Year-by-year analysis of cardiovascular events in the Multiple Outcomes of Raloxifene Evaluation (MORE) trial

Medication Use to Reduce Risk of Breast Cancer: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Breast cancer is the most common nonskin cancer among women in the United States and the second leading cause of cancer death. The median age at diagnosis is 62 years, and an estimated 1 in 8 women will develop breast cancer at some point in their lifetime. African American women are more likely to die of breast cancer compared with women of other races.

OBJECTIVE

To update the 2013 US Preventive Services Task Force (USPSTF) recommendation on medications for risk reduction of primary breast cancer.

EVIDENCE REVIEW

The USPSTF reviewed evidence on the accuracy of risk assessment methods to identify women who could benefit from risk-reducing medications for breast cancer, as well as evidence on the effectiveness, adverse effects, and subgroup variations of these medications. The USPSTF reviewed evidence from randomized trials, observational studies, and diagnostic accuracy studies of risk stratification models in women without preexisting breast cancer or ductal carcinoma in situ.

FINDINGS

The USPSTF found convincing evidence that risk assessment tools can predict the number of cases of breast cancer expected to develop in a population. However, these risk assessment tools perform modestly at best in discriminating between individual women who will or will not develop breast cancer. The USPSTF found convincing evidence that risk-reducing medications (tamoxifen, raloxifene, or aromatase inhibitors) provide at least a moderate benefit in reducing risk for invasive estrogen receptor-positive breast cancer in postmenopausal women at increased risk for breast cancer. The USPSTF found that the benefits of taking tamoxifen, raloxifene, and aromatase inhibitors to reduce risk for breast cancer are no greater than small in women not at increased risk for the disease. The USPSTF found convincing evidence that tamoxifen and raloxifene and adequate evidence that aromatase inhibitors are associated with small to moderate harms. Overall, the USPSTF determined that the net benefit of taking medications to reduce risk of breast cancer is larger in women who have a greater risk for developing breast cancer.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends that clinicians offer to prescribe risk-reducing medications, such as tamoxifen, raloxifene, or aromatase inhibitors, to women who are at increased risk for breast cancer and at low risk for adverse medication effects. (B recommendation) The USPSTF recommends against the routine use of risk-reducing medications, such as tamoxifen, raloxifene, or aromatase inhibitors, in women who are not at increased risk for breast cancer. (D recommendation) This recommendation applies to asymptomatic women 35 years and older, including women with previous benign breast lesions on biopsy (such as atypical ductal or lobular hyperplasia and lobular carcinoma in situ). This recommendation does not apply to women who have a current or previous diagnosis of breast cancer or ductal carcinoma in situ.

Medication Use for the Risk Reduction of Primary Breast Cancer in Women: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Medications to reduce risk of breast cancer are effective for women at increased risk but also cause adverse effects.

OBJECTIVE

To update the 2013 US Preventive Services Task Force systematic review on medications to reduce risk of primary (first diagnosis) invasive breast cancer in women.

DATA SOURCES

Cochrane Central Register of Controlled Trials and Database of Systematic Reviews, EMBASE, and MEDLINE (January 1, 2013, to February 1, 2019); manual review of reference lists.

STUDY SELECTION

Discriminatory accuracy studies of breast cancer risk assessment methods; randomized clinical trials of tamoxifen, raloxifene, and aromatase inhibitors for primary breast cancer prevention; studies of medication adverse effects.

DATA EXTRACTION AND SYNTHESIS

Investigators abstracted data on methods, participant characteristics, eligibility criteria, outcome ascertainment, and follow-up. Results of individual trials were combined by using a profile likelihood random-effects model.

MAIN OUTCOMES AND MEASURES

Probability of breast cancer in individuals (area under the receiver operating characteristic curve [AUC]); incidence of breast cancer, fractures, thromboembolic events, coronary heart disease events, stroke, endometrial cancer, and cataracts; and mortality.

RESULTS

A total of 46 studies (82 articles [>5 million participants]) were included. Eighteen risk assessment methods in 25 studies reported low accuracy in predicting the probability of breast cancer in individuals (AUC, 0.55-0.65). In placebo-controlled trials, tamoxifen (risk ratio [RR], 0.69 [95% CI, 0.59-0.84]; 4 trials [n = 28 421]), raloxifene (RR, 0.44 [95% CI, 0.24-0.80]; 2 trials [n = 17 806]), and the aromatase inhibitors exemestane and anastrozole (RR, 0.45 [95% CI, 0.26-0.70]; 2 trials [n = 8424]) were associated with a lower incidence of invasive breast cancer. Risk for invasive breast cancer was higher for raloxifene than tamoxifen in 1 trial after long-term follow-up (RR, 1.24 [95% CI, 1.05-1.47]; n = 19 747). Raloxifene was associated with lower risk for vertebral fractures (RR, 0.61 [95% CI, 0.53-0.73]; 2 trials [n = 16 929]) and tamoxifen was associated with lower risk for nonvertebral fractures (RR, 0.66 [95% CI, 0.45-0.98]; 1 trial [n = 13 388]) compared with placebo. Tamoxifen and raloxifene were associated with increased thromboembolic events compared with placebo; tamoxifen was associated with more events than raloxifene. Tamoxifen was associated with higher risk of endometrial cancer and cataracts compared with placebo. Symptomatic effects (eg, vasomotor, musculoskeletal) varied by medication.

CONCLUSIONS AND RELEVANCE

Tamoxifen, raloxifene, and aromatase inhibitors were associated with lower risk of primary invasive breast cancer in women but also were associated with adverse effects that differed between medications. Risk stratification methods to identify patients with increased breast cancer risk demonstrated low accuracy.

Neurocognitive, Neuroprotective, and Cardiometabolic Effects of Raloxifene: Potential for Improving Therapeutic Outcomes in Schizophrenia

Raloxifene is a selective estrogen receptor modulator that has been approved for treating osteoporosis and breast cancer in high-risk postmenopausal women. However, recent evidence suggests that raloxifene adjunct therapy improves cognition and reduces symptom severity in men and women with schizophrenia. In animal models, raloxifene increases forebrain neurogenesis and enhances working memory and synaptic plasticity. It may consequently repair the neuronal and synaptic connectivity that is disrupted in schizophrenia. It also reduces oxidative stress and neuroinflammation, which are potent etiological factors in the neuropathology of schizophrenia. Furthermore, in postmenopausal women, raloxifene reduces the risks for atherosclerosis, diabetes mellitus, and weight gain, which are serious adverse effects associated with long-term antipsychotic treatment in schizophrenia; therefore, it may improve the safety and efficacy of antipsychotic drugs. In this review, recent insights into the neurocognitive, neuroprotective, and cardiometabolic effects of raloxifene in relation to therapeutic outcomes in schizophrenia are discussed.

RANKL inhibition with denosumab does not influence 3-year progression of aortic calcification or incidence of adverse cardiovascular events in postmenopausal women with osteoporosis and high cardiovascular risk

Atherosclerosis and osteoporosis are chronic diseases that progress with age, and studies suggest aortic calcification, an indicator of atherosclerosis, is inversely associated with bone mineral density (BMD). The osteoprotegerin (OPG)/receptor activator of NF-κB (RANK)/RANK ligand (RANKL) system has been proposed as a shared regulatory system for bone and vasculature. Denosumab (DMAb), a monoclonal antibody against RANKL, improved BMD and reduced fracture risk in the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial. We evaluated whether or not treatment with DMAb influenced progression of aortic calcification (AC) and incidence of cardiovascular (CV) adverse events. We included 2363 postmenopausal women with osteoporosis (1142 placebo, 1221 DMAb), selected from 7808 participants in the FREEDOM trial (3906 placebo, 3902 DMAb), at high risk of CV events according to modified Raloxifene Use for the Heart (RUTH) criteria. CV adverse events were reported by participants. AC scores were assessed using a semiquantitative method from lateral spine X-rays. Change in AC score from baseline to 12 (n = 1377), 24 (n = 1231), and 36 months (n = 1045) was calculated as AC score at follow-up minus AC score at baseline. AC progression was defined as change in AC score >0. Baseline characteristics, CV risk factors, and AC scores were similar between treatment groups. Mean age of participants was 74 years (range, 60-90), 88% were white, and 77% had AC score >0 at baseline. Frequency of AC progression over 3 years did not differ between women in placebo (22%) and DMAb (22%) groups (p = 0.98). AC progression did not differ between treatment groups when analyzed by baseline estimated glomerular filtration rate or by baseline AC scores. Frequency of CV adverse events did not differ between placebo (40%) and DMAb (38%) groups (p = 0.26). In conclusion, DMAb treatment had no effect on progression of AC or incidence of CV adverse events compared to placebo.

Raloxifene: a selective estrogen-receptor modulator for postmenopausal osteoporosis - a clinical update on efficacy and safety

Selective estrogen-receptor modulators are molecules with specific estrogen-receptor binding affinity. Each selective estrogen-receptor modulator induces a unique conformation in the ligand-receptor complex, which leads to transcriptional activation and/or inhibition. Raloxifene 60 mg/day, a benzothiophene selective estrogen-receptor modulator, is approved for the prevention and treatment of postmenopausal osteoporosis. This article provides an update on new studies and further analyses of clinical trial data for raloxifene. The Multiple Outcomes of Raloxifene Evaluation (MORE) trial of women with osteoporosis has described the efficacy of raloxifene in decreasing vertebral fracture risk over 4 years. The Continuing Outcomes Relevant to Evista((R)) (CORE) trial, designed to assess the effects of raloxifene on breast cancer prevention, is a 4-year continuation of MORE. The skeletal and cardiovascular effects of raloxifene in the CORE study were similar to those observed in MORE. The relative risk of developing breast cancer was significantly decreased in women treated with raloxifene, compared with placebo, after 4 years in MORE and 8 years in the CORE trial. The incidence of uterine bleeding, endometrial hyperplasia and endometrial cancer was similar between raloxifene and placebo after 8 years of treatment. Raloxifene use is associated with a higher incidence of hot flashes and leg cramps, and an increased risk of venous thromboembolic events.

Effect of OS-0544, a selective estrogen receptor modulator, on endothelial function and increased sympathetic activity in ovariectomized rats

Estrogens are known to contribute to endothelial function and sympathetic activity, both of which are strongly associated with the pathogenesis of ischemic heart disease. In addition, estrogens improve impaired lipid profile, a risk factor of endothelial dysfunction. In this study, we investigated the effects of OS-0544, a structurally new selective estrogen receptor modulator (SERM), on endothelial function, sympathetic activity, and plasma cholesterol level in ovariectomized (OVX) rats. Female Sprague-Dawley rats were ovariectomized and orally treated with OS-0544 (or OS-0689, the (R)-enantiomer of OS-0544), or 17beta-estradiol (E2) for 4 weeks, starting the next days after ovariectomy or for 1 week, starting 6 weeks after ovariectomy. Ovariectomy significantly increased vasopressin-induced mean blood pressure (AVP-MBP) (57+/-3.3 mm Hg vs. 46+/-3.5 mm Hg, P<0.05) and decreased acetylcholine (Ach)-induced maximum vasorelaxation response (69+/-5.6% vs. 81+/-4.0%, P<0.05). OS-0544 significantly inhibited AVP-MBP elevation (46+/-3.5 mm Hg vs. 57+/-3.3 mm Hg, P<0.05) and decreased Ach-induced maximum vasorelaxation response (90+/-3.3% vs. 69+/-5.6%, P<0.05) in OVX rats. In addition, OS-0689 as well as E2 significantly reduced (up to 67%) the increase in sympathetic activity in OVX rats. Moreover, like E2, OS-0544 significantly decreased plasma cholesterol level in OVX rats. These results demonstrate that OS-0544 has vascular protective effect on vascular function after ovariectomy. It is therefore believed that OS-0544 has vascular protective effect in postmenopausal woman.

Selective estrogen receptor modulators: an update on recent clinical findings

Recent clinical data on selective estrogen receptor modulators (SERMs) have provided the basis for reassessment of the SERM concept. The molecular basis of SERM activity involves binding of the ligand SERM to the estrogen receptor (ER), causing conformational changes which facilitate interactions with coactivator or corepressor proteins, and subsequently initiate or suppress transcription of target genes. SERM activity is intrinsic to each ER ligand, which accomplishes its unique profile by specific interactions in the target cell, leading to tissue selective actions. We discuss the estrogenic and anti-estrogenic effects of early SERMs, such as clomiphene citrate, used for treatment of ovulation induction, and the triphenylethylene, tamoxifen, which has ER antagonist activity in the breast, and is used for prevention and treatment of ER-positive breast cancer. Since the development of tamoxifen, other triphenylethylene SERMs have been studied for breast cancer prevention, including droloxifene, idoxifene, toremifene, and ospemifene. Other SERMs have entered clinical development more recently, including benzothiophenes (raloxifene and arzoxifene), benzopyrans (ormeloxifene, levormeloxifene, and EM-800), lasofoxifene, pipendoxifene, bazedoxifene, HMR-3339, and fulvestrant, an anti-estrogen which is approved for breast cancer treatment. SERMs have effects on tissues containing ER, such as the breast, bone, uterine and genitourinary tissues, and brain, and on markers of cardiovascular risk. Current evidence indicates that each SERM has a unique array of clinical activities. Differences in the patterns of action of SERMs suggest that each clinical end point must be evaluated individually, and conclusions about any particular SERM can only be established through appropriate clinical trials.

Carotid artery intima-media thickness after raloxifene treatment

BACKGROUND

Raloxifene, a selective estrogen receptor modulator (SERM), decreases total and low-density lipoprotein cholesterol (LDL-C) in postmenopausal women and inhibits increases in intima-media thickness (IMT) in animal models. We tested whether up to 8 years exposure to raloxifene had an effect on subclinical atherosclerosis in the 4-year Multiple Outcomes of Raloxifene Evaluation (MORE) trial and the follow-up study, the 4-year Continuing Outcomes Relevant to Evista (CORE) trial.

METHODS

A subsample of postmenopausal women with osteoporosis, who had completed the MORE and CORE trials and were on average 68 years of age and 19 years postmenopausal at randomization into MORE, participated in this substudy. Within 6 months of cessation of study drug in CORE, right common carotid artery IMT (CIMT) and carotid artery stiffness and arterial compliance were measured at one of two sites (San Diego and San Francisco) using high-resolution B-mode ultrasound. CIMT and arterial stiffness measures were compared between women who had received raloxifene vs. placebo; the primary analysis included only women who were >or=80% drug compliant and had used <or=6 months of lipid-lowering medication during CORE.

RESULTS

For the primary analysis dataset (n = 89), there was no significant difference in mean CIMT between the raloxifene and placebo groups (0.83 and 0.81 mm, respectively, p = 0.62). Carotid artery stiffness and compliance were not significantly different between treatment groups (p = 0.33 and 0.59, respectively).

CONCLUSIONS

These preliminary data suggest that in this self-selected group of elderly post-menopausal women with osteoporosis who were evaluated within 6 months of cessation of study medication, there were no differences between long-term raloxifene treatment and placebo groups in several measures of subclinical atherosclerosis.

Selective Agonists of Estrogen Receptor Isoforms

The cloning of estrogen receptors (ERs) and generation of ER-deficient mice have increased our understanding of the molecular mechanisms underlying the cardiovascular effects of estrogen. It is conceivable that clinical trials of estrogens so far failed to improve cardiovascular health because of the poor ER isoform selectivity and tissue specificity of endogenous hormones as well as incorrect treatment timing and regimens. Tissue-selective ER modulators (SERMs) may be safer agents than endogenous estrogens for cardiovascular disease. Yet, designing isoform-selective ER ligands (I-SERMs) with agonist or antagonist activity is required to pursue improved pharmacological control of ERs, especially taking into account emerging evidence for the beneficial role of vascular ER alpha activation. Ideally, the quest for unique ER ligands targeted to the vascular wall should lead to compounds that merge the pharmacological profiles of SERM and I-SERM agents. This review highlights the current bases for and approaches to selective ER modulation in the cardiovascular system.

Cellular mechanisms underlying the cardiovascular actions of oestrogens

Although pre-menopausal women enjoy relative cardiovascular protection, hormone (oestrogen±progestin)-replacement therapy has not shown cardiovascular benefits in post-menopausal women, suggesting that the effects of oestrogens on the cardiovascular system are much more complex than previously expected. Endothelial cells, smooth muscle cells, cardiac myocytes and fibroblasts, the cellular components of blood vessels and the heart, play important roles in cardiovascular health and disease. During the development and progression of cardiovascular disease, changes occur both in the structure and function of these cells, resulting in a wide range of abnormalities, which affect growth, death and physiological function. These cells contain functional oestrogen receptors and are targets for oestrogen action. This review focuses on recent studies on the effects of oestrogen on cardiovascular cell function. Oestrogens, particularly 17β-oestradiol, exert multiple effects on cardiovascular cells, and these effects may contribute to the gender-associated protection against cardiovascular diseases.

Harnessing Hormonal Signaling for Cardioprotection

Cardiovascular disease is the leading cause of death in women in the Western world and is predominant among the elderly. A large body of evidence suggests that hormonal signaling plays a critical role in the regulation of cardioprotective mechanisms, as premenopausal women are at significantly lower risk of heart disease compared with men, but the risk greatly increases with the onset of menopause. This association indicates that estrogen may protect the heart from cardiovascular disease. Whereas a number of analyses of the effects of hormone replacement therapy (HRT) on postmenopausal women supported the idea that estrogen is a cardioprotective factor, the findings of the more recent Women's Health Initiative (WHI) study suggested that HRT may actually increase the risk of cardiovascular events. These conflicting reports have left both patients and clinicians reluctant to continue using current HRT regimes. The WHI findings do not, however, negate the epidemiological link between menopause and increased cardiovascular risk. Hence, the identification of the specific actions of estrogen that promote cardioprotective pathways without enhancing deleterious vascular mechanisms may provide novel estrogen-based alternatives to current HRT strategies. In this Review, we outline the known actions of estrogen on the cardiovascular system, focusing on cardioprotective mechanisms that may be targeted for the development of new therapeutic approaches.