Coronary heart disease mortality and adjuvant tamoxifen therapy

Sex and sex steroids as determinants of cardiovascular risk

There are considerable sex differences regarding the risk of cardiovascular disease (CVD), including arterial hypertension, coronary artery disease (CAD) and stroke, as well as chronic renal disease. Women are largely protected from these conditions prior to menopause, and the risk increases following cessation of endogenous estrogen production or after surgical menopause. Cardiovascular diseases in women generally begin to occur at a later age than in men (on average with a delay of 10 years). Cessation of estrogen production also impacts metabolism, increasing the risk of developing obesity and diabetes. In middle-aged individuals, hypertension develops earlier and faster in women than in men, and smoking increases cardiovascular risk to a greater degree in women than it does in men. It is not only estrogen that affects female cardiovascular health and plays a protective role until menopause: other sex hormones such as progesterone and androgen hormones generate a complex balance that differentiates heart and blood vessel function in women compared to men. Estrogens improve vasodilation of epicardial coronary arteries and the coronary microvasculature by augmenting the release of vasodilating factors such as nitric oxide and prostacyclin, which are mechanisms of coronary vasodilatation that are more pronounced in women compared to men. Estrogens are also powerful inhibitors of inflammation, which in part explains their protective effects on CVD and chronic renal disease. Emerging evidence suggests that sex chromosomes also play a significant role in shaping cardiovascular risk. The cardiovascular protection conferred by endogenous estrogens may be extended by hormone therapy, especially using bioidentical hormones and starting treatment early after menopause.

The beneficial effects of tamoxifen on arteries: a key player for cardiovascular health of breast cancer patient

Breast cancer is the most common cancer in women. Over the past few decades, advances in cancer detection and treatment have significantly improved survival rate of breast cancer patients. However, due to the cardiovascular toxicity of cancer treatments (chemotherapy, anti-HER2 antibodies and radiotherapy), cardiovascular diseases (CVD) have become an increasingly important cause of long-term morbidity and mortality in breast cancer survivors. Endocrine therapies are prescribed to reduce the risk of recurrence and specific death in estrogen receptor-positive (ER+) early breast cancer patients, but their impact on CVD is a matter of debate. Whereas aromatase inhibitors and luteinizing hormone-releasing hormone (LHRH) analogs inhibit estrogen synthesis, tamoxifen acts as a selective estrogen receptor modulator (SERM), opposing estrogen action in the breast but mimicking their actions in other tissues, including arteries. This review aims to summarize the main clinical and experimental studies reporting the effects of tamoxifen on CVD. In addition, we will discuss how recent findings on the mechanisms of action of these therapies may contribute to a better understanding and anticipation of CVD risk in breast cancer patients.

Analysis of Cre-mediated genetic deletion of Gdf11 in cardiomyocytes of young mice

Administration of active growth differentiation factor 11 (GDF11) to aged mice can reduce cardiac hypertrophy, and low serum levels of GDF11 measured together with the related protein, myostatin (also known as GDF8), predict future morbidity and mortality in coronary heart patients. Using mice with a loxP-flanked ("floxed") allele of Gdf11 and Myh6-driven expression of Cre recombinase to delete Gdf11 in cardiomyocytes, we tested the hypothesis that cardiac-specific Gdf11 deficiency might lead to cardiac hypertrophy in young adulthood. We observed that targeted deletion of Gdf11 in cardiomyocytes does not cause cardiac hypertrophy but rather leads to left ventricular dilation when compared with control mice carrying only the Myh6-cre or Gdf11-floxed alleles, suggesting a possible etiology for dilated cardiomyopathy. However, the mechanism underlying this finding remains unclear because of multiple confounding effects associated with the selected model. First, whole heart Gdf11 expression did not decrease in Myh6-cre; Gdf11-floxed mice, possibly because of upregulation of Gdf11 in noncardiomyocytes in the heart. Second, we observed Cre-associated toxicity, with lower body weights and increased global fibrosis, in Cre-only control male mice compared with flox-only controls, making it challenging to infer which changes in Myh6-cre;Gdf11-floxed mice were the result of Cre toxicity versus deletion of Gdf11. Third, we observed differential expression of cre mRNA in Cre-only controls compared with the cardiomyocyte-specific knockout mice, also making comparison between these two groups difficult. Thus, targeted Gdf11 deletion in cardiomyocytes may lead to left ventricular dilation without hypertrophy, but alternative animal models are necessary to understand the mechanism for these findings. NEW & NOTEWORTHY We observed that targeted deletion of growth differentiation factor 11 in cardiomyocytes does not cause cardiac hypertrophy but rather leads to left ventricular dilation compared with control mice carrying only the Myh6-cre or growth differentiation factor 11-floxed alleles. However, the mechanism underlying this finding remains unclear because of multiple confounding effects associated with the selected mouse model.

Association between tamoxifen use and acute myocardial infarction in women with breast cancer

The relationship between tamoxifen use and acute myocardial infarction in women with breast cancer remains uncertain. The goal of the study was to assess whether tamoxifen use could be associated with acute myocardial infarction in women with breast cancer in Taiwan.A population-based case-control study was conducted to analyze the database of the Taiwan National Health Insurance Program. Totally, 489 women with breast cancer aged 20 to 84 years having the first episode of acute myocardial infarction from 2000 to 2011 were found as the cases. In addition, 1718 women with breast cancer aged 20 to 84 years without any type of ischemic heart disease were selected as the matched controls. Ever use of tamoxifen was classified as the studied women who had at least a prescription for tamoxifen before the index date. Never use of tamoxifen was classified as the studied women who never had a prescription for tamoxifen before the index date. We used the multivariable logistic regression model to estimate the odds ratio (OR) and 95% confidence interval (CI) for acute myocardial infarction associated with tamoxifen use.In a multivariable-adjusted analysis, women with acute myocardial infarction were 1.71 times more likely to be exposed to tamoxifen than those women without acute myocardial infarction (adjusted OR 1.71, 95% CI 1.38-2.13).The odds of tamoxifen use are 1.71 times higher in women with acute myocardial infarction versus those women without acute myocardial infarction in Taiwan.

Tamoxifen Treatment and the Reduced Risk of Hyperlipidemia in Asian Patients With Breast Cancer: A Population-Based Cohort Study

PURPOSE

The association between tamoxifen (TMX) treatment and the risk of developing hyperlipidemia remains unclear.

METHODS

The records of 41,726 patients with breast cancer (28,266 received TMX and 13,460 did not) were obtained from the Taiwan National Health Insurance Research Database for the period from January 2000 to December 2008. Three-fold women without breast cancer were the control group (N = 125, 178). The main end point was developing hyperlipidemia during the follow-up.

RESULTS

During a mean follow-up of 9 years, the patients with breast cancer demonstrated a rate of developing hyperlipidemia that was 6% less (adjusted hazard ratio [HR], 0.94; 95% confidence interval [CI], 0.90-0.97) than that of the control participants without breast cancer. Stratification by age group indicated that only women aged ≥ 55 years who were diagnosed with breast cancer exhibited a significantly reduced risk of hyperlipidemia compared with the control group. With the use of 2 types of adjusted models, we observed that the TMX users (aged ≥ 55 years) consistently exhibited a significantly lower risk of hyperlipidemia than the non-TMX users and control participants (adjusted HRs, 0.79 and 0.82 from models 1 and 2, respectively). Within the 8-year follow-up period, patients with breast cancer and 366 to 1500 days of TMX therapy and > 1500 days of TMX therapy had significantly lower risks of hyperlipidemia compared with patients with ≤ 365 days of TMX therapy (adjusted HR, 0.54; 95% CI, 0.50-0.59; adjusted HR, 0.21; 95% CI, 0.18-0.24, respectively).

CONCLUSIONS

In Asian patients with breast cancer, TMX use was associated with reduced risks of hyperlipidemia.

Cardiotoxicity of systemic agents used in breast cancer

Several breast cancer therapies can lead to cardiovascular toxicity: drugs such anthracyclines can cause permanent damage, anti-HER2 agents may cause transitory and reversible cardiac dysfunction and others, such as those used in endocrine therapy, primarily disturb lipid metabolism. Considering the seriousness of these complications, trials are now being conducted to address cardiotoxicity associated with new drugs; however, to fully understand their toxicity profiles, longer follow-up is needed. In this review, we compile the information available about cardiac toxicity related to well-established systemic breast cancer treatments, as well as newer drugs, including antiangiogenics, mTOR inhibitors and novel anti-HER2 agents. We also describe current and next generation cardiac biomarkers and functional tests that can optimize treatment and reduce and prevent the incidence of treatment-related cardiotoxicity.

Association of tamoxifen use and reduced cardiovascular events among asian females with breast cancer

BACKGROUND

Tamoxifen is used for breast cancer treatment and has been reported to be beneficial for the cardiovascular system, but it is unclear whether tamoxifen exhibits a favorable cardiovascular effect in Asian patients.

METHODS AND RESULTS

From January, 1998 to December, 2006, a breast cancer cohort study was conducted using the Taiwan National Health Insurance database. Patients were divided according to whether tamoxifen was used. Study endpoints were occurrence of acute myocardial infarction (AMI), ischemic or hemorrhagic stroke and total cardiovascular events. A total of 3,690 female subjects were enrolled (mean age 50.1±11.3), 2,056 of whom received tamoxifen and 1,634 did not. During a mean follow-up of 6.9 years, the tamoxifen group had a significantly lower incidence of AMI (0.15% vs. 0.67%, P=0.008), ischemic stroke (1.99% vs. 3.30%, P=0.008), hemorrhagic stroke (0.15% vs. 0.55%, P=0.029), and total cardiovascular events (2.24% vs. 4.16%, P<0.001) than the non-exposed group. After adjusting for comorbidities, tamoxifen was independently associated with a reduced risk of myocardial infarction (hazard ratio [HR] 0.22; 95% confidence interval [CI] 0.07-0.70, ischemic stroke (HR 0.52; 95% CI 0.35-0.78), hemorrhagic stroke (HR 0.25; 95% CI 0.07-0.92), and total cardiovascular events (HR 0.54; 95% CI 0.37-0.78).

CONCLUSIONS

In Asian female breast cancer patients, tamoxifen use was associated with reduced risks of AMI, ischemic, hemorrhagic stroke and total cardiovascular events.

Development of a novel molecular sensor for imaging estrogen receptor-coactivator protein-protein interactions

Anti-estrogens, in particular tissue selective anti-estrogens, have been the bedrock of adjuvant therapy for patients with estrogen receptor alpha (ERα) positive breast cancer. Though current therapies have greatly enhanced patient prognosis, there continues to be an impetus for the development of improved anti-estrogens. ERα is a nuclear receptor transcription factor which activates gene expression through the recruitment of transcriptional coactivator proteins. The SRC family of coactivators, which includes AIB1, has been shown to be of particular importance for ERα mediated transcription. ERα-AIB1 interactions are indicative of gene expression and are inhibited by anti-estrogen treatment. We have exploited the interaction between ERα and AIB1 as a novel method for imaging ERα activity using a split luciferase molecular sensor. By producing a range of ERα ligand binding domain (ER-LBD) and AIB1 nuclear receptor interacting domain (AIB-RID) N- and C-terminal firefly luciferase fragment fusion proteins, constructs which exhibited more than a 10-fold increase in luciferase activity with E2 stimulation were identified. The specificity of the E2-stimulated luciferase activity to ERα-AIB1 interaction was validated through Y537S and L539/540A ER-LBD fusion protein mutants. The primed nature of the split luciferase assay allowed changes in ERα activity, with respect to the protein-protein interactions preceding transcription, to be assessed soon after drug treatment. The novel assay split luciferase detailed in this report enabled modulation of ERα activity to be sensitively imaged in vitro and in living subjects and potentially holds much promise for imaging the efficacy of novel ERα specific therapies.

Clair DK. Manganese superoxide dismutase: beyond life and death

Manganese superoxide dismutase (MnSOD) is a nuclear-encoded antioxidant enzyme that localizes to the mitochondria. Expression of MnSOD is essential for the survival of aerobic life. Transgenic mice expressing a luciferase reporter gene under the control of the human MnSOD promoter demonstrate that the level of MnSOD is reduced prior to the formation of cancer. Overexpression of MnSOD in transgenic mice reduces the incidences and multiplicity of papillomas in a DMBA/TPA skin carcinogenesis model. However, MnSOD deficiency does not lead to enhanced tumorigenicity of skin tissue similarly treated because MnSOD can modulate both the p53-mediated apoptosis and AP-1-mediated cell proliferation pathways. Apoptosis is associated with an increase in mitochondrial levels of p53 suggesting a link between MnSOD deficiency and mitochondrial-mediated apoptosis. Activation of p53 is preventable by application of a SOD mimetic (MnTE-2-PyP(5+)). Thus, p53 translocation to mitochondria and subsequent inactivation of MnSOD explain the observed mitochondrial dysfunction that leads to transcription-dependent mechanisms of p53-induced apoptosis. Administration of MnTE-2-PyP(5+) following apoptosis but prior to proliferation leads to suppression of protein carbonyls and reduces the activity of AP-1 and the level of the proliferating cellular nuclear antigen, without reducing the activity of p53 or DNA fragmentation following TPA treatment. Remarkably, the incidence and multiplicity of skin tumors are drastically reduced in mice that receive MnTE-2-PyP(5+) prior to cell proliferation. The results demonstrate the role of MnSOD beyond its essential role for survival and suggest a novel strategy for an antioxidant approach to cancer intervention.

Randomized trial of tamoxifen versus combined tamoxifen and octreotide LAR Therapy in the adjuvant treatment of early-stage breast cancer in postmenopausal women: NCIC CTG MA.14

PURPOSE

Somatostatin analogs act directly on breast cancer cells and indirectly on insulin and insulin-like growth factor 1 (IGF-1) levels. This trial was undertaken to assess whether octreotide would lower insulin and IGF-1 levels and reduce risk of breast cancer recurrence.

PATIENTS AND METHODS

The NCIC CTG MA.14 (NCIC Clinical Trials Group MA.14) trial randomly assigned postmenopausal women to 5 years of tamoxifen 20 mg daily (TAM) or TAM plus 2 years of octreotide 90 mg depot intramuscular injections monthly (TAM-OCT) as adjuvant therapy. The primary end point was event-free survival (EFS). Secondary end points were relapse-free survival (RFS), overall survival (OS), toxicity, and effects of treatment on IGF physiology.

RESULTS

Among 667 women with a median follow-up of 7.9 years, 220 events occurred-108 with TAM-OCT and 112 with TAM. Adjusted hazard ratios (HRs; TAM-OCT to TAM) were 0.93 for EFS (95% CI, 0.71 to 1.22; P = .62), 0.84 for RFS (95% CI, 0.59 to 1.18; P = .31), and 0.97 for OS (95% CI, 0.69 to 1.37; P = .86). Among patients with normal baseline gallbladder imaging, cholecystectomy was required in 23.0% of those receiving TAM-OCT but in only 1.4% of those receiving TAM (P < .001). At 4 months, TAM-OCT had significantly (P < .001) lowered IGF-1, IGF binding protein 3, and C-peptide levels. Older age (P = .02), tumor size (P = .001), nodal status (P = .01), high C-peptide levels (P < .001), and higher body mass index (BMI) in models excluding C-peptide (P < .001) were associated with poorer EFS in multivariate analysis.

CONCLUSION

Octreotide-related changes in circulating IGF-1 and C-peptide levels were statistically significant. Octreotide did not add significant clinical benefit. High C-peptide levels (surrogate for insulin secretion rate) and high BMI were associated with poor outcome.

Early recurrence risk: aromatase inhibitors versus tamoxifen

Aromatase inhibitors (AIs) are becoming the hormonal treatment of choice for postmenopausal women with early breast cancer. Large, well-controlled clinical studies have established the efficacy and safety of initial adjuvant therapy with letrozole or anastrozole versus the previous standard of 5 years of adjuvant tamoxifen and support using an AI (exemestane, anastrozole or letrozole) following tamoxifen for 2-3 years (early 'switch' treatment) or 5 years (extended adjuvant treatment). Reducing recurrence risk is a primary goal of adjuvant hormonal therapy. There is an early peak of recurrences 2 years after surgery; most are distant metastases rather than local or regional events. Therefore, treatment strategies such as initial therapy with AIs, which reduce early distant recurrence events, can be expected to improve long-term survival outcomes. Switching to an AI following 2-3 years of initial adjuvant tamoxifen is an effective option for patients unable to begin treatment with an AI.

Long-term benefits of 5 years of tamoxifen: 10-year follow-up of a large randomized trial in women at least 50 years of age with early breast cancer

PURPOSE

The Cancer Research UK "Over 50s" trial compared 5 and 2 years of tamoxifen in women with early breast cancer. Results are reported after median follow-up of 10 years.

PATIENTS AND METHODS

Between 1987 and 1997, 3,449 patients age 50 to 81 years with operable breast cancer who had been taking 20 mg of tamoxifen for 2 years were randomly assigned to either stop or continue for an additional 3 years, if they were alive and recurrence free. Data on recurrences, new tumors, deaths, and cardiovascular events were obtained (April 2010).

RESULTS

There were 1,103 recurrences, 755 deaths as a result of breast cancer, 621 cardiovascular (CV) events, and 236 deaths as a result of CV events. Fifteen years after starting treatment, for every 100 women who received tamoxifen for 5 years, 5.8 fewer experienced recurrence, compared with those who received tamoxifen for 2 years. The risk of contralateral breast cancer was significantly reduced (hazard ratio, 0.70; 95% CI, 0.48 to 1.00). Among women age 50 to 59 years, there was a 35% reduction in CV events (P = .005) and 59% reduction in death as a result of a CV event (P = .02); in older women, the effect was much smaller and not statistically significant.

CONCLUSION

Taking tamoxifen for the recommended 5 years reduces the risk of recurrence or contralateral breast cancer 15 years after starting treatment. It also lowers the risk of CV disease and death as a result of a CV event, particularly among those age 50 to 59 years. Women should therefore be encouraged to complete the full course. Although aromatase inhibitors improve disease-free survival, tamoxifen remains a cheap and highly effective alternative, particularly in developing countries.

Orally administered endoxifen is a new therapeutic agent for breast cancer

Endoxifen is the key active metabolite of tamoxifen, a widely used breast cancer drug. Orally administered tamoxifen, is extensively metabolized by cytochrome P450 (CYP) enzymes, namely CYP3A4 and CYP2D6, into active metabolites, especially endoxifen. Due to genetic polymorphism of CYP2D6, significant numbers of women metabolize tamoxifen to varying degree and may not receive the optimal benefit from tamoxifen treatment. We show that oral administration of endoxifen achieved the optimally effective systemic levels reliably, which may eliminate variability associated with tamoxifen metabolism that leads to unpredictability in efficacy. Furthermore, use of endoxifen may avoid a potential serious drug interaction found between tamoxifen and commonly used selective serotonin reuptake inhibitors, antidepressants. Endoxifen was active in inhibiting the growth of various breast tumor cell lines in NCI 60-Cell Line Screen. Orally administered endoxifen is rapidly absorbed and systemically available when tested in female rats. The endoxifen-treated rats showed 787% higher exposure (AUC(0-infinity)) and 1,500% higher concentration (C (max)) levels of endoxifen when compared with tamoxifen. Oral endoxifen administration once a day for 28 consecutive days at dosages 2, 4, and 8 mg/kg proved safe and resulted in progressive inhibition of the growth of the human mammary tumor xenografts in female mice. This is the first ever in vivo report on endoxifen as a potentially new therapeutic agent for breast cancer.

Is tamoxifen a genotoxic carcinogen in women?

The anti-oestrogen tamoxifen, which is widely used in the treatment of breast cancer and is also approved for the prevention of this disease, causes an increased incidence of endometrial cancer in women. The ability of tamoxifen to induce endometrial tumours and the underlying carcinogenic mechanisms have been a subject of intense interest over the last approximately 20 years. They are central to the assessment of risks versus benefits for the drug, especially in a chemopreventive context. This review outlines the clinical justification for using tamoxifen as a chemopreventive agent and describes the genotoxic mechanisms considered responsible for tamoxifen-induced tumours in rat liver and how these might relate to women. In rat hepatic tissue, tamoxifen is metabolically activated via alpha-hydroxylation and sulphate conjugation to give a reactive species that binds to DNA predominantly at the N(2)-position of guanine, producing pro-mutagenic lesions. Whether tamoxifen-DNA adducts contribute similarly to the development of cancers in women depends on whether they can be formed in human tissues and the type of specific molecular and cellular responses they induce, if present. This review discusses the current data relating to these issues and highlights areas where further research is needed.

Tamoxifen treatment in Danish breast cancer patients and 5-year risk of arterial atherosclerotic events: a null association

Although the effectiveness of tamoxifen in preventing the recurrence of breast cancer is well established, associations between tamoxifen and the occurrence of atherosclerotic events are not as clear. Breast cancer patients taking tamoxifen have lower serum cholesterol and other lipid levels than those not taking tamoxifen, suggesting that tamoxifen might prevent atherosclerotic events, but the existing studies are conflicting. We examined the relation between tamoxifen and incident hospitalization of angina pectoris, acute myocardial infarction, heart failure, and stroke. The study population of 16,289 women was identified from the Danish Breast Cancer Cooperative Group nationwide clinical database and includes women diagnosed with stage I or II estrogen receptor-positive breast cancer between 1990 and 2004 at ages 45 to 69. Use of a large population-based sample with complete outcome ascertainment allowed us to calculate precise measures of risks, risk ratios, and adjusted hazard ratios comparing tamoxifen-treated patients with untreated patients. We found strong evidence for null associations for each of the four outcomes of interest during the first year and first 5 years after the start of therapy. These findings are important in risk/benefit analyses as tamoxifen therapy in postmenopausal women is being replaced with aromatase inhibitors.

Translating trial data into patients benefits: making the right choice

Tamoxifen has been the standard first-line adjuvant treatment for postmenopausal women with early breast cancer for over 3 decades. Its use, however, is associated with a number of potentially life-threatening adverse events. As a result, the aromatase inhibitors (AIs), which are generally better tolerated and more efficacious, are now beginning to supersede tamoxifen as the treatment of choice in this setting. Nevertheless, some patients in clinical practice still start or remain on tamoxifen therapy instead of an AI. This review investigates our current understanding of AIs and tamoxifen in the adjuvant hormonal therapy of postmenopausal breast cancer in relation to efficacy, safety and patient benefits. Overall, it is concluded that the AIs show a significant advantage over tamoxifen, with the greatest difference observed at 1-2 years after initiation of treatment. Therefore, using an AI at the earliest opportunity provides patients with the best option to prevent the recurrence and excess adverse events associated with tamoxifen.

Cardiovascular reserve and risk profile of postmenopausal women after chemoendocrine therapy for hormone receptor--positive operable breast cancer

Purpose. To examine cardiovascular function and risk profile of postmenopausal women treated with chemoendocrine therapy (CET) for hormone receptor-positive operable breast cancer. Methods. Forty-seven breast cancer patients and 11 age-matched healthy controls were studied. Participants performed a cardiopulmonary exercise test with expired gas analysis and impedance cardiography to assess peak aerobic power (VO(2peak)) and cardiovascular function (stroke volume, cardiac output, cardiac power output, and cardiac reserve). Traditional (i.e., body mass index, lipid profile, and fasting insulin and glucose) and novel (i.e., C-reactive protein, brain natriuretic peptide) cardiovascular risk biochemical factors were also assessed. Results. Breast cancer patients had significantly lower peak exercise stroke volume (68 +/- 9 versus 76 +/- 11 ml/beat), cardiac output (10.4 +/- 1.5 versus 11.7 +/- 2.4 l/minute), cardiac power output (3.0 +/- 0.5 versus 3.5 +/- 0.9 Watts), cardiac power output reserve (1.7 +/- 0.6 versus 2.4 +/- 0.8 Watts), and VO(2peak) (1.3 +/- 0.3 versus 1.6 +/- 0.2 l x min(-1)) than control subjects (p-values < .05). Patients with the greatest impairment in VO(2peak) had the worse cardiovascular risk profile. Exploratory analyses revealed several differences in study outcomes between the 26 patients receiving hormonal therapy with tamoxifen (TAM) and the 21 patients receiving aromatase inhibitor (AI) therapy. Conclusion. Breast cancer patients treated with adjuvant CET have a significantly and markedly lower cardiorespiratory fitness and cardiac functional reserve compared with age- and sex-matched controls. AI therapy may be associated with a more unfavorable cardiovascular risk profile than TAM. Prospective studies are required to further investigate the clinical value of these findings.

Estrogen receptor genotypes, menopausal status, and the lipid effects of tamoxifen

Tamoxifen induces important changes in serum lipid profiles in some women; however, little information is available to predict which women will experience improved lipid profiles during tamoxifen therapy. As part of a multicenter prospective observational trial in 176 breast cancer patients, we tested the hypothesis that tamoxifen-induced lipid changes were associated with genetic variants in candidate target genes (CYP2D6, ESR1, and ESR2). Tamoxifen lowered low-density lipoprotein cholesterol (P<0.0001) by 23.5 mg/dl (13.5-33.5 mg/dl) and increased triglycerides (P=0.006). In postmenopausal women, the ESR1-XbaI and ESR2-02 genotypes were associated with tamoxifen-induced changes in total cholesterol (P=0.03; GG vs GA/AA) and triglycerides (P=0.01; gene-dose effect), respectively. In premenopausal women, the ESR1-XbaI genotypes were associated with tamoxifen-induced changes in triglycerides (P=0.002; gene-dose effect) and high-density lipoprotein (P=0.004; gene-dose effect). Our results suggest that estrogen receptor genotyping may be useful in predicting which women would benefit more from tamoxifen.

Cardiovascular Actions of Selective Estrogen Receptor Modulators and Phytoestrogens

Cardiovascular disease is the leading cause of death among men and women in Western societies. Over the past decade, interest in a better understanding of gender differences in cardiovascular disease has heightened. Concomitantly, the use of hormone therapy for cardiovascular risk reduction in postmenopausal women has come into question in light of recent landmark clinical studies casting doubt on the benefits of this therapy. As a consequence, alternatives to conventional hormone replacement, including selective estrogen receptor modulators and phytoestrogens, have attracted considerable attention. The authors provide an up-to-date review of the clinical actions of selective estrogen receptor modulators on cardiovascular disease. The actions of tamoxifen, raloxifene, droloxifene, and soy phytoestrogens are discussed in the context of cardiovascular disease epidemiology, coronary events, clinical markers of cardiovascular risk, and vascular function. In addition, the authors' current understanding of the mechanism of action of these agents is discussed and recommendations for clinical practice are reviewed.

Adjuvant endocrine therapy for early breast cancer

Breast cancer is the most common cancer among women and about 80% of breast cancers express hormone receptors. Tamoxifen has been the most important form of adjuvant endocrine therapy over the last 25 years. The third generation aromatase inhibitors (AIs) are a new class of drugs challenging the central role of tamoxifen as adjuvant endocrine treatment in postmenopausal women with hormone receptor-positive breast cancer. Their effectiveness has been demonstrated in first line therapy as well in neoadjuvant setting with a statistically significant superiority over tamoxifen. Here we considered the role of adjuvant AIs in early stage breast cancer with an analysis reviewing the main adjuvant trials. We considered efficacy, side effects, optimal timing, duration of the therapy and whether specific subgroups may achieve particular benefit. In conclusion the upfront use of adjuvant anastrozole or letrozole is superior to tamoxifen with a good relative toxicity profile. Tamoxifen will continue to have a role where recurrence risk is low or if AI is poorly tolerated. Issues including the timing of administration (up-front or sequential), the duration of the therapy and the role of biomarkers such as PgR and HER2 in optimal selection remain unresolved.

Rates of myocardial infarction and coronary artery disease and risk factors in patients treated with radiation therapy for early-stage breast cancer

BACKGROUND

Radiation therapy (RT), a critical component of breast-conserving therapy for breast cancer, has been associated with coronary artery disease (CAD) in numerous older studies, but the risk may be lower with modern techniques.

METHODS

Observed rates of cardiac events in 828 patients treated with breast-conserving surgery and RT at the University of Michigan were compared with expected rates. Relations between potential risk factors and actuarial rates of first CAD event were analyzed.

RESULTS

Observed risks of cardiac events were lower than expected. The standardized incidence ratio (SIR) of myocardial infarction (MI) was 0.44 (95% confidence interval [CI]: 0.21-0.70). The SIR of MI or CAD requiring intervention was 0.50 (95% CI: 0.27-0.68). With a median follow-up of 6.8 years, 12 (1.4%) patients had at least 1 MI on follow-up and 20 (2.4%) had at least 1 MI or CAD requiring intervention. Median age at first cardiac event was 75.9 years (range, 43.1-91.5). Median interval from RT to occurrence of the first cardiac event was 3.7 years (range, 13 days to 15.4 years). The 10-year cumulative incidence of MI was 1.2% and cumulative incidence of MI or CAD requiring intervention was 2.7%. On multivariate analysis, age, diabetes mellitus, active smoking, and laterality of RT were significant predictors of MI. Age and active smoking were significant predictors of MI or CAD requiring intervention.

CONCLUSIONS

Patients in this series had lower risk of ischemic cardiac events than expected. Although small in absolute magnitude, patients radiated to the left side did have a statistically significant increased risk of MI. These findings support further investigation of techniques to minimize the long-term cardiac risks faced by breast cancer patients.

Aromatase inhibitors and cardiac toxicity: getting to the heart of the matter

Recent advances in breast cancer treatment include the advent of aromatase inhibitors (AIs) in the adjuvant setting with better efficacy and toxicity profiles than tamoxifen. However, AIs generally do not improve lipid profile as tamoxifen does, and there has been suggestion of increased cardiovascular risk with AI use. This has become an area of concern, particularly in light of the view that tamoxifen may protect against cardiovascular disease. This review of the current literature and updated trial data examines the effect both AIs and tamoxifen have on lipids and cardiovascular risk. It also highlights the importance of interpreting such data within the larger context of cardiovascular health in postmenopausal women.

Duration of tamoxifen effect on lipidemic profile of postmenopausal breast cancer patients following deprivation of treatment

OBJECTIVE

It was the aim of this study to investigate the effect of tamoxifen withdrawal on markers of lipid metabolism in postmenopausal women with breast cancer who completed tamoxifen therapy and received no further treatment.

METHODS

Lipidemic profile changes were studied in 190 postmenopausal patients with operable breast cancer, following cessation of 5-7 years of tamoxifen treatment. Assessments of total cholesterol, high-density lipoprotein, low-density lipoprotein and total serum triglycerides were performed at baseline, 6 months and 12 months.

RESULTS

By 6 months, both total cholesterol and low-density lipoprotein levels were significantly increased, and total triglyceride levels were significantly reduced compared with baseline values and maintained to 12 months. There was no significant alteration observed for high-density lipoprotein levels over the study period.

CONCLUSION

The beneficial effect of tamoxifen on the lipidemic profile of postmenopausal breast cancer patients seems to be lost in less than 12 months time following cessation of 5-7 years of tamoxifen treatment. A 'rebound effect' on the lipidemic parameters should be expected and those patients should be monitored carefully.

Cost-effectiveness of exemestane versus tamoxifen as adjuvant therapy for early-stage breast cancer after 2-3 years treatment with tamoxifen in Sweden

Aromatase inhibitors are rapidly becoming the cornerstone of endocrine treatment for advanced disease and are now also used as adjuvant treatment in early-stage disease. The objective of this study was to assess the cost-effectiveness of adjuvant treatment with exemestane versus tamoxifen for early-stage breast cancer after 2-3 years treatment with tamoxifen in Sweden. The results are based on findings in the Intergroup Exemestane Study (IES). IES was a randomized controlled trial in which postmenopausal women who had received 2-3 years of tamoxifen therapy following primary treatment of early-stage breast cancer, were randomized to either continue on tamoxifen therapy or be switched to exemestane therapy. The results showed a disease-free survival hazard ratio of exemestane relative to tamoxifen in IES of 0.69. A Markov state-transition model was developed to simulate consequences after the end of the clinical trial, and to integrate the trial data with external data on mortality, costs and quality of life specific for Swedish women. The cost per QALY gained was about euro 20,000 in the base case analysis without inclusion of consequences of coronary heart disease. Inclusion of these events increased the cost-effectiveness ratio to about euro 31,000. This means that, based on our assumption, sequential exemestane treatment in early breast cancer is a cost-effective option compared with tamoxifen alone, although more long-term data on overall survival and consequences of adverse events would be valuable to increase the validity of the analysis further.

Comprehensive side-effect profile of anastrozole and tamoxifen as adjuvant treatment for early-stage breast cancer: long-term safety analysis of the ATAC trial

BACKGROUND

The Arimidex (anastrozole), Tamoxifen, Alone or in Combination (ATAC) trial was designed to compare the efficacy and safety of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with early-stage breast cancer. After an extended follow-up beyond the 5 years of treatment, we aimed to assess the safety, tolerability, and risk-benefit indices of these compounds.

METHODS

We analysed postmenopausal women (mean age 64 years [SD 9]) with localised breast cancer randomly assigned to anastrozole (n=3125) or tamoxifen (n=3116). Efficacy measures, including death and risk-benefit indices, were analysed by intention to treat. Safety analyses were based on treatment first received (n=3092 for anastrozole and n=3094 tamoxifen). We calculated a risk-benefit analysis using the two global indices for the Women's Health Initiative and for Disease-Free Survival and Serious Adverse Events. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230.

FINDINGS

At median follow-up of 68 months (range 1-93), treatment-related adverse events occurred significantly less often with anastrozole than with tamoxifen (1884 [61%] vs 2117 [68%]; p<0.0001), as did treatment-related serious adverse events (146 [5%] vs 277 [9%]; p<0.0001) and adverse events leading to withdrawal (344 [11%] vs 442 [14%]; p=0.0002). Patients given anastrozole had significantly fewer overall events for the Global Index of the Women's Health Initiative (744 [24%] vs 851 [27%]; hazard ratio 0.85 [95% CI 0.77-0.94], p=0.001) and the Global Index of Disease-Free Survival and Serious Adverse Events (1453 [46%] vs 1594 [51%]; 0.88 [0.82-0.94]; p=0.0004).

INTERPRETATION

Anastrozole is tolerated better than tamoxifen by postmenopausal women with early-stage breast cancer, and results in fewer serious adverse events. Furthermore, it has a more favourable overall risk-benefit profile and lower recurrence rate than tamoxifen.

The use of early adjuvant aromatase inhibitor therapy: contributions from the BIG 1-98 letrozole trial

Letrozole has proven efficacious in a variety of therapeutic scenarios, including that of extended adjuvant therapy following 5 years of tamoxifen treatment in postmenopausal women with estrogen-receptor-positive early breast cancer. The Breast International Group 1-98 trial (BIG 1-98) is the first to study the efficacy of upfront letrozole treatment and the first to evaluate the benefits of initial versus sequential aromatase inhibitor therapy. At 25.8 months of follow-up, the primary core analysis of BIG 1-98 compared the efficacy of upfront letrozole treatment with that of upfront tamoxifen treatment in 8,010 postmenopausal women with early breast cancer. The primary endpoint was disease-free survival (DFS). Secondary endpoints included overall survival, distant DFS, systemic DFS, and safety. Letrozole significantly increased DFS, reduced distant recurrences, and prolonged time to distant metastasis compared with tamoxifen. The advantage for letrozole was particularly evident in women at increased risk of recurrence (node-positive and/or chemotherapy treated). Compared with tamoxifen, postmenopausal women receiving letrozole treatment experienced less venous thromboembolic and endometrial events, but more skeletal and grade 3-5 cardiac events, although the frequencies of these latter events were relatively low in both arms (2.1% v 1.1%). There were more deaths from noncancer causes in the letrozole group, but the numbers were small and, overall, there were 14% fewer deaths among patients in the letrozole group. Letrozole has an efficacy advantage over tamoxifen and can now be considered part of standard adjuvant therapy for postmenopausal women with endocrine-responsive breast cancer. Women at increased risk for recurrence may obtain protective benefit from letrozole. Letrozole is generally well tolerated and is associated with a similar frequency of serious side effects, but fewer deaths, than tamoxifen.

Adjuvant Hormonal Therapy in Peri‐ and Postmenopausal Breast Cancer

Tamoxifen has been the mainstay of endocrine treatment for early-stage breast cancer in both premenopausal and postmenopausal women for many years. Since 2001, the results of several large, randomized, clinical trials have provided evidence that aromatase inhibitor (AI) therapy, either upfront or in sequence after tamoxifen, improves disease-free survival and, in certain patients, overall survival for postmenopausal patients with hormone receptor-positive breast cancer. Thus far, with relatively short-term follow-up, AIs have been generally safe and well tolerated among the population of patients treated in these adjuvant trials. However, important side effects such as musculoskeletal and bone-related problems, including the risk for osteoporosis and fractures, remain of concern and warrant continued monitoring and follow-up. Several questions regarding the appropriate AI to use and the timing of AI therapy remain unresolved, and ongoing studies will help address these issues. Caution is warranted in the use of AIs in perimenopausal women, including those that develop chemotherapy-induced amenorrhea, and clinical evidence supports the role for AI use in postmenopausal women only. Areas of active investigation include the mechanisms of resistance to endocrine therapy with tamoxifen and AIs and clinical strategies to overcome this resistance.

Tamoxifen protects against acute tumor necrosis factor alpha-induced cardiac injury via improving mitochondrial functions

Tamoxifen is the most commonly used antiestrogen for the treatment of breast cancer. Several clinical trials demonstrate that tamoxifen reduces the risk of heart disease and osteoporosis. However, the mechanism by which tamoxifen causes cardioprotection is unclear. Because increased levels of tumor necrosis factor alpha (TNFalpha) in tissue and/or plasma have been observed in virtually all forms of cardiac injury, we investigated whether tamoxifen prevents cardiac injury in a murine model of acute TNFalpha challenge. Five- to six-week-old female mice were injected (ip) with tamoxifen at 0.25 mg/kg daily for 3 or 7 days before receiving an injection of TNFalpha. Ultrastructural examination of cardiac tissues revealed remarkable protection against TNFalpha-induced mitochondrial damage in tamoxifen pretreated mice. Tamoxifen treatment significantly improved the mitochondrial respiratory function and enhanced superoxide-scavenging activity of mitochondria. These findings reveal a novel mitochondria-mediated mechanism by which tamoxifen exerts its cardiac protection effect against acute TNFalpha-induced heart injury.

Anastrozole as an adjuvant endocrine treatment for postmenopausal patients with breast cancer: emerging data

The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial compared the efficacy and safety of anastrozole versus tamoxifen versus the combination as initial adjuvant treatment for early breast cancer in over 9,000 postmenopausal women. Analyses at 33 and 47 months median follow-up showed that anastrozole significantly prolonged disease-free survival and time to recurrence and reduced the incidence of contralateral breast cancer compared with tamoxifen. Results of the completed treatment analysis at 68 months median follow-up confirmed the earlier findings, showing that the absolute difference in disease-free survival continued to increase beyond completion of treatment. Mature safety data from the ATAC trial show that, overall, anastrozole has a favorable safety profile compared with tamoxifen. In the absence of current data on further follow-up or the outcome of trials investigating proactive sequencing of endocrine therapies, we present a model based on several trials, including ATAC. This model suggests that using an aromatase inhibitor as initial adjuvant therapy is a better option than switching to an aromatase inhibitor after >/=2 years of tamoxifen. The relative toxicities of the three approved third-generation aromatase inhibitors, anastrozole, letrozole, and exemestane, are discussed. These data suggest that long-term safety profiles may differ between aromatase inhibitors, although comprehensive comparative data for letrozole and exemestane versus tamoxifen are lacking.

Letrozole as adjuvant endocrine therapy in postmenopausal women with breast cancer

The third-generation aromatase inhibitor letrozole offers a promising approach to treating hormone-sensitive breast cancer for postmenopausal women, through potent and specific inhibition of estrogen synthesis. In neoadjuvant and first-line treatment, letrozole demonstrated superior efficacy compared with tamoxifen in randomized Phase III trials. Initial results of Breast InterGroup 1-98, a large ongoing randomized trial investigating primary adjuvant endocrine treatment with either letrozole or tamoxifen, have recently been presented. Patients treated with letrozole demonstrated a 19% improvement in disease-free survival and a significant reduced risk of distant recurrences, holding out the prospect of a survival advantage over tamoxifen treatment with further maturation of the trial. For patients who have already completed 5 years of tamoxifen, extended endocrine therapy with letrozole is a new therapeutic option based on the results of the MA-17 trial. The optimal use of aromatase inhibitors remains an open question, at least until results from randomized trials (BIG 1-98, TEAM) investigating the sequential use of an aromatase inhibitor and tamoxifen in comparison with continuous monotherapy become available.

Emerging Selective Estrogen Receptor Modulators

Menopause, regardless of age at onset, is associated with a marked increase in coronary heart disease (CHD) risk. On the basis of epidemiological studies that demonstrated mainly positive effects of postmenopausal hormone therapy on CHD as well as on risk markers of CHD, it has been suggested that CHD could be prevented in postmenopausal women with long-term hormone therapy. However, since the publications of the Heart and Estrogen/progestin Replacement Study and the Women's Health Initiative trial, prescription of hormone therapy for the prevention of CHD has become controversial. Major efforts have been made to identify alternatives for hormone therapy. Compounds suggested have included selective estrogen receptor modulators (SERMs), which represent a class with a growing number of compounds that act as either estrogen receptor agonists or antagonists in a tissue-specific manner. This pharmacological profile may offer the opportunity to dissociate favourable estrogenic effects on the bone and cardiovascular system from unfavourable stimulatory effects on the breast and endometrium. Two SERMs presently on the market are tamoxifen and raloxifene. The only data available regarding the effects of tamoxifen on cardiovascular events in postmenopausal women are from breast cancer trials. These trials found fewer fatal myocardial events in women randomly assigned to tamoxifen compared with women assigned to placebo. Raloxifene is a second-generation SERM that has been shown to prevent osteoporotic fractures, is safe for the endometrium and holds high promise for the prevention of breast cancer. The effect of raloxifene on CHD is still uncertain. On the basis of the MORE (Multiple Outcomes of Raloxifene Evaluation) trial, raloxifene may offer some protection to women with CHD or to those who are at high risk of CHD. Proof that raloxifene reduces the risk of CHD requires a clinical trial with hard clinical endpoints. Such a study is currently underway. Next-generation SERMs taken into clinical development include idoxifene, droloxifene, ospemifene, arzoxifene, acolbifene/EM-800, levormeloxifene, lasofoxifene, bazedoxifene and HMR 3339. The aim is to find a compound with the ideal profile, that is, alleviation of climacteric symptoms and prevention of osteoporotic fractures, but without an adverse effect on the breast and endometrium, and no negative effect or even a beneficial effect on the cardiovascular system and the brain. Currently, limited data are available with regard to these next-generation SERMs and CHD. Nevertheless, some of these novel agents provide arguments for continuing the search for an ideal SERM.

Cardiovascular Health and Aromatase Inhibitors

Cardiovascular disease is the most frequent cause of death in North American women, and so death resulting from cardiovascular disease, rather than from malignancy, is not uncommon in breast cancer patients. This may be a consequence of the shared risk factors for developing breast cancer and cardiovascular disease, as well as the difficulty of managing cancer patients at higher risk for developing cardiovascular disease. Recently, much attention has focused on understanding the cardiovascular risk factors associated with breast cancer therapies. Tamoxifen has a lowering effect on serum lipids and is reported to decrease the risk of myocardial infarction but to increase the risk of thromboembolic events. Current data indicate that aromatase inhibitors (AIs) are not associated with an increased risk of thromboembolic or cerebrovascular events. Reports of a greater incidence of hypercholesterolaemia when AIs are compared head-to-head with tamoxifen may be a result of the intrinsic lipid-lowering effects of tamoxifen therapy and may be confounded by differences in data collection among trials. The incidence of cardiovascular events associated with AIs in large trials has been reported to be higher in trials comparing AIs with tamoxifen; comparisons within the MA.17 trial, which evaluated an AI versus placebo, did not show increases in hypercholesterolaemia or in cardiovascular events with the AI. When treating breast cancer patients, oncologists should consider the same positive lifestyle changes that are proposed to lower the risk of cardiovascular disease in patients who do not have breast cancer. Moreover, physicians should assess cardiovascular risk, and monitor and treat patients already diagnosed with or at risk for coronary heart disease, according to established guidelines.

Tamoxifen for the prevention of breast cancer: current status of the National Surgical Adjuvant Breast and Bowel Project P-1 study

BACKGROUND

Initial findings from the National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention Trial (P-1) demonstrated that tamoxifen reduced the risk of estrogen receptor-positive tumors and osteoporotic fractures in women at increased risk for breast cancer. Side effects of varying clinical significance were observed. The trial was unblinded because of the positive results, and follow-up continued. This report updates our initial findings.

METHODS

Women (n = 13,388) were randomly assigned to receive placebo or tamoxifen for 5 years. Rates of breast cancer and other events were compared by the use of risk ratios (RRs) and 95% confidence intervals (CIs). Estimates of the net benefit from 5 years of tamoxifen therapy were compared by age, race, and categories of predicted breast cancer risk. Statistical tests were two-sided.

RESULTS

After 7 years of follow-up, the cumulative rate of invasive breast cancer was reduced from 42.5 per 1000 women in the placebo group to 24.8 per 1000 women in the tamoxifen group (RR = 0.57, 95% CI = 0.46 to 0.70) and the cumulative rate of noninvasive breast cancer was reduced from 15.8 per 1000 women in the placebo group to 10.2 per 1000 women in the tamoxifen group (RR = 0.63, 95% CI = 0.45 to 0.89). These reductions were similar to those seen in the initial report. Tamoxifen led to a 32% reduction in osteoporotic fractures (RR = 0.68, 95% CI = 0.51 to 0.92). Relative risks of stroke, deep-vein thrombosis, and cataracts (which increased with tamoxifen) and of ischemic heart disease and death (which were not changed with tamoxifen) were also similar to those initially reported. Risks of pulmonary embolism were approximately 11% lower than in the original report, and risks of endometrial cancer were about 29% higher, but these differences were not statistically significant. The net benefit achieved with tamoxifen varied according to age, race, and level of breast cancer risk.

CONCLUSIONS

Despite the potential bias caused by the unblinding of the P-1 trial, the magnitudes of all beneficial and undesirable treatment effects of tamoxifen were similar to those initially reported, with notable reductions in breast cancer and increased risks of thromboembolic events and endometrial cancer. Readily identifiable subsets of individuals comprising 2.5 million women could derive a net benefit from the drug.

Coronary Heart Disease Mortality After 5 Years of Adjuvant Tamoxifen Therapy: Results from a Randomized Trial

From January 1, 1983, through December 31, 1992, a total of 4610 patients entered a randomized trial that compared mortality among patients receiving 2 years of adjuvant tamoxifen therapy with that in patients receiving 5 years of adjuvant tamoxifen therapy, 4175 of whom were recurrence free after 2 years of tamoxifen therapy. Among the 2046 patients randomly assigned to the 5-year group all-cause mortality, breast cancer-specific mortality, and the incidence of contralateral breast cancer were reduced, compared with those among 2129 patients randomized in the 2-year group, but the incidence of endometrial cancer was increased. In addition, mortality from coronary heart disease was statistically significantly reduced in the 5-year group, compared with that in the 2-year group (hazard ratio = 0.67, 95% confidence interval = 0.47 to 0.94; P = .022 [two-sided Wald test]). Ten years after surgery, 2.1% of the patients in the 5-year group and 3.5% of those in the 2-year group had died from coronary heart disease. No statistically significant increases in mortality from other heart diseases, cerebrovascular diseases, or other vascular diseases were observed.

Tamoxifen-treated breast carcinoma patients and the risk of acute myocardial infarction and newly-diagnosed angina

BACKGROUND

It is known that tamoxifen therapy favorably affects blood cholesterol levels and other cardiovascular disease risk factors; however, to our knowledge, few studies to date have reported a lower risk of heart disease for breast carcinoma patients who are treated with tamoxifen.

METHODS

A nested, matched, case-control study design was used with data from the General Practice Research Database to examine whether patients with breast carcinoma who had been treated with tamoxifen were at reduced risk of having a first acute myocardial infarction (MI) or of developing angina compared with unexposed women. All women between age 30 years and age 85 years who had been diagnosed with breast carcinoma and treated with tamoxifen, or who had been diagnosed with carcinoma of the bladder or colorectum, or nonmelanoma skin cancer between January 1991 and December 1999 were identified. From this population, all women were identified who had newly diagnosed acute MI or angina that occurred at least 1 year after their cancer diagnosis. Four female control participants were matched to each case based on age (+/- 1 year), date of MI or angina diagnosis (corresponding date for matched controls), and date of cancer diagnosis (+/- 6 months). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were generated using conditional logistic regression, controlling for the matching factors, and adjusting for important risk factors, including body mass index, use of hormone replacement therapy, smoking status, and treated hypertension.

RESULTS

Current users of tamoxifen had a reduced rate ratio of acute MI or angina (adjusted OR, 0.4; 95% CI, 0.2-0.7) compared with nonusers. The effect persisted with increasing cumulative dose and length of use.

CONCLUSIONS

The treatment of breast carcinoma with tamoxifen was found to reduce a woman's risk of acute MI or angina during the 5 years of recommended therapy.

Agents that stabilise atherosclerotic plaque

The concept of plaque stabilisation was developed to explain how medications could decrease adverse coronary events without a substantial reduction in the regression of atherosclerosis. With this concept, a comprehensive view of atherosclerosis is now appreciated. A number of imaging modalities are employed to study atherosclerosis; most identify luminal diameter or stenosis, wall thickness and plaque volume. A number of antiatherosclerotic agents have been studied as well to prove this hypothesis. However, the ultimate goal of medical treatment is to cure or prevent diseases caused by atherosclerosis.

Plasma leptin concentration in tamoxifen-treated ovariectomized rats

Leptin, the ob gene product, has an important role in the regulation of body weight. Although tamoxifen, a nonsteroidal antiestrogenic agent, is known to have estrogenic effects on fat metabolism, its influence on adipose tissue remains unknown. In the present study, the effect of tamoxifen on the concentration of leptin was investigated in ovariectomized rats treated with tamoxifen or vehicle. The dosage of tamoxifen was extrapolated from the human dosage. Food intake, adipose tissue weight, and plasma insulin were assessed at the end of the experiment.

RESULTS

Tamoxifen-treated rats showed a significant reduction of body weight gain, food intake, adipose tissue weight and leptin concentration (p < 0.001). The plasma insulin level was significantly higher after tamoxifen treatment (p = 0.01) in tamoxifen-treated rats than in control rats. We concluded that tamoxifen reduces food intake in the acute phase and a reduction of adipose tissue gain may result in reduced levels of plasma leptin in ovariectomized rats. Furthermore, rats treated with tamoxifen may be resistant to insulin action.

Hormone Therapy and Selective Estrogen Receptor Modulators for Prevention of Coronary Heart Disease in Postmenopausal Women

Coronary heart disease is the leading cause of morbidity and mortality in women older than the age of 50 in the United States today. Traditional cardiovascular risk factors (hyperlipidemia, glucose intolerance, and hypertension) are more clearly associated with significant cardiovascular risk after menopause. The increased incidence of cardiovascular events in postmenopausal women and the evidence that cardiovascular disease on average manifests a decade later in women compared with men suggests that estrogen deficiency may predispose women to a higher cardiovascular risk. Numerous biologic mechanisms have been proposed that relate use of hormone therapy (HT) to improved lipid profiles, insulin sensitivity, and vascular reactivity. Early observational trials in the last 2 decades showed a significant decrease in cardiovascular events. Recently published randomized clinical trial results, however, have led to uncertainty about the earlier established cardiovascular benefits of HT. To complicate issues further, alternative estrogenlike compounds, selective estrogen receptor modulators, are being introduced that appear to convey similar cardiovascular benefit and notably less cancer risk than HT. The newly released randomized trials on hormone and nonhormonal agents are reviewed.

Peritoneal carcinoma in women with genetic susceptibility: implications for Jewish populations

Women from families with multiple cases of breast and ovarian cancer, specifically those who carry cancer-associated mutations of BRCA1 or BRCA2 are at increased life-time risk for peritoneal carcinoma, even after previous surgery to remove the ovaries, fallopian tubes and uterus. Hereditary breast-ovarian cancer (HBOC) syndrome and the associated BRCA1 and BRCA2 mutations are particularly prevalent in women of Jewish lineage, and specific BRCA1 and BRCA2 germline mutations have been linked with peritoneal carcinoma and HBOC syndrome in Jewish populations, especially those of Ashkenazi descent. This review presents the currently available data and looks forward toward further and better understanding of peritoneal carcinoma in women with inherited susceptibility. Over 90% of peritoneal cancer in patients from HBOC syndrome kindreds and associated with BRCA1 and BRCA2 mutations are serous carcinomas, which is equivalent with the proportion of ovarian cancers that are serous carcinomas in similar patients. The best indications are that while many peritoneal carcinomas in genetically susceptible women may arise directly from malignant transformation of the peritoneum, others might represent metastases from primary ovarian or fallopian tube carcinomas. Although the incidence of borderline ovarian tumors may not be increased in HBOC syndrome kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, these individuals could be susceptible to malignant transformation of borderline lesions of the ovaries and peritoneum. Moreover, recent reports raise the question of possibly increased risk in Jewish carriers of germline BRCA1 mutations for uterine papillary serous carcinoma, which could be the source of metastasis to the peritoneum in some cases. The penetrance of cancer-associated BRCA1 mutations for ovarian cancer is estimated to be 11%-54%, and for BRCA2 mutations the penetrance for ovarian cancer is 11%-23%. So far, available screening methods appear to be insufficient for early detection of many ovarian cancers. Prophylactic oophorectomy has been found to reduce the risk for ovarian cancer in women from HBOC kindreds and those who carry cancer-associated BRCA1 and BRCA2 mutations, leaving a residual risk for peritoneal carcinomatosis of well less than 5%. Therefore, surgical removal of the ovaries, fallopian tubes and uterus, after child-bearing has been completed and by early in the fifth decade of life, are appropriate prophylactic procedures in women whose genetic susceptibility puts them at increased risk for cancers of mullerian tract origin, including ovarian and fallopian tube carcinomas and possibly serous carcinoma of the uterus. Hysterectomy, as well as salpingo-oophorectomy, removes the gynecologic organs targeted for malignant transformation in genetically susceptible women and simplifies decisions regarding hormone replacement therapy and chemical prophylaxis and treatment of breast cancer. Unless a transabdominal operative approach is otherwise indicated, laparoscopic-assisted transvaginal techniques are well suited for intra-abdominal exploration, cytology, biopsies and prophylactic salpingo-oophorectomy and hysterectomy in women with hereditary susceptibility to gynecologic cancer.