vs. 12.4%); this result held after patients were divided into Black and non-Black or into three different body mass index groups. After adjustment for all the other variables in the final model, patients with PCOS had a significantly lower prevalence of fibroids than those with UI (odds ratio 0.54). No differences in the prevalence of non-cavity-distorting fibroids with any dimensions ≥4 cm or the volume of the largest fibroid was found between the two groups.

CONCLUSION(S)

A lower prevalence of non-cavity-distorting uterine fibroids was found in infertile women with PCOS than in those with UI.

Expanded Somatic Mutation Spectrum of MED12 Gene in Uterine Leiomyomas of Saudi Arabian Women

MED12, a subunit of mediator complex genes is known to harbor genetic mutations, (mostly in exon 2), causal to the genesis of uterine leiomyomas among Caucasian, African American, and Asian women. However, the precise relationship between genetic mutations vs. protein or disease phenotype is not well-explained. Therefore, we sought to replicate the MED12 mutation frequency in leiomyomas of Saudi Arabian women, who represents ethnically and culturally distinct population. We performed molecular screening of MED12 gene (in 308 chromosomes belonging to 154 uterine biopsies), analyzed the genotype-disease phenotype correlations and determined the biophysical characteristics of mutated protein through diverse computational approaches. We discovered that >44% (34/77) leiomyomas of Arab women carry a spectrum of MED12 mutations (30 missense, 1 splice site, and 3 indels). In addition to known codon 44, we observed novel somatic mutations in codons 36, 38, and 55. Most genetically mutated tumors (27/30; 90%) demonstrated only one type of genetic change, highlighting that even single allele change in MED12 can have profound impact in transforming the normal uterine myometrium to leiomyomas. An interesting inverse correlation between tumor size and LH is observed when tumor is positive to MED12 mutation (p < 0.05). Our computational investigations suggest that amino acid substitution mutations in exon-2 region of MED12 might contribute to potential alterations in phenotype as well as the stability of MED12 protein. Our study, being the first one from Arab world, confirms the previous findings that somatic MED12 mutations are critical to development and progression of uterine leiomyomas irrespective of the ethnic background. We recommend that mutation screening, particularly codon 44 of MED12 can assist in molecular diagnostics of uterine leiomyomas in majority of the patients.

Evaluating risk factors for differences in fibroid size and number using a large electronic health record population

OBJECTIVE

To evaluate individual characteristics of women with fibroids in relation to fibroid size and number.

METHODS

This cross-sectional study involved 2302 women (black and white, age range 18-87) with image- or surgery-confirmed fibroids from the Synthetic Derivative, a database of de-identified demographic and clinical information from patient electronic health records (EHRs) from the Vanderbilt University Medical Center. We performed multivariate regression analyses on the following outcomes: volume of largest fibroid, largest dimension of all fibroids, and number of fibroids (single vs multiple). Candidate risk factors included age at diagnosis, body mass index (BMI), race, type 2 diabetes status, and number of living children (a proxy for parity). We assessed potential effect measure modification by race and both age and BMI using a likelihood ratio test.

RESULTS

Black race was strongly associated with having multiple fibroids (adjusted odds ratio [aOR]: 1.83, 95% confidence interval [CI]: 1.49, 2.24) and larger fibroid volume (adjusted beta: 1.77, 95% CI: 1.38, 2.27) and greater largest dimension (adjusted beta: 1.28, 95% CI: 1.18, 1.38). Having multiple fibroids was most strongly associated with ages 43-47 (aOR = 3.37, 95% CI: 2.55, 4.46) compared with the youngest age group (ages 18-36). Having a larger number of living children was associated with having single a fibroid (aOR: 0.88, 95% CI: 0.78, 0.99).

CONCLUSIONS

Our findings suggest that different underlying etiologies are involved for women developing single versus multiple fibroids and small versus large fibroids. Studies are needed of the mechanisms by which these characteristics influence fibroid formation and growth.

African genetic ancestry interacts with body mass index to modify risk for uterine fibroids

Race, specifically African ancestry, and obesity are important risk factors for uterine fibroids, and likely interact to provide the right conditions for fibroid growth. However, existing studies largely focus on the main-effects rather than their interaction. Here, we firstly provide evidence for interaction between categories of body mass index (BMI) and reported-race in relation to uterine fibroids. We then investigate whether the association between inferred local European ancestry and fibroid risk is modified by BMI in African American (AA) women in the Vanderbilt University Medical Center bio-repository (BioVU) (539 cases and 794 controls) and the Coronary Artery Risk Development in Young Adults study (CARDIA, 264 cases and 173 controls). We used multiple logistic regression to evaluate interactions between local European ancestry and BMI in relation to fibroid risk, then performed fixed effects meta-analysis. Statistical significance threshold for local-ancestry and BMI interactions was empirically estimated with 10,000 permutations (p-value = 1.18x10-4). Admixture mapping detected an association between European ancestry and fibroid risk which was modified by BMI (continuous-interaction p-value = 3.75x10-5) around ADTRP (chromosome 6p24); the strongest association was found in the obese category (ancestry odds ratio (AOR) = 0.51, p-value = 2.23x10-5). Evaluation of interaction between genotyped/imputed variants and BMI in this targeted region suggested race-specific interaction, present in AAs only; strongest evidence was found for insertion/deletion variant (6:11946435), again in the obese category (OR = 1.66, p-value = 1.72x10-6). We found nominal evidence for interaction between local ancestry and BMI at a previously reported region in chromosome 2q31-32, which includes COL5A2, and TFPI, an immediate downstream target of ADTRP. Interactions between BMI and SNPs (single nucleotide polymorphisms) found in this region in AA women were also detected in an independent European American population of 1,195 cases and 1,164 controls. Findings from our study provide an example of how modifiable and non-modifiable factors may interact to influence fibroid risk and suggest a biological role for BMI in fibroid etiology.

Epidemiology of Uterine Fibroids: From Menarche to Menopause

Uterine leiomyomata (UL) have a substantial impact on women's health, but relatively few studies have identified opportunities for primary prevention of these neoplasms. Most established risk factors are not modifiable, including premenopausal age, African ancestry, age at menarche, and childbearing history. The main challenge in studying UL is that a large proportion of tumors are asymptomatic. Herein, we review the epidemiology of UL from published studies to date. We highlight the advantages of ultrasound screening studies and the ways in which their innovative methods have helped clarify the etiology of disease. We conclude with a discussion of promising new hypotheses.

Environmental tobacco smoke and risk of late-diagnosis incident fibroids in the Study of Women's Health across the Nation (SWAN)

OBJECTIVE

To assess the longitudinal relationship of environmental tobacco smoke (ETS) exposure during midlife, and its interaction with active smoking, with the risk of late-diagnosis incident uterine fibroids during the menopausal transition.

DESIGN

Thirteen-year prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

Community-based, multiracial/ethnic cohort of 2,575 women aged 42 to 52 years at baseline, undergoing the menopausal transition.

INTERVENTION(S)

Questionnaire and blood draws.

MAIN OUTCOME MEASURE(S)

Discrete-time proportional odds models were used to estimate the conditional odds ratio (OR) and 95% confidence interval (CI) of incident fibroids, adjusted for menopausal status, race/ethnicity, study site, age, education, estradiol levels, sex hormone use, body mass index, timing of blood draw, age at menarche, alcohol use, and smoking status and pack-years.

RESULT(S)

As part of SWAN, at each near-annual study visit, ETS exposure, smoking, and fibroid occurrence were self-reported via questionnaire, and blood draws were collected. Women who were exposed to ETS (≥1 person-hour/week) had 1.28 (95% CI, 1.03, 1.60) times the adjusted odds of incident fibroids in the ensuing year compared the unexposed. The odds were elevated in never smokers (adjusted OR 1.34; 95% CI, 1.06, 1.70) and former smokers (adjusted OR 2.57; 95% CI, 1.05, 7.23).

CONCLUSION(S)

In midlife, ETS exposure was associated with an increased risk of late-diagnosis incident fibroids in women undergoing the menopausal transition.

Dietary components and uterine leiomyomas: a review of published data

Some studies have considered the association between diet and uterine fibroid risk, but the issue is largely unsettled. To identify potential modifiable risk factors for fibroid development, we have herein systematically reviewed prior publications dealing with this aspect. Comprehensive searches in electronic databases were conducted to collect studies published on association between uterine leiomyomas and both nutrients and food groups. We identified 13 publications deriving from 4 case-control, 3 cross-sectional, and 4 cohort studies. A protective effect has been demonstrated for consumption of fruits and green vegetables in both case-control and cohort studies. Moreover, very recent cross-sectional and case-control studies evaluating serum levels of 25-hydroxyvitamin-D3 tend to indicate that vitamin D insufficiency, which may in part be due to the diet intake, may play an important role in the development of uterine fibroids. No association was found with the intake of fibers, vitamin C and E, phytoestrogens and carotenoids, whereas association was controversial for the consumption of meat, fish, dairy products, and vitamin A. Most data have also been discussed herein in light of the available experimental and animal model results. These findings may be useful in devising nutritional strategies to reduce leiomyoma risk in humans.

The association between occupational characteristics and hysterectomies for treating uterine fibroids in Taiwan

This study examined the relationship between the occupational characteristics of women with uterine fibroids (UFs) and the decision to have a hysterectomy. Data from the Longitudinal Taiwan Health Insurance Database (LTHID) from 2000 to 2009 were analyzed to investigate the association between occupation and hysterectomies. Multivariable logistic regression analysis showed that, compared with white-collar UF patients, the odds ratio (OR) for hysterectomy surgery was 1.21 (95% confidence interval (CI) = 1.11-1.32) for blue-collar UF patients. Moreover, non-government employees with UFs also had significantly increased odds of having a hysterectomy compared to government employees with UFs (OR = 1.19, 95% CI = 1.04-1.36). This study provides information regarding the extent to which differences in occupation and decision-making processes might affect the marked variations in the use of hysterectomies for UFs.

Tissue-specific stem cells in the myometrium and tumor-initiating cells in leiomyoma

Tissue-specific (or somatic) stem cells constitute a subset of cells residing in normal adult tissues. By undergoing asymmetric division, they retain their ability to self-renew while producing daughter cells that go on to differentiate and play a role in tissue regeneration and repair. The human uterus consists primarily of endometrium and myometrium (the smooth muscle layer) that rapidly enlarges through its tremendous regenerative and remodeling capacity to accommodate the developing fetus. Such uterine enlargement and remodeling can take place repeatedly and cyclically over the course of a woman's reproductive life. These unique properties of the uterus suggest the existence of endometrial and myometrial stem cell systems. In addition, like somatic cells, tumor stem cells or tumor-initiating cells, a subset of cells within a tumor, retain the ability to reconstitute tumors. Uterine smooth muscle cells are thought to be the origin of leiomyomas that are the most common type of gynecologic tumor. Recent work has identified, isolated, and characterized putative stem/progenitor cells in the myometrium and in leiomyomas. Here, we review current studies of myometrial and leiomyoma stem/progenitor cells and provide a new paradigm for understanding myometrial physiology and pathology and how these cells might contribute to uterine remodeling during pregnancy and the formation of leiomyomas. The role of the WNT/CTNNB1 pathway in the pathogenesis of leiomyoma is also discussed.

Uterine fibroids: current perspectives

Uterine fibroids are a major cause of morbidity in women of a reproductive age (and sometimes even after menopause). There are several factors that are attributed to underlie the development and incidence of these common tumors, but this further corroborates their relatively unknown etiology. The most likely presentation of fibroids is by their effect on the woman's menstrual cycle or pelvic pressure symptoms. Leiomyosarcoma is a very rare entity that should be suspected in postmenopausal women with fibroid growth (and no concurrent hormone replacement therapy). The gold standard diagnostic modality for uterine fibroids appears to be gray-scale ultrasonography, with magnetic resonance imaging being a close second option in complex clinical circumstances. The management of uterine fibroids can be approached medically, surgically, and even by minimal access techniques. The recent introduction of selective progesterone receptor modulators (SPRMs) and aromatase inhibitors has added more armamentarium to the medical options of treatment. Uterine artery embolization (UAE) has now been well-recognized as a uterine-sparing (fertility-preserving) method of treating fibroids. More recently, the introduction of ultrasound waves (MRgFUS) or radiofrequency (VizAblate™ and Acessa™) for uterine fibroid ablation has added to the options of minimal access treatment. More definite surgery in the form of myomectomy or hysterectomy can be performed via the minimal access or open route methods. Our article seeks to review the already established information on uterine fibroids with added emphasis on contemporary knowledge.

Prevalência de diagnóstico médico auto-relatado de miomas uterinos em população brasileira: Padrões demográficos e socioeconômicos no Estudo Pró-Saúde *

Introdução: Os miomas uterinos (MU) são considerados os tumores mais comuns do sistema reprodutor feminino; no entanto, existem poucos estudos epidemiológicos sobre essa condição no Brasil. Objetivo: Estimar as prevalências de história auto-relatada de MU segundo características demográficas, socioeconômicas e de acesso a serviços de saúde. Métodos: Foram analisados dados de 1.733 trabalhadoras de universidade no Rio de Janeiro, participantes da linha de base do Estudo Pró-Saúde (1999-2001), em relação a três desfechos: (1) diagnóstico médico de MU, (2) MU com sintomas prévios ao diagnóstico e (3) casos que realizaram histerectomia pelo tumor. As prevalências e seus intervalos de 95% de confiança (IC 95%) foram estimadas em relação a estratos de variáveis demográficas (idade, cor/raça), socioeconômicas (escolaridade, renda) e marcadoras de acesso a serviços de saúde (teste Papanicolaou , exame de mama, plano de saúde). Resultados: A prevalência de diagnóstico médico de MU foi de 23,3% (IC 95% - 21,3; 25,2); a de MU com sintomas prévios ao diagnóstico, de 13,3% (IC 95% - 11,7; 15,0) e a de histerectomia pelo tumor, de 8,4% (IC 95% - 7,5; 10,3). Entre participantes abaixo de 45 anos de idade, foram observadas prevalências mais elevadas nos estratos de piores condições socioeconômicas e de cor/raça preta. Entre aquelas com 45 anos ou mais, foram encontradas maiores prevalências entre mulheres com melhor acesso a serviços de saúde. Conclusão: Entre as mulheres brasileiras investigadas, os MU constituem problema relevante de saúde, com prevalências e gradientes sociodemográficos similares aos observados em populações de outros países.

Prevalence, symptoms and management of uterine fibroids: an international internet-based survey of 21,746 women

Background

In 2009 the Uterine Bleeding and Pain Women's Research Study (UBP-WRS) was conducted interviewing 21,479 women across 8 countries in order to gain patient-based prevalence data on uterine pain and bleeding indications and investigate uterine symptoms and women's treatment experiences. This article shows relevant results of the study for the indication uterine fibroids providing data on self-reported prevalence, symptomatology and management of uterine fibroids.

Methods

2,500 women (USA: 4,500 women) in each country (Brazil, Canada, France, Germany, Italy, South Korea, the UK, the USA) completed an online survey. Women included were in their reproductive age (age group 15-49 years; USA: 18-49 years) and had ever experienced menstrual bleedings. Quotas were applied for age, region, level of education and household income of respondents. Variables have been analyzed descriptively and exploratory statistical tests have been performed.

Results

The self-reported prevalence of uterine fibroids ranged from 4.5% (UK) to 9.8% (Italy), reaching 9.4% (UK) to 17.8% (Italy) in the age group of 40-49 years. Women with a diagnosis of uterine fibroids reported significantly more often about bleeding symptoms than women without a diagnosis: heavy bleedings (59.8% vs. 37.4%), prolonged bleedings (37.3% vs. 15.6%), bleeding between periods (33.3% vs. 13.5%), frequent periods (28.4% vs. 15.2%), irregular and predictable periods (36.3% vs. 23.9%). Furthermore women with diagnosed uterine fibroids reported significantly more often about the following pain symptoms: pressure on the bladder (32.6% vs. 15.0%), chronic pelvic pain (14.5% vs. 2.9%), painful sexual intercourse (23.5% vs. 9.1%) and pain occurring mid-cycle, after and during menstrual bleeding (31.3%, 16.7%, 59.7%, vs. 17.1%, 6.4%, 52.0%). 53.7% of women reported that their symptoms had a negative impact on their life in the last 12 month, influencing their sexual life (42.9%), performance at work (27.7%) and relationship & family (27.2%).

Conclusions

Uterine fibroid is a common concern in women at fertile age causing multiple bleeding and pain symptoms which can have a negative impact on different aspects in women's life.

Intake of fruit, vegetables, and carotenoids in relation to risk of uterine leiomyomata

BACKGROUND

US black women have higher rates of uterine leiomyomata (UL) and lower intakes of fruit and vegetables than do white women. Whether fruit and vegetable intake is associated with UL in black women has not been studied.

OBJECTIVE

We assessed the association of dietary intake of fruit, vegetables, carotenoids, folate, fiber, and vitamins A, C, and E with UL in the Black Women's Health Study.

DESIGN

In this prospective cohort study, we followed 22,583 premenopausal women for incident UL (1997-2009). Diet was estimated by using food-frequency questionnaires in 1995 and 2001. Cox regression was used to derive incidence rate ratios (IRRs) and 95% CIs for the association between each dietary variable (in quintiles) and UL.

RESULTS

There were 6627 incident cases of UL diagnosed by ultrasonography (n = 4346) or surgery (n = 2281). Fruit and vegetable intake was inversely associated with UL (≥4 compared with <1 serving/d; IRR: 0.90; 95% CI: 0.82, 0.98; P-trend = 0.03). The association was stronger for fruit (≥2 servings/d compared with <2 servings/wk; IRR: 0.89; 95% CI: 0.81, 0.98; P-trend = 0.07) than for vegetables (≥2 servings/d compared with <4 servings/wk: IRR: 0.97; 95% CI: 0.89, 1.05; P-trend = 0.51). Citrus fruit intake was inversely associated with UL (≥3 servings/wk compared with <1 serving/mo: IRR: 0.92; 95% CI: 0.86, 1.00; P-trend = 0.01). The inverse association for dietary vitamin A (upper compared with lower quintiles: IRR: 0.89; 95% CI: 0.83, 0.97; P-trend = 0.01) appeared to be driven by preformed vitamin A (animal sources), not provitamin A (fruit and vegetable sources). UL was not materially associated with dietary intake of vitamins C and E, folate, fiber, or any of the carotenoids, including lycopene.

CONCLUSION

These data suggest a reduced risk of UL among women with a greater dietary intake of fruit and preformed vitamin A.

Reproductive characteristics and risk of uterine leiomyomata

OBJECTIVE

To evaluate whether menstrual and reproductive characteristics may influence development of uterine leiomyomata since sex steroid hormones have been hypothesized to play a role in their development.

DESIGN

A prospective cohort study (Nurses' Health Study II).

SETTING

Participants were identified from 14 states and followed for 14 years.

PATIENT(S)

A cohort of 116,609 female registered nurses ages 25-42 at baseline.

INTERVENTION(S)

We obtained data on uterine leiomyomata incidence and exposures through biennial questionnaires. We calculated hazard ratios and 95% confidence intervals adjusted for known and suspected risk factors.

MAIN OUTCOME MEASURE(S)

Uterine leiomyomata confirmed by ultrasound or hysterectomy.

RESULT(S)

During 1,163,439 person-years of follow-up, 9,847 self-reported cases of hysterectomy- or ultrasound-confirmed uterine leiomyomata were reported. We observed a lower incidence of uterine leiomyomata with later age at menarche, longer menstrual cycles, parity, later age at first and last birth, shorter time since last birth, and breastfeeding.

CONCLUSION(S)

Hormonal and anatomical changes associated with menstruation and pregnancy may influence uterine leiomyomata incidence.

New directions in the epidemiology of uterine fibroids

Although uterine leiomyomata (fibroids) have been the leading indication for hysterectomy in the United States for decades, the epidemiological data on fibroid prevalence and risk factors are limited. Given the hormonal dependence of fibroids, most earlier studies focused on reproductive or hormonal factors. Recent analyses have extended that focus to other areas. We present previously unpublished data on the association between reproductive tract infections and fibroids that highlight the need for more detailed studies. Our review suggests that metabolic, dietary, stress, and environmental factors may also play a role in fibroid development.

Characteristics indicating adenomyosis coexisting with leiomyomas: a case-control study

BACKGROUND

Adenomyosis is rarely diagnosed before hysterectomy and commonly coexists with uterine leiomyomas. The objective of this study was to identify distinct features of a concurrent diagnosis of adenomyosis in women with uterine leiomyomas.

METHODS

We conducted a case-control study of women undergoing hysterectomy with a histologic diagnosis of both adenomyosis and leiomyomas and women with uterine leiomyomas but no adenomyosis. A retrospective medical record review of hospital and ambulatory records was performed to ascertain sociodemographic and anthropometric variables, as well as to confirm intraoperative and pathologic findings.

RESULTS

Our study sample comprised 255 patients, 85 women with adenomyosis and leiomyomas and 170 women with only leiomyomas. In multivariable logistic regression analyses, women with adenomyosis and leiomyomas were more likely to have more pelvic pain [odds ratio (OR) 3.4, 95% confidence interval (CI) 1.8-6.4], have less fibroid burden (OR per doubling in fibroid size 0.6, 95% CI 0.5-0.8), were more likely to be parous (OR 3.8, 95% CI 1.4-10.5) and have lower body mass index (OR per 5 unit increase in BMI 0.8, 95% CI 0.6-1.0) when compared with women with leiomyomas alone.

CONCLUSIONS

Women undergoing hysterectomy with both adenomyosis and leiomyomas have a number of different clinical features compared with women with only leiomyomas at the time of hysterectomy. Women with substantial pain despite a smaller fibroid burden may be more likely to have concomitant adenomyosis.

Breast cancer risk and hysterectomy status: the Multiethnic Cohort study

OBJECTIVE

The main objective was to examine the association between simple hysterectomy (without bilateral oophorectomy) and breast cancer risk. Because hysterectomy prevalence varies by ethnicity, the secondary objective was to examine whether inclusion of women with hysterectomies affects the estimates of breast cancer risk by ethnicity.

METHODS

The Multiethnic Cohort study was assembled between 1993 and 1996 and included 68,065 women from Hawaii and Los Angeles, aged 45-75 years, without any missing information or bilateral oophorectomy. Hysterectomy status was self-reported. After 7.7 years median follow-up, 1,862 cases of invasive breast cancer were identified. Proportional hazards models were used to estimate relative risks (RR) while controlling for known risk factors.

RESULTS

Prevalence of simple hysterectomy varied from 12% to 29% among the ethnic groups (White, African American, Native Hawaiian, Japanese American, and Latina). Overall, hysterectomy was not associated with breast cancer risk (RR = 0.98). Although the RRs were nonsignificantly elevated by 15% in White women and nonsignificantly reduced by 15% in Latinas of non-US origin, the variation by ethnicity was not significant (p(interaction) = 0.48). The breast cancer risk associated with ethnicity was very similar when estimated with and without women with hysterectomies.

CONCLUSIONS

This study suggests that simple hysterectomy status does not alter breast cancer risk. Therefore, inclusion of women with simple hysterectomies does not substantially change estimated risk of breast cancer by ethnicity.

Estrogen receptor alpha (ERalpha) phospho-serine-118 is highly expressed in human uterine leiomyomas compared to matched myometrium

It is thought that the growth of uterine leiomyomas may be mediated by the interaction of estrogen receptor alpha (ERalpha) and growth factor pathways and that phosphorylation of ERalpha at serine 118 (ERalpha-phospho-Ser118) is important in this interaction. In this study, immunoblotting and immunohistochemistry were used to investigate the expression of ERalpha-phospho-Ser118, phosphorylated p44/42 mitogen-activated protein kinase (phospho-p44/42 MAPK), and proliferating cell nuclear antigen (PCNA) in human leiomyoma and myometrial tissues during the proliferative and secretory phases of the menstrual cycle. We found that tumors taken from the proliferative phase expressed significantly higher levels of ERalpha-phospho-Ser118, phospho-p44/42 MAPK, and PCNA compared to patient-matched myometria and had significantly higher ERalpha-phospho-Ser118 and PCNA expression compared to secretory phase tumors. Also, enhanced colocalization and association of phospho-p44/42 MAPK and ERalpha-phospho-Ser118 were observed in proliferative phase tumors by confocal microscopy and immunoprecipitation, respectively. These data suggest that ERalpha-phospho-Ser118 may be important in leiomyoma growth and is possibly phosphorylated by phospho-p44/42 MAPK.