The effect of tibolone in postmenopausal women receiving tamoxifen after surgery for breast cancer: a randomised, double-blind, placebo-controlled trial

Eligibility criteria for using menopausal hormone therapy in breast cancer survivors: a safety report based on a systematic review and meta-analysis

IMPORTANCE

Menopause hormone therapy (MHT) effectively alleviates menopausal symptoms. However, it is generally not recommended for breast cancer survivors, although the scientific evidence is scarce.

OBJECTIVE

This study aimed to establish eligibility criteria for use of the MHT in breast cancer survivors based on a systematic review and meta-analysis of the literature.

EVIDENCE REVIEW

We conducted exhaustive literature searches until June 2022 in MEDLINE, The Cochrane Library, and EMBASE, using a tailored strategy with a combination of controlled vocabulary and search terms related to breast cancer survivors and MHT. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and assessed the risk of bias using the Cochrane and Risk of Bias in Non-randomized Studies - of Interventions tools. The quality of the evidence was graded according to grading quality of evidence and strength of recommendations criteria (A, high; B, moderate; C, low; and D, very low). We categorized MHT use into four levels: category 1 (no restrictions on use), category 2 (the benefits outweigh the risks), category 3 (the risks generally outweigh the benefits), and category 4 (MHT should not be used).

FINDINGS

A total of 12 studies met the eligibility criteria. Analysis of the three randomized clinical trials using combined MHT or tibolone revealed no significant differences concerning tumor recurrence (relative risk [RR], 1.46; 95% CI, 0.99-2.24). A combined analysis of randomized clinical trials, prospective, and retrospective trials found no elevated risk of recurrence (RR, 0.85; 95% CI, 0.54-1.33) or death (RR, 0.91; 95% CI, 0.38-2.19). The eligibility criteria for patients with hormone receptor (HR)-positive tumors fell into categories 3B and 3C for combined MHT or estrogen alone and 4A for tibolone. For HR-negative tumors, the category was 2B and 2C.

CONCLUSIONS AND RELEVANCE

Our findings suggest that MHT could be a viable treatment alternative for breast cancer survivors experiencing menopausal symptoms, especially those with HR-negative tumors. Personalized management is recommended for each peri/postmenopausal woman facing a diminished quality of life because of menopause symptoms. Further randomized trials are needed before considering changes to current standards of care.

The effect of tibolone treatment on apolipoproteins and lipoprotein (a) concentrations in postmenopausal women: A meta-analysis of randomized controlled trials

OBJECTIVE

Tibolone is a synthetic steroid with estrogenic, androgenic and progestogenic properties that is used as hormone replacement therapy (HRT) in postmenopausal women. Treatment with tibolone has been demonstrated to lead to changes of the lipid profile, including alterations in lipoprotein (a) and apolipoprotein levels. Hence, we conducted the present meta-analysis of randomized controlled trials (RCTs) to assess the effect of tibolone treatment on apolipoproteins and lipoprotein (a) values in postmenopausal women.

METHODS

Several databases (Cochrane Library, PubMed/Medline, Scopus, and Google Scholar) were searched for English-language manuscripts published up to September 2023 that scrutinized the effects of tibolone administration on apolipoprotein A-I (ApoA-I), apolipoprotein A-II (ApoA-II), apolipoprotein B (ApoB), and lipoprotein (a) in postmenopausal women. The results were reported as the weighted mean difference (WMD) with a 95% confidence interval (CI), generated using a random-effects model.

RESULTS

Finally, 12 publications with 13 RCT arms were included in the current meta-analysis. The overall results from the random-effects model demonstrated a notable reduction in ApoA-I (n = 9 RCT arms, WMD: -34.96 mg/dL, 95 % CI: -42.44, -27.48, P < 0.001) and lipoprotein (a) (n = 12 RCT arms, WMD: -7.49 mg/dl, 95 % CI: -12.17, -2.81, P = 0.002) after tibolone administration in postmenopausal women. However, treatment with tibolone did not impact ApoA- II (n = 4 RCT arms, WMD: 1.32 mg/dL, 95 % CI: -4.39, 7.05, P = 0.64) and ApoB (n = 9 RCT arms, WMD: -2.68 mg/dL, 95 % CI: -20.98, 15.61, P = 0.77) values. In the subgroup analyses, we noticed a notable decrease in lipoprotein (a) levels when tibolone was prescribed to females aged < 60 years (WMD: -10.78 mg/dl) and when it was prescribed for ≤ 6 months (WMD: -15.69 mg/dl).

CONCLUSION

The present meta-analysis of RCTs highlighted that treatment with tibolone reduces lipoprotein (a) and apolipoprotein A-I levels in postmenopausal women. As the decrease in serum lipids' concentrations is associated with a decrease in the risk of cardiovascular disease (CVD), treatment with tibolone could be a suitable therapy for postmenopausal women with elevated CVD risk.

Factors associated with high placebo response in clinical studies of hot flashes: a meta-analysis

IMPORTANCE

High placebo response can often mask the evaluation of active treatment in clinical studies for women with hot flashes and potentially undermine the evaluation of new treatments.

OBJECTIVE

The aim of this meta-analysis was to determine the factors associated with high placebo response (defined as the reduction in the mean number of hot flash frequency from baseline) in randomized, controlled, double-blind studies enrolling women with hot flashes.

EVIDENCE REVIEW

To identify eligible studies, Embase, MEDLINE, and BIOSIS Previews were searched for English-language articles published between April 1975 and August 2020. Placebo-controlled, double-blind, randomized studies that assessed changes in hot flash frequency were included if they satisfied the defined criteria. We conducted univariate and multivariate analyses using categorical and numerical data. Categorical data included the following variables and levels in brackets: active treatment type (hormone therapy /non- hormone therapy /complementary and alternative medicine), administration route (oral/non-oral), study region (in/excluded the US), breast cancer population (in/excluded), entry criteria of hot flash severity (moderate to severe only/all included), parallel or crossover study, placebo run-in period before treatment (yes/no), and menopausal status (postmenopausal only/include perimenopausal/include premenopausal). Numerical data included published year, pretreatment period duration, treatment period duration, number of sites, number of total participants, number of placebo participants, number of treatment arms, mean age, BMI, and hot flash frequency at baseline.

FINDINGS

Forty-three of the 802 identified publications were included in the review. Multivariate analysis identified three individual factors associated with high placebo response: treatment period duration, number of treatment arms, and BMI.

CONCLUSIONS AND RELEVANCE

We identified several factors associated with high placebo response in clinical studies of women with hot flashes. Knowing these factors may enable proactive implementation of operational and analytic strategies that further aid in determining the true treatment effect of an intervention.

The effect of tibolone treatment on lipid profile in women: A systematic review and dose-response meta-analysis of randomized controlled trials

Inconsistencies exist with regard to influence of tibolone treatment on the lipid profile. The reasons for these inconsistencies might derive from several factors, i.e., differences in baseline variables, intervention duration, participants' health status or baseline body mass index (BMI). To address these inconsistencies, based on a systematic search in Scopus, PubMed/Medline, Web of Science, and Embase for papers published until 21 December 2020, we conducted the current dose-response meta-analysis of randomized controlled trials (RCTs) to determine the impact of tibolone treatment on the lipid profile. The overall findings were derived from 26 RCTs. Tibolone administration decreased total cholesterol (TC) (weighted mean difference, WMD: -18.55 mg/dL, CI: -25.95 to -11.16, P < 0.001), high-density lipoprotein-cholesterol (HDL-C) (WMD: -9.42 mg/dL, CI: -11.83 to -7.01, P < 0.001) and triglyceride (TG) (WMD: -21.43 mg/dL, CI: -27.15 to -15.70, P < 0.001) levels. A significant reduction in LDL-C occurred when tibolone was prescribed for ≤ 26 weeks (WMD: -7.64 mg/dL, 95% CI: -14.58 to -0.70, P = 0.031) versus > 26 weeks (WMD: -8.84 mg/dL, 95% CI: -29.98, 12.29, P = 0.412). The decrease in TG (WMD: -22.64 mg/dL) and TC (-18.55 mg/dL) concentrations was more pronounced in patients with BMI ≥ 25 kg/m²versus BMI < 25 kg/m². This systematic review and meta-analysis discovered that tibolone decreases TC, HDL-C and TG levels. LDL-C concentrations are significantly reduced when tibolone administration lasts for ≤ 26 weeks.

Variation in menopausal vasomotor symptoms outcomes in clinical trials: a systematic review

BACKGROUND

There is substantial variation in how menopausal vasomotor symptoms are reported and measured among intervention studies. This has prevented meaningful comparisons between treatments and limited data synthesis.

OBJECTIVES

To review systematically the outcome reporting and measures used to assess menopausal vasomotor symptoms from randomised controlled trials of treatments.

SEARCH STRATEGY

We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to May 2018.

SELECTION CRITERIA

Randomised controlled trials with a primary outcome of menopausal vasomotor symptoms in women and a sample size of at least 20 women per study arm.

DATA COLLECTION AND ANALYSIS

Data about study characteristics, primary vasomotor-related outcomes and methods of measuring them.

MAIN RESULTS

The search identified 5591 studies, 214 of which were included. Forty-nine different primary reported outcomes were identified for vasomotor symptoms and 16 different tools had been used to measure these outcomes. The most commonly reported outcomes were frequency (97/214), severity (116/214), and intensity (28/114) of vasomotor symptoms or a composite of these outcomes (68/214). There was little consistency in how the frequency and severity/intensity of vasomotor symptoms were defined.

CONCLUSIONS

There is substantial variation in how menopausal vasomotor symptoms have been reported and measured in treatment trials. Future studies should include standardised outcome measures which reflect the priorities of patients, clinicians, and researchers. This is most effectively achieved through the development of a Core Outcome Set. This systematic review is the first step towards development of a Core Outcome Set for menopausal vasomotor symptoms.

TWEETABLE SUMMARY

Menopausal hot flushes and night sweats have been reported in 49 different ways in clinical research. A core outcome set is urgently required.

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.

A systematic review of non-hormonal treatments of vasomotor symptoms in climacteric and cancer patients

The cardinal climacteric symptoms of hot flushes and night sweats affect 24-93% of all women during the physiological transition from reproductive to post-reproductive life. Though efficacious, hormonal therapy and partial oestrogenic compounds are linked to a significant increase in breast cancer. Non-hormonal treatments are thus greatly appreciated.

This systematic review of published hormonal and non-hormonal treatments for climacteric, and breast and prostate cancer-associated hot flushes, examines clinical efficacy and therapy-related cancer risk modulation.

A PubMed search included literature up to June 19, 2014 without limits for initial dates or language, with the search terms, (hot flush* OR hot flash*) AND (clinical trial* OR clinical stud*) AND (randomi* OR observational) NOT review). Retrieved references identified further papers. The focus was on hot flushes; other symptoms (night sweats, irritability, etc.) were not specifically screened. Included were some 610 clinical studies where a measured effect of the intervention, intensity and severity were documented, and where patients received treatment of pharmaceutical quality. Only 147 of these references described studies with alternative non-hormonal treatments in post-menopausal women and in breast and prostate cancer survivors; these results are presented in Additional file 1.

The most effective hot flush treatment is oestrogenic hormones, or a combination of oestrogen and progestins, though benefits are partially outweighed by a significantly increased risk for breast cancer development.

This review illustrates that certain non-hormonal treatments, including selective serotonin reuptake inhibitors, gabapentin/pregabalin, and Cimicifuga racemosa extracts, show a positive risk-benefit ratio.

Key points

Several non-hormonal alternatives to hormonal therapy have been established and registered for the treatment of vasomotor climacteric symptoms in peri- and post-menopausal women.

There are indications that non-hormonal treatments are useful alternatives in patients with a history of breast and prostate cancer. However, confirmation by larger clinical trials is required.

Risk factors, pathophysiology, and treatment of hot flashes in cancer

Hot flashes are prevalent and severe symptoms that can interfere with mood, sleep, and quality of life for women and men with cancer. The purpose of this article is to review existing literature on the risk factors, pathophysiology, and treatment of hot flashes in individuals with cancer. Electronic searches were conducted to identify relevant English-language literature published through June 15, 2012. Results indicated that risk factors for hot flashes in cancer include patient-related factors (eg, age, race/ethnicity, educational level, smoking history, cardiovascular risk including body mass index, and genetics) and disease-related factors (eg, cancer diagnosis and dose/type of treatment). In addition, although the pathophysiology of hot flashes has remained elusive, these symptoms are likely attributable to disruptions in thermoregulation and neurochemicals. Therapies that have been offered or tested fall into 4 broad categories: pharmacological, nutraceutical, surgical, and complementary/behavioral strategies. The evidence base for this broad range of therapies varies, with some treatments not yet having been fully tested or showing equivocal results. The evidence base surrounding all therapies is evaluated to enhance hot flash treatment decision-making by clinicians and patients.

How are Interactions Taken into Account in Studies on Conventional and Complementary Therapies for Breast Cancer Patients with Menopausal Complaints?

Introduction: Postmenopausal symptoms in breast cancer patients undergoing antihormone treatment lead to high drop-out rates from the therapy. From the therapeutic point of view, methods of both conventional and complementary medicine are concerned. Interactions are being discussed in cases of natural substances. However, they are also relevant for conventional medical substances. The aim of this analysis is to answer the question as to what extent potential interactions are taken into account in clinical studies and reviews on supportive therapies. Materials and Methods: Clinical studies and reviews were identified by means of a systematic search and analysed with regard to the consideration of potential interactions. Results: Altogether 46 clinical studies and one Cochrane review were found. Among the 35 studies on conventional drug therapies, 5 (14 %) took possible interactions into account. Among the 17 studies on complementary medicine, there were 2 (11.7 %) such publications. The Cochrane review did not mention interactions. Discussion: For future studies in which interactions cannot be excluded, a strategy to control for their clinically relevant consequences should be developed. The present authors suggest that the use of survival and recurrence data as secondary endpoints, also for studies on purely supportive therapies, is a reasonable approach. The resulting considerations for study routines are listed thematically.

Effect of escitalopram on hot flash interference: a randomized, controlled trial

OBJECTIVE

To estimate the effect of escitalopram (10-20 mg/d) versus placebo for reducing hot flash interference in daily life and understand correlates and predictors of reductions in hot flash interference, a key measure of quality of life.

DESIGN

Multisite, randomized, double-blind, placebo-controlled clinical trial.

SETTING

MsFLASH clinical sites in Boston, Indianapolis, Oakland, and Philadelphia.

PATIENT(S)

A total of 205 midlife women (46% African-American) who met criteria participated.

INTERVENTION(S)

After baseline, women were randomized to one pill of escitalopram 10 mg/d (n = 104) or placebo (n = 101) with follow-up at 4 and 8 weeks. At week 4, those not achieving 50% fewer hot flashes were increased to two pills daily (20 mg/d or 2 placebo pills).

MAIN OUTCOME MEASURE(S)

The Hot Flash Related Daily Interference Scale; correlates were variables from hot flash diaries; predictors were baseline demographics, clinical variables, depression, anxiety, sleep quality, and hot flashes.

RESULT(S)

Compared to placebo, escitalopram significantly reduced hot flash interference by 6.0 points at week 4 and 3.4 points at week 8 more than placebo. Reductions in hot flash interference correlated with changes in hot flash diary variables. However, baseline variables did not significantly predict reductions in hot flash interference.

CONCLUSION(S)

Escitalopram (10-20 mg/d) for 8 weeks improves women's quality of life and this benefit did not vary by demographic, clinical, mood, sleep, or hot flash variables.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00894543.

Short and long term effects of tibolone in postmenopausal women

BACKGROUND

Tibolone is an option available for the treatment of menopausal symptoms, based on short-term data on its efficacy. However, there is a need to consider the balance between the benefits and risks of tibolone as there are concerns about breast and endometrial cancer as well as stroke.

OBJECTIVES

To evaluate the effectiveness and safety of tibolone in treating postmenopausal women.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group (MDSG) Specialised Register (19 April 2011), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, 2nd Quarter), MEDLINE (from inception to 19 April 2011), EMBASE (1980 to week 3 April 2011), PsycINFO (1806 to week 3 April 2011), Clinical Trials.gov (30 April 2011). Individual researchers and the current manufacturer of tibolone were contacted to identify unpublished and ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared tibolone versus placebo, estrogens or combined hormone replacement therapy (HT) by assessing the percentage of women with menopausal symptoms, the severity of those symptoms and the occurrence of safety outcomes in postmenopausal women.

DATA COLLECTION AND ANALYSIS

Four review authors independently extracted information from the articles, resolving discrepancies by consensus. All outcomes studied were dichotomous. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using the random-effects model. Heterogeneity of studies was taken into account before deciding to combine the data.

MAIN RESULTS

When compared to placebo, tibolone was more effective in relieving the frequency of vasomotor symptoms (two RCTs, n = 847; OR 0.42, 95% CI 0.25 to 0.69), although only the 2.5 mg/day dose of tibolone was significantly better than placebo; but with increased vaginal bleeding (seven RCTs, n = 7462; OR 2.75, 95% CI 1.99 to 3.80). When compared to equipotent doses of combined HT, tibolone reduced vaginal bleeding (15 RCTs, n = 6342; OR 0.32, 95% CI 0.24 to 0.42) but was less effective in relieving the frequency of vasomotor symptoms (two RCTs, n = 545; OR 4.16, 95% CI 1.50 to 11.58).As for long term safety, two major RCTs of tibolone versus placebo provided the most relevant data. An RCT of 3098 women with breast cancer and menopausal symptoms was halted after 3.1 years because of increased tumour recurrence (OR 1.50; 95% CI 1.21 to 1.85). However, in another RCT that selected osteoporotic women with negative mammograms (n = 4506) tibolone was associated with a reduction in breast cancer compared to placebo after 2.8 years (OR 0.32, 95% CI 0.13 to 0.79) although the trial was not specifically designed to assess that outcome and the number of overall events was low. In the same RCT, an excess risk of stroke was observed (OR 2.18, 95% CI 1.12 to 4.21). There was no clear evidence of a tibolone effect on endometrial cancer compared with placebo given the low number of events (seven RCTs, n = 8152; OR 1.98, 95% CI 0.73 to 5.32).There was no evidence of a difference in long term safety between tibolone and combined HT.

AUTHORS' CONCLUSIONS

Tibolone, used at the daily dose of 2.5 mg, may be less effective than combined HT in alleviating menopausal symptoms although it reduced the incidence of vaginal bleeding. There was evidence that treatment with combined HT was more effective in managing menopausal symptoms than was tibolone. Available data on the long term safety of tibolone is concerning given the increase in the risk of breast cancer in women who had already suffered from breast cancer in the past and in a separate trial the increase in the risk of stroke in women whose mean age was over 60 years. Similar concerns may exist for estroprogestins but their overall benefit-risk profile is better known and is more directly related to women with menopausal symptoms.

Tibolone in postmenopausal women: a review based on recent randomised controlled clinical trials

AIM

To critically discuss the use of tibolone (T), in light of a series of very recent double-blind placebo (PL) controlled trials (LISA, LIFT, OPAL, THEBES, LIBERATE) conducted worldwide in a large number of postmenopausal women (PMW).

METHODS

The most relevant publications on T therapy in PMW were considered with emphasis on menopausal symptoms, quality of life, sexuality, bone, cardiovascular system (CVS) and oncologic risk.

RESULTS

T significantly relieves climacteric symptoms and improves mood and sexual well-being (LISA). T is as effective as estrogen-progestin therapy in preventing bone loss and reducing the relative risk of vertebral and non-vertebral fractures (LIFT). By using surrogate endpoints of the individual risks for the CVS, studies show mixed results, but a favourable effect on acute miocardial infarction and thromboembolism has been documented (THEBES, LIFT, OPAL). Although findings about endometrial and colon cancer are reassuring, conclusive data on breast cancer risk with T are not available and an increased risk of recurrence in women with previous breast cancer emerged (LIBERATE).

CONCLUSIONS

T is effective in treating menopausal syndrome with a good tolerability profile. In spite of some unsolved issues in term of safety, T is still a good treatment option for early PMW.

Managing menopausal symptoms and depression in tamoxifen users: implications of drug and medicinal interactions

OBJECTIVE

Tamoxifen, a medication used in the treatment of breast cancer, often induces menopausal symptoms. Certain medications and natural supplements taken or prescribed to alleviate tamoxifen-induced hot flashes and depressive states in women with breast cancer interact with tamoxifen. This paper reviews potentially problematic interactions and offers treatment recommendations.

METHODS

Medline (1950-June 1, 2010), Embase Classic+Embase (1947-June 1, 2010) and PsycINFO (1967-June 1, 2010) were searched through Ovid. The word "tamoxifen" was searched with "depression" and then with "menopaus*" and "symptoms", with "treatment" as a limit. "Tamoxifen" was later searched with the MeSH terms "drug interaction" or "drug incompatibility".

RESULTS

Venlafaxine is efficacious for the treatment of hot flashes and depression and safe to use in combination with tamoxifen. Gabapentin is also efficacious in treating tamoxifen-induced hot flashes and, since it does not interact with cytochrome P450 system, is likely safe to use in patients using tamoxifen. Desvenlafaxine and pregabalin may be alternatives to venlafaxine and gabapentin, respectively, although desvenlafaxine has not yet been studied in this population. Paroxetine, fluoxetine and bupropion are strong CYP2D6 inhibitors which should be avoided in tamoxifen users. Fluvoxamine and nefazodone both inhibit CYP3A, which could potentially affect the metabolism of tamoxifen. Clonidine can be an alternative agent but may carry significant side effects. Evidence of medicinal products for the treatment of tamoxifen-induced hot flashes is equivocal at best.

CONCLUSIONS

Clinicians should remain cautious about using strong inhibitors and/or inducers of cytochrome 2D6 and 3A4 concomitantly with tamoxifen. Use of natural menopausal supplements and diets rich in isoflavones should not be encouraged in tamoxifen users until more data is available. There are however safe treatments for hot flashes and depression in tamoxifen users.

Women's health, breast health: a review of the gynecologic effects of breast cancer

Breast cancer is very common and seen in both premenopausal and postmenopausal women. Research into prevention, better screening, and more effective treatments is occurring continually, and changes are translated into clinical practice relatively quickly. It is important for women's health care providers to have an understanding of breast cancer treatments and the gynecologic side effects. For premenopausal women interested in fertility, options should be discussed prior to chemotherapy. Issues pertaining to pregnancy after breast cancer should be discussed in a multidisciplinary fashion, involving the obstetrician/gynecologist, breast surgeon, and oncologist. Ovarian suppression is often used as part of breast cancer treatment in premenopausal women with hormone positive disease, and menopausal symptoms may be severe. Hormonal therapies including tamoxifen and the aromatase inhibitors are used in the treatment of hormone positive breast cancers. Each of these drugs has a variety of gynecologic implications. Understanding the options for treatment for menopausal complaints in breast cancer patients is important for women's health providers. Although most breast cancers are sporadic, a small percentage will be due to mutations in the BRCA genes. It is important for women's health providers to take an appropriate family history and refer to genetic counselors for possible testing when hereditary cancer is suspected. This review focuses on the various women's health issues pertaining to breast cancer and treatment.

Safety of alternative treatments for menopausal symptoms after breast cancer: a qualitative systematic review

AIM

This qualitative review analyzes systematically the safety of drugs used to alleviate menopausal symptoms, other than hormone replacement therapy, in breast cancer patients.

METHODS

We searched systematically studies using tibolone, serotonin reuptake inhibitors, clonidine, veralipride, gabapentin, black cohosh and phytoestrogens in breast cancer patients. We selected five studies for which we evaluated the methodology, characteristics of the studied populations, outcomes in terms of mortality and recurrence rates.

RESULTS

Four trials were conducted using tibolone in breast cancer patients: one double-blind, randomized trial, one prospective controlled study, and two uncontrolled studies. They considerably lack power to detect any difference in breast cancer recurrence or mortality between the treated and control patients. Similar conclusions have to be drawn from the only controlled retrospective study analyzing the safety of antidepressants and antihistamines. We were unable to find studies reporting the safety of the other drugs in breast cancer patients.

CONCLUSIONS

There are no valuable data indicating the absence of a harmful effect of drugs used to alleviate climacteric symptoms in breast cancer patients. There is a need for randomized trials to assess the safety of these drugs. In the meantime, patients should be informed about the absence of safety data.

Safety and efficacy of tibolone in breast-cancer patients with vasomotor symptoms: a double-blind, randomised, non-inferiority trial

BACKGROUND

Vasomotor symptoms and bone loss are complications frequently induced by adjuvant treatment for breast cancer. Tibolone prevents both side-effects, but its effect on cancer recurrence is unknown. The aim of this study was to show non-inferiority of tibolone to placebo regarding risk of recurrence in breast-cancer patients with climacteric complaints.

METHODS

Between July 11, 2002, and Dec 20, 2004, women surgically treated for a histologically confirmed breast cancer (T(1-3)N(0-2)M(0)) with vasomotor symptoms were randomly assigned to either tibolone 2.5 mg daily or placebo at 245 centres in 31 countries. Randomisation was done by use of a centralised interactive voice response system, stratified by centre, with a block size of four. The primary endpoint was breast-cancer recurrence, including contralateral breast cancer, and was analysed in the intention-to-treat (ITT) and per-protocol populations; the margin for non-inferiority was set as a hazard ratio of 1.278. This study is registered with ClinicalTrials.gov, number NCT00408863.

FINDINGS

Of the 3148 women randomised, 3098 were included in the ITT analysis (1556 in the tibolone group and 1542 in the placebo group). Mean age at randomisation was 52.7 years (SD 7.3) and mean time since surgery was 2.1 years (SD 1.3). 1792 of 3098 (58%) women were node positive and 2185 of 3098 (71%) were oestrogen-receptor positive. At study entry, 2068 of 3098 (67%) women used tamoxifen and 202 of 3098 (6.5%) women used aromatase inhibitors. The mean daily number of hot flushes was 6.4 (SD 5.1). After a median follow-up of 3.1 years (range 0.01-4.99), 237 of 1556 (15.2%) women on tibolone had a cancer recurrence, compared with 165 of 1542 (10.7%) on placebo (HR 1.40 [95% CI 1.14-1.70]; p=0.001). Results in the per-protocol population were similar (209 of 1254 [16.7%] women in the tibolone group had a recurrence vs 138 of 1213 [11.4%] women in the placebo group; HR 1.44 [95% CI 1.16-1.79]; p=0.0009). Tibolone was not different from placebo with regard to other safety outcomes, such as mortality (72 patients vs 63 patients, respectively), cardiovascular events (14 vs 10, respectively), or gynaecological cancers (10 vs 10, respectively). Vasomotor symptoms and bone-mineral density improved significantly with tibolone, compared with placebo.

INTERPRETATION

Tibolone increases the risk of recurrence in breast cancer patients, while relieving vasomotor symptoms and preventing bone loss.

FUNDING

Schering-Plough (formerly NV Organon, Oss, Netherlands).

Tibolone: the way to beat many a postmenopausal ailments

OBJECTIVE

The effects of tibolone on climacteric symptoms, osteoporosis, cardiovascular disease, breasts and the endometrium are summarised, and its role in clinical practice is reviewed in this article.

BACKGROUND

Tibolone has tissue-specific effects on receptors and enzymes that influence the synthesis and metabolism of endogenous sexual steroid hormones.

METHODS

This evaluation was based on the findings from several randomised studies, which addressed the basic and clinical research on tibolone.

RESULTS/CONCLUSION

Clinical trials prove that tibolone is effective in the treatment of the menopausal symptoms and for the postponement and calming of symptoms accompanying age-related diseases. The findings of basic researchers that tibolone affects the metabolism of every cell, including malignant cells, opened a door to a whole new domain of research that has a promising future.

Safety of tibolone in the treatment of vasomotor symptoms in breast cancer patients--design and baseline data 'LIBERATE' trial

Many patients with a history of breast cancer (BC) will suffer from vasomotor symptoms, which can be induced or exacerbated by treatment with tamoxifen or aromatase inhibitors. The LIBERATE trial was designed as a randomized, double-blind, multicenter trial to demonstrate that tibolone 2.5mg/day (Livial) is non-inferior to placebo regarding BC recurrence in women with vasomotor symptoms surgically treated for primary BC within the last 5 years. Secondary objectives are effects on vasomotor symptoms as well as overall survival, bone mineral density and health-related quality of life. Mean age at randomization was 52.6 years, and the mean time since surgery was 2.1 years. The mean daily number of hot flushes and sweating episodes was 7.3 and 6.1, respectively. For the primary tumor, Stage IIA or higher was reported for >70% of the patients. In subjects whose receptor status was known, 78.2% of the tumors were estrogen receptors positive. At randomization, tamoxifen was given to 66.2% of all patients and aromatase inhibitors to 7%. Chemotherapy was reported by 5% at randomization. The adjuvant tamoxifen use in LIBERATE allows a comparison with the Stockholm trial (showing no risk of BC recurrence associated with hormone therapy), which was stopped prematurely subsequent to HABITS. The LIBERATE trial is the largest, ongoing, well-controlled study for treatment of vasomotor symptoms in BC patients.

Climacteric Complaints after Breast Cancer - Is HRT an Option?

Systemic estrogen depletion is the mechanism of action of most endocrine treatment strategies, and a common side effect of most chemotherapy regimens that are currently used to treat invasive breast cancer. The ensuing immediate and profound decline in estrogen levels is, however, often associated with considerable climacteric complaints. While oral estrogen add-back therapy is effective in alleviating menopausal symptoms, it is feared that it might also promote tumor cell growth. This concern is largely based on circumstantial evidence from large trials in healthy women, in which hormone replacement therapy (HRT) resulted in a slight, albeit significant, increase in incident breast cancer. In breast cancer survivors, however, evidence from studies remains controversial. Despite these caveats, the severity of symptoms and the lack of effective alternatives still cause many women to opt for HRT. Nevertheless, HRT cannot generally be recommended as first-line therapy for climacteric complaints in women with a history of breast cancer. It may, however, be a valid option for selected women with climacteric symptoms refractory to previous non-hormonal treatments. In these cases, an individualized risk-benefit analysis is imperative before treatment initiation, and a treatment duration of less than 5 years with intermittent withdrawal attempts should be aimed for.

Role of androgens, progestins and tibolone in the treatment of menopausal symptoms: a review of the clinical evidence

Estrogen-containing hormone therapy (HT) is the most widely prescribed and well-established treatment for menopausal symptoms. High quality evidence confirms that estrogen effectively treats hot flushes, night sweats and vaginal dryness. Progestins are combined with estrogen to prevent endometrial hyperplasia and are sometimes used alone for hot flushes, but are less effective than estrogen for this purpose. Data are conflicting regarding the role of androgens for improving libido and well-being. The synthetic steroid tibolone is widely used in Europe and Australasia and effectively treats hot flushes and vaginal dryness. Tibolone may improve libido more effectively than estrogen containing HT in some women. We summarize the data from studies addressing the efficacy, benefits, and risks of androgens, progestins and tibolone in the treatment of menopausal symptoms.

Breast cancer and climacteric complaints: Weighing up risks of hormone therapy against quality of life

Women with severe menopausal symptoms can, at their request, be treated effectively with hormone therapy. Good information about the advantages and disadvantages of hormone therapy should precede this decision. For women with breast cancer or an inherited increased risk of breast cancer and severe, often therapy-related climacteric symptoms, a high degree of reticence is appropriate in relation to hormone therapy. If the quality of life is seriously affected in these often-young women with these iatrogenic climacteric complaints, then careful consideration must be given to the various treatment modalities.

Effect of Tibolone on Breast Cancer Cell Proliferation in Postmenopausal ER+ Patients: Results from STEM Trial

PURPOSE

Tibolone is a selective tissue estrogenic activity regulator, approved for the treatment of vasomotor symptoms in postmenopausal women. We have done an exploratory, double-blind, randomized, placebo-controlled pilot trial to investigate the tissue-specific effects of 2.5 mg tibolone on breast cancer in postmenopausal women, in particular on tissue proliferation (STEM, Study of Tibolone Effects on Mamma carcinoma tissue).

EXPERIMENTAL DESIGN

Postmenopausal women with initially stage I/II, estrogen receptor-positive (ER+) primary breast cancer, were randomly assigned to 14 days of placebo or 2.5 mg/d tibolone. Core biopsies of the primary tumor were obtained before and after treatment. Ki-67 and apoptosis index were analyzed in baseline and corresponding posttreatment specimen.

RESULTS

Of 102 enrolled patients, 95 had evaluable data. Baseline characteristics were comparable between both treatment groups. Breast cancer cases are mainly invasive (99%), stage I or II (42% and 50% respectively), and ER+ (99%). Median intratumoral Ki-67 expression at baseline was 13.0% in the tibolone group and 17.8% in the placebo group, and decreased to 12.0% after 14 days of tibolone while increasing to 19.0% in the placebo group. This change from baseline was not significantly different between tibolone and placebo (Wilcoxon test; P=0.17). A significant difference was observed between the treatment groups when the median change from baseline apoptosis index was compared between the treatment groups (tibolone, 0.0%; placebo, +0.3%; Wilcoxon test; P=0.031). The incidence of adverse effects was comparable.

CONCLUSIONS

In ER+ breast tumors, 2.5 mg/d tibolone given for 14 days has no significant effect on tumor cell proliferation.

Is HRT justified for symptom management in women at higher risk of developing breast cancer?

Hormone replacement therapy (HRT) is the most efficacious intervention for the treatment of estrogen-deficiency symptoms. Prescriptions for HRT have fallen over the last 3 years due to anxiety provoked about breast cancer risk and recurrence that has been generated by recent clinical trials. In women at population risk of breast cancer, these trials have not shown risks greater than estimates from clinical trial evidence that predated them. For women at increased breast cancer risk due to a family history or high-risk benign breast conditions, clinical trial data are limited but suggest a lack of an additive effect of HRT on risk. In symptomatic breast cancer survivors, observational data suggest no increase in recurrence but these data are open to bias. Interim analyses of large, randomized trials have shown contradictory outcomes and, as a result, three large HRT randomized trials have now been closed. The randomized LIBERATE trial evaluating tibolone in breast cancer survivors is fully recruited and continuing. The current clinical climate is 'HRT adverse' but, due to a lack of effective alternatives for symptom relief, women at higher breast cancer risk and breast cancer survivors are still requesting information about HRT. In this situation, discussion of the current clinical uncertainty surrounding the use of HRT must be undertaken to ensure that women are adequately informed.

Therapeutic options for the management of hot flashes in breast cancer survivors: An evidence-based review

BACKGROUND

Women with breast cancer may experience treatment-induced menopausal symptoms or natural menopause. Menopausal symptoms, particularly hot flashes, are reported at a high frequency in this group and tend to be more severe, distressing, and of greater duration than in controls. Because of the contribution of sex hormones to breast cancer, the use of hormonal agents for the control of hot flashes is problematic in these women. Safer nonhormonal alternatives are recommended for this patient group.

OBJECTIVES

This was a systematic review of the therapeutic options for the treatment of hot flashes in breast cancer survivors.

METHODS

MEDLINE was searched from 1990 to July 2006 using the disease-specific term breast neoplasms and the subheadings menopause and hot flashes. EMBASE was searched from 1990 to March 2006 using the disease-specific subject headings breast tumor/ breast cancer and menopause and the key word hot flashes. The reference lists of the identified articles and relevant review articles were examined for additional publications. Pertinent articles and abstracts of large randomized controlled trials focusing on the treatment of hot flashes in breast cancer survivors were selected for review. Pilot studies were excluded.

RESULTS

A number of nonpharmacologic approaches are available for the treatment of hot flashes in breast cancer survivors, although they appear to be of limited effectiveness. Complementary alternative medicine therapies and vitamin E have been found to have modest effectiveness at best, and data on their long-term safety are not available. Centrally active agents such as the antidepressants venlafaxine and paroxetine and the anti seizure agent gabapentin have shown clinical effectiveness and appear to be reasonably well tolerated in this population.

CONCLUSIONS

Centrally active agents (eg, venlafaxine, paroxetine, gabapentin) are regarded as the most promising nonhormonal treatments for hot flashes in breast cancer survivors. Nonpharmacologic and complementary alternative medicine therapies have limited effectiveness.

Tibolone and breast cancer

Tibolone is a relatively new drug for postmenopausal women, which is structurally related to 19-nortestosterone derivatives and exhibits weak oestrogenic, progestogenic and androgenic activities. The effect of tibolone on breast tissue is still obscure. In vitro studies have shown conflicting results regarding the effects of tibolone on breast cells. On the other hand, although epidemiological studies show an increase in the risk of breast cancer among women treated with tibolone, accumulation of data obtained from radiological studies presents promising results. However, the safety of tibolone with regard to breast tissue needs to be investigated further, especially through well-designed, large-scale, randomised-controlled trials.

A randomized controlled pilot study of acupuncture for postmenopausal hot flashes: effect on nocturnal hot flashes and sleep quality

OBJECTIVE

To assess the effectiveness of acupuncture on postmenopausal nocturnal hot flashes and sleep.

DESIGN

Prospective randomized placebo-controlled study.

SETTING

Stanford University School of Medicine and private acupuncture offices.

INTERVENTION(S)

Active or placebo acupuncture was administered for nine sessions over seven weeks.

MAIN OUTCOME MEASURE(S)

Severity and frequency of nocturnal hot flashes from daily diaries and Pittsburgh Sleep Quality Index (PSQI).

PATIENT(S)

Twenty-nine postmenopausal women experiencing at least seven moderate to severe hot flashes daily, with E(2) <18 pg/mL and FSH 30.0-110.0 IU/L.

RESULT(S)

Nocturnal hot-flash severity significantly decreased in the active acupuncture group (28%) compared with the placebo group (6%), P=.017. The frequency of nocturnal hot flashes also decreased in the active group (47%, P=.001), though it was not significantly different from the placebo group (24%, P=.170; effect size = 0.65). Treatment did not differentially influence sleep; however, correlations between improvements in PSQI and reductions in nocturnal hot flash severity and frequency were significant (P<.026).

CONCLUSION(S)

Acupuncture significantly reduced the severity of nocturnal hot flashes compared with placebo. Given the strength of correlations between improvements in sleep and reductions in nocturnal hot flashes, further exploration is merited.

Genistein stimulates growth of human breast cancer cells in a novel, postmenopausal animal model, with low plasma estradiol concentrations

We have demonstrated that genistein (GEN) stimulates growth of estrogen-dependent breast tumors in vivo. In this study, we evaluated whether dietary GEN can act in an additive manner with low circulating levels of 17beta-estradiol (E2). We developed an E2 delivery system using silastic implants that yield low circulating plasma E2 levels similar to those observed in postmenopausal women. We inserted various concentrations of E2 silastic implants (1:127, 1:63, 1:31, 1:15 and 1:7 = E2:cholesterol) and injected estrogen-dependent human breast cancer (MCF-7) cells into ovariectomized athymic mice. The E2 implants tested (1:127-1:7) generated 30.1-101.6 pM E2 in plasma, which is comparable to the E2 levels observed in postmenopausal women. The E2 implants stimulated MCF-7 tumor growth in a dose-dependent manner. We selected the 1:31 ratio of E2 implant to evaluate if dietary GEN acts in an additive manner with low E2 levels to influence the growth of MCF-7 tumors. Ovariectomized mice were divided into four groups: MCF-7 control, 500 ppm GEN, 1:31 E2, and 1:31 E2 + 500 ppm GEN. At week 17, the average tumor sizes were 7.6, 32.1, 67.4 and 106.8 mm2 for these groups, respectively (P < 0.05), demonstrating that 500 ppm GEN additively stimulated MCF-7 tumor growth in the presence of low levels of E2. In summary, we established a preclinical mouse model that results in E2 blood concentrations similar to those found in postmenopausal women. Further, we observed that these concentrations regulate the growth rate of MCF-7 breast tumors. Using this model, we demonstrated that dietary GEN in the presence of low levels of circulating E2 act in an additive manner to stimulate estrogen-dependent tumor growth in vivo. Results from this study suggest that consumption of products containing GEN may not be safe for postmenopausal women with estrogen-dependent breast cancer.

The thoughts of physicians regarding the need to start hormone replacement therapy in breast cancer survivors

OBJECTIVES

To investigate how physicians felt about HRT use in breast cancer survivors a half year after the WHI trial.

METHODS

In December 2002, a questionnaire was conducted in Flanders (Belgium). The survey contained a presentation of a 35-year-old breast cancer survivor who presented with climacteric symptoms after treatment with tamoxifen.

RESULTS

With a response rate of 33.65%, a majority of the physicians did not prescribe classical oral HRT (5.40%) in this patient. Physicians prefer to prescribe tibolone (30.68%) or other alternative treatment (50.00%). The main reason was the fear for increased recurrence of breast cancer. Furthermore the WHI oestrogen plus progestin trial and its attention in the media, a half year prior to the survey, influenced one-third of the physician's prescribing attitude.

CONCLUSIONS

Two-thirds of the physicians did not change prescribing attitude after the WHI oestrogen plus progestin trial. HRT is a well proven effective treatment in breast cancer survivors with severe climacteric complaints, but a majority of physicians is not convinced of its safety in breast cancer survivors. Therefore, a majority of physicians do not find the need to prescribe HRT in breast cancer survivors.

Therapy for Menopausal Symptoms During and After Treatment for Breast Cancer

Breast cancer is the most common newly diagnosed cancer in women. Life-time risk in the US is 1 in 8 (13.2%), in the UK it is 1 in 9 and in Australia it affects 1 in 11 women, of whom approximately 27% will be premenopausal at the time of their diagnosis. Many of these women will experience a sudden menopause as a result of chemotherapy, endocrine therapy or surgical interventions. For these women, the onset of menopausal symptoms is often sudden and severe. The management of such symptoms remains controversial. Women experiencing menopausal symptoms after breast cancer should be encouraged to avoid identifiable triggers for their symptoms and to consider lifestyle modification as a means of controlling those symptoms. When such measures fail, non-hormonal treatments may also be considered. These include clonidine, gabapentin and some antidepressants. Randomised trials have shown a significant difference in the symptom relief associated with various selective serotonin reuptake inhibitors and selective serotonin and noradrenaline (norepinephrine) reuptake inhibitors compared with placebo. Many women elect to use non-prescription complementary therapies to alleviate their menopausal symptoms. Systematic reviews of phytoestrogens have, however, failed to demonstrate significant relief of menopausal symptoms. More than 20 clinical trials have been conducted examining the relationship between postmenopausal hormone replacement therapy and breast cancer recurrence. The majority of these have been observational and have shown no increased risk of recurrence. However, the largest randomised trial that has thus far been conducted was recently halted because of a reported increase in the risk of recurrence amongst users of hormone replacement therapy. Tibolone, a selective tissue estrogen activity regulator, is a compound that exerts clinical effects both by receptor-mediated actions and tissue selective enzyme inhibition, and has been shown in preclinical studies to have different effects to estrogen on the breast. Although tibolone may prove safer than estrogen for long-term use in breast cancer survivors, the results of a large randomised trial are awaited to confirm this.The decision on how best to manage menopausal symptoms must thus be made on an individual basis and after thorough discussion and evaluation of the risks and benefits of each potential intervention.

Postmenopausal hormone therapy before and after breast cancer: clinical experiences

Conventional oestrogen-based hormone therapy (HT) increases the incidence of breast pain and tenderness, mammographic density and the risk of breast cancer. Combined oestrogen plus progestogen therapy (EPT) increases the risk of breast cancer to a greater degree than oestrogen alone (ET). Attention must therefore be focused on identifying women at risk of breast cancer or on producing a HT that has fewer breast side effects. Randomised controlled trials have shown that while EPT induces breast tenderness or pain in up to 50% of women and increases mammographic density in up to 70% during the first year of treatment, only about as many as one-tenth women report breast tenderness or pain with tibolone and increases in mammographic density are rare, occurring with a similar incidence as seen in untreated controls. Many women with breast cancer suffer vasomotor symptoms rather than risk recurrence with conventional HT. However, in a small randomised controlled trial in women with early breast cancer undergoing adjuvant tamoxifen treatment, tibolone reduced hot flushes, night sweats and improved quality of life compared with placebo.