Conventional-dose hormone therapy (HT) and tibolone, but not low-dose HT and raloxifene, increase markers of activated coagulation

OBJECTIVES

Hormone therapy (HT) is associated with a modest, but significantly increased risk for arterial and venous thromboembolism. We have compared the effects of estrogen, tibolone, and raloxifene on relevant markers of coagulation activation and investigated whether there is a dose-response relationship of oral HT.

METHODS

Randomized, open-label, comparative study of 202 healthy women who were assigned to receive treatment for 12 weeks with either low-dose hormone therapy containing 1 mg 17beta-estradiol + 0.5 mg norethisterone acetate (NETA) (n=50), conventional-dose HT containing 2 mg 17beta-estradiol and 1 mg NETA (n=50), 2.5 mg tibolone (n=51), or 60 mg raloxifene (n=51).

RESULTS

The groups were comparable with regard to demographic characteristics and laboratory variables at baseline. D-dimer increased markedly in the conventional-dose HT group, but remained unchanged in the low-dose HT group. Tibolone was associated with a medium increase, whereas raloxifene was associated with a decrease in D-dimer levels. Changes in prothrombin fragment 1 + 2 showed a similar pattern for all four groups, whereas no significant differences in changes of thrombin-antithrombin complex were observed.

CONCLUSIONS

Our data suggest that low-dose HT is associated with less activation of coagulation than conventional-dose HT. This finding may be of clinical importance since randomized clinical trials showing increased risk of thrombosis have utilized conventional-dose HT.

Postmenopausal advanced breast cancer: Options for therapy after tamoxifen and aromatase inhibitors

All patients receiving endocrine treatment for advanced breast cancer (ABC) eventually progress, resulting in a need for new therapies that lack cross-resistance with existing agents. Oestrogen receptor (ER) modulators such as toremifene and raloxifene have poor efficacy following tamoxifen failure, whereas the non-steroidal aromatase inhibitors (AIs), anastrozole and letrozole and the steroidal AI exemestane are effective. Fulvestrant is a new ER antagonist with no agonist effects that is as effective as anastrozole in treating patients who have progressed on tamoxifen. AIs are replacing tamoxifen as first-line treatments for ABC and in the adjuvant setting, necessitating a re-evaluation of optimal sequencing. Preliminary data suggest that tamoxifen, exemestane and fulvestrant have activity in patients who have progressed on non-steroidal AIs and hence could be considered for use in this setting. Due to the apparent lack of cross-resistance between non-steroidal and steroidal AIs, non-steroidal AIs could also be effective following steroidal AI failure. Clinical trials are underway to assess the most appropriate treatment sequence following non-steroidal AI failure, with comparisons of fulvestrant and exemestane of major interest.

Effect of Raloxifene on the Incidence of Invasive Breast Cancer in Postmenopausal Women with Osteoporosis Categorized by Breast Cancer Risk

PURPOSE

To assess the effect of raloxifene, indicated for osteoporosis treatment and prevention, on invasive breast cancer in subgroups of postmenopausal women defined by risk factors for breast cancer.

EXPERIMENTAL DESIGN

Data from the 4-year Multiple Outcomes of Raloxifene Evaluation (MORE) trial (N=7,705) and a follow-up study, the 4-year Continuing Outcomes Relevant to Evista (CORE) trial (N=4,011), were analyzed. Prespecified subgroups were defined by age (>or=65 versus<65 years), age at menopause (>or=49 versus<49 years), body mass index (>or=25 versus<25 kg/m2), family history of breast cancer (yes/no), serum estradiol level (5-10 versus<5, >10 versus<5 pmol/L), prior estrogen therapy (yes/no), and bone mass at MORE baseline, and 5-year predicted risk, assessed using the modified Gail model (>or=1.67 versus<1.67%), at CORE baseline. Time-to-first invasive breast cancer was analyzed using Cox proportional hazards models.

RESULTS

In the placebo group, older age, higher estradiol level, and a family history of breast cancer were associated with an increased breast cancer risk (P<0.05). Raloxifene therapy was associated with a reduced breast cancer risk in both women at lower and those at higher breast cancer risk. Hazard ratio point estimates were 0.11 to 0.67, corresponding to a 33% to 89% reduction in breast cancer risk with raloxifene versus placebo. The therapy by family history interaction was significant (P=0.04).

CONCLUSIONS

Raloxifene therapy was associated with a reduced risk of invasive breast cancer in postmenopausal women irrespective of the presence/absence of risk factors; its effect was greater in women with a family history of breast cancer.

A Canadian observational study of the optimal method of transition from postmenopausal hormone therapy to raloxifene

OBJECTIVE

To determine the optimal method of transition from postmenopausal hormone therapy (HT) to raloxifene (RLX) therapy in order to minimize hot flashes and night sweats.

METHODS

Postmenopausal women in Canada who had discontinued HT (estrogen with or without progestogen) in the preceding nine months and who were starting RLX were followed for approximately nine months in this observational study. The method of transition from HT to RLX therapy (method and duration of tapering HT, duration of washout) and the frequency and severity of hot flashes during the transition and RLX treatment periods were recorded.

RESULTS

There were 373 women who participated in this study. Most women (86.3%) had a washout period between HT and RLX, and 55.2% had tapered their HT in some fashion. After beginning RLX, women who had had a washout duration of more than one week were found to be more likely to have an improvement in the severity of hot flashes (odds ratio [OR] = 6.3), and in the frequency of hot flashes (OR = 4.6), than women with a shorter washout or no washout period at all. The method of tapering of HT did not seem to affect either the severity or the frequency of hot flashes once on RLX. Women who had undergone a tapering period of more than one week's duration were more likely (OR = 2.6) to experience an improvement in the frequency (but not the severity) of hot flashes on RLX.

CONCLUSION

Women who had a washout period following HT had better amelioration of hot flashes on RLX therapy.

Development and therapeutic options for the treatment of raloxifene-stimulated breast cancer in athymic mice

PURPOSE

Selective estrogen receptor modulators (SERM) are used for the treatment and prevention of breast cancer (tamoxifen) and osteoporosis (raloxifene). Mechanisms of tamoxifen-resistance in breast cancer are incompletely understood but current research is focused on crosstalk between growth factor receptors and the estrogen receptor alpha (ERalpha) pathway. There is increasing clinical use of raloxifene for the treatment of osteoporosis, but the widespread use of this SERM will have consequences for the treatment of breast cancer in raloxifene-exposed women.

EXPERIMENTAL DESIGN

We took the strategic step of developing a raloxifene-resistant tumor (MCF-7RALT) model in vivo and investigating the mechanisms responsible for resistance.

RESULTS

MCF-7RALT tumors exhibited phase I SERM resistance, growing in response to SERMs and 17beta-estradiol. Epidermal growth factor receptor/HER1 and HER2/neu mRNAs were increased in MCF-7RALT tumors. The HER2/neu blocker, trastuzumab, but not the epidermal growth factor receptor blocker, gefitinib, decreased the growth of MCF-7RALT tumors in vivo. Consequently, trastuzumab decreased prosurvival/proliferative proteins: phospho-HER2/neu, total HER2/neu, phospho-Akt (protein kinase B), glycogen synthetase kinase-3, cyclin D1, and the antiapoptotic protein X chromosome-linked inhibitor of apoptosis, whereas increasing the proapoptotic protein, caspase-7, in raloxifene-treated MCF-7RALT tumors. Interestingly, ERalpha protein was overexpressed in untreated MCF-7RALT tumors and hyperactivated in cells derived from these tumors. Only fulvestrant completely inhibited the growth and ERalpha activity of MCF-7RALT tumors. The coactivator of ERalpha, amplified in breast cancer-1 protein was modestly increased in the raloxifene-treated MCF-7RALT tumors and increased both basal and estradiol-induced activity of ERalpha in cells derived from the MCF-7RALT tumors.

CONCLUSIONS

These results suggest that overexpression and increased activity of HER2/neu might be responsible for the development of raloxifene-resistant breast cancer. The results also suggest that increased expression of basal activity of ERalpha could contribute to the hypersensitivity of MCF-7RALT tumors in response to estradiol because only fulvestrant blocked growth and ERalpha activity.

Lasofoxifene enhances vaginal mucus formation without causing hypertrophy and increases estrogen receptor β and androgen receptor in rats

OBJECTIVE

Lasofoxifene, a new selective estrogen-receptor modulator (SERM), shows efficacy in vaginal and vulvar atrophy in postmenopausal women. Here, we sought to explore the possible mechanisms of action for this effect in comparison with other SERMs using an immature ovariectomized rat model.

DESIGN

SERMs (lasofoxifene, raloxifene, and tamoxifen) and 17alpha-ethinyl estradiol were administered orally to immature ovariectomized rats daily for 1 or 4 days. Vaginal and uterine tissues were weighed and processed for histomorphometric measurements, vaginal mucopolysaccharide staining, and immunohistochemistry of 5-bromo-2'-deoxyuridine and steroid receptors. Receptor quantification was determined by a novel ultrasensitive enzyme-linked immunosorbent assay method.

RESULTS

Lasofoxifene and raloxifene showed a minimal increase in vaginal and uterine weight, epithelial cell proliferation, and epithelial thickness in comparison with estradiol and tamoxifen. Lasofoxifene significantly enhanced vaginal mucus formation in a dose-dependent manner. Vaginal progesterone receptor protein was increased fivefold by estradiol and all three SERMs tested. 17alpha-Ethinyl estradiol caused a significant decrease in estrogen receptor alpha, but no change with other treatments. Only lasofoxifene significantly increased vaginal estrogen receptor beta and androgen receptor protein levels.

CONCLUSIONS

These results demonstrated that lasofoxifene stimulated vaginal mucus formation without causing cell proliferation in the rat reproductive tract. These effects may be due to the increased vaginal estrogen receptor beta and androgen receptor levels. This cellular and molecular profile of lasofoxifene in the vagina may account for its efficacy in the treatment of vaginal and vulvar atrophy in postmenopausal women.

Model-based drug development: the road to quantitative pharmacology

High development costs and low success rates in bringing new medicines to the market demand more efficient and effective approaches. Identified by the FDA as a valuable prognostic tool for fulfilling such a demand, model-based drug development is a mathematical and statistical approach that constructs, validates, and utilizes disease models, drug exposure-response models, and pharmacometric models to facilitate drug development. Quantitative pharmacology is a discipline that learns and confirms the key characteristics of new molecular entities in a quantitative manner, with goal of providing explicit, reproducible, and predictive evidence for optimizing drug development plans and enabling critical decision making. Model-based drug development serves as an integral part of quantitative pharmacology. This work reviews the general concept, basic elements, and evolving role of model-based drug development in quantitative pharmacology. Two case studies are presented to illustrate how the model-based drug development approach can facilitate knowledge management and decision making during drug development. The case studies also highlight the organizational learning that comes through implementation of quantitative pharmacology as a discipline. Finally, the prospects of quantitative pharmacology as an emerging discipline are discussed. Advances in this discipline will require continued collaboration between academia, industry and regulatory agencies.

Adherence and Persistence Associated with the Pharmacologic Treatment of Osteoporosis in a Managed Care Setting

BACKGROUND

The effectiveness of chronic therapies can be compromised by poor adherence and persistence.

MATERIALS AND METHODS

Investigators identified a continuously benefit-eligible cohort of women from a large, geographically diverse, national managed care plan who were newly diagnosed and treated for osteoporosis with alendronate, risedronate, or raloxifene. Drug utilization parameters were evaluated over a 12-month follow-up period for the study population. Adherence was assessed using a medication possession ratio calculated as total days of therapy for medication dispensed/365 days of study follow-up. Persistence was defined as continuous therapy on the same drug for each month over the entire study period. Adherence and persistence were also evaluated for all three study agents in women > or = 65 years of age.

RESULTS

In the study cohort (N = 10,566), 12-month adherence/ persistence rates were alendronate 61%/21%, risedronate 58%/19%, and raloxifene 54%/16%. Rates in women > or = 65 years were similar to those in the entire study cohort. Weekly bisphosphonate users had slightly higher 12-month adherence (63% versus 54%, P < 0.05) and persistence (22% versus 19%, P = NS) rates than did daily users, independent of agent.

CONCLUSION

Chronic oral-dosed osteoporosis therapies are associated with poor adherence and persistence, regardless of age or dosing regimen. Drug therapies and patient management approaches associated with improved adherence and persistence could improve the likelihood of achieving the therapeutic benefits observed in rigorously controlled clinical trials.

Raloxifene attenuation of methotrexate cytotoxicity in human bone marrow by sequence-dependent administration of raloxifene, 5-FU/methotrexate

BACKGROUND

Increasing evidence suggests that adjuvant systemic chemotherapy is necessary for the survival of breast cancer patients. Antitumor agents are more effective when used in combination with drugs exhibiting different mechanisms of action than when used alone. Previous studies from this laboratory have shown that raloxifene (RAL) attenuation of 5-fluorouracil/methotrexate (5-FU/MTX) cytotoxicity to breast cancer cells was sequence-dependent. The aim was to evaluate the same combination of RAL, 5-FU and MTX to determine the most effective regimes and cellular mechanisms of action to mitigate MTX cytotoxicity in human bone marrow cells.

MATERIALS AND METHODS

The sequence-dependent interaction among MTX, 5-FU and RAL on the proliferation and viability of human bone marrow HS-5 cells was determined by the MTT assay and the Trypan blue dye exclusion assay by exposing the cells to MTX, 5-FU and RAL alone, RAL 24 h prior to 5-FU followed 2 h later by MTX, and 5-FU 2 h prior to MTX followed 24 h later by RAL. The control cells were untreated.

RESULTS

The growth rate in MCF-7 in early RAL was 68 +/- 3.07% and late RAL 37 +/- 2.05% of the control rate, whereas in bone marrow the same drug combinations exhibit a significant protection against MTX cytotoxity, with the early RAL combination yielding 81 +/- 3.77% and late 54 +/- 2.74% of the control. The finding was further supported by cell flow cytometry and Western blot analysis.

CONCLUSION

Sequence-dependent administration of RAL in combination with 5-FU/MTX may have maximum antineoplastic activity in breast cancer while at the same time provide protection to human bone marrow.

Prevention of bone loss in postmenopausal women treated with lasofoxifene compared with raloxifene

OBJECTIVE

Osteoporosis is a significant health problem in postmenopausal women. Consequently, new and effective therapies are being sought to preserve bone mass and prevent osteoporosis in this population of women. The objective of this study was to compare the effects of lasofoxifene with raloxifene and placebo on indices of bone health in postmenopausal women.

DESIGN

A randomized, double-blind, placebo- and active treatment-controlled study of 2 years duration was conducted. Women included 410 postmenopausal women aged 47 to 74 years. The four treatment groups were: lasofoxifene 0.25 mg/day, or 1.0 mg/day, raloxifene 60 mg/day, or placebo daily. All women received daily calcium and vitamin D supplements. The primary endpoint was percent change from baseline to 2 years in lumbar spine bone mineral density (BMD) in all women having baseline and at least one follow-up bone density measurement. Total hip BMD, biochemical markers of bone turnover, low-density lipoprotein cholesterol, and safety were also evaluated in all women.

RESULTS

Both doses of lasofoxifene significantly increased lumbar spine BMD compared with raloxifene (P < or = 0.05) and with placebo treatment (P < or = 0.05). Least squares mean increases (95% CI) from baseline in lumbar spine BMD, compared with placebo, were 3.6% (1.9, 5.2) for lasofoxifene 0.25 mg/day, 3.9% (2.4, 5.5) for lasofoxifene 1.0 mg/day, and 1.7% (0.3, 3.0) for raloxifene. The two doses of lasofoxifene and raloxifene were equally effective at increasing total hip BMD. Lasofoxifene and raloxifene significantly reduced the levels of biochemical markers of bone turnover compared with placebo. In general, the effects of lasofoxifene were greater than the responses to raloxifene. At 2 years, lasofoxifene significantly (P < or = 0.05) reduced low-density lipoprotein cholesterol levels by 20.6% and 19.7% with 0.25 mg/day and 1 mg/day, respectively, compared with raloxifene (12.1%) and placebo (3.2%). Lasofoxifene and raloxifene had a similar adverse event profile with low rate of discontinuations due to adverse events.

CONCLUSIONS

Lasofoxifene may be an effective and well-tolerated treatment option for the prevention of bone loss in postmenopausal women.

Raloxifene attenuation of 5-FU/methotrexate cytotoxicity in human breast cancer cells: the importance of sequence in combination chemotherapy

BACKGROUND

The selective estrogen receptor modulator raloxifene (RAL), used to treat and prevent osteoporosis, is under investigation for its use in the treatment and prevention of breast cancer. RAL in combination with the antimetabolites methotrexate (MTX) and 5-fluorouracil (5-FU) has not been extensively studied. Because RAL and the antimetabolites target different phases of the cell cycle and exhibit different mechanisms of action and clinical toxicity, the effects of sequence of administration on the growth inhibition of MCF-7 human breast cancer cells were investigated.

MATERIALS AND METHODS

MCF-7 human breast cancer cells were exposed to vehicle alone, 10 microM MTX, 1 microM 5-FU, 10 microM RAL, 10 microM RAL 24 hours prior to 1 microM 5-FU followed 2 hours later by 10 microM MTX, and 1 microM 5-FU 2 hours prior to 10 microM MTX followed 24 hours later by 10 microM RAL. The cells were evaluated for viability and proliferation. The retinoblastoma (Rb) protein, a cell cycle regulator which when phosphorylated allows the progression of cells from G1- to S-phase, was used as a marker to determine the effects of early RAL and late RAL on cellular progression at the molecular level.

RESULTS

Early RAL administration exhibited a cell viability of 66.83 +/- 6.17% of the control. However, late RAL administration exhibited cell viability 39.40 +/- 17.03% of the control. Late RAL was a more cytotoxic combination than RAL alone or early RAL. These findings from manual cell counting were also supported by cell flow cytometric analysis and Western blot data.

CONCLUSION

Late RAL in combination with 5-FU and MTX, due to greater cytotoxicity, is a more desirable combination to treat breast cancer than RAL alone.

Administration of raloxifene reduces sensorimotor and working memory deficits following traumatic brain injury

Hormonal differences between males and females have surfaced as a crucial component in the search for effective treatments after experimental models of traumatic brain injury (TBI). Recent findings have shown that selective estrogen receptor modulators (SERMs) may have therapeutic benefit. The present study examined the effects of raloxifene, a SERM, on functional recovery after bilateral cortical contusion injury (bCCI) or sham procedure. Male rats received injections of raloxifene (3.0mg/kg, i.p.) or vehicle (1.0 ml/kg, i.p.) 15 min, 24, 48, 72, and 96 h after bCCI or sham procedure. Rats were tested on both sensorimotor (bilateral tactile removal and locomotor placing tests) and cognitive tests (reference and working memory in the Morris water maze). Raloxifene-treated animals showed a significant reduction in the initial magnitude of the deficit and facilitated the rate of recovery for the bilateral tactile removal test, compared to vehicle-treated animals. The raloxifene-treated animals also showed a significant improvement in the acquisition of working memory compared to vehicle-treated animals. However, raloxifene did not significantly improve the acquisition of reference memory or locomotor placing ability. Raloxifene treatment also did not result in a significant reduction in the size of the lesion cavity. Thus, the task-dependent improvements seen following raloxifene treatment do not appear to be the result of cortical neuroprotection. However, these results suggest that raloxifene improves functional outcome following bCCI and may present an interesting avenue for future research.

A 5-year study on the effect of hormone therapy, tibolone and raloxifene on vaginal bleeding and endometrial thickness

OBJECTIVES

To study the effect of standard and low-dose estrogen-progestin therapy (EPT), tibolone and raloxifene on the incidence of vaginal spotting/bleeding and endometrial thickness over a 5-year period.

METHODS

Seven hundred eighty-six postmenopausal women were studied in an open prospective design. Vaginal spotting/bleeding and endometrial thickness as assessed by transvaginal ultrasonography was compared between six categories of women over a 5-year period: three categories in women on continuous combined estrogen-progestin therapy, one category under tibolone, one category under raloxifene and one under no treatment. More specifically, women received tibolone 2.5 mg (N = 204), raloxifene HCl 60 mg (N = 137), conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5mg (N = 122), 17beta-estradiol 2mg/norethisterone acetate 1mg (N = 58), 17beta-estradiol 1mg/norethisterone acetate 0.5mg (N = 76) or no therapy (controls, N = 189). Women with suspected endometrial pathology were referred for hysteroscopy.

RESULTS

Bleeding/spotting incidence was highest among standard dose EPT users (conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5mg: 40.1%, 17beta-estradiol 2mg/norethisterone acetate 1mg: 44.8%, p < 0.001 compared to controls). Low-dose EPT associated with lower incidence of spotting/bleeding (34.1%). The incidence under tibolone and raloxifene was 22.5% and 2.9%, respectively, while 3.2% of women not receiving therapy reported vaginal spotting/bleeding. Mean endometrial thickness was not significantly affected in any of the groups studied. The drop-out rate due to spotting/bleeding was higher in the two higher dose EPT regimens. After logistic regression analysis, age at baseline was the only significant predictor of subsequent spotting/bleeding (b = -0.25, S.E. = 0.09, p = 0.006), while menopausal age and pre-treatment serum FSH had marginal significance.

CONCLUSIONS

EPT, tibolone and raloxifene do not appear to associate with significant changes in endometrial thickness in the majority of cases. The low-dose EPT regimen associated with a decreased incidence of unscheduled spotting/bleeding compared to the standard dose regimens. Tibolone expressed a favorable endometrial profile, as seen in its effect on unscheduled spotting/bleeding and mean endometrial thickness. Raloxifene associated with the lowest incidence in S/B and the lowest drop-out rate.s.

The effect of raloxifene after discontinuation of long-term alendronate treatment of postmenopausal osteoporosis

OBJECTIVE

The aim of this study was to compare bone mineral density (BMD) and biochemical markers of bone turnover in patients receiving long-term alendronate therapy who continued alendronate, were switched to raloxifene, or discontinued antiresorptive therapy.

DESIGN, PATIENTS, AND INTERVENTIONS

Ninety-nine ambulatory women who were diagnosed with postmenopausal osteoporosis and treated with alendronate (10 mg/d) for a mean period of 43 months were randomized to double-blind raloxifene (60 mg/d; n = 33), placebo (n = 33), or continuation of open-label alendronate (n = 33) for 12 months. Patients continued their assigned treatment in a subsequent 12-month, open-label extension phase. All patients received supplemental calcium (500 mg/d) and vitamin D (800 IU/d).

MAIN OUTCOME MEASURES

BMD (lumbar spine, total femur, femoral neck, distal forearm, and total body) and biochemical markers (serum intact amino-terminal propeptide of type I procollagen, type 1 collagen cross-linked C-telopeptide, and osteocalcin) were measured at baseline and follow-up visits.

RESULTS

Discontinuation of alendronate therapy resulted in a decrease in lumbar spine BMD at 12 months (-2.66%; P < 0.05), but did not change total femur BMD (+0.35%; nonsignificant). Raloxifene and alendronate, compared with discontinuation, prevented lumbar spine BMD loss (-0.75% and -0.54% at 12 months, respectively; P < 0.05). Raloxifene and alendronate caused a similar increase in total femur BMD at 12 months (1.45% and 1.56%; both P < 0.05 vs. baseline; nonsignificant vs. discontinuation). Patients, who discontinued alendronate therapy experienced an increase in bone turnover. Bone turnover increases were less pronounced in patients taking raloxifene and were absent in those who continued alendronate. Of the three groups, mean bone turnover in raloxifene patients was the closest to premenopausal mean values.

CONCLUSIONS

BMD preservation and increase were most pronounced in patients continuing alendronate. Raloxifene treatment, compared with placebo, demonstrated beneficial effects on BMD and bone turnover after discontinuation of long-term alendronate therapy.

Endocrine therapy for early breast cancer

Breast cancer is a significant cause of morbidity and mortality. Adjuvant tamoxifen therapy for estrogen receptor-positive early breast cancer has had a major impact on mortality in clinical trials, and the observation that breast cancer mortality started to decline shortly after widespread tamoxifen prescription was introduced in several countries inevitably leads us to conclude that this intervention is responsible. Aromatase inhibitor therapy will undoubtedly become part of everyday practice in the future, although the optimization of aromatase inhibitor therapy as part of the overall endocrine package needs further definition. However, to suppose that a unified optimal sequence and duration is applicable to all patients is probably a fallacy, and underlying the overall effects of different treatments are individual patients with individual but potentially classifiable tumors requiring different management strategies. Characterization and individualization of therapies based on gene and proteomic expression profiling is a massive research undertaking, but could guide us towards a fairly simple set of key gene or protein expression profiles to guide adjuvant hormonal, chemotherapeutic or new biologic agent strategies that will define optimal treatment packages for women with early breast cancer. Within the next 5 years, the clinical reservations regarding adjuvant aromatase inhibitors and financial obstacles to access the aromatase inhibitors are likely to be overcome and, unless we are able to identify a cohort of women who will gain no additional benefit or who have a better outcome with tamoxifen, most postmenopausal women will be treated with aromatase inhibitor monotherapy or a sequential combination utilizing an aromatase inhibitor.

[Raloxifene in postmenopausal women]

Since the diffusion of the WHI's trial and MWS results, which reported a negative risk/benefit balance of hormone therapy, the management of postmenopausal women has deeply changed over the last 2-3 years. In particular, for the prevention of osteoporosis, the use of other efficient agents tends now to be more widely recommended rather than estrogens. The SERMs with raloxifene are new molecules that have estrogen agonist effects on bone and estrogen antagonist or neutral effects on endometrial and breast tissue. The efficacy of raloxifene to inhibit postmenopausal bone loss as well as to reduce the incidence of vertebral fractures has been demonstrated in women at high risk for osteoporosis through a large randomized placebo-controlled trial involving several thousands of postmenopausal women (MORE trial). Furthermore, the extraskeletal effects of raloxifene might represent an advantage for a global management approach of postmenopausal women, although to date, its exclusive indication is namely the prevention of osteoporosis. However, the estrogen antagonist effects of raloxifene on breast tissue as well as its good safety profile with regard to both the endometrium and the risk of heart diseases are likely to make raloxifene of particular interest for women around the age of 60 years old. Adverse events associated with raloxifene only included an increase in the absolute risk of venous thromboembolism in a comparable manner as with estrogen therapy. Also, its lack of efficacy in reducing hot flushes or preventing vaginal dryness may limit its use in young symptomatic postmenopausal women. Also, its lack of reimbursement in women with no prior fragility fracture must be taken into account.

Effects of estrogen, raloxifene, and hormone replacement therapy on serum C-reactive protein and homocysteine levels

OBJECTIVES

To investigate the effects of conjugated equine estrogen (CEE), CEE plus medroxyprogesterone acetate (MPA), CEE plus Nomegestrol acetate (NA), and raloxifene on serum high sensitivity C-reactive protein (hs-CRP) and homocysteine (Hcy) levels in healthy postmenopausal women.

MATERIALS

One hundred seven healthy postmenopausal women were recruited in a prospective, randomized, and placebo-controlled 6 months study. Of these, 18 were hysterectomized and received daily oral 0.625 mg CEE. Eighty nine non-hysterectomized women were randomly allocated to one of four groups: a group (22 patients) treated with CEE, 0.625 mg/daily plus MPA 2.5 mg/daily; a group (22 patients) treated with CEE, 0.625 mg/daily plus NA 5 mg/daily; a group (23 patients) treated with raloxifene hydrochloride, 60 mg once daily; and a placebo group (22 patients). Hcy and hs-CRP were measured at baseline and at 3 and 6 months.

RESULTS

CEE (20%, P=0.03) and CEE+MPA (59%, P=0.006) increased serum hs-CRP levels significantly, whereas CEE+NA decreased serum hs-CRP by 25% (P=0.01). Raloxifene had no significant effect on serum hs-CRP levels during and after the treatment. In all active treatment groups serum Hcy levels decreased significantly compared to baseline and placebo.

CONCLUSIONS

Conjugated equine estrogen, hormone replacement therapies, and raloxifene lower serum Hcy levels to a comparable extent in postmenopausal women. Hs-CRP, as a cardiovascular risk factor, is not influenced by raloxifene, whereas CEE and CEE plus MPA significantly increase hs-CRP levels. Treatment with CEE plus NA reduces serum hs-CRP levels.

Raloxifene for postmenopausal women with systemic lupus erythematosus: a pilot randomized controlled study

OBJECTIVE

To study the effects of raloxifene on disease activity and bone mineral density (BMD) in postmenopausal women with systemic lupus erythematosus (SLE).

METHODS

Postmenopausal women with osteopenia and inactive SLE were randomly assigned to receive either raloxifene (60 mg/day) plus elemental calcium (1,200 mg/day) or elemental calcium alone (control). Patients with a history of thromboembolism or antiphospholipid antibody positivity were excluded. BMD at various sites was serially measured, and lupus activity was serially assessed using the Safety of Estrogens in Lupus Erythematosus: National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI).

RESULTS

The study group comprised 33 patients (16 assigned to receive raloxifene and 17 controls, mean +/- SD age 53.8 +/- 5.3 years). Age, body mass index, and baseline BMD values did not differ significantly between the 2 groups of patients. All patients were receiving low-dose prednisolone. After 12 months, femoral neck BMD (mean +/- SD -2.6 +/- 1.0%; P = 0.02) and lumbar spine BMD (-3.3 +/- 0.8%; P = 0.001) decreased significantly in the controls but not in the raloxifene group. No patient had a major flare of lupus, but mild/moderate flares occurred in 4 raloxifene-treated and 6 control patients (P = 0.79). The total area under the curve of SELENA-SLEDAI scores was not significantly different between the 2 groups. A significant increase in the high-density lipoprotein cholesterol level and a reduction in the low-density lipoprotein cholesterol level were observed in the raloxifene group but not in controls. One patient in the raloxifene group (6%) withdrew from the study because of hot flushes. No thromboembolic events were reported.

CONCLUSION

Raloxifene was well tolerated in Chinese patients with SLE who had inactive disease and in whom hypercoagulability was not identified. Raloxifene maintained femoral neck and spinal BMD in patients receiving corticosteroids.

[Hormonal replacement therapy and selective estrogen receptor modulators in prevention of cardiovascular disease]

Postmenopausal women are at higher risk of cardiovascular disease because of increased prevalence of major coronary artery disease risk factors. The protective activity on cardiovascular system of estrogen was postulated. The data from many studies indicate favourable effect of estrogen replacement therapy. However prospective, randomized clinical trials have not proved protective influence of hormonal replacement therapy (HRT) on cardiovascular system. Moreover it was found to increased the risk of cardiovascular disease events. This article presents mechanism of estrogens activity and results of major clinical trials concerning hormonal replacement therapy. Activity of selective estrogen receptor modulators (SERMs) was also described.

Standardized bending and breaking test for the normal and osteoporotic metaphyseal tibias of the rat: effect of estradiol, testosterone, and raloxifene

The fracture of bone plays a key role in osteoporosis. BMD measurement, however, is only an indirect parameter of this phenomenon. We therefore developed a highly sensitive three-point bending test for the metaphyseal tibias in rats to evaluate stiffness and strength. This was validated in a right-left comparison and a bioassay with soy-free food, estradiol, raloxifene, and testosterone in orchidectomized rats.

INTRODUCTION

Osteoporosis becomes manifest predominantly in the metaphyseal rat tibia. The anti-osteoporotic character of substances should, therefore, be tested (mechanically) in this bone area.

MATERIALS AND METHODS

We evaluated a new three-point bending test for the metaphyseal tibia in rats in a right-left trial. In an animal experiment, we studied the change of bone quality under estradiol (E)-, raloxifene (R)-, and testosterone (T)-supplemented food and compared it with trabecular BMD (qCT).

RESULTS

In the right-left comparison, the mean difference between the metaphyseal loads of both tibias in 37 rats was 8.43% for the maximum load (Fmax) and 6.46% for the failure load (fL). These results show the high reproducibility of the test, because they are close to the usual intraindividual difference of the two extremities. In a second experiment, four groups of 11 3-month-old male orchidectomized rats were fed with soy-free food only (C) or with the additives E, T, or R for 12 weeks. E and R were similar for Fmax and fL. There were significant differences in the stiffness (E = 406.92 N/mm versus R = 332.08 N/mm), the yield load (yL; E = 99.17 N versus R = 83.33 N), and the ratio between yL and Fmax (E = 86.33% versus R = 76.37%). T was similar to the controls concerning F(max), fL, and stiffness. There were significant differences in yL (T = 49.00N versus C = 39.5N) and the ratio between yL and Fmax (T = 64.28% versus C = 51.28%).

CONCLUSIONS

Estradiol is superior to raloxifene concerning stiffness and yield load, and both are superior to testosterone. We conclude that the described three-point bending test for the metaphyseal tibia is a highly sensitive method to study hormones and substances with regard to their osteoprotective character. The precision and the low SD of the presented results are superior to the data from qCT and the calculated index of stiffness (SSI).

[Bisphosphonate or Raloxifene?: which drug we can choose for osteoporotic patients?]

Raloxifene is preferred because of free from empty stomach and amelioration of lipid metabolism in spite of the significant effect of bisphosphonate on BMD and metabolic markers. As compliance is essential for the prevention of fracture, physicians should discuss about the treatment with their patients. There are no scientific evidences which drug is more suitable to osteoporotic patients. Therefore, bisphosphonate is recommended to the patients with severe osteoporosis, recognition of the disease, and/or expectation for the prevention of hip fracture by the treatment, on the condition that patients are not vitamin D deficiency. Raloxifene is recommended to the patients with mild osteoporosis, poor recognition of the disease, and/or low risk of the new fracture (s). The hyperlipidemic patients with osteoporosis are another candidates for raloxifene.