Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women

Occult breast tumor reservoir: biological properties and clinical significance

Small, occult, undiagnosed breast cancers are found at autopsy in up to 15.6 % of women dying from unrelated causes with an average of 7 % from eight separate studies. The mammographic detection threshold of breast tumors ranges from 0.88 to 1.66 cm in diameter based on the patient's age. Tumor growth rates, expressed as "effective doubling times," vary from 10 to >700 days. We previously reported two models, based on iterative analysis of these parameters, to describe the biologic behavior of undiagnosed, occult breast tumors. Our models facilitate interpretation of the Women's Health Initiative (WHI) and antiestrogen breast cancer prevention studies. A nude mouse xenograft model was used to validate our assumption that breast tumors grow in a log-linear fashion. We then used our previously reported occult tumor growth (OTG) and computer-simulated tumor growth models to analyze various clinical trial data. Parameters used in the OTG model included a 200-day effective doubling time, 7 % prevalence of occult tumors, and 1.16 cm detection threshold. These models had been validated by comparing predicted with observed incidence of breast cancer in eight different populations of women. Our model suggests that menopausal hormone therapy with estrogens plus a progestogen (E + P) in the WHI trial primarily promoted the growth of pre-existing, occult lesions and minimally initiated de novo tumors. We provide a potential explanation for the lack of an increase in breast cancer incidence in the subgroup of women in the WHI who had not received E + P prior to randomization. This result may have reflected a leftward skew in the distribution of occult tumor doublings and insufficient time for stimulated tumors to reach the detection threshold. Our model predicted that estrogen alone reduced the incidence of breast cancer as a result of apoptosis. Understanding of the biology of occult tumors suggests that breast cancer "prevention" with antiestrogens or aromatase inhibitors represents early treatment rather than a reduction in de novo tumor formation. Our models suggest that occult, undiagnosed tumors are prevalent, grow slowly, and are the biologic targets of a hormone therapy in menopausal women and of antiestrogen therapy for prevention.

Invasive lobular carcinoma stable for 4.5 years in a postmenopausal woman user of hormone therapy for 25 years

We present a case of a 72-year-old woman referred to the breast disorder service due to abnormalities on mammography and breast ultrasound. The patient reported using different hormone therapy (HT) formulations during 25 years and had stopped taking HT for 4 years. Physical examination showed no alterations in the breasts or axilla. Mammography from 2012 detected asymmetry at the 3 o'clock position in the anterior right breast. Ultrasound revealed an irregular, hypoechoic mass with indistinct margins, and posterior acoustic shadowing. A retrospective analysis of mammographies from 2007, 2009 and 2010 showed that a very subtle asymmetry had existed since 2007. Follow-up imaging demonstrated no change in asymmetry during 4.5 years. The patient underwent breast-conserving therapy and sentinel lymph node biopsy. Histopathologic examination demonstrated classic invasive lobular carcinoma. There were no sentinel node metastases. The patient received radiotherapy and endrocrine therapy. This case demonstrates that breast cancer may remain stable and not grow for many years. This aspect should be kept in mind by all professionals dealing with women's healthcare, in particular HT users who may develop breast cancer with a less aggressive behavior. Any suspicious finding on mammography, despite being unchanged for a number of years, must be investigated.

Progestogens used in postmenopausal hormone therapy: differences in their pharmacological properties, intracellular actions, and clinical effects

The safety of progestogens as a class has come under increased scrutiny after the publication of data from the Women's Health Initiative trial, particularly with respect to breast cancer and cardiovascular disease risk, despite the fact that only one progestogen, medroxyprogesterone acetate, was used in this study. Inconsistency in nomenclature has also caused confusion between synthetic progestogens, defined here by the term progestin, and natural progesterone. Although all progestogens by definition have progestational activity, they also have a divergent range of other properties that can translate to very different clinical effects. Endometrial protection is the primary reason for prescribing a progestogen concomitantly with postmenopausal estrogen therapy in women with a uterus, but several progestogens are known to have a range of other potentially beneficial effects, for example on the nervous and cardiovascular systems. Because women remain suspicious of the progestogen component of postmenopausal hormone therapy in the light of the Women's Health Initiative trial, practitioners should not ignore the potential benefits to their patients of some progestogens by considering them to be a single pharmacological class. There is a lack of understanding of the differences between progestins and progesterone and between individual progestins differing in their effects on the cardiovascular and nervous systems, the breast, and bone. This review elucidates the differences between the substantial number of individual progestogens employed in postmenopausal hormone therapy, including both progestins and progesterone. We conclude that these differences in chemical structure, metabolism, pharmacokinetics, affinity, potency, and efficacy via steroid receptors, intracellular action, and biological and clinical effects confirm the absence of a class effect of progestogens.

Postmenopausal hormone therapy: risks and benefits

Postmenopausal hormone therapy (PMHT) is used for the relief of menopausal symptoms, but the dosage has varied greatly throughout its existence. By the end of the 1990s, PMHT was mainly used to prevent chronic diseases such as osteoporosis, coronary heart disease and dementia, and large prevention trials were undertaken in this context. Following the initial negative reports of these trials, use of PMHT dramatically decreased. These reports noted surprisingly increased risks, notably of coronary heart disease, stroke and breast cancer, in people who used PMHT. Nowadays, considering the currently available data, it seems that an important distinction should be made between the treatment of climacteric symptoms in young, generally healthy, postmenopausal women and the prevention of chronic diseases in elderly women. PMHT seems to be beneficial and safe for postmenopausal symptomatic women aged <60 years. Treatments with a high safety profile should be the preferred option, including low-dose PMHT, oestrogen-only therapy in women who have had a hysterectomy, and vaginal oestrogen therapy for women with atrophic vaginitis. Nonandrogenic progestin might have a reduced thrombotic and breast cancer risk, and transdermal oestrogen could have a reduced thrombotic risk. Nevertheless, PMHT should not be used for the prevention of chronic diseases in the elderly (>70 years old) owing to the increased risk of stroke and breast cancer in these patients.

Usefulness of pretreatment neutrophil to lymphocyte ratio in predicting disease-specific survival in breast cancer patients

PURPOSE

The purpose of this study was to investigate the prognostic impact of pretreatment neutrophil to lymphocyte ratio (NLR) on breast cancer in view of disease-specific survival and the intrinsic subtype.

METHODS

We retrospectively studied patients diagnosed with primary breast cancer that had completed all phases of primary treatment from 2000 to 2010. The association between pretreatment NLR and disease-specific survival was analyzed.

RESULTS

A total of 442 patients were eligible for analysis. Patients with higher NLR (2.5 ≤NLR) showed significantly lower disease-specific survival rate than those with lower NLR (NLR <2.5). Higher NLR along with negative estrogen receptor status and positive nodal status were independently correlated with poor prognosis, with hazard ratio 4.08 (95% confidence interval [CI], 1.62-10.28), 9.93 (95% CI, 3.51-28.13), and 11.23 (95% CI, 3.34-37.83), respectively. Luminal A subtype was the only intrinsic subtype in which higher NLR patients showed significantly poor prognosis (87.7% vs. 96.7%, p=0.009).

CONCLUSION

Patients with an elevated pretreatment NLR showed poorer disease-specific survival than patients without elevated NLR, most evident in the luminal A subtype. Further validation and a feasibility study are required before it can be considered for clinical use.

Estrogen plus progestin and breast cancer incidence and mortality in the Women's Health Initiative Observational Study

BACKGROUND

In the Women's Health Initiative (WHI) randomized trial, estrogen plus progestin increased both breast cancer incidence and mortality. In contrast, most observational studies associate estrogen plus progestin with favorable prognosis breast cancers. To address differences, a cohort of WHI observational study participants with characteristics similar to the WHI clinical trial was studied.

METHODS

We identified 41 449 postmenopausal women with no prior hysterectomy and mammogram negative within 2 years who were either not hormone users (n = 25 328) or estrogen and progestin users (n = 16 121). Multivariable-adjusted Cox proportional hazard regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CI). All statistical tests were two-sided.

RESULTS

After a mean of 11.3 (SD = 3.1) years, with 2236 breast cancers, incidence was higher in estrogen plus progestin users than in nonusers (0.60% vs 0.42%, annualized rate, respectively; HR = 1.55, 95% CI = 1.41 to 1.70, P < .001). Women initiating hormone therapy closer to menopause had higher breast cancer risk with linear diminishing influence as time from menopause increased (P < .001). Survival after breast cancer, measured from diagnosis, was similar in combined hormone therapy users and nonusers (HR = 1.03, 95% CI = 0.79 to 1.35). On a population basis, there were somewhat more deaths from breast cancer, measured from cohort entry (HR = 1.32, 95% CI = 0.90 to 1.93, P = .15), and more all-cause deaths after breast cancer (HR = 1.65, 95% CI = 1.29 to 2.12, P < .001) in estrogen plus progestin users than in nonusers.

CONCLUSIONS

Consistent with WHI randomized trial findings, estrogen plus progestin use is associated with increased breast cancer incidence. Because prognosis after diagnosis on combined hormone therapy is similar to that of nonusers, increased breast cancer mortality can be expected.

Progesterone receptor isoforms PRA and PRB differentially contribute to breast cancer cell migration through interaction with focal adhesion kinase complexes

Conditionally expressed progesterone receptor isoforms PRA and PRB enhance breast cancer cell migration through interaction with focal adhesion kinase (FAK) and differential regulation of FAK phosphorylation and turnover. PRB-stimulated migration is reduced by progestins, which is prevented by PR antagonists or agonist-bound PRA.

Progesterone receptor (PR) and progestins affect mammary tumorigenesis; however, the relative contributions of PR isoforms A and B (PRA and PRB, respectively) in cancer cell migration remains elusive. By using a bi-inducible MDA-MB-231 breast cancer cell line expressing PRA and/or PRB, we analyzed the effect of conditional PR isoform expression. Surprisingly, unliganded PRB but not PRA strongly enhanced cell migration as compared with PR(–) cells. 17,21-Dimethyl-19-norpregna-4,9-dien-3,20-dione (R5020) progestin limited this effect and was counteracted by the antagonist 11β-(4-dimethyl­amino)­phenyl-17β-hydroxy-17-(1-propynyl)­estra-4,9-dien-3-one (RU486). Of importance, PRA coexpression potentiated PRB-mediated migration, whereas PRA alone was ineffective. PR isoforms differentially regulated expressions of major players of cell migration, such as urokinase plasminogen activator (uPA), its inhibitor plasminogen activator inhibitor type 1, uPA receptor (uPAR), and β1-integrin, which affect focal adhesion kinase (FAK) signaling. Moreover, unliganded PRB but not PRA enhanced FAK Tyr397 phosphorylation and colocalized with activated FAK in cell protrusions. Because PRB, as well as PRA, coimmunoprecipitated with FAK, both isoforms can interact with FAK complexes, depending on their respective nucleocytoplasmic trafficking. In addition, FAK degradation was coupled to R5020-dependent turnovers of PRA and PRB. Such an effect of PRB/PRA expression on FAK signaling might thus affect adhesion/motility, underscoring the implication of PR isoforms in breast cancer invasiveness and metastatic evolution with underlying therapeutic outcomes.

Demographic and health factors associated with enrollment in posttrial studies: the Women's Health Initiative Hormone Therapy Trials

BACKGROUND

After clinical trials end, continued follow-up of the assembled cohort often is desirable for additional research. Factors influencing participants' decisions to consent to additional follow-up and how these shape posttrial cohorts have not been broadly studied.

PURPOSE

We examined how two re-enrollment campaigns and the passage of time altered features of the posttrial cohorts compared with the original Women's Health Initiative (WHI) Hormone Therapy clinical trials.

METHODS

We examined associations that markers of sociodemography, health, lifestyle, and on-trial experiences had with re-enrollment and contrasted the characteristics of successive posttrial cohorts with those of the original enrollees.

RESULTS

The posttrial enrollment campaigns re-enrolled 81.1% and 82.5% of available women, respectively. Women who re-enrolled tended to have better health characteristics than those not re-enrolled. Compared to women of comparable age in the original cohort, women retained for the second posttrial follow-up less often had a history of cardiovascular disease (odds ratio (OR) = 0.36), hypertension (OR = 0.57), diabetes (OR = 0.59), or measured cognitive deficit (OR = 0.40). These women more often had graduated from high school (OR = 1.72) and had participated in other WHI trials (OR = 1.76).

LIMITATIONS

We have examined experience with creating follow-up cohorts from participants in a single study. Thus, our findings may not apply to other cohorts and protocols.

CONCLUSIONS

Posttrial enrollment in follow-up studies can be successful; however, the characteristics of the resulting cohort may differ substantially from the originally assembled group of trial participants. Collection during the original trial of potential predictors of differential re-enrollment may strengthen interpretation of findings.

Modulation of higher-primate adrenal androgen secretion with estrogen-alone or estrogen-plus-progesterone intervention

OBJECTIVE

Circulating adrenal steroids rise during the menopausal transition in most middle-aged women and may contribute to differences in between-women symptoms and ultimate health outcomes. However, the mechanisms for this shift in adrenal steroid production in middle-aged women are not known. This study aims to determine whether hormone therapy (HT) for 1 year can modulate adrenal androgen production.

METHODS

Younger (9.8 [0.4] years, n = 20) and older (22.7 [0.4] years, n = 37) female laboratory macaques were ovariectomized, and each group was treated with different regimens of HT for up to 1 year. Changes in adrenal histology and circulating adrenal androgens were monitored after estrogen-alone (E) or estrogen plus progesterone (E + P) treatment, and these changes were compared with the same measures in similarly aged animals given vehicle.

RESULTS

Zona reticularis area, serum dehydroepiandrosterone (DHEA), and serum dehydroepiandrosterone sulfate (DHEAS) were higher in younger vehicle-treated animals compared with older vehicle-treated animals (P < 0.02). Both E and E + P treatments decreased circulating DHEAS in the younger group (P < 0.05). Although E treatment also decreased DHEAS in the older group, this was not statistically significant. In contrast, E + P treatment in the older group resulted in a rise in DHEAS over vehicle, which was significantly higher than the results of E treatment (P < 0.01). Circulating concentrations of DHEA exhibited similar trends, but these changes did not reach statistical significance.

CONCLUSIONS

These data demonstrate that intervention with ovarian steroids can modulate adrenal androgen production in female higher primates and that both animal age and type of HT regimen determine adrenal response.

A genome-wide association study to identify genetic susceptibility loci that modify ductal and lobular postmenopausal breast cancer risk associated with menopausal hormone therapy use: a two-stage design with replication

Menopausal hormone therapy (MHT) is associated with an elevated risk of breast cancer in postmenopausal women. To identify genetic loci that modify breast cancer risk related to MHT use in postmenopausal women, we conducted a two-stage genome-wide association study (GWAS) with replication. In stage I, we performed a case-only GWAS in 731 invasive breast cancer cases from the German case-control study Mammary Carcinoma Risk Factor Investigation (MARIE). The 1,200 single nucleotide polymorphisms (SNPs) showing the lowest P values for interaction with current MHT use (within 6 months prior to breast cancer diagnosis), were carried forward to stage II, involving pooled case-control analyses including additional MARIE subjects (1,375 cases, 1,974 controls) as well as 795 cases and 764 controls of a Swedish case-control study. A joint P value was calculated for a combined analysis of stages I and II. Replication of the most significant interaction of the combined stage I and II was performed using 5,795 cases and 5,390 controls from nine studies of the Breast Cancer Association Consortium (BCAC). The combined stage I and II yielded five SNPs on chromosomes 2, 7, and 18 with joint P values <6 × 10(-6) for effect modification of current MHT use. The most significant interaction was observed for rs6707272 (P = 3 × 10(-7)) on chromosome 2 but was not replicated in the BCAC studies (P = 0.21). The potentially modifying SNPs are in strong linkage disequilibrium with SNPs in TRIP12 and DNER on chromosome 2 and SETBP1 on chromosome 18, previously linked to carcinogenesis. However, none of the interaction effects reached genome-wide significance. The inability to replicate the top SNP × MHT interaction may be due to limited power of the replication phase. Our study, however, suggests that there are unlikely to be SNPs that interact strongly enough with MHT use to be clinically significant in European women.

Bone mineral density is a prognostic factor for postmenopausal caucasian women with breast cancer

Numerous studies have convincingly shown that women with low bone mineral density have lower risk of breast cancer. As many risk factors for breast cancer are also prognostic factors, we hypothesized that women with breast cancer and low bone mineral density will have lower breast cancer recurrence rates than women with normal bone densities. A prospectively collected data base of breast cancer patients was used to identify postmenopausal Caucasian women. Their records were reviewed and 309 patients with complete follow-up and bone density tests within 1 year of their surgery were identified. The outcome of patients with low bone density (t > -1.0) was compared to the outcome for patients with normal bone density (t < -1.1). Among the 193 patients with invasive breast cancers and low bone density, distant disease-free survival at 5 years was 96% compared to 84% for 114 patients with invasive breast cancers and normal bone density (p = 0.0239). Local disease-free survival was 94% for low bone density patients compared to 86% for patients with normal bone densities (p = 0.0794). Bone mineral density is a significant prognostic factor for postmenopausal Caucasian women with breast cancer. Low bone mineral density is associated with a lower local and distant rate of recurrence.

Molecular mapping the presence of druggable targets in preinvasive and precursor breast lesions: a comprehensive review of biomarkers related to therapeutic interventions

The analysis of clinical breast samples using biomarkers is integral to current breast cancer management. Currently, a limited number of targeted therapies are standard of care in breast cancer treatment. However, these targeted therapies are only suitable for a subset of patients and resistance may occur. Strategies to prevent the occurrence of invasive lesions are required to reduce the morbidity and mortality associated with the development of cancer. In theory, application of targeted therapies to pre-invasive lesions will prevent their progression to invasive lesions with full malignant potential. The diagnostic challenge for pathologists is to make interpretative decisions on early detected pre-invasive lesions. Overall, only a small proportion of these pre-invasive lesions will progress to invasive carcinoma and morphological assessment is an imprecise and subjective means to differentiate histologically identical lesions with varying malignant potential. Therefore differential biomarker analysis in pre-invasive lesions may prevent overtreatment with surgery and provide a predictive indicator of response to therapy. There follows a review of established and emerging potential druggable targets in pre-invasive lesions and correlation with lesion morphology.

Breast cancer subtypes in Asian-Americans differ according to Asian ethnic group

Breast cancer prognosis and breast cancer molecular subtype vary by race/ethnicity. We determined whether the distribution of breast cancer subtypes varies among different Asian ethnic groups. Using immunohistochemical surrogates for the four molecularly defined breast cancer subtypes, we characterized breast cancer subtype for 346 Asian subjects treated at two New York City institutions. We found that Chinese and Japanese had a higher proportion of good-prognosis luminal A cancers (66.7 and 80.0%, respectively) compared to Filipinos and Koreans (48.5 and 47.1%) (P = 0.001). Filipinos had a higher proportion of HER-2/neu positive cancers (45.6%) compared to other ethnic groups (23.6%) (P = 0.002).Koreans had a higher proportion of triple negative cancers(23.5%) compared to other ethnic groups (7.5%) (P =0.06). The results suggest that differences exist in breast cancer tumor biology among distinct Asian ethnic groups and have implications for cancer care and research. Future studies of breast cancer in Asian-Americans should distinguish among the different ethnic groups.

Tissue selective estrogen complexes (TSECs) differentially modulate markers of proliferation and differentiation in endometrial cells

Selective estrogen receptor modulators (SERMs) have tissue-specific estrogen receptor (ER) modulating properties. Combining an SERM with one or more estrogens to form a tissue selective estrogen complex (TSEC) can provide an improved blend of tissue-specific ER agonist and antagonist effects. While both estrogens and SERMs affect the uterine endometrium, not all TSECs reverse the endometrial effects of estrogens preventing endometrial proliferation and hyperplasia. Their action in uterine cells is not completely understood. HOXA 10, leukemia inhibitory factor (LIF), progesterone receptor (PR), and EMX2 are genes known to regulate endometrial proliferation and differentiation. The expression of these genes was used to assess endometrial effects of SERMs and TSECs. We evaluated the effects of raloxifene (RAL), tamoxifen (TAM), lasofoxifene (LAS), bazedoxifene acetate (BZA), and progesterone (P) alone and in combination with estradiol (E2) in Ishikawa cells. Increased HOXA10, LIF, PR, and EMX2 messenger RNA (mRNA) expression was noted in E2-treated cells compared with vehicle-treated controls. All TSECs maintained E2-induced PR expression and all except TAM prevented estrogen-induced LIF expression. The TSEC containing BZA uniquely decreased HOXA10 expression and increased EMX2 expression. The TSECs alter endometrial cell proliferation by selective modulation of estrogen responsive genes, maintaining the antiproliferative effects mediated by PR and inhibiting LIF. The differential effect of TSECs on endometrial gene expression suggests a mechanism by which they manifest differential effects on endometrial safety against the risk of estrogen-induced endometrial hyperplasia.

Ospemifene, vulvovaginal atrophy, and breast cancer

The incidence and severity of vulvovaginal atrophy (VVA) in postmenopausal breast cancer patients has a significant impact on quality of life. While the etiology of VVA is primarily related to low estrogen levels seen in menopause, women with breast cancer have an added risk of VVA induced by a combination of chemotherapy, hormonal therapy, and menopause. Ospemifene is a new, non-hormonal selective estrogen receptor modulator (SERM) triphenylethylene derivative that is effective in treating VVA in postmenopausal women. Although other SERMs have antagonistic effects on the vagina, ospemifene exerts an estrogen-like effect on the vaginal epithelium. This review will focus on data demonstrating the antiestrogenic activity of ospemifene in several unique breast cancer animal models, and the implications for utilizing ospemifene in patients with breast cancer suffering from VVA. Additional research addressing the expanded use of ospemifene in breast cancer patients is also warranted.

The hyperplastic phenotype in PR-A and PR-B transgenic mice: lessons on the role of estrogen and progesterone receptors in the mouse mammary gland and breast cancer

Progesterone receptor (PR) belongs to the superfamily of steroid receptors and mediates the action of progesterone in its target tissues. In the mammary gland, in particular, PR expression is restricted to the luminal epithelial cell compartment. The generation of estrogen receptor-α (ER) and PR knockout mice allowed the specific characterization of the roles of each of these in mammary gland development: ER is critical for ductal morphogenesis, whereas PR has a key role in lobuloalveolar differentiation. To further study the role PR isoforms have in mammary gland biology, transgenic mice overexpressing either the "A" (PR-A) or the "B" (PR-B) isoforms of PR were generated. Overexpression of the A isoform of PR led to increased side branching, multilayered ducts, loss of basement membrane integrity, and alterations in matrix metalloproteinase activation in the mammary gland. Moreover, levels of TGFβ1 and p21 were diminished and those of cyclin D1 increased. Interestingly, the phenotype was counteracted by antiestrogens, suggesting that ER is essential for the manifestation of the hyperplasias. Mice overexpressing the B isoform of PR had limited ductal growth but retained the ability to differentiate during pregnancy. Levels of latent and active TGFβ1 were increased compared to PR-A transgenics. The phenotypes of these transgenic mice are further discussed in the context of the impact of progesterone on mammary stem cells and breast cancer. We conclude that an adequate balance between the A and B isoforms of PR is critical for tissue homeostasis. Future work to further understand the biology of PR in breast biology will hopefully lead to new and effective preventive and therapeutic alternatives for patients.

Progesterone-inducible cytokeratin 5-positive cells in luminal breast cancer exhibit progenitor properties

Progestins play a deleterious role in the onset of breast cancer, yet their influence on existing breast cancer and tumor progression is not well understood. In luminal estrogen receptor (ER)- and progesterone receptor (PR)-positive breast cancer, progestins induce a fraction of cells to express cytokeratin 5 (CK5), a marker of basal epithelial and progenitor cells in the normal breast. CK5(+) cells lose expression of ER and PR and are relatively quiescent, increasing their resistance to endocrine and chemotherapy compared to intratumoral CK5(-)ER(+)PR(+) cells. Characterization of live CK5(+) cells has been hampered by a lack of means for their direct isolation. Here, we describe optical (GFP) and bioluminescent (luciferase) reporter models to quantitate and isolate CK5(+) cells in luminal breast cancer cell lines utilizing the human KRT5 gene promoter and a viral vector approach. Using this system, we confirmed that the induction of GFP(+)/CK5(+) cells is specific to progestins, is dependent on PR, can be blocked by antiprogestins, and does not occur with other steroid hormones. Progestin-induced, fluorescence-activated cell sorting-isolated CK5(+) cells had lower ER and PR mRNA, were slower cycling, and were relatively more invasive and sphere forming than their CK5(-) counterparts in vitro. Repeated progestin treatment and selection of GFP(+) cells enriched for a persistent population of CK5(+) cells, suggesting that this transition can be semi-permanent. These data support that in PR(+) breast cancers, progestins induce a subpopulation of CK5(+)ER(-)PR(-) cells with enhanced progenitor properties and have implications for treatment resistance and recurrence in luminal breast cancer.

Brain angiotensin and dopaminergic degeneration: relevance to Parkinson's disease

The pathogenic mechanism of Parkinson's disease (PD) appears to be multifactorial. However, oxidative stress and neuroinflammation, including activation of NADPH-dependent oxidases, play a major role in the progression of dopaminergic cell death. The renin-angiotensin system (RAS) was described as a circulating humoral system that regulates blood pressure and water homeostasis. However, there exist local RAS in many tissues, and locally formed angiotensin activates NADPH-dependent oxidases, which are a major source of superoxide and are upregulated in major aging-related diseases such as hypertension, diabetes and atherosclerosis. Furthermore, an intracellular or intracrine RAS, with still unknown functions, has been identified in several cell types. The brain has an independent local RAS, which has been involved in several brain disorders, including neurodegenerative diseases. It is particularly interesting for PD the important interaction observed between angiotensin and dopamine, which counterregulate each other in renal cells and also in the striatum and substantia nigra. In recent studies, we have observed both a local and an intracellular RAS in the rodent, monkey and human substantia nigra, and that dopamine depletion induced RAS upregulation possibly as a compensatory mechanism. However, RAS hyperactivation also exacerbated oxidative stress and neuroinflammation, which contributed to progression of dopaminergic degeneration. In addition, we observed increased RAS activity in the nigra of animals with higher vulnerability of dopaminergic neurons to degeneration, such as aged males, menopausal females and rats subjected to chronic brain hypoperfusion. RAS activity and dopaminergic vulnerability were significantly reduced by treatment with angiotensin type I receptor antagonists. Manipulation of the brain RAS may constitute an effective neuroprotective strategy against dopaminergic degeneration in PD.

Progestin modulates the lipid profile and sensitivity of breast cancer cells to docetaxel

Progestins induce lipid accumulation in progesterone receptor (PR)-positive breast cancer cells. We speculated that progestin-induced alterations in lipid biology confer resistance to chemotherapy. To examine the biology of lipid loaded breast cancer cells, we used a model of progestin-induced lipid synthesis. T47D (PR-positive) and MDA-MB-231 (PR-negative) cell lines were used to study progestin response. Oil red O staining of T47D cells treated with progestin showed lipid droplet formation was PR dependent, glucose dependent and reduced sensitivity to docetaxel. This protection was not observed in PR-negative MDA-MB-231 cells. Progestin treatment induced stearoyl CoA desaturase-1 (SCD-1) enzyme expression and chemical inhibition of SCD-1 diminished lipid droplets and cell viability, suggesting the importance of lipid stores in cancer cell survival. Gas chromatography/mass spectroscopy analysis of phospholipids from progestin-treated T47D cells revealed an increase in unsaturated fatty acids, with oleic acid as most abundant. Cells surviving docetaxel treatment also contained more oleic acid in phospholipids, suggesting altered membrane fluidity as a potential mechanism of chemoresistance mediated in part by SCD-1. Lastly, intact docetaxel molecules were present within progestin induced lipid droplets, suggesting a protective quenching effect of intracellular lipid droplets. Our studies suggest the metabolic adaptations produced by progestin provide novel metabolic targets for future combinatorial therapies for progestin-responsive breast cancers.

The anticancer agent YC-1 suppresses progestin-stimulated VEGF in breast cancer cells and arrests breast tumor development

Recent epidemiological studies show that postmenopausal women taking estrogen-progestin hormone replacement therapy (HRT) have a higher risk of breast cancer than women on an HRT regimen lacking progestins. This may be related to the observation that progestin-treated breast cancer cells express and secrete high levels of vascular endothelial growth factor (VEGF), a potent angiogenic factor that promotes breast tumor growth. Anti-progestins such as RU-486 block this effect, indicating that progesterone receptors (PR) are involved in promoting VEGF induction; however antiprogestins cross-react with other steroid receptors which limits their clinical use. Alternative strategies are, therefore, needed to arrest the growth of progestin-dependent tumors. 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1), a novel anticancer drug initially developed as an inhibitor of HIF-1α, is currently undergoing preclinical trials against various forms of cancer. Since HIF-1α has recently been implicated in PR-mediated VEGF synthesis, we undertook studies to determine whether YC-1 inhibits progestin-dependent VEGF induction and tumor progression. Surprisingly, we found that YC-1 downregulated PR in human breast cancer cells, both in vivo and in vitro, thereby blocking progestin-dependent induction of VEGF and tumor growth. YC-1 also inhibited progestin-accelerated DMBA-induced mammary tumors in rats, properties which would likely render it effective against progestin-dependent tumors which frequently develop in post-menopausal women. We, therefore, propose that based on our observations, YC-1 warrants further investigation as a novel agent which could prove extremely useful as an anti-angiogenic chemotherapeutic drug.

Fertility (male and female) and Menopause

The impact of oncologic treatments on fertility and menopausal symptoms is often significant for patients with cancer. Surgery, radiation, and chemotherapy can all damage the reproductive organs or the hypothalamic pituitary axis that controls them, impairing fertility and causing hormonally mediated symptoms such as hot flashes.

Understanding these risks and strategies to mitigate them may substantially improve cancer survivorship care. For both female and male patients who desire a future biologic child, there are a variety of fertility preservation techniques that should be considered. For cancer survivors who experience menopausal symptoms, lifestyle changes may be beneficial, and hormonal and nonhormonal pharmacologic agents are well proven to reduce symptom burden.

A multimineral natural product from red marine algae reduces colon polyp formation in C57BL/6 mice

The goal of this study was to determine if a multimineral natural product derived from red marine algae could reduce colon polyp formation in mice on a high-fat diet. C57BL/6 mice were maintained for up to 18 mo either on a high-fat "Western-style" diet or on a low-fat diet (AIN 76A), with or without the multimineral-supplement. To summarize, colon polyps were detected in 22 of 70 mice (31%) on the high-fat diet but in only 2 of 70 mice (3%) receiving the mineral-supplemented high-fat diet (P < 0.0001). Colon polyps were detected in 16 of 70 mice (23%) in the low-fat group; not significantly different from high-fat group but significantly higher than the high-fat-supplemented group (P = 0.0006). This was in spite of the fact that the calcium level in the low-fat diet was comparable to the level of calcium in the high-fat diet containing the multimineral-product. Supplementation of the low-fat diet reduced the incidence to 8 of 70 mice (11% incidence). Taken together, these findings demonstrate that a multimineral natural product can protect mice on a high-fat diet against adenomatous polyp formation in the colon. These data suggest that increased calcium alone is insufficient to explain the lower incidence of colon polyps.

Preventive effects of phytoestrogens against postmenopausal osteoporosis as compared to the available therapeutic choices: An overview

Estrogen deficiency is a major risk factor for osteoporosis in postmenopausal women. Although hormone replacement therapy (HRT) has been rampantly used to recompense for the bone loss, but the procedure is coupled with severe adverse effects. Hence, there is a boost in the production of newer synthetic products to ward off the effects of menopause-related osteoporosis. As of today, there are several prescription products available for the treatment of postmenopause osteoporosis; most of these are estrogenic agents and combination products. Nevertheless, in view of the lack of effect and/or toxicity of these products, majority of the postmenopausal women are now fascinated by highly publicized natural products. This is an offshoot of the generalized consensus that these products are more effective and free from any adverse effects. Recently, certain plant-derived natural products, mostly phytoestrogens (isoflavones, lignans, coumestanes, stilbenes, flavonoids) and many more novel estrogen-like compounds in plants have been immensely used to prevent menopause-related depletion in bone mineral density (BMD). Although, a number of papers are published on menopause-related general symptoms, sexual dysfunction, cardiovascular diseases, Alzheimer's disease, diabetes, colon, and breast cancers, there is paucity of literature on the accompanying osteoporosis and its treatment. In view of the controversies on synthetic hormones and drugs and drift of a major population of patients toward natural drugs, it was found worthwhile to investigate if these drugs are suitable to be used in the treatment of postmenopausal osteoporosis. Preparation of this paper is an attempt to review the (a) epidemiology of postmenopausal osteoporosis, (b) treatment modalities of postmenopausal osteoporosis by hormones and synthetic drugs and the associated drawbacks and adverse effects, and (c) prevention and treatment of postmenopausal osteoporosis by phytoestrogens, their drawbacks and toxicity. It is apparent that both the categories of treatment are useful and both have adverse effects, but the plant products are nonscientific and hence are not advised to be used till more studies are undertaken to ensure that the benefits clearly outweigh the risk, in addition to recognition by Food and Drug Administration.

Breast cancer incidence by estrogen receptor status in Denmark from 1996 to 2007

During the past 50 years, breast cancer incidence has increased by 2-3 % annually. Despite many years of testing for estrogen receptors (ER), evidence is scarce on breast cancer incidence by ER status. The aim of this paper was to investigate the increase in breast cancer incidence by ER status. Data were obtained from the clinical database of the Danish Breast Cancer Cooperative Group which holds nationwide data on diagnosis, including pathology, treatment, and follow-up on primary breast cancers since 1977. All Danish women <80 years diagnosed with primary breast cancer 1996-2007 were identified in this prospective register based study. ER status was evaluated using immunohistochemical staining by standardized laboratory methods in the Danish Pathology Departments and reported to the database. From 1996 to 2007, breast cancer incidence increased overall with a tendency to level off after 2002. In all women a significant decrease was found in ER unknown tumors. However, in both pre- and postmenopausal women, significant increases were seen in incidence of ER+ tumors; though the increase levelled off for premenopausal women after 2002. In postmenopausal women, the incidence of ER- breast cancer decreased significantly throughout the period. In women <35 years, we found a minor non-significant increase in both ER+ and ER- tumors. ER unknown decreased in all women and was the most distinct in premenopausal women aged 35+. We found a significant increase in ER+ breast cancer incidence in postmenopausal women whereas the incidence in premenopausal women (aged 35+) levelled off after 2002.

Progesterone and estrogen receptors segregate into different cell subpopulations in the normal human breast

Progesterone is critical in normal breast development and its synthetic derivatives are emerging as major drivers of breast cancer risk. The recent demonstration that progesterone regulates the stem cell compartment in the murine mammary gland, despite the absence of progesterone receptor (PR) in mammary stem cells, highlights the fact that PR distribution in progenitor cell subsets in the human breast remains to be conclusively shown. By utilising two independent cell sorting strategies to fractionate cells into distinct subpopulations enriched for different cell lineage characteristics, we have demonstrated a consistent enrichment of PR transcripts, relative to estrogen receptor transcripts, in the bipotent progenitor subfraction in the normal human breast. We have also shown co-expression of both steroid hormone receptors with basal markers in a subset of human breast cells, and finally we have demonstrated that PR+ bipotent progenitor cells are estrogen-insensitive, and that estrogen regulates PR in mature luminal cells only.

Estrogen plus progestin and colorectal cancer incidence and mortality

PURPOSE

During the intervention phase in the Women's Health Initiative (WHI) clinical trial, use of estrogen plus progestin reduced the colorectal cancer diagnosis rate, but the cancers were found at a substantially higher stage. To assess the clinical relevance of the findings, analyses of the influence of combined hormone therapy on colorectal cancer incidence and colorectal cancer mortality were conducted after extended follow-up.

PATIENTS AND METHODS

The WHI study was a randomized, double-blind, placebo-controlled clinical trial involving 16,608 postmenopausal women with an intact uterus who were randomly assigned to daily 0.625 mg conjugated equine estrogen plus 2.5 mg medroxyprogesterone acetate (n = 8,506) or matching placebo (n = 8,102). Colorectal cancer diagnosis rates and colorectal cancer mortality were assessed.

RESULTS

After a mean of 5.6 years (standard deviation [SD], 1.03 years) of intervention and 11.6 years (SD, 3.1 years) of total follow-up, fewer colorectal cancers were diagnosed in the combined hormone therapy group compared with the placebo group (diagnoses/year, 0.12% v 0.16%; hazard ratio [HR], 0.72; 95% CI, 0.56 to 0.94; P = .014). Bowel screening examinations were comparable between groups throughout. Cancers in the combined hormone therapy group more commonly had positive lymph nodes (50.5% v 28.6%; P < .001) and were at higher stage (regional or distant, 68.8% v 51.4%; P = .003). Although not statistically significant, there was a higher number of colorectal cancer deaths in the combined hormone therapy group (37 v 27 deaths; 0.04% v 0.03%; HR, 1.29; 95% CI, 0.78 to 2.11; P = .320).

CONCLUSION

The findings, suggestive of diagnostic delay, do not support a clinically meaningful benefit for combined hormone therapy on colorectal cancer.

Labisia pumila Prevents Complications of Osteoporosis by Increasing Bone Strength in a Rat Model of Postmenopausal Osteoporosis

Estrogen replacement therapy (ERT) is the main treatment postmenopausal osteoporosis. However, ERT causes serious side effects, such as cancers and thromboembolic problems. Labisia pumila var. alata (LPva) is a herb with potential as an alternative to ERT to prevent complications of osteoporosis, especially fragility fractures. This study was conducted to determine the effects of LPva on the biomechanical strength of femora exposed to osteoporosis due to estrogen deficiency, using the postmenopausal rat model. Thirty-two female rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LP), and ovariectomized with ERT (Premarin) (ERT). The LPva and ERT were administered via oral gavage daily at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized, and their right femora were prepared for bone biomechanical testing. The results showed that ovariectomy compromised the femoral strength, while LPva supplementation to the ovariectomized rats improved the femoral strength. Therefore, LPva may be as effective as ERT in preventing fractures due to estrogen-deficient osteoporosis.

The tissue selective estrogen complex: a promising new menopausal therapy

Menopause is associated with health concerns including vasomotor symptoms, vulvar/vaginal atrophy (VVA), and osteoporosis. Estrogen therapy or combined estrogen-progestin therapy (EPT) are primary treatment options for menopausal symptom relief and osteoporosis prevention. Because EPT has been associated with some safety/tolerability concerns relating to undesirable effects of estrogen and progestin, alternative options are needed. The tissue selective estrogen complex (TSEC) is a novel class of agents pairing a selective estrogen receptor modulator (SERM) with 1 or more estrogens. The TSEC combines the established efficacy of estrogens on menopausal symptoms and bone with the protective effects of a SERM on the reproductive tract. The pairing of bazedoxifene (BZA) with conjugated estrogens (CE) has been evaluated in a series of phase 3 clinical trials. BZA 20 mg/CE 0.45 mg and BZA 20 mg/CE 0.625 mg have shown efficacy in reducing the frequency and severity of hot flushes, relieving VVA symptoms, and maintaining bone mass while protecting the endometrium and breast. These BZA/CE doses have been associated with a favorable safety/tolerability profile, with higher rates of cumulative amenorrhea and lower incidences of breast pain than those reported for EPT. Thus, BZA/CE may be a promising alternative to conventional EPT for treating non-hysterectomized, postmenopausal women.

Can breast cancer patients use soyafoods to help reduce risk of CHD?

Over the past 20 years, the popularity of soyafoods has increased in part because of research suggesting that these foods convey health benefits independent of their nutrient content. For example, in 1999, the US Food and Drug Administration approved a health-claim for soyafoods and CHD based on the hypocholesterolaemic effects of soya protein. However, soyafoods have become controversial in recent years because of concerns that their uniquely rich phyto-oestrogen (isoflavone) content may cause untoward effects in some individuals. Most notable in this regard is the concern that soyafoods are contraindicated for breast cancer patients and women at high risk of developing this disease. Furthermore, the hypocholesterolaemic effects of soya protein have been challenged. However, the results of recently published meta-analyses indicate that soya protein directly lowers circulating LDL-cholesterol levels by approximately 4 %. There is also intriguing evidence that soyafoods reduce CHD risk independent of their effects on lipid levels. In regard to the breast cancer controversy, recently published clinical and epidemiological data do not support observations in rodents that soyabean isoflavones increase breast cancer risk. In postmenopausal women, isoflavone exposure does not adversely affect breast tissue density or breast cell proliferation. Furthermore, both US and Chinese prospective epidemiological studies show that post-diagnosis soya consumption is associated with an improved prognosis. Therefore, soyafoods should be considered by women as healthy foods to include in diets aimed at reducing the risk of CHD regardless of their breast cancer status.

The role of genetic breast cancer susceptibility variants as prognostic factors

Recent genome-wide association studies identified 11 single nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk. We investigated these and 62 other SNPs for their prognostic relevance. Confirmed BC risk SNPs rs17468277 (CASP8), rs1982073 (TGFB1), rs2981582 (FGFR2), rs13281615 (8q24), rs3817198 (LSP1), rs889312 (MAP3K1), rs3803662 (TOX3), rs13387042 (2q35), rs4973768 (SLC4A7), rs6504950 (COX11) and rs10941679 (5p12) were genotyped for 25 853 BC patients with the available follow-up; 62 other SNPs, which have been suggested as BC risk SNPs by a GWAS or as candidate SNPs from individual studies, were genotyped for replication purposes in subsets of these patients. Cox proportional hazard models were used to test the association of these SNPs with overall survival (OS) and BC-specific survival (BCS). For the confirmed loci, we performed an accessory analysis of publicly available gene expression data and the prognosis in a different patient group. One of the 11 SNPs, rs3803662 (TOX3) and none of the 62 candidate/GWAS SNPs were associated with OS and/or BCS at P<0.01. The genotypic-specific survival for rs3803662 suggested a recessive mode of action [hazard ratio (HR) of rare homozygous carriers=1.21; 95% CI: 1.09-1.35, P=0.0002 and HR=1.29; 95% CI: 1.12-1.47, P=0.0003 for OS and BCS, respectively]. This association was seen similarly in all analyzed tumor subgroups defined by nodal status, tumor size, grade and estrogen receptor. Breast tumor expression of these genes was not associated with prognosis. With the exception of rs3803662 (TOX3), there was no evidence that any of the SNPs associated with BC susceptibility were associated with the BC survival. Survival may be influenced by a distinct set of germline variants from those influencing susceptibility.

The pharmacogenomics of sex hormone metabolism: breast cancer risk in menopausal hormone therapy

With women in western countries spending nearly one-third of their lifetime beyond menopause and a substantial number of these women facing severe menopausal symptoms, the goal of sex hormone pharmacogenomics is to promote the safe use of hormone replacement therapy (HRT). This could be achieved by providing molecular predictors for the upfront stratification of women in need of relief from menopausal symptoms into those with a likely benefit from HRT and those with a contraindication due to an HRT-associated breast cancer risk or other adverse effects. An increasing knowledge base of sex hormone metabolism and its variability, HRT outcomes and breast cancer susceptibility, as well as emerging examples of pharmacogenomic predictors, underscore the potential relevance of genetic variations for HRT outcome. The genes responsible for the metabolism, signaling and action of sex hormones are at the heart of this research; however, pharmacogenomic investigation of their therapeutic effects due to the enormous complexity of the biological pathways involved is still in its infancy. This article discusses the current knowledge, challenges and potential future directions towards the goal of genotype-guided safer HRT use.

Hormone therapy, estrogen metabolism, and risk of breast cancer in the Women's Health Initiative Hormone Therapy Trial

BACKGROUND

In the Women's Health Initiative Hormone Trials (WHI-HT), breast cancer risk was increased with estrogen plus progestin (E+P) but not with unopposed estrogen (E-alone). We hypothesized that E+P would preferentially metabolize to 16α-hydroxyestrone (16α-OHE1) rather than 2-hydroxyestrone (2-OHE1), and that breast cancer risk would be associated with baseline and 1 year changes in estrogen metabolites: positively for 16α-OHE1 levels and negatively for levels of 2-OHE-1 and the 2:16 ratio.

METHODS

In a prospective case-control study nested in the WHI-HT, 845 confirmed breast cancer cases were matched to 1,690 controls by age and ethnicity. Using stored serum, 2-OHE1 and 16α-OHE1 levels were measured by enzyme immunoassay at baseline, and for those randomized to active treatment (n = 1,259), at 1 year.

RESULTS

The 1-year increase in 16α-OHE1 was greater with E+P than E-alone (median 55.5 pg/mL vs. 43.5 pg/mL, P < 0.001), but both increased 2-OHE1 by ∼300 pg/mL. Breast cancer risk was modestly associated with higher baseline levels of 2-OHE1 and the 2:16 ratio, and for estrogen receptor+/progesterone+ cases only, higher baseline 16α-OHE1 levels. For those randomized to active treatment, breast cancer risk was associated with greater increase in 2-OHE-1 and the 2:16 ratio, but associations were not significant.

CONCLUSIONS

Although E+P modestly increased 16α-OHE1 more than E-alone, increase in 16α-OHE1 was not associated with breast cancer.

IMPACT

Study results do not explain differences between the WHI E+P and WHI E-alone breast cancer results but metabolism of oral HT, which may explain smaller than expected increase in breast cancer compared with endogenous estrogens.

Osteoporosis: screening and treatment in women

Osteoporosis is frequently called the silent disease because it lacks symptoms or signs until a fracture has occurred. Osteoporosis is common in aging women because of progressive postmenopausal bone loss. Fractures related to bone loss can result in reduced quality of life, lengthy hospital stays, long-term institutionalization, and death. Early diagnosis and treatment of low bone mass to reduce fracture risk is a cost-effective element of routine health care for women. With appropriate patient screening, ObGyn care providers can implement effective interventions before fractures occur, thereby improving patients' quality of life and reducing society's osteoporosis-related costs.

Effects of omega-3 fatty acids on progestin stimulation of invasive properties in breast cancer

Clinical studies have shown that progestins increase breast cancer risk in hormone replacement therapy, while we and others have previously reported that progestins stimulate invasive properties in progesterone receptor (PR)-rich human breast cancer cell lines. Based on others' reports that omega-3 fatty acids inhibit metastatic properties of breast cancer, we have reviewed the literature for possible connections between omega-3 fatty-acid-driven pathways and progestin-stimulated pathways in an attempt to suggest theoretical mechanisms for possible omega-3 fatty acid inhibition of progestin stimulation of breast cancer invasion. We also present some data suggesting that fatty acids regulate progestin stimulation of invasive properties in PR-rich T47D human breast cancer cells, and that an appropriate concentration of the omega-3 fatty acid eicosapentaenoic acid inhibits progestin stimulation of invasive properties. It is hoped that focus on the inter-relationship between pathways by which omega-3 fatty acids inhibit and progestins stimulate breast cancer invasive properties will lead to further in vitro, in vivo, and clinical studies testing the hypothesis that omega-3 fatty acids can inhibit progestin stimulation of invasive properties in breast cancer, and ameliorate harmful effects of progestins which occur in combined progestin-estrogen hormone replacement therapy.

Patient-derived luminal breast cancer xenografts retain hormone receptor heterogeneity and help define unique estrogen-dependent gene signatures

Bypassing estrogen receptor (ER) signaling during development of endocrine resistance remains the most common cause of disease progression and mortality in breast cancer patients. To date, the majority of molecular research on ER action in breast cancer has occurred in cell line models derived from late stage disease. Here we describe patient-derived ER+ luminal breast tumor models for the study of intratumoral hormone and receptor action. Human breast tumor samples obtained from patients post surgery were immediately transplanted into NOD/SCID or NOD/SCID/ILIIrg(-/-) mice under estrogen supplementation. Five transplantable patient-derived ER+ breast cancer xenografts were established, derived from both primary and metastatic cases. These were assessed for estrogen dependency, steroid receptor expression, cancer stem cell content, and endocrine therapy response. Gene expression patterns were determined in select tumors ±estrogen and ±endocrine therapy. Xenografts morphologically resembled the patient tumors of origin, and expressed similar levels of ER (5-99 %), and progesterone and androgen receptors, over multiple passages. Four of the tumor xenografts were estrogen dependent, and tamoxifen or estrogen withdrawal (EWD) treatment abrogated estrogen-dependent growth and/or tumor morphology. Analysis of the ER transcriptome in select tumors revealed notable differences in ER mechanism of action, and downstream activated signaling networks, in addition to identifying a small set of common estrogen-regulated genes. Treatment of a naïve tumor with tamoxifen or EWD showed similar phenotypic responses, but relatively few similarities in estrogen-dependent transcription, and affected signaling pathways. Several core estrogen centric genes were shared with traditional cell line models. However, novel tumor-specific estrogen-regulated potential target genes, such as cancer/testis antigen 45, were uncovered. These results evoke the importance of mapping both conserved and tumor-unique ER programs in breast cancers. Furthermore, they underscore the importance of primary xenografts for improved understanding of ER+ breast cancer heterogeneity and development of personalized therapies.

The 2012 hormone therapy position statement of: The North American Menopause Society

OBJECTIVE

This position statement aimed to update the evidence-based position statement published by The North American Menopause Society (NAMS) in 2010 regarding recommendations for hormone therapy (HT) for postmenopausal women. This updated position statement further distinguishes the emerging differences in the therapeutic benefit-risk ratio between estrogen therapy (ET) and combined estrogen-progestogen therapy (EPT) at various ages and time intervals since menopause onset.

METHODS

An Advisory Panel of expert clinicians and researchers in the field of women's health was enlisted to review the 2010 NAMS position statement, evaluate new evidence, and reach consensus on recommendations. The Panel's recommendations were reviewed and approved by the NAMS Board of Trustees as an official NAMS position statement.

RESULTS

Current evidence supports the use of HT for perimenopausal and postmenopausal women when the balance of potential benefits and risks is favorable for the individual woman. This position statement reviews the effects of ET and EPT on many aspects of women's health and recognizes the greater safety profile associated with ET.

CONCLUSIONS

Recent data support the initiation of HT around the time of menopause to treat menopause-related symptoms and to prevent osteoporosis in women at high risk of fracture. The more favorable benefit-risk ratio for ET allows more flexibility in extending the duration of use compared with EPT, where the earlier appearance of increased breast cancer risk precludes a recommendation for use beyond 3 to 5 years.

Long term hormone therapy for perimenopausal and postmenopausal women

BACKGROUND

Hormone therapy (HT) is widely used for controlling menopausal symptoms and has also been used for the management and prevention of cardiovascular disease, osteoporosis and dementia in older women. This is an updated version of a Cochrane review first published in 2005.

OBJECTIVES

To assess the effects of long term HT on mortality, cardiovascular outcomes, cancer, gallbladder disease, fractures, cognition and quality of life in perimenopausal and postmenopausal women, both during HT use and after cessation of HT use.

SEARCH METHODS

We searched the following databases to February 2012: Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO.

SELECTION CRITERIA

We included randomised double-blind studies of HT versus placebo, taken for at least one year by perimenopausal or postmenopausal women. HT included oestrogens, with or without progestogens, via oral, transdermal, subcutaneous or intranasal routes.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRS) for dichotomous data and mean differences (MDs) for continuous data, with 95% confidence intervals (CIs). Where findings were statistically significant, we calculated the absolute risk (AR) in the intervention group (the overall risk of an event in women taking HT).

MAIN RESULTS

Twenty-three studies involving 42,830 women were included. Seventy per cent of the data were derived from two studies (WHI 1998 and HERS 1998). Most participants were postmenopausal American women with at least some degree of co-morbidity, and the mean participant age in most studies was over 60 years. None of the studies focused on perimenopausal women. In relatively healthy postmenopausal women (that is generally fit, without overt disease) combined continuous HT significantly increased the risk of a coronary event (after one year's use: AR 4 per 1000, 95% CI 3 to 7), venous thrombo-embolism (after one year's use: AR 7 per 1000, 95% CI 4 to 11), stroke (after three years' use: AR 18 per 1000, 95% CI 14 to 23), breast cancer (after 5.6 years' use: AR 23 per 1000, 95% CI 19 to 29), gallbladder disease (after 5.6 years' use: AR 27 per 1000, 95% CI 21 to 34) and death from lung cancer (after 5.6 years' use plus 2.4 years' additional follow-up: AR 9 per 1000, 95% CI 6 to 13). Oestrogen-only HT significantly increased the risk of venous thrombo-embolism (after one to two years' use: AR 5 per 1000, 95% CI 2 to 10; after 7 years' use: AR 21 per 1000, 95% CI 16 to 28), stroke (after 7 years' use: AR 32 per 1000, 95% CI 25 to 40) and gallbladder disease (after seven years' use: AR 45 per 1000, 95% CI 36 to 57) but did not significantly increase the risk of breast cancer. Among women aged over 65 years who were relatively healthy and taking continuous combined HT, there was a statistically significant increase in the incidence of dementia (after 4 years' use: AR 18 per 1000, 95% CI 11 to 30). Among women with cardiovascular disease, long term use of combined continuous HT significantly increased the risk of venous thrombo-embolism (at one year: AR 9 per 1000, 95% CI 3 to 29). Women taking HT had a significantly decreased incidence of fractures with long term use (after 5.6 years of combined HT: AR 86 per 1000, 95% CI 79 to 84; after 7.1 years' use of oestrogen-only HT: AR 102 per 1000, 95% CI 91 to 112). Risk of fracture was the only outcome for which there was strong evidence of clinical benefit from HT. There was no strong evidence that HT has a clinically meaningful impact on the incidence of colorectal cancer.One trial analysed subgroups of 2839 relatively healthy 50 to 59 year old women taking combined continuous HT and 1637 taking oestrogen-only HT versus similar-sized placebo groups. The only significantly increased risk reported was for venous thrombo-embolism in women taking combined continuous HT: their absolute risk remained low, at less than 1/500. However, other differences in risk cannot be excluded as this study was not designed to have the power to detect differences between groups of women within 10 years of the menopause.

AUTHORS' CONCLUSIONS

HT is not indicated for primary or secondary prevention of cardiovascular disease or dementia, nor for preventing deterioration of cognitive function in postmenopausal women. Although HT is considered effective for the prevention of postmenopausal osteoporosis, it is generally recommended as an option only for women at significant risk, for whom non-oestrogen therapies are unsuitable. There are insufficient data to assess the risk of long term HT use in perimenopausal women or postmenopausal women younger than 50 years of age.

Modeling of the growth kinetics of occult breast tumors: role in interpretation of studies of prevention and menopausal hormone therapy

BACKGROUND

Autopsy studies report a reservoir of small, occult, undiagnosed breast cancers in up to 15.6% of women dying from unrelated causes. The effective doubling times (EDT) of these occult neoplasms range from 70 to 350 days and mammographic detection threshold diameters from 0.88 to 1.66 cm. Modeling of the biologic behavior of these occult tumors facilitates interpretation of tamoxifen breast cancer prevention and menopausal hormone therapy studies.

METHODS

We used iterative and mathematical techniques to develop a model of occult tumor growth (OTG) whose parameters included prevalence, EDT, and detection threshold. The model was validated by comparing predicted with observed incidence of breast cancer in several populations.

RESULTS

Iterative analysis identified a 200-day EDT, 7% prevalence and 1.16 cm detection threshold as optimal parameters for an OTG model as judged by comparison with Surveillance Epidemiology and End Results (SEER) population incidence rates in the United States. We validated the model by comparing predicted incidence rates with those observed in five separate population databases, in three long-term contralateral breast cancer detection studies, and with data from a computer-simulated tumor growth (CSTG) model. Our model strongly suggests that breast cancer prevention with anti-estrogens or aromatase inhibitors represents early treatment not prevention. In addition, menopausal hormone therapy does not primarily induce de novo tumors but promotes the growth of occult lesions.

CONCLUSIONS

Our OGTG model suggests that occult, undiagnosed tumors are prevalent, grow slowly, and are the biologic targets of anti-estrogen therapy for prevention and hormone therapy for menopausal women.

The biology of progesterone receptor in the normal mammary gland and in breast cancer

This paper reviews work on progesterone and the progesterone receptor (PR) in the mouse mammary gland that has been used extensively as an experimental model. Studies have led to the concept that progesterone controls proliferation and morphogenesis of the luminal epithelium in a tightly orchestrated manner at distinct stages of development by paracrine signaling pathways, including receptor activator of nuclear factor κB ligand (RANKL) as a major paracrine factor. Progesterone also drives expansion of stem cells by paracrine signals to generate progenitors required for alveologenesis. During mid-to-late pregnancy, progesterone has another role to suppress secretory activation until parturition mediated in part by crosstalk between PR and prolactin/Stat5 signaling to inhibit induction of milk protein gene expression, and by inhibiting tight junction closure. In models of hormone-dependent mouse mammary tumors, the progesterone/PR signaling axis enhances pre-neoplastic progression by a switch from a paracrine to an autocrine mode of proliferation and dysregulation of the RANKL signaling pathway. Limited experiments with normal human breast show that progesterone/PR signaling also stimulates epithelial cell proliferation by a paracrine mechanism; however, the signaling pathways and whether RANKL is a major mediator remains unknown. Work with human breast cancer cell lines, patient tumor samples and clinical studies indicates that progesterone is a risk factor for breast cancer and that alteration in progesterone/PR signaling pathways contributes to early stage human breast cancer progression. However, loss of PR expression in primary tumors is associated with a less differentiated more invasive phenotype and worse prognosis, suggesting that PR may limit later stages of tumor progression.

Progesterone regulation of stem and progenitor cells in normal and malignant breast

Progesterone plays an important, if not controversial, role in mammary epithelial cell proliferation and differentiation. Evidence supports that progesterone promotes rodent mammary carcinogenesis under some conditions, progesterone receptors (PR) are necessary for murine mammary gland tumorigenesis, and exogenous progestin use in post-menopausal women increases breast cancer risk. Thus, the progesterone/PR signaling axis can promote mammary tumorigenesis, albeit in a context-dependent manner. A mechanistic basis for the tumor promoting actions of progesterone has thus far remained unknown. Recent studies, however, have identified a novel role for progesterone in controlling the number and function of stem and progenitor cell populations in the normal human and mouse mammary glands, and in human breast cancers. These discoveries promise to reshape our perception of progesterone function in the mammary gland, and have spawned new hypotheses for how progestins may increase the risk of breast cancer. Here we review studies on progesterone regulation of mammary stem cells in normal and malignant tissue, and their implications for breast cancer risk, tumorigenesis, and tumor behavior.

From the ranks of mammary progesterone mediators, RANKL takes the spotlight

Whether during the diestrus phase of the estrous cycle or with pregnancy onset, the mitogenic effects of progesterone are well-established in the murine mammary epithelium. Importantly, progesterone-induced mitogenicity is critical for mammary tumor promotion, providing one explanation for the increase in breast cancer-risk observed with prolonged progestin-based hormone therapy. At the cellular level, progesterone projects its mitogenic influence through an evolutionary conserved paracrine mechanism of action. In this regard, recent studies provide compelling support for receptor activator of NF-kB ligand (RANKL) as a key paracrine mediator of the progesterone mitogenic signal. Induction of RANKL is sufficient to elicit mammary ductal side-branching and alveologenesis, the very morphogenetic responses elicited by progesterone during pregnancy and at diestrus. Significantly, the proliferative and pro-survival signals triggered by RANKL are also required for progestin-promotion of mammary tumorigenesis, underscoring a dual role for RANKL in progesterone-dependent mammary morphogenesis and tumorigenesis. Recently, RANKL has been shown to be critical for progesterone-induced expansion of the mammary stem cell population (and its lineal descendents), thereby advancing our conceptual understanding not only of RANKL's involvement in normal mammary morphogenesis but also in breast cancer risk associated with sustained hormone exposure. Finally, these studies together suggest that chemotherapeutic intervention of RANKL signaling represents a feasible approach for the effective prevention and/or treatment of hormone-responsive breast cancers.

Multiple nuclear receptor signaling pathways mediate the actions of synthetic progestins in target cells

Synthetic progestins are used clinically to treat a variety of women's health issues. Although progestins are designed to signal through the progesterone receptor (PR) to elicit specific pharmacological effects, they can also variably bind to and influence the activity of other nuclear receptors within target tissues, particularly the androgen and glucocorticoid receptors and, in some cases, they regulate mineralocorticoid and estrogen receptors. This article reviews current knowledge on progestin cross-talk to nuclear receptors other than PR, their resultant effect on receptor function in different in vitro models and the potential consequences of this activity for breast, ovarian and endometrial cancer. The impact of cell and tissue context, assay type, steroid metabolism and hormonal milieu in determining progestin-mediated activity are also presented. Collectively this review highlights the complexity of progestin action and the need for consideration of multiple mechanisms that act in concert to influence their ultimate biological activity.

Phosphorylated and sumoylation-deficient progesterone receptors drive proliferative gene signatures during breast cancer progression

INTRODUCTION

Progesterone receptors (PR) are emerging as important breast cancer drivers. Phosphorylation events common to breast cancer cells impact PR transcriptional activity, in part by direct phosphorylation. PR-B but not PR-A isoforms are phosphorylated on Ser294 by mitogen activated protein kinase (MAPK) and cyclin dependent kinase 2 (CDK2). Phospho-Ser294 PRs are resistant to ligand-dependent Lys388 SUMOylation (that is, a repressive modification). Antagonism of PR small ubiquitin-like modifier (SUMO)ylation by mitogenic protein kinases suggests a mechanism for derepression (that is, transcriptional activation) of target genes. As a broad range of PR protein expression is observed clinically, a PR gene signature would provide a valuable marker of PR contribution to early breast cancer progression.

METHODS

Global gene expression patterns were measured in T47D and MCF-7 breast cancer cells expressing either wild-type (SUMOylation-capable) or K388R (SUMOylation-deficient) PRs and subjected to pathway analysis. Gene sets were validated by RT-qPCR. Recruitment of coregulators and histone methylation levels were determined by chromatin immunoprecipitation. Changes in cell proliferation and survival were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and western blotting. Finally, human breast tumor cohort datasets were probed to identify PR-associated gene signatures; metagene analysis was employed to define survival rates in patients whose tumors express a PR gene signature.

RESULTS

'SUMO-sensitive' PR target genes primarily include genes required for proliferative and pro-survival signaling. DeSUMOylated K388R receptors are preferentially recruited to enhancer regions of derepressed genes (that is, MSX2, RGS2, MAP1A, and PDK4) with the steroid receptor coactivator, CREB-(cAMP-response element-binding protein)-binding protein (CBP), and mixed lineage leukemia 2 (MLL2), a histone methyltransferase mediator of nucleosome remodeling. PR SUMOylation blocks these events, suggesting that SUMO modification of PR prevents interactions with mediators of early chromatin remodeling at 'closed' enhancer regions. SUMO-deficient (phospho-Ser294) PR gene signatures are significantly associated with human epidermal growth factor 2 (ERBB2)-positive luminal breast tumors and predictive of early metastasis and shortened survival. Treatment with antiprogestin or MEK inhibitor abrogated expression of SUMO-sensitive PR target-genes and inhibited proliferation in BT-474 (estrogen receptor (ER)+/PR+/ERBB2+) breast cancer cells.

CONCLUSIONS

We conclude that reversible PR SUMOylation/deSUMOylation profoundly alters target gene selection in breast cancer cells. Phosphorylation-induced PR deSUMOylation favors a permissive chromatin environment via recruitment of CBP and MLL2. Patients whose ER+/PR+ tumors are driven by hyperactive (that is, derepressed) phospho-PRs may benefit from endocrine (antiestrogen) therapies that contain an antiprogestin.

Menopausal Hormone Therapy (MHT)

The perceptions of menopausal hormone therapy (MHT) have evolved considerably. Observational studies suggested that MHT could relieve vasomotor symptoms and prevent coronary heart disease (CHD). However, randomized controlled trials later showed no reduction in CHD and an increased risk of stroke. Subsequent analyses of these trials have shown that in women younger and closer to menopause, the risks associated with MHT may not be as great as originally thought. Several organizations, including the North American Menopause Society, the International Menopause Society, and the Endocrine Society, have published guidelines and statements that help health care providers translate the research findings into clinical practice. A common theme from these organizations is the need for health care providers to tailor information to their patients so they may make informed treatment decisions (especially considering the media attention MHT has received). It is particularly important to individualize therapy, considering patients’ risk factors for atherosclerotic disease, venous thromboembolic disease, osteoporosis, and breast cancer. Ongoing research in women younger than those in prior trials is evaluating lower doses of MHT and directly comparing transdermal and oral formulations. Such research should help define the population of women most likely to benefit from MHT without undue risk of adverse outcomes.