Endometrial pathologies associated with postmenopausal tamoxifen treatment

Endometrial stromal polyps in rodents: biology, etiology, and relevance to disease in women

Endometrial stromal polyps (ESP) are a common spontaneous reproductive tract lesion in the female rat. However, there is limited information concerning the etiology, biology, and significance of these polyps as an end point in toxicology and carcinogenicity studies. This paper reviews relevant literature to address these aspects of ESP with respect to potential relevance to human uterine tumors. Endometrial stromal polyps in rodents appear as age-related lesions. There are only a few chemicals tested for carcinogenicity in rat and mouse cancer bioassays associated with increased incidence of ESP with no common characteristics or mechanism of action. Uterine endometrial polyps that occur in women and the uterine stromal polyps that occur in rodents have distinct characteristics, although both types of uterine lesions are common, benign, and noncancerous. Human endometrial polyps develop from both endometrial and stromal components, whereas rodent polyps develop from the stromal component of the uterus. Endometrial polyps in women are hormone sensitive, but there is no scientific or experimental evidence to date that suggests that uterine stromal polyps in rodents are hormone sensitive. Therefore, based on differences in their etiology and biology, endometrial stromal polyps observed in rodent toxicity and carcinogenicity studies appear to have limited relevance to human endometrial polyps occurring in women.

Endometrial stromal sarcoma: A review of the literature

Endometrial stromal sarcomas are rare malignant tumors of the uterus, and most of the information available in literature is based on small series or case reports. A proper preoperative diagnosis is difficult and in most cases the diagnosis is confirmed after hysterectomy for a presumed benign disease. Endometrial sampling, ultrasound, and magnetic resonance imaging can provide diagnostic clues. Total hysterectomy with bilateral salpingo-oopherectomy is the main line of management and for early disease complete cure is a reality. Ovarian conservation may be possible in young women with early stage disease and the role of lymphadenectomy is controversial. Adjuvant hormone therapy in the form of progesterone, gonadotropin releasing hormone analogues, and aromatase inhibitors are found to be effective in preventing recurrences. Hormone therapy, radiotherapy and surgical excision of the metastasis are recommended for recurrences.

Comparing the performance of two clinical models in estimating the risk of endometrial cancer in symptomatic postmenopausal women

OBJECTIVE

The aim of this study was to internally evaluate the accuracy measures of the two newly developed predictive models, called DEFAB and DFAB, used to estimate the risk of endometrial cancer in postmenopausal women presenting with vaginal bleeding.

STUDY DESIGN

Prospective study including postmenopausal women presenting with vaginal bleeding.

RESULTS

Over a 46-month-period, 3795 postmenopausal women presented with vaginal bleeding and were included in the study. A total of 221 (6%) women were diagnosed with endometrial carcinoma. The DEFAB predictive model incorporates known risk factors such as presence of Diabetes, Endometrial thickness measurement on transvaginal ultrasonography, Frequency of bleeding, Age, and Body mass index. The DFAB model is based on the above clinical characteristics excluding the ultrasonography result. For the recommended cut-off values, there was no evidence (p-value=0.221) of a difference in the diagnostic ability with respect to sensitivity, specificity, area under receiver operating curve, positive predictive value and negative predictive value. There was strong evidence (p-value<0.0001) to suggest that the diagnostic ability of DEFAB and DFAB agree as evidenced by the excellent Kappa statistic 0.950 (95% CI 0.940-0.960). We found strong evidence (p-value<0.0001) that the variables incorporated in both predictive models simultaneously correctly classify an individual to either having cancer or not having cancer with respect to logistic discriminant analysis.

CONCLUSION

We recommend that these two predictive models can be used interchangeably.

The effect of tamoxifen and raloxifene on estrogen metabolism and endometrial cancer risk

Selective estrogen receptor modulators (SERMs) demonstrate differential endometrial cancer (EC) risk. While tamoxifen (TAM) use increases the risk of endometrial hyperplasia and malignancy, raloxifene (RAL) has neutral effects on the uterus. How TAM increases the risk of EC and why TAM and RAL differentially modulate the risk for EC, however, remain elusive. Here, we tested the hypothesis that TAM increases the risk for EC, at least in part, by enhancing the local estrogen biosynthesis and directing estrogen metabolism towards the formation of genotoxic and hormonally active estrogen metabolites. In addition, the differential effects of TAM and RAL in EC risk are attributed to their differential effect on estrogen metabolism/metabolites. The endometrial cancer cell line (Ishikawa cells) and the nonmalignant immortalized human endometrial glandular cell line (EM1) were used for the study. The profile of estrogen/estrogen metabolites (EM), depurinating estrogen-DNA adducts, and the expression of estrogen-metabolizing enzymes in cells treated with 17β-estradiol (E2) alone or in combination with TAM or RAL were investigated using high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS(2)), ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS), and Western blot analysis, respectively. TAM significantly increased the total EM and enhanced the formation of hormonally active and carcinogenic estrogen metabolites, 4-hydroxestrone (4-OHE1) and 16α-hydroxyestrone, with concomitant reduction in the formation of antiestrogenic and anticarcinogenic 2-hydroxyestradiol and 2-methoxyestradiol. Furthermore, TAM increased the formation of depurinating estrogen-DNA adducts 4-OHE1 [2]-1-N7Guanine and 4-OHE1 [2]-1-N3 Adenine. TAM-induced alteration in EM and depurinating DNA adduct formation is associated with altered expression of estrogen metabolizing enzymes CYP1A1, CYP1B1, COMT, NQO1, and SF-1 as revealed by Western blot analysis. In contrast to TAM, RAL has minimal effect on EM, estrogen-DNA adduct formation, or estrogen-metabolizing enzymes expression. These data show that TAM perturbs the balance of estrogen-metabolizing enzymes and alters the disposition of estrogen metabolites, which can explain, at least in part, the mechanism for TAM-induced EC. These results also implicate the differential effect of TAM and RAL on estrogen metabolism/metabolites as a potential mechanism for their disparate effects on the endometrium.

Endometrioid ovarian carcinoma benefits from aromatase inhibitors: case report and literature review

Aromatase inhibitors have not been adequately assessed in treatment of ovarian cancer. The aromatase inhibitor letrozole (2.5 mg daily) was administered in 2 cases of advanced endometrioid ovarian cancer with positive estrogen receptor. CASE 1: A 52-year-old woman with a grade 2-3, stage iiic endometrioid ovarian cancer was optimally debulked and received 6 cycles of intravenous paclitaxel and intraperitoneal cisplatin-paclitaxel. Post chemotherapy, one of several biopsies showed residual disease during the second-look laparoscopy. This patient was treated with letrozole and remained disease-free during 30 months of follow-up. CASE 2: A 47-year-old woman with a grade 3, stage iiic endometrioid ovarian cancer was optimally debulked and treated with intravenous carboplatin-paclitaxel. After a 15-month remission, her first recurrent disease was treated with carboplatin-docetaxel. The second remission lasted only 11 months, after which the patient was treated with splenectomy and subsequent liposomal doxorubicin. Letrozole was administered after the chemotherapy. The patient had a 30-month remission before the next recurrence of her disease.

CONCLUSIONS

Endometrioid ovarian carcinoma may benefit from aromatase inhibitors, especially when the tumour burden is low after primary chemotherapy or when the inhibitor is used as maintenance therapy between chemotherapies.

Sessile polyps and pedunculated polyps respond differently to oral contraceptives

Endometrial polyp is the lesion frequently found by hysteroscopy. The presence of endometrial polyp is associated with abnormal uterine bleeding and is probably associated with infertility. Until today, clinical guidelines for endometrial polyp remain elusive. The aim of this preliminary study was to estimate whether the shape of endometrial polyps affects the response to the treatment with an oral contraceptive (OC). We performed a retrospective case series study on 50 women diagnosed as endometrial polyps by hysteroscopy and managed by the administration of OC. Hysteroscopy was performed in the follicular phase of the menstrual cycle before medical treatment. Endometrial polyps were classified as pedunculated polyps (n = 25) or sessile polyps (n = 25). After diagnosis, OC was administered for 2-5 months (median 3 months) intermittently: To quantify the regression rate of lesions, the area index of endometrial polyps was assessed. In the study group, when comparing the efficacy of treatment with OC, there was a statistically significant difference in the regression rate between sessile polyps and pedunculated polyps (76% vs. 44%, p = 0.042). We conclude that sessile polyps are more sensitive to OC treatment than pedunculated polyps, implying usefulness of the hysteroscopic classification of the shape of polyps in the management of endometrial polyps.

Personal history of breast cancer as a significant risk factor for endometrial serous carcinoma in women aged 55 years old or younger

A comparative study between endometrial serous carcinoma (ESC) and endometrial endometrioid carcinoma (EEC) was performed to determine whether a personal history of breast cancer is a risk factor for ESC in women aged ≤ 55 yr. Study subjects consisted of 348 women who were diagnosed with ESC and 830 comparison subjects who had EEC. Variables studied included age at diagnosis, a history of breast cancer, tamoxifen therapy, hormonal replacement therapy and smoking history. Overall, 19.4% of women with ESC had a history of breast cancer, which was significantly higher than that of 3% in comparison subjects. Among the study subjects, the incidence of a prior breast cancer was significantly higher in patients who were 55 yr of age or younger (41.5%) than those who were older than 55 yr (16%). The statistical significance of both of the aforementioned comparisons was independent of tamoxifen usage on multivariate analyses. The mean time interval between prior breast cancer and endometrial cancer was 92.5 mo (range 7-240 mo) in the study group and 79 mo (range 7-192 mo) in the comparison group. For the whole cohort and individual subgroups (ESC, EEC, ≤ 55 yr and >55 yr), a personal history of breast cancer did not adversely affect the patient outcomes, which was largely dependent on standard clinicopathologic parameters such as International Federation of Gynecology and Obstetrics stage, as has previously been demonstrated. These findings suggest that a personal history of breast cancer may be a significant risk factor for the development of ESC in women aged ≤ 55 yr. Further studies are needed to clarify the relationship between these two cancers in this age group and whether this increased risk is reflective of a genetic predisposition.

Evaluation of adverse effects in tamoxifen exposed healthy female dogs

Background

Mammary tumors are among the most frequent neoplasms in female dogs, but the strategies employed in animal treatment are limited. In human medicine, hormone manipulation is used in cancer therapy. Tamoxifen citrate is a selective inhibitor of oestrogen receptors and exerts a potent anti-oestrogen effect on the mammary gland. The aim of this study was to evaluate the adverse effects when exposing healthy female dogs to tamoxifen.

Methods

Tamoxifen was administered for 120 days at a dose of 0.5 or 0.8 mg/kg/day to either intact or spayed female dogs. The effects were assessed through clinical examination, haematology, serum biochemistry, ophthalmology and bone marrow aspirate examination. Ovariohysterectomy was performed and the uterus examined by histopathology.

Results

Vulva oedema and purulent vaginal discharge developed with 10 days of tamoxifen exposure in all groups. Pyometra was diagnosed after around 90 days of exposure in intact females with frequencies increasing during the following 30 days of exposure. Up to 50% of dogs within the groups developed retinitis but none of the dogs had signs of reduced visual acuity. The prevalence of retinitis in each group was similar after 120 days of exposure. Haematological, biochemical and bone marrow changes were not observed. Due to the high risk of developing pyometra after prolonged exposure to tamoxifen, only spayed animals should be given this medication.

Conclusions

A dose of 0.8 mg tamoxifen/kg body weight/day is recommended when treating tamoxifen-responsive canine mammary tumors. Due to the high risk of developing pyometra, ovariohysterectomy is recommended.

Prophylactic and risk-reducing bilateral salpingo-oophorectomy: recommendations based on risk of ovarian cancer

Women who do not have a documented germline mutation or who do not have a strong family history suspicious for a germline mutation are considered to be at average risk of ovarian cancer. Women who have confirmed deleterious BRCA1 and BRCA2 germline mutations are high risk of ovarian cancer. In addition, women who have a strong family history of either ovarian or breast cancer may carry a deleterious mutation and must be presumed to be at higher-than-average risk, even if they have not been tested, because there could be other mutations that are either untested or yet undiscovered that confirm higher-than-average risk of these diseases. We reviewed studies pertaining to prophylactic bilateral salpingo-oophorectomy in women at average risk of ovarian cancer who are undergoing hysterectomy for benign disease. We also reviewed the role of prophylactic bilateral salpingo-oophorectomy in preventing ovarian cancer based on the level of risk of the patient. For women at average risk of ovarian cancer who are undergoing a hysterectomy for benign conditions, the decision to perform prophylactic bilateral salpingo-oophorectomy should be individualized after appropriate informed consent, including a careful analysis of personal risk factors. Several studies suggest an overall negative health effect when prophylactic bilateral salpingo-oophorectomy is performed before the age of menopause. Ovarian conservation before menopause may be especially important in patients with a personal or strong family history of cardiovascular or neurological disease. Conversely, women at high risk of ovarian cancer should undergo risk-reducing bilateral salpingo-oophorectomy.

Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation

The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide)-85:15 (PLGA) was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w) and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM) and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.

Non-contraceptive applications of the levonorgestrel intrauterine system

Intrauterine progestins have many important current and potential gynecologic applications. This article describes the evidence for use of intrauterine progestin for common gynecologic conditions beyond its important role in contraception. The pharmacology of and selection criteria for use of the levonorgestrel intrauterine device is discussed, and the evidence for use of intrauterine progestin delivery for menorrhagia, endometriosis management, uterine fibroids, adenomyosis and endometrial hyperplasia is reviewed.

Endometrial safety: a key hurdle for selective estrogen receptor modulators in development

Selective estrogen receptor modulators (SERMs) have the ability to provide mixed functional estrogen receptor (ER) agonist or antagonist activity, depending on the target tissue. Tamoxifen, the first SERM available for clinical use, is regarded as a highly effective agent for the prevention and treatment of breast cancer. However, tamoxifen exhibits ER agonist activity in the uterus and is associated with an increased risk of endometrial hyperplasia and malignancy. Endometrial safety has been an important consideration in the clinical development of SERMs, with improved benefit-risk profiles. Raloxifene, which is currently approved for the prevention and treatment of postmenopausal osteoporosis and for the prevention of breast cancer, seems to have neutral effects on the uterus. Promising results have been observed with the targeted development of newer and more tissue-specific SERMs, many of which are under investigation for postmenopausal osteoporosis. Of the newer SERMs in development, lasofoxifene has been shown to reduce fracture risk and decrease the incidence of breast cancer but has been associated with an increased incidence of vaginal bleeding, endometrial thickening, and endometrial polyps. Lasofoxifene and ospemifene have shown beneficial effects on the vaginal epithelium. Phase 3 clinical data have shown that bazedoxifene is effective in preventing and treating postmenopausal osteoporosis, without adverse effects on the endometrium or breast. Arzoxifene has been evaluated in phase 3 trials for postmenopausal osteoporosis and has been studied for the treatment of uterine malignancies but is no longer in clinical development. Further investigation of newer SERMs is warranted to more clearly define the endometrial safety of these agents.

Intrauterine progestins, progesterone antagonists, and receptor modulators: a review of gynecologic applications

Intrauterine progestins, progesterone receptor modulators, and antagonists have many important current and potential gynecologic applications. This article will describe the evidence for use of intrauterine progestin for common gynecologic conditions beyond its important role in contraception. We will review the evidence for use of intrauterine progestin delivery for menorrhagia, endometriosis management, adenomyosis treatment, uterine fibroids, endometrial hyperplasia, and its concurrent use in women on hormone replacement therapy or tamoxifen.

Predicting the risk of endometrial cancer in postmenopausal women presenting with vaginal bleeding: the Norwich DEFAB risk assessment tool

Background:

This study aimed to show the longitudinal use of routinely collected clinical data from history and ultrasound evaluation of the endometrium in developing an algorithm to predict the risk of endometrial carcinoma for postmenopausal women presenting with vaginal bleeding.

Methods:

This prospective study collected data from 3047 women presenting with postmenopausal bleeding. Data regarding the presence of risk factors for endometrial cancer was collected and univariate and multivariate analyses were performed.

Results:

Age distribution ranged from 35 to 97 years with a median of 59 years. A total of 149 women (5% of total) were diagnosed with endometrial carcinoma. Women in the endometrial cancer group were significantly more likely to be older, have higher BMI, recurrent episodes of bleeding, diabetes, hypertension, or a previous history of breast cancer. An investigator best model selection approach was used to select the best predictors of cancer, and using logistic regression analysis we created a model, ‘Norwich DEFAB’, which is a clinical prediction rule for endometrial cancer. The calculated Norwich DEFAB score can vary from a value of 0 to 9. A Norwich DEFAB value equal to or greater than 3 has a positive predictive value (PPV) of 7.78% and negative predictive value (NPV) of 98.2%, whereas a score equal to or greater than 5 has a PPV of 11.9% and NPV of 97.8%.

Conclusion:

The combination of clinical information with our investigation tool for women with postmenopausal vaginal bleeding allows the clinician to calculate a predicted risk of endometrial malignancy and prioritise subsequent clinical investigations.

Distribution of second primary malignancies suggests a bidirectional effect between breast and endometrial cancer: a population-based study

INTRODUCTION

The aim of this study was to investigate the incidence of second primary tumors in patients with breast cancer (BC), with particular regard to bidirectional risk for endometrial cancer (EC).

METHODS

A total of 7512 and 343 patients with first and second primary BC, respectively, were referenced to the expected number of cases calculated using the standardized incidence ratio (SIR) over the same period, to evaluate the observed and expected ratio between the groups. Data on tamoxifen use were also considered.

RESULTS

A total of 499 women with primary BC developed a second tumor. The total SIR, that is, the ratio between observed second primary cancer among patients with BC and the expected primary cancers in the general population, was significantly higher (SIR = 1.23; 95% confidence interval, 1.12-1.34; P = 0.007), particularly for melanoma (2.25), EC (2.15), ovarian cancer (1.74), hematologic malignancies (1.36), and bilateral BC (1.25). A greater risk of BC after thyroid (2.22) and EC (1.62) was also observed. Furthermore, the risk of developing EC was higher in patients treated with tamoxifen (SIR = 2.50 vs 1.34).

CONCLUSIONS

Bidirectional risk of endometrial cancer was not exclusively related to tamoxifen use.

Endometrial profile of tamoxifen and low-dose estradiol combination therapy

PURPOSE

Combination estrogen + progestin therapy has been associated with increased breast cancer risk in postmenopausal women. Selective estrogen receptor modulators (SERM) are potential alternatives to progestins, although the endometrial safety of estrogen + SERM co-therapies is not known. The goal of this study was to evaluate the endometrial profile of low-dose estradiol and the SERM tamoxifen alone and in combination.

EXPERIMENTAL DESIGN

Twenty-four postmenopausal female cynomolgus macaques were randomized by social group to receive placebo, low-dose micronized estradiol (E(2); 0.25 mg/1,800 kcal), the SERM tamoxifen (Tam; 20 mg/1,800 kcal), or E(2) + Tam for 4 months in a parallel-arm design.

RESULTS

Tamoxifen alone resulted in overlapping but distinct effects compared with E(2). Both E(2) and Tam increased uterine weight and endometrial thickness, whereas only E(2) increased endometrial proliferation. Morphologic effects were similar for Tam and E(2) + Tam, which both induced stromal fibrosis and cystic change. Tamoxifen inhibited E(2)-induced proliferation and expression of genes related to cell cycle progression while exhibiting mixed agonist and antagonist effects on gene markers of estrogen receptor activity. The gene expression profile for E(2) + Tam was distinct from either E(2) or Tam alone but dominated by the Tam effect for estrogen-regulated genes. Tam also attenuated E(2) effects on both vaginal maturation and cervical epithelial height.

CONCLUSIONS

These findings characterize a novel phenotype resulting from estrogen + SERM co-therapy. The predominance of Tam effects on endometrial proliferation, morphology, and transcriptional profiles suggests that endometrial risks for E(2) + Tam may be similar to Tam alone.

Bazedoxifene, a selective estrogen receptor modulator: effects on the endometrium, ovaries, and breast from a randomized controlled trial in osteoporotic postmenopausal women

OBJECTIVE

The aim of this study was to evaluate the endometrial, ovarian, and breast safety of bazedoxifene used as a treatment for postmenopausal osteoporosis.

METHODS

Healthy women (aged 55-85 y) with osteoporosis were enrolled in a randomized, double-blind, placebo-controlled phase 3 trial. Participants were randomized to treatment with bazedoxifene 20 or 40 mg, raloxifene 60 mg, or placebo daily for 3 years. Endometrial and ovarian safety was assessed by periodic transvaginal ultrasonography and endometrial biopsy through 24 months. Gynecologic and breast-related adverse events were recorded throughout the study.

RESULTS

Among 753 participants with available transvaginal ultrasonography data, there were no significant between-group differences in overall endometrial thickness or in the percentage of participants with endometrial thickness greater than 5 mm at 12 or 24 months. Changes in the mean endometrial thickness (+/-SE) from baseline were -0.07 +/- 0.11 mm (bazedoxifene 20 mg), 0.10 +/- 0.11 mm (bazedoxifene 40 mg), 0.16 +/- 0.12 mm (raloxifene 60 mg), and -0.08 +/- 0.11 mm (placebo) at 24 months. There was one report of endometrial hyperplasia in each group, and there were zero, two, two, and three reports of endometrial carcinoma with bazedoxifene 20 and 40 mg, raloxifene 60 mg, and placebo, respectively. There were no clinically important changes from baseline in the number or size of ovarian cysts among groups. There was a significantly lower incidence of fibrocystic breast disease (P <or= 0.05) with bazedoxifene compared with raloxifene 60 mg.

CONCLUSION

Bazedoxifene was associated with a favorable endometrial, ovarian, and breast safety profile in postmenopausal women with osteoporosis.

Recent advances on the action of estrogens and progestogens in normal and pathological human endometrium

Hormonal control in the development of the normal endometrium is of the utmost importance. It is well established that the two main hormones involved in this process are estradiol and progesterone, which are also implicated in the pathological conditions concerning endometriosis and endometrial carcinoma. There are two types of endometrial carcinoma: type I which represents 80%–90% is hormone-dependent, whereas the remainder is type II and is hormone-independent. The endometrial tissue contains all the enzymatic systems in the formation and transformation of the various hormones, including aromatases, sulfatases, sulfotransferases, hydroxysteroid dehydrogenases, hydroxylases, and glucuronidases. It is interesting to note that increased sulfatase activity is correlated with severity of endometriosis. An increased sulfatase/sulfotransferase ratio represents a poor prognosis in patients with endometrial carcinoma. Treatment with hormone replacement therapy (estrogens+progestogens), as well as with tibolone, is most effective in protecting this tissue by climacteric alterations, owing to the significant decrease of ovarian hormones. In conclusion, enzymatic control can open appealing perspectives to protect this organ from possible pathological alterations.

Tamoxifen use and endometrial lesions: hysteroscopic, histological, and immunohistochemical findings in postmenopausal women with breast cancer

OBJECTIVE

To evaluate immunohistochemical, hysteroscopic, and histological findings in postmenopausal women taking tamoxifen for breast cancer.

METHODS

Forty postmenopausal women taking 20 mg/day tamoxifen for breast cancer underwent hysteroscopy and endometrial biopsy from January 2000 to December 2003. Medical records and paraffin blocks were analyzed retrospectively, and Ki-67, estrogen receptors (ERs), and progesterone receptors were measured using an immunohistochemical technique.

RESULTS

The mean +/- SD age of the women was 59 +/- 14 years at hysteroscopy (95% CI, 54.2-63.7) and 45.1 +/- 7 years at menopause (95% CI, 42.6-47.6). Mean +/- SD duration of tamoxifen therapy was 27.3 +/- 16.5 months (95% CI, 22.0-32.5). Hysteroscopies were performed because of abnormal sonographic findings in 60% of the women and postmenopausal bleeding in 40%. The most common hysteroscopic and histological findings were endometrial polyps (32.5%) and atrophic endometria (22.5%). Immunohistochemistry showed that 85% of the women were progesterone receptor positive, 75% were ER positive, and 50% were Ki-67 positive. Endometrial polyps and polyps associated with atrophic endometrium were ER positive (P = 0.019). Results that were ER negative were more frequent in atrophic endometria (P = 0.01). The longer the time since menopause, the lower the Ki-67 expression in the endometrium was (P = 0.03). Ki-67 expression was greater in the endometrium of younger postmenopausal women (P = 0.01).

CONCLUSIONS

The expression of steroid receptors in the endometrium was high in our series. All cases of endometrial polyps were ER positive. Estrogen receptors may play a major role in the development of endometrial polyps in postmenopausal women taking tamoxifen. Although most histological findings were benign, 22.5% were atrophic.

Levonorgestrel intrauterine system for endometrial protection in women with breast cancer on adjuvant tamoxifen

BACKGROUND

Adjuvant tamoxifen reduces the risk of breast cancer recurrence in women with estrogen receptor-positive breast cancer. Tamoxifen also increases the risk of postmenopausal bleeding, endometrial hyperplasia, polyps, and endometrial cancer. The levonorgestrel-releasing intrauterine system (LNG-IUS) causes profound endometrial suppression. This systematic review considered the evidence that the LNG-IUS prevents the development of endometrial pathology in women taking tamoxifen as adjuvant endocrine therapy for breast cancer.

OBJECTIVES

To determine the effectiveness of the levonorgestrel intrauterine system in preventing the development of endometrial hyperplasia, polyps, and adenocarcinoma in pre and postmenopausal women taking adjuvant tamoxifen following breast cancer.

SEARCH STRATEGY

All reports which described randomised controlled trials of effects of the levonorgestrel intrauterine system on the endometrium in breast cancer patients taking adjuvant tamoxifen were obtained through searches of the Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009), MEDLINE (1996 to August 2009), EMBASE (1980 to August 2009), CINAHL (Cumulative Index to Nursing and Allied Health Literature) (1982 to August 2009).

SELECTION CRITERIA

Randomised controlled trials of women with breast cancer on adjuvant tamoxifen that compared endometrial surveillance or placebo alone versus the LNG-IUS. Women with known endometrial pathology or contraindications to LNG-IUS were excluded.

DATA COLLECTION AND ANALYSIS

Only two randomised controlled trials were identified and are included in this review. Risk of bias assessment and data extraction were performed independently by two review authors. The outcome measures were endometrial pathology (including polyps, endometrial hyperplasia, or adenocarcinoma) diagnosed at hysteroscopy or endometrial biopsy; any reported side effects of treatment; and abnormal vaginal bleeding.

MAIN RESULTS

In both included studies, the active treatment arm was the Mirena 20 mug/day levonorgestrel-releasing intrauterine device (Bayer Health Care, US). The LNG-IUS in tamoxifen users led to a significant reduction in the incidence of endometrial polyps (Peto odds ratio 0.14, 95% confidence interval 0.03 to 0.61). Neither trial was sufficiently powered to detect whether LNG-IUS leads to significant changes in the incidence of endometrial hyperplasia or adenocarcinoma in tamoxifen users, nor whether LNG-IUS leads to any increased risk of breast cancer recurrence. There appeared to be more vaginal bleeding in the Mirena treatment group, in the first six months only. However, the bleeding patterns at 12 months were fairly similar for both groups.

AUTHORS' CONCLUSIONS

The Mirena LNG-IUS appears to prevent the development of benign endometrial polyps in breast cancer patients taking tamoxifen, over a one-year period. There is no clear evidence from the available randomised controlled trials that LNG-IUS prevents endometrial hyperplasia or adenocarcinoma in these patients. Larger studies are necessary to assess the effects of LNG-IUS in preventing endometrial hyperplasia and endometrial cancer, and to determine whether LNG-IUS might have an impact on the risk of breast cancer recurrence.

Long-term endometrial effects in postmenopausal women with early breast cancer participating in the Intergroup Exemestane Study (IES)--a randomised controlled trial of exemestane versus continued tamoxifen after 2-3 years tamoxifen

BACKGROUND

The antiestrogen tamoxifen may have partial estrogen-like effects on the postmenopausal uterus. Aromatase inhibitors (AIs) are increasingly used after initial tamoxifen in the adjuvant treatment of postmenopausal early breast cancer due to their mechanism of action: a potential benefit being a reduction of uterine abnormalities caused by tamoxifen.

PATIENTS AND METHODS

Sonographic uterine effects of the steroidal AI exemestane were studied in 219 women participating in the Intergroup Exemestane Study: a large trial in postmenopausal women with estrogen receptor-positive (or unknown) early breast cancer, disease free after 2-3 years of tamoxifen, randomly assigned to continue tamoxifen or switch to exemestane to complete 5 years adjuvant treatment. The primary end point was the proportion of patients with abnormal (> or =5 mm) endometrial thickness (ET) on transvaginal ultrasound 24 months after randomisation.

RESULTS

The analysis included 183 patients. Two years after randomisation, the proportion of patients with abnormal ET was significantly lower in the exemestane compared with tamoxifen arm (36% versus 62%, respectively; P = 0.004). This difference emerged within 6 months of switching treatment (43.5% versus 65.2%, respectively; P = 0.01) and disappeared within 12 months of treatment completion (30.8% versus 34.7%, respectively; P = 0.67).

CONCLUSION

Switching from tamoxifen to exemestane significantly reverses endometrial thickening associated with continued tamoxifen.

Designing the ideal selective estrogen receptor modulator--an achievable goal?

Selective estrogen receptor modulators (SERMs), which lack the estrogen steroid moiety yet retain the ability to bind the estrogen receptor (ER), are known to confer mixed ER agonist or antagonist effects depending on the target tissue. The tissue-selective effects of SERMs have led to considerations in the clinical profile of an ideal SERM, which would have ER agonist activity in tissues where mimicking the action of estrogens is desirable, and ER neutral or antagonist activity in tissues estrogens have been shown to adversely stimulate. A number of newer SERMs, including bazedoxifene, lasofoxifene, ospemifene, and arzoxifene, are currently in clinical development for the prevention and treatment of postmenopausal osteoporosis and for other indications. Although the possibility of developing a single agent that has all of the desired characteristics of an ideal SERM seems to be unlikely, progress in the clinical development of SERMs targeted to the ER suggests that these newer compounds may have attributes that represent an improvement relative to existing SERMs. Further clinical investigation will help to clarify the relative benefits and risks of novel SERMs in development within specific indications.

Aromatase inhibitors in breast cancer

Estrogens play important roles in breast cancer development and progression. In postmenopausal women, traditional endocrine therapies such as tamoxifen have sought to inhibit estrogen action by targeting the estrogen receptor itself. However, newer treatments are evolving that target estrogen production in postmenopausal tissues through inhibition of the aromatase enzyme. Clinical data demonstrate that these aromatase inhibitors are superior to tamoxifen as adjuvant therapy for breast cancer and have now replaced tamoxifen as first line therapy in a number of treatment regimens for postmenopausal breast cancer patients.

Obstructive uropathy associated with primary ureteral endometrioma: case report and review of the literature

We report the case of a 56-year-old postmenopausal woman who presented with incidental left hydronephrosis during an investigation for a gastrointestinal complaint. The patient denied any history of flank pain or hematuria. Contrast-enhanced computed tomography revealed severe right-sided ureterohydronephrosis as well as renal atrophy. The contralateral kidney was normal, as was the patient's overall renal function. A retrograde ureterogram demonstrated complete ureteral obstruction 4 cm proximal to the ureterovesical junction. Subsequent ureteroscopy revealed a polypoid mass completely occupying the ureteral lumen, of which the biopsies demonstrated inconclusive atypical urothelial changes. The patient underwent a laparoscopic nephrectomy with open dissection of the distal ureter. The patient recovered well postoperatively. Final pathology revealed a benign obstructing endometrioma without evidence of invasion from periureteral tissue. This appears to be the first reported case of asymptomatic primary ureteral endometrioma with secondary renal atrophy. Earlier investigation and treatment may have allowed for renal preservation earlier in the course of the disease.

Differential actions of estrogen and SERMs in regulation of the actin cytoskeleton of endometrial cells

Estrogen and selective estrogen receptor modulators (SERMs) differentially impact endometrial cell function, however, the biological basis of these differences is not established. Deregulated cell adhesion to the extracellular matrix, cell movement and invasion are related to endometrial disorders, such as endometriosis or endometrial cancer. Remodeling of the actin cytoskeleton is required to achieve cell adhesion and movement. Estrogen receptor (ER) regulates actin and cell membrane remodeling through extra-nuclear signaling cascades. In this article, we show that administration of 17beta-estradiol (E2) and tamoxifen (TAM) to immortalized Ishikawa endometrial cells or to human endometrial stromal cells (ESC) results in remodeling of actin fibers and cell membrane. This is linked to rapid phosphorylation on Thr(558) of the actin-binding protein moesin and enhanced migration and invasion of normal and Ishikawa cells. Raloxifene (RAL) does not result in moesin activation or actin remodeling. When endometrial cells are exposed to E2 in the presence of TAM or RAL, both SERMs interfere with the recruitment of moesin, with the remodeling of the cytoskeleton, and with cell movement and migration induced by E2. The differential actions of E2, TAM and RAL are linked to a distinct modulation of the extra-nuclear signaling of ER to G proteins and to the Rho-associated kinase. These findings increase our understanding of the actions of estrogen and SERMs in endometrial cells and highlight potential molecular targets to interfere with the estrogen-related altered cell adhesion encountered in endometrial disorders.

[Tamoxifen in the adjuvant setting for breast cancer: Reflexions about the risk of uterine carcinosarcoma]

A descriptive analysis of available data on reported cases of uterine carcinosarcomas associated with tamoxifen therapy is undertaken. The role of aromatase inhibitors as alternative to tamoxifen therapy in the adjuvant setting of breast cancer is discussed. The eventual implications of the presumed association of uterine carcinosarcoma and tamoxifen therapy on the choice of the therapeutic agent in the adjuvant setting of hormone-sensitive breast cancer are discussed.

Tissue microarray analysis of hormonal signaling pathways in uterine carcinosarcoma

OBJECTIVES

To evaluate the relationship of hormone (estrogen receptor alpha, estrogen receptor beta, progesterone receptor) and growth factor receptor (insulin-like growth factor receptor, human epidermal growth factor receptor 2) expression with disease progression in uterine carcinosarcoma.

STUDY DESIGN

Immunohistochemistry was performed on tissue arrays using standard methodology. Differences between groups were evaluated by the Wilcoxon rank-sum test. Interactions between tumor stage and receptor expression were determined by linear trend analysis.

RESULTS

Compared with normal endometrium, carcinosarcomas exhibited low estrogen receptor alpha and progesterone receptor expression (all P < .01), but overexpressed estrogen receptor beta (P = .02). Estrogen receptor beta expression increased in advanced stage disease (P = .02). Insulin-like growth factor receptor expression was lower in carcinosarcoma compared with normal endometrium (P = .01). Human epidermal growth factor receptor 2 expression was elevated and increased with disease progression (P < .01).

CONCLUSION

In uterine carcinosarcoma, estrogen receptor beta expression is elevated and increases with disease progression, whereas estrogen receptor alpha and progesterone receptor are suppressed. Human epidermal growth factor receptor 2 expression is increased, whereas insulin-like growth factor receptor is lower than in normal endometrium. These data support a potential role for estrogen receptor beta in disease progression via crosstalk with human epidermal growth factor receptor 2.

Endometrial polyps and associated factors in Danish women aged 36-74 years

OBJECTIVE

To identify factors associated with endometrial polyps.

STUDY DESIGN

Case-control study of 140 women with endometrial polyps and 367 controls. Information on potentially associated factors was obtained by a validated questionnaire.

RESULTS

In an age-adjusted logistic regression model, the following was positively associated with endometrial polyps: current use of hormone therapy (odds ratio, 2.81; 95% CI, 1.29-6.13) and being overweight (body mass index > 25 kg/m(2)) (odds ratio, 2.06; 95% CI, 1.12-3.79) (postmenopausal women). Negatively associated was use of oral contraceptive pills (odds ratio, 0.20; 95% CI, 0.06-0.66). Histopathology diagnosed benign endometrial polyps (n = 137), polyp with premalignant disease (n = 3), and benign polyp with concomitant complex hyperplasia/endometrial cancer (n = 3).

CONCLUSION

Being overweight and current use of hormone therapy in postmenopausal women were positively associated, whereas the use of oral contraceptive pills was negatively associated with endometrial polyps. Hypertension and cervical polyps were not associated with endometrial polyps. Endometrial polyps were infrequently related to premalignant and malignant disease.

Early aberrant insulin-like growth factor signaling in the progression to endometrial carcinoma is augmented by tamoxifen

Tamoxifen is an important selective estrogen receptor (ER) modulator for treatment of steroid hormone positive breast cancer. In addition to the beneficial effect, tamoxifen is one risk factor for endometrial carcinoma (EnCa) development. We hypothesized that, (1) dysregulation of gene expression and protein phosphorylation of the insulin-like growth factor (IGF) and steroid hormone receptor-signaling occur early in benign endometrial tissues and (2) signaling differences would be detected between patients with or without tamoxifen treatment. Seventy-eight tissues, including 2 benign cohorts from patients treated with (n = 24) or without tamoxifen (n = 28) (hyperproliferative endometrium, hyperplasia, polyps), EnCa (n = 12) with endometrium controls (n = 14) were analyzed for expression of 15 genes from the IGF and steroid hormone receptor-signaling, including the target genes Syncytin-1, PAX2 and c-myc. Total and phosphorylated protein expression were examined for ERalpha, PTEN, AKT, mTOR and Syncytin-1. Compared to controls similar significant deregulation of IGF and steroid hormone receptor-signaling, Syncytin-1 and PAX2 occurred in both benign cohorts, irrelevant of tamoxifen treatment. Comparing both benign cohorts with and without tamoxifen significant expression differences were noted. Increased total protein and phosphorylation of pERalpha-Ser118, pPTEN-Thr380, pAKT-Thr308, pAKT-Ser473, pmTOR-Ser2448 and Syncytin-1 were noted in early benign tissue stages associating with tamoxifen, especially polyps. Functional kinetic studies following tamoxifen treatment of the PTEN mutated RL95-2 EnCa cell line, demonstrated a doubling of phosphorylation of pERalpha-Ser118 and a 4.2-fold induction of pAKT-Thr308 along with Syncytin-1 induction. This study supports that dysregulated IGF and steroid hormone receptor signaling is prominent in endometrial benign stages and these alterations could represent clinical indicators for the risk of EnCa and also help in development of new therapies.

The effect of tamoxifen on the genital tract

Tamoxifen is a selective estrogen receptor modulator (SERM) that is widely used in the treatment of patients with breast cancer and for chemoprophylaxis in high risk women. Tamoxifen results in a spectrum of abnormalities involving the genital tract, the most significant being an increased incidence of endometrial cancer and uterine sarcoma. This article reviews the effects of tamoxifen on the genital tract and the strengths and weaknesses of various imaging modalities for evaluating the endometrium.

Morphometric analysis of the urethra of castrated female rats treated with tamoxifen

OBJECTIVES

The aim of this study was to evaluate the effects of tamoxifen on the weight and thickness of the urethral epithelium of castrated female rats.

METHODS

Forty castrated adult female Wistar-Hannover rats were randomly divided into two groups: Group I (n=20) in which the animals received only the vehicle (propylene glycol) and Group II (n=20) in which the rats received tamoxifen 250microg/day by gavage. After 30 days of treatment, all animals were sacrificed and the urethra was immediately removed for weighing. Next, the urethra was divided into the proximal and distal segments, which were fixed in 10% formaldehyde and submitted to routine histological techniques for morphometric study. The data were analyzed using the weighted minimum mean-square error method and Student's t-test for two independent samples (p<0.05).

RESULTS

There was a significant increase in the mean weight of the urethra in the rats of Group II compared to the control group, 32.0+/-2.0mg and 22.0+/-1.6mg, respectively (p<0.001). The mean thickness of the distal urethral epithelium of the animals treated with tamoxifen was significantly greater than that of the control group, 42.8+/-2.0microm and 36.6+/-1.5microm, respectively (p<0.001). There was no statistically significant difference between the two groups with respect to the epithelial thickness of the proximal urethra (p=0.514).

CONCLUSION

Treating castrated adult rats with 250microg/day of tamoxifen for 30 days may increase the weight of the urethra and the thickness of the distal urethral epithelium.

Signaling by estrogens and tamoxifen in the human endometrium

Tamoxifen is used as adjuvant treatment for postmenopausal breast cancer patients. The mechanism of action of tamoxifen in breast cancer patients is that tamoxifen inhibits growth of cancer cells by competitive antagonism for estrogens at the estrogen receptor (ER). In the endometrium, tamoxifen has an effect that varies with the ambient concentration of estrogen: in premenopausal women (high estrogen levels), tamoxifen displays an estrogen-antagonistic effect, while in postmenopausal women (low estrogen levels), tamoxifen displays an estrogen-agonistic mode of action. Here, using microarray technology we have compared estrogen signaling with tamoxifen signaling in the human endometrium. It was observed that on the one hand tamoxifen-treatment results in modulation of expression of specific genes (370 genes) and on the other hand tamoxifen-treatment results in modulation of a set of genes which are also regulated by estrogen treatment (142 genes). Upon focusing on regulation of proliferation, we found that tamoxifen-induced endometrial proliferation is largely accomplished by using the same set of genes as are regulated by estradiol. So, as far as regulation of proliferation goes, tamoxifen seems to act as estrogen agonist. Furthermore, tamoxifen-specific gene regulation may explain why tamoxifen-induced endometrial tumors behave more aggressively than sporadic endometrial tumors.

Tumorigenic effects of tamoxifen on the female genital tract

Tamoxifen is widely used for endocrine treatment and breast cancer prevention. It acts as both an estrogen antagonist in breast tissue and an estrogen agonist in the female lower genital tract. Tamoxifen causes severe gynecologic side effects, such as endometrial cancer. This review focuses on the effects of prolonged tamoxifen treatment on the human female genital tract and considers its tumorigenicity in the gynecologic organs through clinical data analysis. Tamoxifen is associated with an increased incidence of benign endometrial lesions such as polyps and hyperplasia and a two- to four-fold increased risk of endometrial cancer in postmenopausal patients. Moreover, the incidence of functional ovarian cysts is significantly high in premenopausal tamoxifen users. To prevent tamoxifen from having severe side effects in gynecologic organs, frequent gynecological examination should be performed for both premenopausal and postmenopausal patients with breast cancer who are treated with this drug.

Histopathology of endometrial hyperplasia and endometrial carcinoma: an update

Endometrial cancer (EC) is the most common malignancy of the female genital tract in the western world. Conceptually, a dualistic model of endometrial carcinogenesis exists for sporadic EC, based on molecular findings with a good correlation to the morphologic phenotype and clinical behavior. Type 1 endometrial carcinoma represents an estrogen-related tumor, which usually arises in the setting of endometrial hyperplasia, has endometrioid histology with low grade, and tends to be biologically indolent. Grade 3 endometrioid cancers, which constitute a minority of EC, also behave aggressively. The type 2 cancers are not estrogen-driven and have a higher grade, various histologies, particularly serous carcinomas and clear-cell carcinomas, and a poorer prognosis. The diagnostic criteria of endometrial hyperplasia, endometrial in situ carcinoma, and of the different histologic types of EC, according to the most recent World Health Organization classification, are given in detail. In addition, the risk of progression of endometrial hyperplasia into endometrioid type EC and their treatment modalities are discussed. Endometrial pathologies in patients with breast cancer, receiving tamoxifen, and women affected by hereditary nonpolyposis colorectal cancer syndrome are described, including their pathogenetic aspects. Finally, a short practical description for the handling of surgical specimens from fractional curetting and hysterctomies is given.