The incidence of breast cancer and changes in the use of hormone replacement therapy: A review of the evidence

Interplay between Estrogen, Kynurenine, and AHR Pathways: An immunosuppressive axis with therapeutic potential for breast cancer treatment

Breast cancer is one of the most common malignancies among women worldwide. Estrogen exposure via endogenous and exogenous sources during a lifetime, together with environmental exposure to estrogenic compounds, represent the most significant risk factor for breast cancer development. As breast tumors establish, multiple pathways are deregulated. Among them is the aryl hydrocarbon receptor (AHR) signaling pathway. AHR, a ligand-activated transcription factor associated with the metabolism of polycyclic aromatic hydrocarbons and estrogens, is overexpressed in breast cancer. Furthermore, AHR and estrogen receptor (ER) cross-talk pathways have been observed. Additionally, the Tryptophan (Trp) catabolizing enzymes indolamine-2,3-dioxygenase (IDO) and tryptophan-2,3-dioxygenase (TDO) are overexpressed in breast cancer. IDO/TDO catalyzes the formation of Kynurenine (KYN) and other tryptophan-derived metabolites, which are ligands of AHR. Once KYN activates AHR, it stimulates the expression of the IDO enzyme, increases the level of KYN, and activates non-canonical pathways to control inflammation and immunosuppression in breast tumors. The interplay between E2, AHR, and IDO/TDO/KYN pathways and their impact on the immune system represents an immunosuppressive axis on breast cancer. The potential modulation of the immunosuppressive E2-AHR-IDO/TDO/KYN axis has aroused great expectations in oncotherapy. The present article will review the mechanisms implicated in generating the immunosuppressive axis E2-AHR-IDO/TDO/KYN in breast cancer and the current state of knowledge as a potential therapeutic target.

Characterizing breast cancer incidence and trends among Asian American, Native Hawaiian, and non-Hispanic White women in Hawai'i, 1990-2014

PURPOSE

To characterize breast cancer (BC) incidence by age at diagnosis and BC subtype among disaggregated Asian American, Native Hawaiian, and Pacific Islander (AANHPI) women and non-Hispanic White (NHW) women in Hawai'i.

METHODS

Using 1990-2014 data from the Hawai'i tumor registry, we estimated age-adjusted incidence rates (AAIR) of BC and the annual percent change in BC incidence by age (<50 and ≥50 years) and BC subtype (hormone receptor [HR]+/human epidermal growth factor receptor 2 [HER2]-, HR+/HER2+, HR-/HER2+, triple negative BC) for Filipino American (FA), Japanese American (JA), Native Hawaiian (NH), and NHW women.

RESULTS

Among young (<50 years) women, annual BC incidence increased 2.9% (1994-2014) among JA and 1.0% (1990-2014) among NHW women. Incidence was highest among young JA women (2010-2014 AAIR 52.0 per 100,000; 95% confidence interval [CI] 45.6, 58.9). HR+/HER2- BC, the major BC subtype, was similarly highest among young JA women (AAIR 39.5; 95% CI 33.9, 45.4). Among older (≥50 years) women, annual BC incidence increased 1.6% (1990-2014) among FA and 4.2% (2006-2014) for JA women. BC incidence was highest among older NH women (AAIR 137.6, 95% CI 128.2, 147.4), who also displayed highest incidence of two subtypes: HR+/HER2- (AAIR 106.9; 95% CI 98.6, 115.5) and HR+/HER2+ (AAIR 12.1; 95% CI 9.4, 15.1).

CONCLUSION

We observed high and increasing BC incidence among JA women ages <50 years and high incidence among NH women ages ≥50 years. These results highlight racial and ethnic differences in BC incidence among disaggregated AANHPI populations in Hawai'i by age and BC subtype.

Five-year relative survival by stage of breast and colon cancers in northern Italy

The aim of this study is to present the 5-year relative survival by stage of breast and colorectal cancer patients in a northern Italian province. For the period 2013-2015, cases were selected from the Reggio Emilia Cancer Registry. Breast cancer patients were divided into 3 age groups: <45, 45-74 (the target screening population) and 74+. Colorectal cancers patients were classified into <50, 50-69 (the target screening population), and over 69 years. Carcinomas in situ and unknown stage were both excluded from the survival analyses. The five-year relative survival was estimated using the Pohar Perme method. During the period examined, 1,450 breast cancers and 992 colorectal cancer cases were registered. Analyzing in detail the patients with breast cancer for the entire 2013-2015 period, we noted that 50.4% were in stage I, 33.6% in stage II, 10.8% in stage III and 3.8% in stage IV. The stage was unknown in only 1.3% of patients (19 cases). The stage data of patients with colorectal cancer showed 24.5% were in stage I, 26.1% in stage II, 23.4% in stage III, and 24.6% in stage IV, and 1.4% unknown. Breast cancer 5-year survival was 100%, 89.7%, 71.4%, and 29.1% for stages I, II, III and IV, respectively and for colon cancer 96.7%, 83.4%, 70.8% and 16.2%, respectively.The presence of cancer screening, associated with effective treatments, account for the high survival rate of early-stage breast and colon cancers.

International trends in cancer incidence in middle-aged and older adults in 44 countries

OBJECTIVE

We examine international incidence trends of lung, colorectal, prostate, and breast cancers, as well as all cancers combined excluding non-melanoma skin cancer (NMSC) in adults aged 50 and older, over a fifteen-year period using data from 113 high quality population-based cancer registries included in the Cancer in Five Continents (CI5) series and NORDCAN.

MATERIALS AND METHODS

We calculated annual incidence rates between 1998 and 2012 for ages 50-64, 65-74, and 75+, by sex and both sexes combined. We estimated average annual percentage change (AAPC) in rates using quasi-Poisson regression models.

RESULTS

From 1998 to 2012, incidence trends for all cancers (excluding NMSC) have increased in most countries across all age groups, with the greatest increase observed in adults aged 75+ in Ecuador (AAPC = +3%). Colorectal cancer incidence rates increased in the majority of countries, across all age groups. Lung cancer rates among females have increased but decreased for males. Prostate cancer rates have sharply increased in men aged 50-64 with AAPC between 5% and 15% in 24 countries, while decreasing in the 75+ age group in 21 countries, by up to -7% in Bahrain. Female breast cancer rates have increased across all age groups in most countries, especially in the 65-74 age group and in Asia with AAPC increasing to 7% in the Republic of Korea.

CONCLUSIONS

These findings assist with anticipating changing patterns and needs internationally. Due to the specific needs of older patients, it is urgent that cancer systems adapt to address their growing number.

Hormone-Replacement Therapy and Its Association with Breast Cancer Subtypes: A Large Retrospective Cohort Study

Purpose

The study examined trends in breast cancer incidence, mammography testing rates, hormone-replacement therapy (HRT) use and breast cancer subtypes in a large Israeli health maintenance organization during 2000-2014.

Methods

Annual rates of mammography tests and HRTs use were analyzed in women age ≥45. Annual incidence rates of breast cancer were analyzed in women age ≥20. Estimated annual percentage changes were used to test changes in incidence rates. Invasive breast cancer subtypes were approximated by treatments received. We compared annual rates and duration of HRTs use between women diagnosed with breast cancer and those who were not, as well as HRT use between subtypes of invasive breast cancer.

Results

We identified 14,092 breast cancer cases (88% invasive, 12% in situ). The age-adjusted incidence rate of invasive breast cancer peaked in 2005, consistent with increased mammography screening that year, and decreased thereafter. HRT use decreased from 13.2% in 2002 to 4.6% in 2014. The subtypes distribution of 7771 patients diagnosed with invasive breast cancer during 2007-2014 was: luminal A and B without HER2 over-expression (HR+/HER2-), 69.7%; Luminal B with HER2 over-expression (HR+/HER2+), 8.9%; Hormone receptor-negative HER2 enriched (HR-/HER2+), 5.4%; triple negative (HR-/HER2-), 10.0%; unknown, 6.0%. Overall, in women age ≥45 diagnosed with invasive breast cancer, 76-86% did not have HRT exposure vs 14-24% who were current (within 1 year before the breast cancer diagnosis), recent (within 2-5 years), or past users (>5 years). Current/recent HRT use was statistically significantly higher in luminal vs non-luminal/unknown breast cancer subtypes (13.9% vs 8.9%, respectively; p < 0.001).

Conclusion

Our results show a decrease in breast cancer incidence that parallels the global and local decrease in HRT use. Yet, our results imply that current/recent HRT exposure may contribute to the incidence of luminal breast cancer tumors in particular. The magnitude of the effect supports findings from population-based studies.

Use of Oral Contraceptives as a Potential Risk Factor for Breast Cancer: A Systematic Review and Meta-Analysis of Case-Control Studies Up to 2010

Despite numerous studies evaluating the risk of breast cancer among oral contraception users, the effect of oral contraceptive on developing breast cancer remains inconclusive. Therefore, we conducted a systematic review of literature with meta-analysis in order to quantitative estimate this association. The bibliographic database MEDLINE and EMBASE, and reference lists of identified articles were searched, with no language restrictions, from the start of publication to August 2010. We performed a reanalysis and overall estimate of 79 case-control studies conducted between 1960-2010, including a total of 72,030 incidents, histologically confirmed cases of breast cancer and 123,650 population/hospital controls. A decrease was observed in cancer risk in OC users before age 25 years (0.91, 0.83-1.00). However, the use of OCs before the first full-term pregnancy had a significant increased risk of breast cancer (OR, 1.14, 1.01-1.28, p = 0.04), as did OC use longer than 5 years (1.09, 1.01-1.18, p = 0.02). Pooled crude odds ratios of breast cancer in ever-users of oral contraceptives was 1.01 [95% confidence interval (CI), 0.95-1.07], compared with never-users. There was no significant increase in risk among premenopausal women (1.06, 0.92-1.22), postmenopausal women (0.99, 0.89-1.10), or nulliparous women (1.02, 0.82-1.26). Oral contraceptives do not appear to increase the risk of breast cancer among users. However, OC use before a first full-term pregnancy or using them longer than 5 years can modify the development of the breast cancer.

Breast cancer rate after oophorectomy: A Prospective Danish Cohort Study

The association between oophorectomy and risk of breast cancer in the general population is uncertain. The aim of our study was to determine the breast cancer rate in women from the general population after oophorectomy (performed before/after menopause), and whether this varies by use of hormone replacement therapy (HRT), hysterectomy, body mass index (BMI) and shift work. The study included 24 409 female nurses (aged ≥45 years) participating in the Danish Nurse Cohort. Nurses were followed from cohort entry until date of breast cancer, death, emigration or end of follow-up at 31 December 2018, whichever came first. Poisson regression with log-transformed person-years as the offset examined the association between oophorectomy and breast cancer (all ages and stratified by menopausal status at time of oophorectomy). The potential modifying effect of HRT use, hysterectomy, BMI and shift work on the associations was estimated. During 502 463 person-years of follow-up, 1975 (8.1%) nurses were diagnosed with breast cancer. Bilateral oophorectomy was associated with a reduced breast cancer rate compared to nurses with preserved ovaries, adjusted rate ratio (95% confidence interval): 0.79 (0.64; 0.99). Similar associations (magnitude and direction) were detected for unilateral oophorectomy and when stratifying according to menopausal status at time of oophorectomy, but without statistical significance. Unilateral and bilateral oophorectomy is associated with a reduced breast cancer rate in women from the general population. This association is not modified by use of HRT, hysterectomy, BMI or shift work.

Selective activation of the estrogen receptor-β by the polysaccharide from Cynanchum wilfordii alleviates menopausal syndrome in ovariectomized mice

The menopausal syndrome caused by rapid changes in hormone levels greatly influences the quality of life of women. Though hormone replacement therapy (HRT) is widely used to treat the menopausal syndrome, it exhibits many side effects, including the risk of thrombosis, cardiovascular diseases, and increased incidence of breast cancer; thus, diversifying the interest for phytotherapy-based materials as alternatives to HRT. Here, we isolated a crude polysaccharide fraction (CWPF) from Cynanchum wilfordii root that alleviated the ovariectomy-induced uterine atrophy and bone loss without changes in plasma estradiol concentration in mice. Increased plasma levels of follicle-stimulating hormone (FSH), alkaline phosphatase (ALP), osteocalcin (OC) in ovariectomized mice were also reduced to normal levels by CWPF administration. We found that the inhibitory effects of CWPF on menopausal symptoms were mediated by the estrogen receptor β (ER-β) specific activation, not ER-α. Moreover, CWPF treatment suppressed the phosphorylation of Akt, suggesting that CWPF alleviates post-menopausal symptoms by regulating ER-β related Akt signaling pathway. These results demonstrate that the polysaccharides corresponding to CWPF among the water-soluble extracts of CW could be used as a beneficial herbal alternative for the development of therapeutic agents to prevent menopausal syndrome in women.

Incidence and survival outcomes of early male breast cancer: a population-based comparison with early female breast cancer

Background

Male breast cancer (MBC) is a rare malignancy. We aimed to analyze the incidence trends, clinicopathological characteristics, and survival outcomes in early MBC comparison with early female breast cancer (FBC).

Methods

We included eligible MBC and FBC patients with stage I-II disease in the Surveillance, Epidemiology, and End Results (SEER) database from 2000-2015. Joinpoint regression was used to evaluate the trends in age-adjusted incidence. A one-to-four propensity score matching (PSM) analysis was performed to reduce bias in a retrospective study. Survival outcomes were evaluated using Kaplan-Meier analyses with the log-rank test and Cox proportional hazards regression analysis.

Results

Trends in the age-adjusted incidence rates of early MBC were stable [2000-2015, annual percentage change (APC) =0.50, 95% confidence interval (CI): -0.1 to 1.1, P=0.102]; however, the incidence of early FBC changed significantly over the time period (2000-2015, APC = 0.30, 95% CI: 0.0 to 0.6, P=0.045). In the matched cohort, unmarried status, higher grade, larger tumor size, and advanced lymph node (LN) status were associated with a higher risk of breast cancer death and death of any causes both in early MBC and FBC patients. The hormone receptor (HR) status was as a prognostic factor in FBC patients, but not in MBC. Early MBC had worse breast cancer-specific survival (BCSS) and overall survival (OS) than early FBC in stage I, stage II and HR-positive subgroup of patients.

Conclusions

The biological behavior, clinicopathological features, and clinical outcomes of early MBC are different from that of FBC. Further studies on individualized treatment approaches in MBC are needed.

International Patterns and Trends in Endometrial Cancer Incidence, 1978-2013

Background

Cancers of the corpus uteri-primarily of the endometrium-rank as the sixth most common neoplasm in women worldwide. Analyses of the global patterns and trends of uterine cancer rates are needed in view of the ongoing obesity epidemic, a major risk factor for the disease.

Methods

Data on endometrial cancer (ICD-10 C54) incidence from population-based cancer registries in 43 populations, published in CI5plus or by registries, were extracted for 1978 to 2013. Age-standardized incidence rates were computed for all ages and for pre- (25-49 years) and postmenopausal ages (50 years and older). Temporal trends were assessed with Joinpoint analysis, and the effects of birth cohort and year of diagnosis on the overall trends were examined using age-period-cohort modeling.

Results

In 2006 to 2007, rates varied 10-fold across countries. The highest rates were in North America, Eastern and Northern Europe (19 cases per 100 000 among whites in the United States, 95% confidence interval [CI] = 18 to 20, and in Slovakia, 95% CI = 18 to 21), and the lowest rates were in middle-income countries (South Africa 1, 95% CI = 0 to 3, and India 3, 95% CI = 3 to 4). Rates during the most recent 10 data years increased in 26 of the 43 populations considered in this study, with South Africa and several countries in Asia showing the largest increase. The risk of endometrial cancer increased both in consecutive generations and over time in 11 of 23 populations, with the increases more pronounced in Japan, the Philippines, Belarus, Singapore, Costa Rica, and New Zealand.

Conclusions

Endometrial cancer incidence rates increased over time and in successive generations in several countries, especially in those countries with rapid socioeconomic transitions.

Impact of mammography screening programmes on breast cancer mortality in Switzerland, a country with different regional screening policies

INTRODUCTION

In the past decades, mortality due to breast cancer has declined considerably in Switzerland and other developed countries. The reasons for this decline remain controversial as several factors occurred almost simultaneously, including important advances in treatment approaches, breast cancer awareness and the introduction of mammography screening programmes in many European countries. In Switzerland, mammography screening programmes (MSPs) have existed in some regions for over 20 years but do not yet exist in others. This offers the possibility to analyse its effects with modern spatiotemporal methodology. We aimed to assess the spatiotemporal patterns and the effect of MSPs on breast cancer mortality.

SETTING

Switzerland.

PARTICIPANTS

The study covers breast cancer deaths of the female population of Switzerland during the period 1969-2012. We retrieved data from the Swiss Federal Statistical Office aggregated on a small-area level.

DESIGN

We fitted Bayesian hierarchical spatiotemporal models on death rates indirectly standardised by national references. We used linguistic region, degree of urbanisation, duration of population-based screening programmes and socioeconomic index as covariates.

RESULTS

In Switzerland, breast cancer mortality in women slightly increased until 1989-1992 and declined strongly thereafter. Until 2009-2012, the standardised mortality ratio declined to 57% (95% CI 54% to 60%) of the 1969-1972 value. None of the other coefficients of the spatial regressions had a significant effect on breast cancer mortality. In 2009-2012, no region had significantly elevated or reduced breast cancer mortality at 95% credible interval level compared with the national mean.

CONCLUSION

There has been a strong reduction of breast cancer mortality from the 1990s onwards. No important spatial disparities were observed. The factors studied (urbanisation, language, duration of population-based MSP and socioeconomic characteristics) did not seem to have an influence on them. Low participation rates and opportunistic screening use may have contributed to the low impact of MSPs.

State of the evidence 2017: an update on the connection between breast cancer and the environment

BACKGROUND

In this review, we examine the continually expanding and increasingly compelling data linking radiation and various chemicals in our environment to the current high incidence of breast cancer. Singly and in combination, these toxicants may have contributed significantly to the increasing rates of breast cancer observed over the past several decades. Exposures early in development from gestation through adolescence and early adulthood are particularly of concern as they re-shape the program of genetic, epigenetic and physiological processes in the developing mammary system, leading to an increased risk for developing breast cancer. In the 8 years since we last published a comprehensive review of the relevant literature, hundreds of new papers have appeared supporting this link, and in this update, the evidence on this topic is more extensive and of better quality than that previously available.

CONCLUSION

Increasing evidence from epidemiological studies, as well as a better understanding of mechanisms linking toxicants with development of breast cancer, all reinforce the conclusion that exposures to these substances - many of which are found in common, everyday products and byproducts - may lead to increased risk of developing breast cancer. Moving forward, attention to methodological limitations, especially in relevant epidemiological and animal models, will need to be addressed to allow clearer and more direct connections to be evaluated.

Mammographic Density Change With Estrogen and Progestin Therapy and Breast Cancer Risk

Background

Estrogen plus progestin therapy increases both mammographic density and breast cancer incidence. Whether mammographic density change associated with estrogen plus progestin initiation predicts breast cancer risk is unknown.

Methods

We conducted an ancillary nested case-control study within the Women's Health Initiative trial that randomly assigned postmenopausal women to daily conjugated equine estrogen 0.625 mg plus medroxyprogesterone acetate 2.5 mg or placebo. Mammographic density was assessed from mammograms taken prior to and one year after random assignment for 174 women who later developed breast cancer (cases) and 733 healthy women (controls). Logistic regression analyses included adjustment for confounders and baseline mammographic density when appropriate.

Results

Among women in the estrogen plus progestin arm (97 cases/378 controls), each 1% positive change in percent mammographic density increased breast cancer risk 3% (odds ratio [OR] = 1.03, 95% confidence interval [CI] = 1.01 to 1.06). For women in the highest quintile of mammographic density change (>19.3% increase), breast cancer risk increased 3.6-fold (95% CI = 1.52 to 8.56). The effect of estrogen plus progestin use on breast cancer risk (OR = 1.28, 95% CI = 0.90 to 1.82) was eliminated in this study, after adjusting for change in mammographic density (OR = 1.00, 95% CI = 0.66 to 1.51).

Conclusions

We found the one-year change in mammographic density after estrogen plus progestin initiation predicted subsequent increase in breast cancer risk. All of the increased risk from estrogen plus progestin use was mediated through mammographic density change. Doctors should evaluate changes in mammographic density with women who initiate estrogen plus progestin therapy and discuss the breast cancer risk implications.

[Does fertility treatment increase the risk of breast cancer? Current knowledge and meta-analysis]

OBJECTIVE

The objective of this review was to assess the level of risk of breast cancer for women exposed to ovulation-inducing therapy (OIT).

METHODS

The 25 selected studies were extracted from the PUBMED database from January 2000 until March 2016 with the following key-words: "fertility agents", "infertility treatments", "clomiphene citrate", "buserelin", "ovarian stimulation", "assisted reproductive technology" and "breast cancer". Our meta-analysis was performed using Review Manager software, Cochrane Collaboration, 2014. The results were calculated by type of OIT, as well as globally.

RESULTS

The analysis of these published epidemiological studies confirms that exposition to OIT is not a breast cancer risk factor, but the results are contradictory. Two studies have shown a significantly increased risk of breast cancer in a population of infertile women, while two others have found a significant decrease of this risk. The twenty others did not show any impact of IOT over this risk. Our meta-analysis of 20 selected studies has not identified a significant association between exposition to OIT and breast cancer risk (relative risk=0,96; IC 95: (0,81-1,14) for cohort studies and odds ratio=0,94; IC 95% (0,81-1,10) for case-control studies).

CONCLUSION

Exposition to OIT is not an identified risk factor for breast cancer. A message reassuring about a possible risk of OIT-related breast cancer should be given to these women. Exposition to OIT is therefore not an indication of increased breast surveillance.

Paxillin, a novel controller in the signaling of estrogen to FAK/N-WASP/Arp2/3 complex in breast cancer cells

Breast cancer is the major cause of cancer-related death in women. Its treatment is particularly difficult when metastasis occurs. The ability of cancer cells to move and invade the surrounding environment is the basis of local and distant metastasis. Cancer cells are able to remodel the actin cytoskeleton, which requires the recruitment of numerous structural and regulatory proteins that modulate actin filaments dynamics, including Paxillin or the Neural Wiskott-Aldrich Syndrome Protein (N-WASP). We show that 17-β estradiol (E2) induces phosphorylation of Paxillin and its translocation toward membrane sites where focal adhesion complexes are assembled. This cascade is triggered by a Gαi1/Gβ protein-dependent signaling of estrogen receptor α (ERα) to c-Src, focal adhesion kinase (FAK) and Paxillin. Within this complex, activated Paxillin recruits the small GTPase Cdc42, which triggers N-WASP phosphorylation. This results in the redistribution of Arp2/3 complexes at sites where membrane structures related to cell movement are formed. Recruitment of Paxillin, Cdc42 and N-WASP is necessary for cell adhesion, migration and invasion induced by E2 in breast cancer cells. In parallel, we investigated whether Raloxifene (RAL), a selective estrogen receptor modulator (SERMs), could inhibit or revert the effects of E2 in breast cancer cell movement. We found that, in the presence of E2, RAL acts as an ER antagonist and displays an inhibitory effect on estrogen-promoted cell adhesion and migration via FAK/Paxillin/N-WASP. Our findings identify an original mechanism through which estrogen regulates breast cancer cell motility and invasion via Paxillin. These results may have clinical relevance for the development of new therapeutic strategies for cancer treatment.

Cysteine Prevents Menopausal Syndromes in Ovariectomized Mouse

Cysteine (Cys) is well known to be involved in oxidation-reduction reactions, serving as a source of sulfides in the body. Amino acids are known to improve menopausal symptoms and significantly reduce morbidity. This study aims to find an unrevealed effect of Cys with estrogenic and osteogenic actions. Ovariectomized (OVX) mice were treated with Cys daily for 8 weeks. Estrogen-related and osteoporosis-related factors were analyzed in the vagina, serum, and tibia. Cys was treated in estrogen receptor (ER)-positive human osteoblast-like MG-63 cells and ER-positive human breast cancer Michigan Cancer Foundation-7 (MCF-7) cells. Cysteine administration ameliorated overweightness of the body and vaginal atrophy in the OVX mice. Cysteine increased the levels of alkaline phosphatase (ALP) and 17β-estradiol in the serum of the OVX mice and improved the bone mineral density in the OVX mice. In MG-63 cells, Cys increased the proliferation, ERβ messenger RNA (mRNA) expression, and estrogen response element (ERE) activity. Cysteine increased the ALP activity and the phosphorylation of extracellular signal-regulated kinase. In MCF-7 cells, Cys also increased the proliferation, ERβ mRNA expression, and ERE activity. Taken together, these results demonstrated that Cys has estrogenic and osteogenic activities in OVX mice, MG-63 cells, and MCF-7 cells. The novel insights gained here strongly imply the potential use of Cys as a new agent for postmenopausal women.

Safflower polysaccharide inhibits the proliferation and metastasis of MCF-7 breast cancer cell

Breast cancer accounts for 22.9% of all types of cancer in females worldwide. Safflower polysaccharide (SPS) is an active fraction purified from safflower petals (Carthamus tinctorius L). The present study investigated the effects of safflower polysaccharide on the proliferation and metastasis of breast cancer cells. Cell viability was analyzed using an MTT assay following treatment of the MCF‑7 cells with increasing concentrations of SPS. The results demonstrated that the SPS compound significantly inhibited the proliferation of the MCF‑7 human breast cancer cell line and these inhibitory effects increased in a dose‑ and time‑dependent manner. The half maximal inhibitory concentration (IC50) value of SPS on breast cancer cells, following treatment for 72 h, was detected using an MTT assay and was calculated as 0.12 mg/ml. The apoptotic rate was detected using flow cytometry in the MCF‑7 human breast cancer cell line and the results revealed that SPS induced cell apoptosis. The apoptotic rate of the MCF‑7 cells treated with SPS was significantly higher compared with that of the untreated cells and increased in a dose‑dependent manner. The expression of B‑cell lymphoma 2 (Bcl‑2) was downregulated and the expression of Bcl‑2‑associated X protein was upregulated in the MCF‑7 cells treated with SPS in a time‑dependent manner. Additionally, the expression of matrix metalloproteinase‑9 was significantly reduced and the expression of tissue inhibitor of metalloproteinase‑1 was increased in the MCF‑7 human breast cancer cell treated with SPS. These results demonstrated that SPS inhibited the metastasis of MCF‑7 breast cancer cells and understanding the underlying mechanisms may provide novel strategies in breast cancer therapy.

Breast cancer in younger women in Switzerland 1996-2009: a longitudinal population-based study

BACKGROUND

Breast cancer (BC) is the most commonly diagnosed cancer and a leading cause of death in younger women.

METHODS

We analysed incidence, mortality and relative survival (RS) in women with BC aged 20-49 years at diagnosis, between 1996 and 2009 in Switzerland. Trends are reported as estimated annual percentage changes (EAPC).

RESULTS

Our findings confirm a slight increase in the incidence of BC in younger Swiss women during the period 1996-2009. The increase was largest in women aged 20-39 years (EAPC 1.8%). Mortality decreased in both age groups with similar EAPCs. Survival was lowest among women 20-39 years (10-year RS 73.4%). We observed no notable differences in stage of disease at diagnosis that might explain these differences.

CONCLUSIONS

The increased incidence and lower survival in younger women diagnosed with BC in Switzerland indicates possible differences in risk factors, tumour biology and treatment characteristics that require additional examination.

Health issues for menopausal women: the top 11 conditions have common solutions

Multiple health issues affect women throughout the life course differently from men, or do not affect men at all. Although attention to women's health is important in all stages in life, health among middle-aged and elderly women has not received sufficient attention by scientists and policy-makers. Related to the menopausal transition and the experiences accumulated until that age, many diseases occur or further develop in middle-aged and elderly women. To improve women's quality of life and guarantee a long-lasting and active role for middle-aged and elderly women in society, prevention of chronic diseases and disability is a key aspect. In this manuscript we give an overview of the major health issues for peri- and post-menopausal women, we summarize risk factors and interventions to improve menopausal health. Based on the available scientific literature and the global burden of disease endeavor, we have selected and herein describe the following top 11 key health issues, selected in terms of burden exerted in women's mortality, morbidity, disability and quality of life: cardiovascular disease, musculoskeletal disorders, cancer, cognitive decline and dementia, chronic obstructive pulmonary disease, diabetes mellitus, metabolic syndrome, depression, vasomotor symptoms, sleep disturbances and migraine.

Assessment of the proliferative capacity of the flavanones 8-prenylnaringenin, 6-(1.1-dimethylallyl)naringenin and naringenin in MCF-7 cells and the rat mammary gland

8-Prenylnaringenin (8-PN) and naringenin (Nar) are phytoestrogens found in food items and nutritional supplements, while 6-(1.1-dimethylallyl)naringenin (6-DMAN) is a component of an African plant. Besides their assumed beneficial effects they may promote mammary and endometrial cancer. We therefore assessed their proliferative and estrogenic potential on the mammary gland in vitro and in vivo. In competitive estrogen receptor (ER) ligand binding assays 8-PN displayed a high relative binding affinity for both ERs with a preference for ERα and had the strongest mitotic effect on MCF-7 cells among the test substances. In a three day exposure in young adult ovariectomized female rats 15 mg/kg 8-PN had the highest capacity to increase the number of terminal end buds (TEB) in the mammary gland and stimulated expression of proliferation markers in epithelial ductal cells, followed by 6-DMAN and Nar, but overall their capacity to stimulate proliferation was weak in comparison to 17β-Estradiol (E2).

Molecular and structural basis of androgen receptor responses to dihydrotestosterone, medroxyprogesterone acetate and Δ(4)-tibolone

Medroxyprogesterone acetate (MPA) has widely been used in hormone replacement therapy (HRT), and is associated with an increased risk of breast cancer, possibly due to disruption of androgen receptor (AR) signaling. In contrast, the synthetic HRT Tibolone does not increase breast density, and is rapidly metabolized to estrogenic 3α-OH-tibolone and 3β-OH-tibolone, and a delta-4 isomer (Δ(4)-TIB) that has both androgenic and progestagenic properties. Here, we show that 5α-dihydrotestosterone (DHT) and Δ(4)-TIB, but not MPA, stabilize AR protein levels, initiate specific AR intramolecular interactions critical for AR transcriptional regulation, and increase proliferation of AR positive MDA-MB-453 breast cancer cells. Structural modeling and molecular dynamic simulation indicate that Δ(4)-TIB induces a more stable AR structure than does DHT, and MPA a less stable one. Microarray expression analyses confirms that the molecular actions of Δ(4)-TIB more closely resembles DHT in breast cancer cells than either ligand does to MPA.

Effects of short-term estradiol and norethindrone acetate treatment on the breasts of normal postmenopausal women

OBJECTIVE

The aim of this study was to evaluate among postmenopausal women the effects of a 3-month treatment with estradiol (E2) alone or in combination with norethindrone acetate (NA) on expression of hormone receptors and proliferation in the breast as well as on lipids and climacteric symptoms.

METHODS

Sixty healthy postmenopausal women were computer-randomized into two groups, with one group receiving 1 mg of E2 and the other group receiving 1 mg of E2 and 0.5 mg of NA daily for 12 weeks. Before and after treatment, middle-needle biopsies were obtained for histology and investigation of the expression levels of estrogen receptors (ERs; ER-α and ER-β), progesterone receptors (PRs; PR-A and PR-B), androgen receptor (AR), the proliferation marker Ki67, and collagen. Climacteric symptoms were recorded, and serum was collected to measure lipoprotein levels.

RESULTS

Fifty-six women finished the 12-week study. Proliferating cells (Ki67-positive) were very rare in all but a few of the untreated women. There were proliferating cells in both E2- and E2/NA-treated groups; however, these were not widespread and limited to nests of cells that amounted to 2% of the total epithelial cells. Some of these nests were positive for human epithelial growth factor receptor 2. Treatments caused no marked changes in the expression of ER-α, ER-β, or AR. However, both treatments resulted in an increase in PR-A and PR-B expressions. The presence of collagen was clearly associated with a mammographic diagnosis of dense breasts, but neither hormone treatment affected breast density. Both E2 and E2/NA treatments were effective in relieving hot flashes and sweating without adverse effects on blood pressure, weight, and liver, kidney, and thyroid functions. A decrease in cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol was induced by E2/NA but not by E2.

CONCLUSIONS

This short-term prospective study shows that E2 and estrogen-progestogen treatment can up-regulate PRs but do not significantly affect ERs, AR, proliferation, or breast density.

Cancer prevalence in United States, Nordic Countries, Italy, Australia, and France: an analysis of geographic variability

BACKGROUND

The objectives of this study were to quantitatively assess the geographic heterogeneity of cancer prevalence in selected Western Countries and to explore the associations between its determinants.

METHODS

For 20 cancer sites, 5-year cancer prevalence, incidence, and survival were observed and age standardised for the mid 2000s in the United States, Nordic European Countries, Italy, Australia, and France.

RESULTS

In Italy, 5-year crude prevalence for all cancers was 1.9% in men and 1.7% in women, while it was ∼1.5% in all other countries and sexes. After adjustment for the different age distribution of the populations, cancer prevalence in the United States was higher (20% in men and 10% in women) than elsewhere. For all cancers combined, the geographic heterogeneities were limited, though relevant for specific cancers (e.g., prostate, showing >30% higher prevalence in the United States, or lung, showing >50% higher prevalence in USA women than in other countries). For all countries, the correlations between differences of prevalence and differences of incidence were >0.9, while prevalence and survival were less consistently correlated.

CONCLUSION

Geographic differences and magnitude of crude cancer prevalence were more strongly associated with incidence rates, influenced by population ageing, than with survival rates. These estimates will be helpful in allocating appropriate resources.

An international comparison of male and female breast cancer incidence rates

Global international trends in female breast cancer incidence have been described previously but no comparable analysis of male breast cancer incidence rates has been conducted. We obtained male and female case and population data using Cancer Incidence in Five Continents (CI5). We calculated age-adjusted, sex-specific incidence rates and female-to-male incidence rate ratios (FMIRRs) and compared trends of such for the period 1988-2002. This analysis included 8,681 male breast cancer cases and 1.14 million female breast cancer cases. The highest male incidence rate was observed in Israel at 1.24 per 100,000 man-years, and the highest female incidence rate was observed in the United States at 90.7 per 100,000 woman-years. The lowest incidence rates for males (0.16) and females (18.0) were observed in Thailand. In general, male breast cancer incidence trends were variable; a minority of countries displayed evidence for an increase. In contrast, female incidence rates have been increasing in a majority of countries. The Pearson correlation coefficient (r) for male and female breast cancer incidence rates by country during 1988-2002 was 0.69. Male breast cancer rates were generally less than 1 per 100,000 man-years, in contrast to the much higher rates of female breast cancer, providing for an overall FMIRR of 122. The differences in both incidence rates and time trends between males and females may reflect sex differences in underlying risk factors, pathogenesis, and/or overdiagnosis. Conversely, the high correlation between male and female breast cancer incidences may indicate that both sexes share some common risk factors for breast cancer.

Aromatase inhibitors in the treatment of elderly women with metastatic breast cancer

The proportion of elderly women in the population is rising, and in tandem, the incidence of breast cancer rises with age. Because of health and tolerability concerns, as well as life expectancy, physicians may be reluctant to advise a standard treatment regimen for elderly patients with metastatic breast cancer. To elucidate this issue, we performed a literature review of clinical studies that included women with metastatic breast cancer who were over the age of 65. Our results show that although little clinical evidence exists, what is available suggests that standard treatment is tolerated and beneficial for patients meeting certain criteria. A geriatric assessment may identify specific patient groups (independent, dependent, or frail) and thereby guide treatment. Treatment recommendations for elderly patients with metastatic breast cancer are sparse, although first-line endocrine treatment, usually aromatase inhibitors or tamoxifen, is recommended for hormone-sensitive disease. In general, the evidence from clinical studies suggests that aromatase inhibitors are more effective than either tamoxifen or megestrol acetate as first- or second-line treatment in postmenopausal women with metastatic breast cancer. Ultimately, quality of life, treatment effects, and comorbidities are important aspects in this population and may guide treatment choice. To provide evidence-based treatment guidance, future clinical trials should include more patients over the age of 65 years.

Downregulation of the tumor-suppressor miR-16 via progestin-mediated oncogenic signaling contributes to breast cancer development

Introduction

Experimental and clinical evidence points to a critical role of progesterone and the nuclear progesterone receptor (PR) in controlling mammary gland tumorigenesis. However, the molecular mechanisms of progesterone action in breast cancer still remain elusive. On the other hand, micro RNAs (miRNAs) are short ribonucleic acids which have also been found to play a pivotal role in cancer pathogenesis. The role of miRNA in progestin-induced breast cancer is poorly explored. In this study we explored progestin modulation of miRNA expression in mammary tumorigenesis.

Methods

We performed a genome-wide study to explore progestin-mediated regulation of miRNA expression in breast cancer. miR-16 expression was studied by RT-qPCR in cancer cell lines with silenced PR, signal transducer and activator of transcription 3 (Stat3) or c-Myc, treated or not with progestins. Breast cancer cells were transfected with the precursor of miR-16 and proliferation assays, Western blots or in vivo experiments were performed. Target genes of miR-16 were searched through a bioinformatical approach, and the study was focused on cyclin E. Reporter gene assays were performed to confirm that cyclin E 3'UTR is a direct target of miR-16.

Results

We found that nine miRNAs were upregulated and seven were downregulated by progestin in mammary tumor cells. miR-16, whose function as a tumor suppressor in leukemia has already been shown, was identified as one of the downregulated miRNAs in murine and human breast cancer cells. Progestin induced a decrease in miR-16 levels via the classical PR and through a hierarchical interplay between Stat3 and the oncogenic transcription factor c-Myc. A search for miR-16 targets showed that the CCNE1 gene, encoding the cell cycle regulator cyclin E, contains conserved putative miR-16 target sites in its mRNA 3' UTR region. We found that, similar to the molecular mechanism underlying progestin-modulated miR-16 expression, Stat3 and c-Myc participated in the induction of cyclin E expression by progestin. Moreover, overexpression of miR-16 abrogated the ability of progestin to induce cyclin E upregulation, revealing that cyclin E is a novel target of miR-16 in breast cancer. Overexpression of miR-16 also inhibited progestin-induced breast tumor growth in vitro and in vivo, demonstrating for the first time, a role for miR-16 as a tumor suppressor in mammary tumorigenesis. We also found that the ErbB ligand heregulin (HRG) downregulated the expression of miR-16, which then participates in the proliferative activity of HRG in breast tumor cells.

Conclusions

In this study, we reveal the first progestin-regulated miRNA expression profile and identify a novel role for miR-16 as a tumor suppressor in progestin- and growth factor-induced growth in breast cancer.

The descriptive epidemiology of female breast cancer: an international comparison of screening, incidence, survival and mortality

BACKGROUND

This paper presents the latest international descriptive epidemiological data for invasive breast cancer amongst women, including incidence, survival and mortality, as well as information on mammographic screening programmes.

RESULTS

Almost 1.4 million women were diagnosed with breast cancer worldwide in 2008 and approximately 459,000 deaths were recorded. Incidence rates were much higher in more developed countries compared to less developed countries (71.7/100,000 and 29.3/100,000 respectively, adjusted to the World 2000 Standard Population) whereas the corresponding mortality rates were 17.1/100,000 and 11.8/100,000. Five-year relative survival estimates range from 12% in parts of Africa to almost 90% in the United States, Australia and Canada, with the differential linked to a combination of early detection, access to treatment services and cultural barriers. Observed improvements in breast cancer survival in more developed parts of the world over recent decades have been attributed to the introduction of population-based screening using mammography and the systemic use of adjuvant therapies.

CONCLUSION

The future worldwide breast cancer burden will be strongly influenced by large predicted rises in incidence throughout parts of Asia due to an increasingly "westernised" lifestyle. Efforts are underway to reduce the global disparities in survival for women with breast cancer using cost-effective interventions.

Adult BMI Change and Risk of Colon Cancer in Postmenopausal Women

Purpose. We recently reported an association of adult BMI change with colon cancer risk. Here, we sought to further explore this association with respect to postmenopausal HRT use in a larger study population. Methods. We included 1,457 postmenopausal women participating in an ongoing population-based case-control study of colon cancer. Results. We confirmed a previously reported association of adulthood weight gain and increased risk of colon cancer: compared to those with <5 kg/m(2) change of BMI, women who reported moderate (5-10 kg/m(2)) and large (>10 kg/m(2)) BMI changes since their 20s had OR estimates of 1.54 (95% CI = 1.09-2.19) and 1.45 (95% CI = 0.90-2.33), respectively (P for trend = 0.05). Stratified analyses showed that this association was limited to HRT nonusers: ORs were 1.77 (95% CI = 1.02-3.05) and 2.21 (95% CI = 1.09-4.45), respectively (P for trend = 0.03), for BMI changes occurring between the 20s decade and time of recruitment among non-users. Similar associations were observed for BMI changes since the 30s decade. There was no association among HRT users. Conclusion. Our results suggest early adulthood weight gain increases colon cancer risk in postmenopausal women who do not use HRT.

Estrogen treatment affects brain functioning after menopause

Sex hormones have powerful neuromodulatory effects on functional brain organization and cognitive functioning. This paper reviews findings from studies investigating the influence of sex hormones in postmenopausal women with and without hormone therapy (HT). Functional brain organization was investigated using different behavioural tasks in postmenopausal women using either estrogen therapy or combined estrogen plus gestagen therapy and age- and IQ-matched postmenopausal women not taking HT. The results revealed HT-related modulations in specific aspects of functional brain organization including functional cerebral asymmetries and interhemispheric interaction. In contrast to younger women during the menstrual cycle, however, it seems that HT, and especially estrogen therapy, after menopause affects intrahemispheric processing rather than interhemispheric interaction. This might be explained by a faster and more pronounced age-related decline in intrahemispheric relative to interhemispheric functioning, which might be associated with higher sensitivity to HT. Taken together, the findings suggest that the female brain retains its plasticity even after reproductive age and remains susceptible to the effects of sex hormones throughout the lifetime, which might help to discover new clinical approaches in the hormonal treatment of neurological and psychiatric disorders.

Incidence and Outcome of Male Breast Cancer: An International Population-Based Study

Purpose

Male breast cancer is a rare disease with an incidence rate less than 1% of that of female breast cancer. Given its low incidence, few studies have assessed risk and prognosis.

Methods

This population-based study, including 459,846 women and 2,665 men diagnosed with breast cancer in Denmark, Finland, Geneva, Norway, Singapore, and Sweden over the last 40 years, compares trends in incidence, relative survival, and relative excess mortality between the sexes.

Results

World standardized incidence rates of breast cancer were 66.7 per 105 person-years in women and 0.40 per 105 person-years in men. Women were diagnosed at a younger median age (61.7 years) than men (69.6 years). Male patients had a poorer 5-year relative survival ratio than women (0.72 [95% CI, 0.70 to 0.75] v 0.78 [95% CI, 0.78 to 0.78], respectively), corresponding to a relative excess risk (RER) of 1.27 (95% CI, 1.13 to 1.42). However, after adjustment for age and year of diagnosis, stage, and treatment, male patients had a significantly better relative survival from breast cancer than female patients (RER, 0.78; 95% CI, 0.62 to 0.97).

Conclusion

Male patients with breast cancer have later onset of disease and more advanced disease than female patients. Male patients with breast cancer have lower risk of death from breast cancer than comparable female patients.

17β-Estradiol enhances breast cancer cell motility and invasion via extra-nuclear activation of actin-binding protein ezrin

Estrogen promotes breast cancer metastasis. However, the detailed mechanism remains largely unknown. The actin binding protein ezrin is a key component in tumor metastasis and its over-expression is positively correlated to the poor outcome of breast cancer. In this study, we investigate the effects of 17β-estradiol (E2) on the activation of ezrin and its role in estrogen-dependent breast cancer cell movement. In T47-D breast cancer cells, E2 rapidly enhances ezrin phosphorylation at Thr⁵⁶⁷ in a time- and concentration-dependent manner. The signalling cascade implicated in this action involves estrogen receptor (ER) interaction with the non-receptor tyrosine kinase c-Src, which activates the phosphatidylinositol-3 kinase/Akt pathway and the small GTPase RhoA/Rho-associated kinase (ROCK-2) complex. E2 enhances the horizontal cell migration and invasion of T47-D breast cancer cells in three-dimensional matrices, which is reversed by transfection of cells with specific ezrin siRNAs. In conclusion, E2 promotes breast cancer cell movement and invasion by the activation of ezrin. These results provide novel insights into the effects of estrogen on breast cancer progression and highlight potential targets to treat endocrine-sensitive breast cancers.

Risk of osteoporotic fractures after discontinuation of menopausal hormone therapy: results from the E3N cohort

While current use of menopausal hormone therapy (MHT) reduces the risk of osteoporotic fractures, epidemiologic studies suggest that protection wears off rapidly after discontinuation of treatment. The authors identified 5,589 first osteoporotic fractures (2,235 major osteoporotic fractures) among 70,182 postmenopausal women from the French E3N cohort (1992-2008) and used Cox multivariate proportional hazards regression models to estimate hazard ratios. Persistence of protection against major osteoporotic fractures after MHT discontinuation was only observed when MHT had been used for at least 5 years, with a slightly more important decrease within the 5 years after discontinuation (compared with never use of MHT, hazard ratio = 0.68, 95% confidence interval: 0.50, 0.92) than beyond 5 years (hazard ratio = 0.83, 95% confidence interval: 0.69, 0.99); the P value for homogeneity between the 2 estimates was not significant. Oral estrogen use and transdermal estrogen use conveyed similar estimates in past users. Among current users, the authors confirmed a protective effect of MHT against risk of osteoporotic fractures. These findings, which relied on a number of MHT combinations, suggested that such therapies should be used for 5 years or more for reducing risk of fracture after treatment discontinuation.

Sex hormone therapy and functional brain plasticity in postmenopausal women

Several studies have shown that fluctuating levels of sex hormones (estrogen and progesterone) can affect fundamental principles of brain organization, including functional cerebral asymmetries (FCAs) and interhemispheric interactions. The majority of findings come from studies investigating younger women tested during distinct hormonal phases of the menstrual cycle, an approach that does not necessarily allow for conclusions about the causal relationship between hormonal changes and functional brain organization. An alternative approach is to manipulate the hormonal status of participants directly. This research focuses on the effects of hormone therapy (HT) on FCAs and interhemispheric interactions in postmenopausal women. Functional brain organization was tested in postmenopausal women using either estrogen therapy or combined estrogen plus gestagen therapy. The results are then compared to age- and IQ-matched postmenopausal women not taking HT. The results indicate HT-related modulations in both FCAs and interhemispheric interaction. In contrast to normally cycling women, however, it seems that HT, and especially estrogen therapy, after menopause affects intrahemispheric processing rather than interhemispheric crosstalk. The findings indicate a faster and more pronounced age-related decline in intrahemispheric relative to interhemispheric processing which seems to be accompanied by a higher sensitivity to HT. Aging processes together with differences in the hormonal status (exogenous changes as a result of HT vs. endogenous changes during the menstrual cycle) may also explain divergent (cognitive) behavioral outcomes in postmenopausal women and younger women. Taken together, the findings suggest that the female brain retains its plasticity even after reproductive age and remains susceptible to the effects of sex hormones throughout the lifetime. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

Breast cancer in a multi-ethnic Asian setting: results from the Singapore-Malaysia hospital-based breast cancer registry

Two hospital-based breast cancer databases (University Malaya Medical Center, Malaysia [n = 1513] and National University Hospital, Singapore [n = 2545]) were merged into a regional registry of breast cancer patients diagnosed between 1990 and 2007. A review of the data found 51% of patients diagnosed before the age of 50 years. and 72% percent of the women were Chinese followed by Malays (16%), Indians (8%), and other races (4%). Median tumor size at presentation was 26 mm and about 25% of patients presented with TNM stage III or IV disease. Most tumors were of ductal histology (87%). Fifty-seven percent of tumors were estrogen receptor positive and 40% were poorly differentiated. Of those patients who had surgery, 70% had mastectomy while 30% had breast conserving surgery. Overall, chemotherapy was administered to 56% of patients and hormonal treatment to 60%. Five-year overall survival was 82.5% in patients with TNM stage 0 to stage II cancer, and 30.2% in those with later stages.

Synthetic progestins induce growth and metastasis of BT-474 human breast cancer xenografts in nude mice

OBJECTIVE

Previous studies have shown that sequential exposure to estrogen and progesterone or medroxyprogesterone acetate (MPA) stimulates vascularization and promotes the progression of BT-474 and T47-D human breast cancer cell xenografts in nude mice (Liang et al, Cancer Res 2007, 67:9929). In this follow-up study, the effects of progesterone, MPA, norgestrel (N-EL), and norethindrone (N-ONE) on BT-474 xenograft tumors were compared in the context of several different hormonal environments. N-EL and N-ONE were included in the study because synthetic progestins vary considerably in their biological effects and the effects of these two progestins on the growth of human tumor xenografts are not known.

METHODS

Estradiol-supplemented intact and ovariectomized immunodeficient mice were implanted with BT-474 cells. Progestin pellets were implanted simultaneously with estradiol pellets either 2 days before tumor cell injection (ie, combined) or 5 days after tumor cell injections (ie, sequentially).

RESULTS

Progestins stimulated the growth of BT-474 xenograft tumors independent of exposure timing and protocol, MPA stimulated the growth of BT-474 xenograft tumors in ovariectomized mice, and progestins stimulated vascular endothelial growth factor elaboration and increased tumor vascularity. Progestins also increased lymph node metastasis of BT-474 cells. Therefore, progestins, including N-EL and N-ONE, induce the progression of breast cancer xenografts in nude mice and promote tumor metastasis.

CONCLUSIONS

These observations suggest that women who ingest progestins for hormone therapy or oral contraception could be more at risk for developing breast cancer because of proliferation of existing latent tumor cells. Such risks should be considered in the clinical setting.

Sex steroids and breast cancer metastasis

Sex steroids, particularly estrogen and progesterone, promote normal breast tissue growth and differentiation. Prolonged exposure of estrogen and/or progesterone is considered a risk factor for breast cancer carcinogenesis, and the effects of sex steroids on breast cancer metastasis are controversial. Emerging evidence indicates that sex steroids regulate breast cancer metastatic processes via nongenomic and genomic mechanisms. Through the regulation of actin-binding proteins estrogen and progesterone rapidly provoke actin cytoskeleton reorganization in breast cancer cells, leading to formation of membrane structures facilitating breast cancer cell migration and invasion. In addition, steroid receptors interact and trans-activate receptor tyrosine kinases (including epidermal growth factor receptor and insulin-like growth factor receptor), resulting in growth factor-like effects that promote cancer cell invasive behavior. Moreover, sex steroids regulate the expression of metastasis-associated molecules, such as E-cadherin, matrix metalloproteinases, growth factors, chemokines and their receptors, leading to epithelial-to-mesenchymal-like transition. However, there is also evidence that sex steroids and their receptors protect against breast cancer cell invasiveness through distinct mechanisms. Here, we present an overview of the currently identified actions of sex steroids on breast cancer metastasis and their potential clinical implications.

Differential effects of 17beta-estradiol and raloxifene on bone and lipid metabolism in rats with chronic kidney disease and estrogen insufficiency

OBJECTIVE

The aim of this study was to evaluate the effect of 17beta-estradiol, raloxifene, and 1-alpha,25-dihydroxycholecalciferol or calcitriol on bone and lipid metabolism in chronic kidney disease and estrogen insufficiency.

METHODS

Six-month-old female Sprague-Dawley rats (n = 48) were ovariectomized and nephrectomized (seven eighths). One week after surgery, the rats were divided into six groups and treated with (1) placebo, (2) 17beta-estradiol 10 microg kg day, (3) raloxifene 1 mg kg day, (4) calcitriol 10 ng kg day, (5) 17beta-estradiol + calcitriol, and (6) raloxifene + calcitriol. A group of untreated animals with chronic kidney disease and normal ovarian function was used as a control group (n = 5). The rats were killed after 8 weeks of treatment. Blood samples were drawn for serum analyses; the right tibia was removed to perform histomorphometric analyses, uteri were used as tissue markers of estrogen replacement, and paraffin-embedded sections of the uterus and the fourth breast were used for histopathologic evaluation.

RESULTS

Raloxifene, alone or combined with calcitriol, and 17beta-estradiol combined with calcitriol significantly diminished total cholesterol level compared with placebo. Qualitative histological and histomorphometric analyses showed that both the single treatments and their combinations were able to increase the trabecular connectivity compared with placebo. The less beneficial results were obtained with 17beta-estradiol alone, whereas the more beneficial results were obtained with the combined treatments, particularly with raloxifene and calcitriol.

CONCLUSIONS

In summary, this experimental study demonstrates the advantages of replacing both hormonal deficiencies together. The combination of calcitriol and raloxifene, a selective estrogen receptor modulator, showed a better lipid, uterus, and bone profile.

Venous thrombosis in the elderly: incidence, risk factors and risk groups

The incidence of venous thrombosis (VT) increases sharply with age: it is very rare in young individuals (<1 per 10,000 per year) but increases to ∼ 1% per year in the elderly, which indicates that aging is one of the strongest and most prevalent risk factor for venous thrombosis. The cause of this steep age gradient is as yet, unexplained. The aim of this review was to provide an overview of studies on the effect of conventional risk factors as well as age-specific risk factors for thrombosis in the elderly. Limited data are available on risk factors for thrombosis in the elderly, i.e. all results are based on small study groups. Results indicate that, of the conventional risk factors, malignant disease, the presence of co-morbidities and the genetic risk factors factor (F)V Leiden and the prothrombin mutation seem to be associated with an increased risk of venous thrombosis. In the elderly, the population attributable risk (PAR) of malignancy is approximately 35%, for co-morbidities a PAR up to 25% is found, and the contribution of genetic risk factors to the thrombosis incidence is estimated to be 7-22%. Age-specific risk factors of thrombosis, i.e. endothelial dysfunction and frailty may be important in the explanation of the increased incidence of VT in the elderly. In conclusion, as aging is a major risk factor for thrombosis, further identification of the risk factors for thrombosis in the elderly is needed to elucidate the age gradient of the incidence of VT and to target preventive measures.

Estrogen receptor-alpha promotes breast cancer cell motility and invasion via focal adhesion kinase and N-WASP

The ability of cancer cells to move and invade the surrounding environment is the basis of local and distant metastasis. Cancer cell movement requires dynamic remodeling of the cytoskeleton and cell membrane and is controlled by multiprotein complexes including focal adhesion kinase (FAK) or the Neural Wiskott-Aldrich Syndrome Protein (N-WASP). We show that 17β-estradiol induces phosphorylation of FAK and its translocation toward membrane sites where focal adhesion complexes are assembled. This process is triggered via a Gα/Gβ protein-dependent, rapid extranuclear signaling of estrogen receptor α interacts in a multiprotein complex with c-Src, phosphatidylinositol 3-OH kinase, and FAK. Within this complex FAK autophosphorylation ensues, and activated FAK recruits the small GTPase cdc42, which, in turn, triggers N-WASP phosphorylation. This results in the translocation of Arp2/3 complexes at sites where membrane structures related to cell movement are formed. Recruitment of FAK and N-WASP is necessary for cell migration and invasion induced by 17β-estradiol in breast cancer cells. Our findings identify an original mechanism through which estrogen promotes breast cancer cell motility and invasion. This information helps to understand the effects of estrogen on breast cancer metastasis and may provide new targets for therapeutic interventions.

Menopausal hormone therapy and subsequent risk of specific invasive breast cancer subtypes in the California Teachers Study

BACKGROUND

Although it is well established that combined estrogen-progestin therapy (EPT) increases breast cancer risk, questions remain regarding the effect of different formulations of hormones, whether certain women are at particularly high risk, and whether risk varies by tumor subtype.

METHODS

We investigated hormone therapy (HT) use in relation to breast cancer risk in the California Teachers Study cohort; after a mean follow-up of 9.8 years, 2,857 invasive breast cancers were diagnosed.

RESULTS

Compared with women who had never used HT, women who reported 15 or more years of estrogen therapy (ET) use had a 19% greater risk of breast cancer (95% confidence interval, 1.03-1.37), whereas women using EPT for 15 or more years had an 83% greater risk (95% confidence interval, 1.48-2.26). Breast cancer risk was highest among women using continuous combined EPT regimens. Risks associated with EPT and ET use were increased with duration of HT use for women with a body mass index (BMI) of <29.9 kg/m(2) but not for women with BMI of >or=30 kg/m(2). Elevated risks associated with EPT and ET use were confined to tumors that were positive for both estrogen and progesterone receptors and those that were HER2+ but were slightly diminished for HER2- tumors.

CONCLUSIONS

Breast cancer risks increased with longer duration of ET and EPT use, and risks were highest for continuous-combined EPT use. Furthermore, risks varied by BMI and tumor subtype.

IMPACT

These findings underscore the need for personalized risk-benefit discussions with women contemplating HT use.

How to judge the association of postmenopausal hormone therapy and the risk of breast cancer

The relevance of postmenopausal hormone therapy (HT) for breast cancer risk has been long debated, although it is one of the most important barriers for women to accept HT. Various opinions have been reported from recent randomized clinical trials and epidemiological studies. These unanswered questions include: whether HT has a positive impact on breast cancer; whether risks of therapy with unopposed estrogen and combined estrogen-progestin are different; and whether different types and routes of estrogen and progestogens, as well as the duration and cessation of HT use, have different impacts on this disorder. Recently, there has been some good news such as the following: the currently available data do not provide sufficient evidence to prove a causal relationship between postmenopausal HT and breast cancer; breast cancer in postmenopausal women using HT usually has better prognosis than that of nonusers. In conclusion, HT is still the most effective method of relieving climacteric symptoms for many postmenopausal women. However, a possible risk of breast cancer associated with long-term HT usage should not be ignored. With respect to prevention of breast cancer, regular evaluation of individual breast cancer susceptibility and close follow-up through mammography and/or breast sonography are necessary strategies for the safety of HT use.