Reversal by medical treatment of endometrial hyperplasia caused by estrogen replacement therapy

Endometrial hyperplasia-related inflammation: its role in the development and progression of endometrial hyperplasia

BACKGROUND

Endometrial hyperplasia (EH) is one of the most common gynecologic diseases in the world. Different statistical categories implicate an imbalance of estrogens and progestogens in the etiology of this disease. We propose that inflammation also plays a key role in the progression of endometrial hyperplasia.

OBJECTIVE

The aim of this study is to evaluate the role of inflammation in the transformation and progression of endometrial hyperplasia, using local inflammatory cytokines and nonspecific protease levels, CD 45(+) expression, and histological examination.

DESIGN

The study included 107 patients (ages 29-49 years) with different forms of endometrial hyperplasia. The enrolled patients were randomized into one of the four groups: normal endometrium (n = 18) as the control group, simple hyperplasia (n = 41), complex hyperplasia without atypia (n = 36), complex atypical hyperplasia or endometrioid adenocarcinoma (n = 12).

METHODS

The following were evaluated for patients with different forms of EH: steroid hormone levels in blood serum and uterine flushings, immunohistochemical estrogen and progesterone receptor expression patterns in the endometrial tissue, CD 45(+) (common leukocyte antigen) expression, the levels of the cytokines IL-1β, IL-6, and TNF-α, and nonspecific proteases and their inhibitors.

RESULTS

The level of estradiol in blood serum and especially in uterine flushings was elevated dramatically in simple EH as compared to that of controls, but there was no significant difference between estradiol levels among the different forms of EH. The estimation of CD 45(+), the levels of the cytokines IL-1β, IL-6, and TNF-α, and the activity of proteases (elastase-like and trypsin-like activities) and their inhibitors showed that levels of nonspecific inflammatory markers increase with EH progression.

CONCLUSIONS

We suggest that the initial responsibility for the development of simple endometrial hyperplasia belongs to systemic hyperestrogenemia and, in particular, local hyperestrogenia, but that the role of inflammatory processes increases in complex and atypical EH. Development of inflammatory changes in endometrial hyperplasia may be considered as a factor in the promotion and progression of pathology, as well as an attributed risk factor for malignancy in endometrial hyperplasia. In this study, we have established a role for CD 45(+) expression cells, non-specific proteases, and the inflammatory cytokines IL-1β, IL-6, and TNF-α in endometrial hyperplasia-related inflammation.

Therapeutic options for management of endometrial hyperplasia

Endometrial hyperplasia (EH) comprises a spectrum of changes in the endometrium ranging from a slightly disordered pattern that exaggerates the alterations seen in the late proliferative phase of the menstrual cycle to irregular, hyperchromatic lesions that are similar to endometrioid adenocarcinoma. Generally, EH is caused by continuous exposure of estrogen unopposed by progesterone, polycystic ovary syndrome, tamoxifen, or hormone replacement therapy. Since it can progress, or often occur coincidentally with endometrial carcinoma, EH is of clinical importance, and the reversion of hyperplasia to normal endometrium represents the key conservative treatment for prevention of the development of adenocarcinoma. Presently, cyclic progestin or hysterectomy constitutes the major treatment option for EH without or with atypia, respectively. However, clinical trials of hormonal therapies and definitive standard treatments remain to be established for the management of EH. Moreover, therapeutic options for EH patients who wish to preserve fertility are challenging and require nonsurgical management. Therefore, future studies should focus on evaluation of new treatment strategies and novel compounds that could simultaneously target pathways involved in the pathogenesis of estradiol-induced EH. Novel therapeutic agents precisely targeting the inhibition of estrogen receptor, growth factor receptors, and signal transduction pathways are likely to constitute an optimal approach for treatment of EH.

Chromatin composition alterations and the critical role of MeCP2 for epigenetic silencing of progesterone receptor-B gene in endometrial cancers

OBJECTIVE

To understand the epigenetic mechanism underlying the PR-B gene silencing in endometrial cancer (EC) cells, we compared the chromatin composition between transcriptionally active and silenced PR-B genes in EC cell lines and cancer tissues.

METHODS

Chromatin Immunoprecipitation (ChIP) assay was performed to measure MBD occupancy and histone acetylation/methylation in transcriptionally active and silenced PR-B genes. PR-B-positive/-negative, as well as epigenetic inhibitor-treated/-untreated EC cells were used as study models. Real-time polymerase chain reaction (PCR) and Western blot analysis were applied to measure the mRNA and protein levels of PR-B, MBD, and histones.

RESULTS

A close association among PR-B methylation, MBD binding and PR-B gene silencing was observed. Treatment with epigenetic inhibitors led to dynamic changes in the PR-B chromatin composition and gene expression. Increased H3/H4 acetylation and H3-K4 methylation, and decreased H3-K9 methylation were found to be associated with re-activation of silenced PR-B genes. MeCP2 knockdown resulted in a decreased MeCP2 binding to PR-B genes and an increased PR-B expression. ChIP analysis of MeCP2 binding to PR-B genes in the PR-B-positive/-negative EC samples confirmed the significant role of MeCP2 in PR-B silencing.

CONCLUSION

PR-B gene expression is regulated by a concerted action of epigenetic factors including DNA methylation, MBD binding, and histone modifications. MeCP2 occupancy of PR-B genes plays a critical role in PR-B gene silencing. These findings enriched our knowledge of the epigenetic regulation of PR-B expression in EC, and suggested that the epigenetic re-activation of PR-B could be explored as a potential strategy to sensitize the PR-B-negative endometrial cancers to progestational therapy.

Estradiol plus drospirenone therapy increases mammographic breast density in perimenopausal women

OBJECTIVE

To investigate the effects of 17β-estradiol 1mg plus drospirenone 2mg (E2/DRSP) treatment on mammographic breast density in perimenopausal women.

STUDY DESIGN

In this prospective study, 80 healthy perimenopausal women aged 41-49 years were enrolled and assigned to either E2/DRSP (n=40) or a control group (n=40). Mammograms were performed at baseline and after 12 months of treatment. Mammographic breast density was quantified according to the Wolfe classification.

RESULTS

We demonstrated an increase in mammographic breast density in 37% (95% CI (confidence interval): 18.8-55.3%) of women treated with E2/DRSP after 12 months. The percentage of women with increased density was 0% (95% CI: 0.0-0.0%) in the control group. The difference in breast density between the E2/DRSP group and the control group was statistically very significant (p<0.001).

CONCLUSIONS

E2/DRSP therapy for 12 months in perimenopausal women significantly increased mammographic breast density in comparison to a control group. Further long-term and large scale prospective studies are needed to evaluate this issue.

Apoptosis induction and inhibition of hyperplasia formation by 2-[piperidinoethoxyphenyl]-3-[4-hydroxyphenyl]-2H-benzo(b)pyran in rat uterus

OBJECTIVE

The study was undertaken to explore the antiproliferative mechanism of action of 2-[piperidinoethoxyphenyl]-3-[4-hydroxyphenyl]-2H-benzo(b)pyran (K-1) in estradiol-induced rat uterine hyperplasia.

STUDY DESIGN

Adult ovariectomized rats received vehicle or estradiol alone (20 μg/kg) or estradiol along with K-1 (100 or 200 μg/kg) for 14 days. Uterine histomorphometric analysis and immunoblotting were performed. Caspase-3 activity and terminal deoxynucleotidyl transferase-mediated nick end-labeling staining were performed to analyze the apoptotic potential of compound.

RESULTS

Compound inhibited estradiol-induced uterine weight and histomorphometric changes pertaining to endometrial growth and down-regulated the expression of estrogen response element and activator protein-1 regulated genes and transcription factors. The compound significantly induced apoptosis, interfered with Akt activation, decreased X-linked inhibitor of apoptosis protein expression leading to an increased cleavage of caspase-9, caspase-3, poly(adenosine diphosphate-ribose) polymerase, increased Bax/Bcl2 ratio, and caspase-3 activity.

CONCLUSION

K-1 inhibits endometrial proliferation via nonclassical estrogen receptor signaling mechanisms. It interfered with Akt activation and induced apoptosis via the intrinsic pathway and inhibited estradiol-induced hyperplasia formation in rat uterus.

Safety, efficacy and patient acceptability of drospirenone and estradiol in the treatment of menopausal vasomotor symptoms: a review

During menopause vasomotor symptoms are one of the main complaints about which women seek medical advice. For symptom control, several therapies have been used, among which hormone therapy has produced good results. One of these is estrogen monotherapy, which unfortunately may induce endometrial hyperplasia in women with an intact uterus. A progestin must be added to avoid this risk. Progestins may induce several secondary effects such as breast tenderness, hirsutism, edema and unfavorable lipid profile modifications. Recently a new progestin called drospirenone has been synthesized and used in combination with estradiol for the treatment of postmenopausal women. This progestin is derived from spironolactone, and lacks estrogenic, androgenic and glucocorticoid activities. Several studies have evaluated safety, efficacy and patient tolerability, and have shown a good profile in all these parameters. All studies agree that the combination of estradiol 1 mg plus drospirenone 2 mg is a good choice for postmenopausal women with vasomotor symptoms.

Progestin therapy of complex endometrial hyperplasia with and without atypia

OBJECTIVE

To assess the likelihood of histologic persistence/progression of complex hyperplasia and atypical hyperplasia among women treated with progestin compared with those not treated, with attention to type, dose, and duration.

METHODS

This was a cohort study at an integrated health plan of women, ages 18-85 years, with complex or atypical hyperplasia on independent pathology review with a second endometrial specimen in the 2-6 months after the index diagnosis. Progestin therapy between index diagnosis and follow-up biopsy was determined from the pharmacy database. Medical record abstraction was performed. Relative risks (RRs), adjusted for age and body mass index, were calculated.

RESULTS

Among 185 women, average age 55.9 years, follow-up 16.1 weeks, 115 had complex and 70 had atypical hyperplasia. Among women with complex hyperplasia, 28.4% of those treated with progestin and 30.0% of those not treated had persistence/progression (RR 1.20, 95% confidence interval [CI] 0.53-2.72). Among women with atypical hyperplasia, 26.9% of those treated with progestin and 66.7% of those not treated had persistence/progression (RR 0.39, 95% CI 0.21-0.70); there was a suggestion that use of at least a medium dose, or a duration of at least 3 months, was associated with a particularly low probability of persistence/progression.

CONCLUSION

Although progestin treatment of women with atypical hyperplasia was associated with a substantial increase in the likelihood of regression of the lesion during the ensuing 2-6 months, persistence/progression was nonetheless present in more than one quarter of treated women. Regression of complex hyperplasia without atypia was common whether progestin had or had not been used.

Endometrial cancer risk in estrogen users after switching to estrogen-progestin therapy

OBJECTIVE

It is unknown whether postmenopausal unopposed estrogen users are better off, in terms of endometrial cancer risk, switching to a combined estrogen-progestin regimen or stopping hormone use altogether.

METHODS

We analyzed data from a series of three population-based case-control studies in western Washington state during 1985-1999, comparing proportions of "switchers" and "stoppers" in cases and controls. We also assessed whether the risk of endometrial cancer in either group of former unopposed estrogen users returned to that of never users.

RESULTS

After multivariate adjustment using unconditional logistic regression, women who switched to a combined regimen with a progestin added for at least ten days/month (37 cases, 47 controls) had half the risk of endometrial cancer of women who stopped hormone use altogether (86 cases, 78 controls) (adjusted odds ratio = 0.5, 95% confidence interval: 0.3-1.1). Most subgroups of former users, whether they switched or stopped, had some increased risk of endometrial cancer compared to never users.

CONCLUSIONS

Results from this study suggest that unopposed estrogen users may reduce their risk of endometrial cancer more by switching to a combined regimen with progestin added for at least ten days/month than by stopping hormone use altogether.

Clinical and pathological responses of progestin therapy for non-atypical endometrial hyperplasia: A prospective study

AIMS

To evaluate the clinical and pathological responses and factors predicting non-responders to various progestins currently prescribed for the treatment of non-atypical endometrial hyperplasia.

METHODS

A prospective observational study was conducted in the Gynecologic Endocrinology Unit, Faculty of Medicine, Siriraj Hospital, Thailand, from 1998 to 2003. A 6-month course of progestin therapy was offered to all patients. The clinical response was evaluated from the vaginal bleeding pattern during the first 4 months of treatment. The pathological response was evaluated from the histopathology of the endometrium after completion of the 6-month therapy.

RESULTS

Of 250 registered patients, the number of cases qualified for the evaluation of the clinical and pathological response were 198 and 134 cases, respectively, revealing the overall clinical and pathological response rates of 93.4% and 92.5%, respectively. Among 13 clinical non-responders, 84.6% might have associated pelvic pathology. Among 10 pathological non-responders, three had surgical treatment, and progressive disease was found in one case. Significant factors predicting clinical non-responders included a history of prior bleeding (odds ratio [OR] = 8.79, 95% confidence interval [CI] = 1.63, 47.53), the presence of associated pelvic pathology (OR = 25.52, 95% CI = 3.21, 203.01), and treatment using progestins other than medroxyprogesterone acetate. Factors predicting pathological non-responders were not statistically significant.

CONCLUSIONS

The current regimens of progestin therapy for non-atypical endometrial hyperplasia have high response rates. Patients who fail to have a clinical response should be evaluated for associated pelvic pathology. Follow-up endometrial biopsy should be offered to the patients, because 7.5% have persistent or progressive lesions, necessitating aggressive treatment.

The effects of the levonorgestrel intrauterine system (Mirena coil) on endometrial morphology

AIMS

The Mirena coil is a levonorgestrel releasing intrauterine device that is in widespread use. This study aims to document the endometrial morphology associated with this device.

METHODS

Endometrial specimens from 75 women with the Mirena coil were reviewed and the histological features detailed.

RESULTS

Morphological features found in most of the endometria were decidualisation of stroma (72 of 75 cases), atrophy of endometrial glands (65 of 75 cases), a surface papillary pattern (38 of 75 cases), and a stromal inflammatory cell infiltrate (59 of 75 cases). Additional common histological features were the presence of foci of stromal myxoid change (29 of 75 cases) and stromal haemosiderin pigment (24 of 75 cases). Reactive atypia of surface glands, glandular metaplastic changes, stromal necrosis, and stromal calcifications were found in small numbers of cases.

CONCLUSION

The endometrial features are characteristic and relatively constant and are in keeping with the effects of both a progestogenic compound and a mechanical device. Pathologists should be aware of these histological features because the Mirena coil is in widespread use.

P53 expression in spontaneous and estradiol-induced endometrial hyperplasia during menopause

OBJECTIVE

To determine the percentage of endometrial hyperplasia positive for p53 expression in both spontaneously occurring cases or following the use of unopposed estradiol.

METHODS

Fifty-four postmenopausal patients with endometrial hyperplasia diagnosed by endometrial biopsy and hysteroscopy were recruited to this study. Thirty-three patients had used unopposed estradiol for periods of time from 1 to 3 years. P53 expression was detected in paraffin-embedded endometrial specimens by immunohistochemical methods.

RESULTS

The percentage of endometrial hyperplasia positive for p53 expression was significantly greater in spontaneously occurring hyperplasia than in cases induced by the unopposed use of estradiol.

CONCLUSION

Endometrial hyperplasia caused by the unopposed use of estradiol during menopause probably harbors fewer genomic errors than those cases occurring spontaneously.