Increased Rate of Mesh Erosion in Breast Cancer Survivors Taking Antiestrogen Therapy.

IMPORTANCE: There are no current data investigating the relationship between mesh-exposure complications after midurethral sling surgery and antiestrogen therapy. OBJECTIVES: We sought to determine if there are increased mesh-exposure complications between a breast cancer population versus a noncancer population particularly in conjunction with hormone suppression (HS) therapy. STUDY DESIGN: A retrospective chart review was performed on patients with a history of breast cancer undergoing tension-free vaginal tape (TVT) surgery at our institution between 2013 and 2021. A group of patients who underwent TVT surgery without a history of cancer served as our control. Univariate and multivariate logistic regression analyses were performed to identify predictors of mesh exposure complications. RESULTS: One hundred twenty-one patients with breast cancer had TVT surgery. Two hundred ninety-seven patients without cancer had TVT surgery during the same period. Baseline characteristics across all groups were similar. Twenty-nine patients (6.9%) experienced mesh exposure. This occurred at a higher rate in our cancer (15.7%) versus the noncancer population (3.4%). Women with breast cancer taking HS therapy had a higher rate of mesh exposure complications compared with those not taking HS therapy (25.0% versus 6.6%; P = 0.005). The highest rate of mesh exposure complications occurred in the cohort taking estrogen receptor modulators, selective estrogen receptor modulator (10/36 [27.8%]) versus aromatase inhibitors (5/24 [20.8%]) versus no HS therapy (4/61 [6.6%]; P = 0.014). On multivariate analysis, HS therapy use (odds ratio, 1.57; P = 0.007) and diabetes mellitus (odds ratio, 4.53; P = 0.018) were associated with increased TVT-related complications. CONCLUSION: Women with breast cancer had a higher rate of mesh exposure complications from TVT surgery compared with women without cancer, particularly those taking antiestrogenic therapy.

Tibolone and Breast Tissue: a Review.

The safety profile of hormone replacement therapy (HRT) on breast is still controversial. Tibolone is an option of treatment for climacteric syndrome of postmenopausal women. Its risk profile on breast is debated. This is an updated narrative review focusing on the impact of tibolone on breast. Particularly, we will report data from major preclinical and clinical studies regarding the effects of the use of this compound on breast tissue and breast density. Moreover, we will analyze and discuss the most relevant findings of the principal studies evaluating the relationship between tibolone and breast cancer risk. Our purpose is making all clinicians who are particularly involved in women's health more aware of the effects of this compound on breast and, thus, more experienced in the management of menopausal symptoms with this drug. According to the available literature, tibolone seems to be characterized by an interesting safety profile on breast tissue.

Changes in serum estradiol levels with Estring in postmenopausal women with breast cancer treated with aromatase inhibitors.

BACKGROUND: Anti-estrogen therapy is an effective intervention for preventing reoccurrence of hormone receptor-positive breast cancer in women. However, the side effects of anti-estrogen therapy, including urogenital symptoms, have been reported to cause significant morbidity. There is controversial data, mainly due to small sample sizes, reporting on the safety and efficacy of using vaginal estrogen to treat urogenital symptoms in patients on aromatase inhibitor therapy. METHODS: We proposed a prospective trial to measure the change in blood estradiol levels in postmenopausal women with hormone receptor-positive breast cancer undergoing treatment with aromatase inhibitors when treated with vaginal estrogen preparation, Estring, for their urogenital symptoms. Only 8 prospective patients were enrolled, and the study was amended to include 6 retrospective patients who were treated similarly. Blood estradiol levels were measured at baseline and at week 16 for all patients. RESULTS: The median age for all patients was 55 years, and the majority of them were treated with anastrozole. There was no significant difference between baseline and week 16 estradiol levels (p = 0.81). In addition, patients in the prospective group reported subjective improvement in their vaginal dryness symptoms questionnaires. CONCLUSIONS: The vaginal estrogen preparation, Estring, did not cause persistent elevations in serum estradiol levels and might be a safer option for women with significant urogenital symptoms requiring estrogen therapy. IMPLICATIONS FOR CANCER SURVIVORS: Vaginal estrogen preparation, Estring, might be an option for women with hormone receptor positive breast cancer who have persistent urogenital symptoms.

Tibolone as Hormonal Therapy and Neuroprotective Agent.

Tibolone (TIB), a selective tissue estrogenic activity regulator (STEAR) in clinical use by postmenopausal women, activates hormonal receptors in a tissue-specific manner. Estrogenic activity is present mostly in the brain, vagina, and bone, while the inactive forms predominate in the endometrium and breast. Conflicting literature on TIB's actions has been observed. While it has benefits for vasomotor symptoms, bone demineralization, and sexual health, a higher relative risk of hormone-sensitive cancer has been reported. In the brain, TIB can improve mood and cognition, neuroinflammation, and reactive gliosis. This review aims to discuss the systemic effects of TIB on peri- and post-menopausal women and its role in the brain. We suggest that TIB is a hormonal therapy with promising neuroprotective properties.

Association Between Hormone-Modulating Breast Cancer Therapies and Incidence of Neurodegenerative Outcomes for Women With Breast Cancer.

Importance: The association between exposure to hormone-modulating therapy (HMT) as breast cancer treatment and neurodegenerative disease (NDD) is unclear. Objective: To determine whether HMT exposure is associated with the risk of NDD in women with breast cancer. Design, Setting, and Participants: This retrospective cohort study used the Humana claims data set from January 1, 2007, to March 31, 2017. The Humana data set contains claims from private-payer and Medicare insurance data sets from across the United States with a population primarily residing in the Southeast. Patient claims records were surveyed for a diagnosis of NDD starting 1 year after breast cancer diagnosis for the duration of enrollment in the claims database. Participants were 57 843 women aged 45 years or older with a diagnosis of breast cancer. Patients were required to be actively enrolled in Humana claims records for 6 months prior to and at least 3 years after the diagnosis of breast cancer. The analyses were conducted between January 1 and 15, 2020. Exposure: Hormone-modulating therapy (selective estrogen receptor modulators, estrogen receptor antagonists, and aromatase inhibitors). Main Outcomes and Measures: Patients receiving HMT for breast cancer treatment were identified. Survival analysis was used to determine the association between HMT exposure and diagnosis of NDD. A propensity score approach was used to minimize measured and unmeasured selection bias. Results: Of the 326 485 women with breast cancer in the Humana data set between 2007 and 2017, 57 843 met the study criteria. Of these, 18 126 (31.3%; mean [SD] age, 76.2 [7.0] years) received HMT, whereas 39 717 (68.7%; mean [SD] age, 76.8 [7.0] years) did not receive HMT. Mean (SD) follow-up was 5.5 (1.8) years. In the propensity score-matched population, exposure to HMT was associated with a decrease in the number of women who received a diagnosis of NDD (2229 of 17 878 [12.5%] vs 2559 of 17 878 [14.3%]; relative risk, 0.89; 95% CI, 0.84-0.93; P < .001), Alzheimer disease (877 of 17 878 [4.9%] vs 1068 of 17 878 [6.0%]; relative risk, 0.82; 95% CI, 0.75-0.90; P < .001), and dementia (1862 of 17 878 [10.4%] vs 2116 of 17 878 [11.8%]; relative risk, 0.88; 95% CI, 0.83-0.93; P < .001). The number needed to treat was 62.51 for all NDDs, 93.61 for Alzheimer disease, and 69.56 for dementia. Conclusions and Relevance: Among patients with breast cancer, tamoxifen and steroidal aromatase inhibitors were associated with a decrease in the number who received a diagnosis of NDD, specifically Alzheimer disease and dementia.

Curcumin: a phytochemical modulator of estrogens and androgens in tumors of the reproductive system.

Curcumin (Cur) is an active derivative extracted from turmeric which exerts a wide range of interactions with biomolecules through complex signaling pathways. Cur has been extensively shown to possess potential antitumor properties. In addition, there is growing body of evidence suggesting that Cur may exert potential anti-estrogen and anti-androgen activity. In vitro and in vivo studies suggest that anticancer properties of Cur against tumors affecting the reproductive system in females and males may be underlied by the Cur-mediated inhibition of androgen and estrogen signaling pathways. In this review we examine various studies assessing the crosstalk between Cur and both androgen and estrogen hormonal activity. Also, we discuss the potential chemopreventive and antitumor role of Cur in the most prevalent cancers affecting the reproductive system in females and males.

Treatment strategies to prevent and reduce gynecomastia and/or breast pain caused by antiandrogen therapy for prostate cancer : Statement from the DEGRO working group prostate cancer.

AIM: To provide an overview on the available treatments to prevent and reduce gynecomastia and/or breast pain caused by antiandrogen therapy for prostate cancer. METHODS: The German Society of Radiation Oncology (DEGRO) expert panel summarized available evidence published and assessed the validity of the information on efficacy and treatment-related toxicity. RESULTS: Eight randomized controlled trials and one meta-analysis were identified. Two randomized trials demonstrated that prophylactic radiation therapy (RT) using 1â€¯× 10 Gy or 2â€¯× 6 Gy significantly reduced the rate of gynecomastia but not breast pain, as compared to observation. A randomized dose-finding trial identified the daily dose of 20 mg tamoxifen (TMX) as the most effective prophylactic dose and another randomized trial described that daily TMX use was superior to weekly use. Another randomized trial showed that prophylactic daily TMX is more effective than TMX given at the onset of gynecomastia. Two other randomized trials described that TMX was clearly superior to anastrozole in reducing the risk for gynecomastia and/or breast pain. One comparative randomized trial between prophylactic RT using 1â€¯× 12 Gy and TMX concluded that prophylactic TMX is more effective compared to prophylactic RT and furthermore that TMX appears to be more effective to treat gynecomastia and/or breast pain when symptoms are already present. A meta-analysis confirmed that both prophylactic RT and TMX can reduce the risk of gynecomastia and/or breast pain with TMX being more effective; however, the rate of side effects after TMX including dizziness and hot flushes might be higher than after RT and must be taken into account. Less is known regarding the comparative effectiveness of different radiation fractionation schedules and more modern RT techniques. CONCLUSIONS: Prophylactic RT as well as daily TMX can significantly reduce the incidence of gynecomastia and/or breast pain. TMX appears to be an effective alternative to RT also as a therapeutic treatment in the presence of gynecomastia but its side effects and off-label use must be considered.

[Analysis of influencing factors of endometrial disease of patients with breast cancer after operation].

Objective: To study influencing factors which cause the endometrial diseases in patients with breast cancer after operation. Methods: A retrospective study was performed on 212 breast cancer post-operation patients with endometrial diseases between June 2006 and January 2018 in Women's Hospital School of Medicine Zhejiang University to analyse the factors which influenced the endometrial diseases. Results: The abnormal uterine bleeding and endometrial thickness were related to the severity of endometrial disease in patients with breast cancer, and they were independent risk factors for breast cancer patients to have endometrial cancer (P<0.05) . When the diagnostic cut off value of endometrial thickness was ≥0.49 cm, the sensitivity and specificity to endometrial cancer were 78% and 25%, respectively. The average endometrial thickness was (0.56±0.39) cm in patients who were treated by selective estrogen receptor modulator (SERM) after gynecological surgery, which was significantly thicker than that of aromatase inhibitor (AI) group [ (0.33±0.23) cm] and no treatment group [ (0.44±0.28) cm, P<0.05]. The endometrial disease recurrent rate and reoperation rate in SERM group were (26.2%, 14.3%) slightly higher than that of AI group (9.5%, 4.8%) and no treatment group (21.6%, 4.9%), but there were not significant differences (all P>0.05). Conclusions: The clinical symptom of abnormal uterine bleeding and thickening endometrium are risk factors for breast cancer patients to have endometrial cancer. The endometrial thickness has high predictive value for breast cancer patients to diagnose endometrial cancer. The SERM treatment increases the endometrial thickness, recurrent rate and reoperation rate in post-operation patients.

Tibolon - the only one member of STEARs group.

Tibolon is the only therapeutic approach to climacteric symptoms, prevention of osteoporosis and urogenital atrophy with the same efficacy as hormone replacement therapy. Tibolon has more positive effects on sexuality and mood changes in menopausal women. It decreases the mammographic density. Its safety for breast cancer is the same as for only estrogen therapy and better than for estrogen-gestagen therapy. Tibolon is the first choice for postmenopausal women with mood and sexuality disorders, women with mastodynia and high mammographic density.

Natural Estrogen Receptor Modulators and Their Heterologous Biosynthesis.

Estrogen receptors (ERs) are transcription factors highly involved in physiological development and metabolism in the human body. They also play important roles in the treatment of cancer and metabolic diseases. Chemicals that interact with ERs can be used to treat diseases and maintain health. Phytoestrogens are natural chemicals that have been documented to possess significant ER modulatory activities. However, since phytoestrogens usually exist at low quantities in nature, heterologous biosynthesis techniques have quickly developed in recent years in order meet the demands for needed therapeutic amounts. In this review, the performance of phytoestrogens as ER modulators is described along with recent advances in biosynthesis techniques.

Late-onset progression of keratoconus after therapy with selective tissue estrogenic activity regulator.

We describe the association of rapid progression of keratoconus in a 49-year-old woman on selective tissue estrogenic activity regulator (STEAR) therapy for endometriosis. Approximately 4 months after initiation of therapy with STEAR therapy and 3 months after ovariectomy, Scheimpflug images showed a massive increase in the previously stable ectasia. During this period, the maximum increase in the keratometry values was 2.7 diopters (D) in the right eye and 3.8 D in the left eye. Corneal crosslinking (CXL) was performed in both eyes. This resulted in excessive flattening of 5.5 D in the right eye and 6.1 D in the left eye at 9 months postoperatively. Patients having STEAR therapy must be monitored closely for corneal changes.

Sangrado y terapia hormonal en la menopausia (THM) / Bleeding during menopause hormone therapy (MHT)

La definición de sangrado ginecológico anormal durante terapia hormonal de la menopausia es aquel sangrado no programado durante el uso de la terapia. Este artículo es un pauteo que describe: 1) cuándo diagnosticar unsangrado anormal, ya que difiere según el tipo de esquema hormonal utilizado; 2) eldiagnóstico diferencial del origen del sangrado anormal; 3) los métodos de evaluación para diagnosticar el origen del sangrado. Se destacan los aspectos principales para el diagnóstico diferencial entre patología orgánica versus disrupción endometrial debida al tratamiento hormonal. Además, se describen los ajustes posibles para resolver el sangrado cuando éste se debe a disrupción del endometrio.

Abnormal bleeding related to menopausal hormone therapy is defined as unscheduled bleeding during the use of the therapy. This article outlines when to diagnose an abnormal bleeding -as this differs according to the type of hormonal scheme used-, the differential diagnosis of the origin of abnormal bleeding, and the methods of evaluation to assess the origin of the bleeding. The main aspects are highlighted on the differentiation of organic pathology versus disruption of the endometrium due to treatment. Also, treatment adjustments to resolve bleeding when it is due to disruption of the endometrium are outlined.

Tibolone and risk of gynecological hormone sensitive cancer.

Risk of ovarian cancer with hormone therapy is associated with use of both unopposed estrogen therapy and combined estrogen-progestin therapy, whereas for endometrial cancer addition of continuous progestin decreases the estrogen induced increased risk. Less is known about risk with use of tibolone; a synthetic steroid with estrogenic, progestagenic and androgenic properties. We assessed these associations in a prospective cohort study, including all Danish women 50-79 years of age and followed 1995-2009. National Danish Registers captured individually updated exposure information, cancer cases including histology and confounding factors. Poisson regression analyses provided multiple adjusted incidence rate ratios (IRRs). More than 900,000 women were followed for 9.8 years on average; 4,513 were diagnosed with ovarian cancer and 6,202 with endometrial cancer. Compared to women never on postmenopausal hormone therapy, current users of tibolone had an increased IRR for ovarian cancer (1.42(95% confidence interval [CI], 1.01-2.00) and serous ovarian tumors (2.21(95%CI 1.48-3.32)). The risk increased with duration of use, particularly for serous ovarian tumors. Compared to never users, the IRR of endometrial cancer was 3.56(95%CI 2.94-4.32) among current users of tibolone and 3.80(95%CI 3.08-4.69) of Type I endometrial cancer. The steepest risk increase with duration of use was for Type I tumors. In conclusion, tibolone is associated with increased risk for ovarian and endometrial cancer overall; and particular the risk of serous ovarian tumors and Type I endometrial cancer. Because the associations are stronger with increasing durations of use - and for hormone sensitive tumors - the results seem indicative of causality.

Premenopausal women with early breast cancer treated with estradiol suppression have severely deteriorated bone microstructure.

BACKGROUND: In premenopausal women with early estrogen-receptor-positive breast cancer, combined ovarian suppression and aromatase inhibition reduce estradiol production precipitously. The resulting unbalanced and rapid bone remodelling replaces older bone with less bone that is less fully mineralized. We hypothesized that these changes result in severe microstructural deterioration and reduced matrix mineralization density. METHODS: Images of the distal radius and distal tibia were acquired using high-resolution peripheral quantitative computed tomography in a cross-sectional study of 27 premenopausal women, mean age 43.3years (range 30.4 to 53.7) with early breast cancer made estradiol deficient for 17months (range 6-120) using ovarian suppression and aromatase inhibition, 42 healthy age-matched premenopausal and 35 postmenopausal controls, mean age 62.6years (range 60.2 to 65.5). Cortical and trabecular microstructure were quantified using Strax software. RESULTS: Compared with premenopausal controls, the women with breast cancer had 0.75 SD (95% CI 0.21 to 1.29) lower distal radial trabecular bone volume due to 1.29 SD (0.71 to 1.87) fewer trabeculae. Cortical porosity was 1.25 SD (0.59 to 1.91) higher but cortical thickness was not reduced. Compared with postmenopausal controls 20years older, cases had comparable or lower trabecular bone volume and comparable cortical porosity and thickness. Matrix mineral density was 1.56 SD (0.90 to 2.22) lower than in premenopausal controls and 2.17 SD (1.50 to 2.84) lower than in postmenopausal controls. Results at the tibia were similar. CONCLUSION: The severe cortical porosity and trabecular deterioration associated with estradiol depletion and the longevity of premenopausal women with early breast cancer treated with endocrine therapy provide a compelling rationale to investigate the efficacy of antiresorptive therapy initiated at the time of breast cancer treatment.

Decreased contralateral breast volume after mastectomy, adjuvant chemotherapy, and anti-estrogen therapy, in particular in breasts with high density.

Adjuvant chemotherapy and anti-estrogenic therapy can result in decreased volume of the contralateral breast, following mastectomy for the treatment of breast cancer. However, no data on the effect of adjuvant therapy on contralateral breast volume have previously been reported. We aimed to evaluate the extent to which adjuvant therapy and differences in breast density contribute to decreased breast volume. We conducted a prospective cohort study, selecting 40 nonconsecutive patients who underwent immediate breast reconstruction with mastectomy and expander insertion followed by expander replacement. We measured the contralateral breast volume before each procedure. The extent of the change was analyzed with respect to adjuvant therapy and breast density measured by preoperative mammography. The greatest decrease in breast volume was 135.1 cm3. The decrease in breast volume was significantly larger in the adjuvant therapy (+) group, particularly in patients with high breast density, than in the adjuvant therapy (-) group. Significant differences between the chemotherapy (+), tamoxifen (+) group and the chemotherapy (-), tamoxifen (+) group were not found. Breast density scores had a range of 2.0-3.3 (mean: 2.8). In breast reconstruction, particularly when performed in one stage, preoperative mammography findings are valuable to plastic surgeons, and possible decreases in the contralateral breast volume due to adjuvant therapy, particularly in patients with high breast density, should be considered carefully.

Hormone-receptor positive breast cancer: highlights from the 39TH San Antonio Breast Cancer Symposium.

The San Antonio Breast Cancer Symposium is considered one of the most influential international meetings focusing on breast cancer management, covering several areas of study from basic research to clinical practice topics. a number of oral presentations addressing hormone receptor-positive breast cancer brought new data about critical subjects like the optimal duration of adjuvant endocrine therapy, new prognostic markers and their potential role in guiding adjuvant treatment choices, new insights into genomic alterations acquired during the metastatic process, and pharmacologic strategies to overcome resistance to endocrine therapy. This article aims at summarizing some of the presentations that, in our opinion, are expected to have an impact on clinical practice and research programs in this patient population.

Activating Mutations of ESR1, BRCA1 and CYP19 Aromatase Genes Confer Tumor Response in Breast Cancers Treated with Antiestrogens.

BACKGROUND: Four decades of erroneous breast cancer therapy with antiestrogens yielded the chaotic mixture of manifestations of artificial ER-inhibition and compensatory activating ER-mutations together with unreckonable tumor responses. OBJECTIVE: Due to the confusions between the anticancer and carcinogenic impacts of antiestrogens and synthetic estrogens, the old principle needs to be revised as concerns ER-signaling induced DNAdamage and breast cancer development. METHOD: Results of genetic studies on both estrogen- and antiestrogen-treated tumors were reanalyzed and associations among ER-blockade, compensatory restoration of ER-signaling and clinical behavior of cancers were investigated. RESULTS: There are no direct correlations between estrogen concentrations and mammary tumor development; the highest risk for breast cancer is rather the severe defect of ER-signaling. Upregulation of ER-signaling induced by natural estrogens is a beneficial process even in tumor cells promoting their domestication and elimination while in case of antiestrogen administration; increased ER-signaling is a compensatory action to strengthen residual genome stabilization. In genetically proficient patients, extreme upregulation of ER-activity and estrogen synthesis provoked by antiestrogens provides transiently enhanced genomic stabilization with the promotion of spontaneous tumor death. Recent patents reveal correlations between activating ESR1 mutations and antiestrogen induced tumor response. Conversely, in the majority of patients with genetic defects, antiestrogen administration evokes weak counteractive increase in estrogen synthesis and ER-expression, which is not satisfactory in terms of tumor response. CONCLUSION: Activating mutations affecting ERs play key roles in both the machinery of genome stabilization of healthy cells and the restoration of altered genetic pathways of DNA-repair in tumor cells.

Short-term and long-term effects of tibolone in postmenopausal women.

BACKGROUND: Tibolone is a synthetic steroid used for the treatment of menopausal symptoms, on the basis of short-term data suggesting its efficacy. We considered the balance between the benefits and risks of tibolone. OBJECTIVES: To evaluate the effectiveness and safety of tibolone for treatment of postmenopausal and perimenopausal women. SEARCH METHODS: In October 2015, we searched the Gynaecology and Fertility Group (CGF) Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and PsycINFO (from inception), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and clinicaltrials.gov. We checked the reference lists in articles retrieved. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing tibolone versus placebo, oestrogens and/or combined hormone therapy (HT) in postmenopausal and perimenopausal women. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures of The Cochrane Collaboration. Primary outcomes were vasomotor symptoms, unscheduled vaginal bleeding and long-term adverse events. We evaluated safety outcomes and bleeding in studies including women either with or without menopausal symptoms. MAIN RESULTS: We included 46 RCTs (19,976 women). Most RCTs evaluated tibolone for treating menopausal vasomotor symptoms. Some had other objectives, such as assessment of bleeding patterns, endometrial safety, bone health, sexuality and safety in women with a history of breast cancer. Two included women with uterine leiomyoma or lupus erythematosus. Tibolone versus placebo Vasomotor symptomsTibolone was more effective than placebo (standard mean difference (SMD) -0.99, 95% confidence interval (CI) -1.10 to -0.89; seven RCTs; 1657 women; moderate-quality evidence), but removing trials at high risk of attrition bias attenuated this effect (SMD -0.61, 95% CI -0.73 to -0.49; odds ratio (OR) 0.33, 85% CI 0.27 to 0.41). This suggests that if 67% of women taking placebo experience vasomotor symptoms, between 35% and 45% of women taking tibolone will do so. Unscheduled bleedingTibolone was associated with greater likelihood of bleeding (OR 2.79, 95% CI 2.10 to 3.70; nine RCTs; 7814 women; I2 = 43%; moderate-quality evidence). This suggests that if 18% of women taking placebo experience unscheduled bleeding, between 31% and 44% of women taking tibolone will do so. Long-term adverse eventsMost of the studies reporting these outcomes provided follow-up of two to three years (range three months to three years). Breast cancerWe found no evidence of differences between groups among women with no history of breast cancer (OR 0.52, 95% CI 0.21 to 1.25; four RCTs; 5500 women; I2= 17%; very low-quality evidence). Among women with a history of breast cancer, tibolone was associated with increased risk (OR 1.5, 95% CI 1.21 to 1.85; two RCTs; 3165 women; moderate-quality evidence). Cerebrovascular eventsWe found no conclusive evidence of differences between groups in cerebrovascular events (OR 1.74, 95% CI 0.99 to 3.04; four RCTs; 7930 women; I2 = 0%; very low-quality evidence). We obtained most data from a single RCT (n = 4506) of osteoporotic women aged 60 to 85 years, which was stopped prematurely for increased risk of stroke. Other outcomesEvidence on other outcomes was of low or very low quality, with no clear evidence of any differences between the groups. Effect estimates were as follows:• Endometrial cancer: OR 2.04, 95% CI 0.79 to 5.24; nine RCTs; 8504 women; I2 = 0%.• Cardiovascular events: OR 1.38, 95% CI 0.84 to 2.27; four RCTs; 8401 women; I2 = 0%.• Venous thromboembolic events: OR 0.85, 95% CI 0.37 to 1.97; 9176 women; I2 = 0%.• Mortality from any cause: OR 1.06, 95% CI 0.79 to 1.41; four RCTs; 8242 women; I2 = 0%. Tibolone versus combined HT Vasomotor symptomsCombined HT was more effective than tibolone (SMD 0.17, 95% CI 0.06 to 0.28; OR 1.36, 95% CI 1.11 to 1.66; nine studies; 1336 women; moderate-quality evidence). This result was robust to a sensitivity analysis that excluded trials with high risk of attrition bias, suggesting a slightly greater disadvantage of tibolone (SMD 0.25, 95% CI 0.09 to 0.41; OR 1.57, 95% CI 1.18 to 2.10). This suggests that if 7% of women taking combined HT experience vasomotor symptoms, between 8% and 14% of women taking tibolone will do so. Unscheduled bleedingTibolone was associated with a lower rate of bleeding (OR 0.32, 95% CI 0.24 to 0.41; 16 RCTs; 6438 women; I2 = 72%; moderate-quality evidence). This suggests that if 47% of women taking combined HT experience unscheduled bleeding, between 18% and 27% of women taking tibolone will do so. Long-term adverse eventsMost studies reporting these outcomes provided follow-up of two to three years (range three months to three years). Evidence was of very low quality, with no clear evidence of any differences between the groups. Effect estimates were as follows:• Endometrial cancer: OR 1.47, 95% CI 0.23 to 9.33; five RCTs; 3689 women; I2 = 0%.• Breast cancer: OR 1.69, 95% CI 0.78 to 3.67; five RCTs; 4835 women; I2 = 0%.• Venous thromboembolic events: OR 0.44, 95% CI 0.09 to 2.14; four RCTs; 4529 women; I2 = 0%.• Cardiovascular events: OR 0.63, 95% CI 0.24 to 1.66; two RCTs; 3794 women; I2 = 0%.• Cerebrovascular events: OR 0.76, 95% CI 0.16 to 3.66; four RCTs; 4562 women; I2 = 0%.• Mortality from any cause: only one event reported (two RCTs; 970 women). AUTHORS' CONCLUSIONS: Moderate-quality evidence suggests that tibolone is more effective than placebo but less effective than HT in reducing menopausal vasomotor symptoms, and that tibolone is associated with a higher rate of unscheduled bleeding than placebo but with a lower rate than HT.Compared with placebo, tibolone increases recurrent breast cancer rates in women with a history of breast cancer, and may increase stroke rates in women over 60 years of age. No evidence indicates that tibolone increases the risk of other long-term adverse events, or that it differs from HT with respect to long-term safety.Much of the evidence was of low or very low quality. Limitations included high risk of bias and imprecision. Most studies were financed by drug manufacturers or failed to disclose their funding source.