Hormone replacement therapy (HRT), breast cancer and tumor pathology

Pregnancy, abortion, and birth control methods' complicity with breast cancer occurrence

Reproductive factors play significantly important roles in determining the breast cancer (BC) risk. The impact of pregnancy, abortion, and birth control methods on tumor development remains unclear. It has been found that early full-term pregnancies in young women can lower their lifetime risk of developing the type of cancer in question. However, having a first full-term pregnancy at an older age can increase this risk. The relationship between pregnancy and breast cancer (BC) is, however, much more complicated. Both induced and spontaneous abortions lead to sudden changes in hormonal balance, which could cause different effects on sensitive breast epithelial cells, making abortion a potential risk factor for breast cancer. The influence of hormonal contraception on carcinogenesis is not comprehensively understood, and therefore, more exhaustive analysis of existing data and further investigation is needed. This review explores how the mentioned reproductive factors affect the risk of breast cancer (BC), focusing on the molecular mechanisms that contribute to its complexity. By comprehending this intricate network of relationships, we can develop new strategies for predicting and treating the disease.

Severity and risk factors of interval breast cancer in Queensland, Australia: a population-based study

BACKGROUND

Interval breast cancers (BC) are those diagnosed within 24 months of a negative mammogram. This study estimates the odds of being diagnosed with high-severity BC among screen-detected, interval, and other symptom-detected BC (no screening history within 2 years); and explores factors associated with being diagnosed with interval BC.

METHODS

Telephone interviews and self-administered questionnaires were conducted among women (n = 3,326) diagnosed with BC in 2010-2013 in Queensland. Respondents were categorised into screen-detected, interval, and other symptom-detected BCs. Data were analysed using logistic regressions with multiple imputation.

RESULTS

Compared with screen-detected BC, interval BC had higher odds of late-stage (OR = 3.50, 2.9-4.3), high-grade (OR = 2.36, 1.9-2.9) and triple-negative cancers (OR = 2.55, 1.9-3.5). Compared with other symptom-detected BC, interval BC had lower odds of late stage (OR = 0.75, 0.6-0.9), but higher odds of triple-negative cancers (OR = 1.68, 1.2-2.3). Among women who had a negative mammogram (n = 2,145), 69.8% were diagnosed at their next mammogram, while 30.2% were diagnosed with an interval cancer. Those with an interval cancer were more likely to have healthy weight (OR = 1.37, 1.1-1.7), received hormone replacement therapy (2-10 years: OR = 1.33, 1.0-1.7; > 10 years: OR = 1.55, 1.1-2.2), conducted monthly breast self-examinations (BSE) (OR = 1.66, 1.2-2.3) and had previous mammogram in a public facility (OR = 1.52, 1.2-2.0).

CONCLUSION

These results highlight the benefits of screening even among those with an interval cancer. Women-conducted BSE were more likely to have interval BC which may reflect their increased ability to notice symptoms between screening intervals.

Maximizing the Estrogenic Potential of Soy Isoflavones through the Gut Microbiome: Implication for Cardiometabolic Health in Postmenopausal Women

Soy isoflavones have been suggested as an alternative treatment for managing postmenopausal symptoms and promoting long-term health due to their structural similarity to mammalian estrogen and ability to bind to estrogen receptors. Among all soy isoflavones and their metabolites, (S)-equol is known for having the strongest estrogenic activity. Equol is a metabolite of the soy isoflavone daidzein produced through intestinal bacterial metabolism. However, more than half of the human population is not able to produce equol due to the lack of equol-producing bacteria in their gastrointestinal tract. The interpersonal variations in the gut microbiome complicate the interpretation of data collected from humans. Furthermore, because rodents are efficient equol-producers, translatability between rodent models and humans is challenging. Herein, we first summarized the current knowledge of the microbial conversion of daidzein to equol, its relation to health, and proposed the need for developing model systems by which equol production can be manipulated while controlling other known confounding factors. Determining the necessity of equol-producing capacity within a gut microbial community when consuming soy as a functional ingredient, and identifying strategies to maximize equol production by modulating the gut microbiome, may provide future therapeutic approaches to improve the health of postmenopausal women.

Estrogenic Effects of Extracts and Isolated Compounds from Belowground and Aerial Parts of Spartina anglica

Menopause, caused by decreases in estrogen production, results in symptoms such as facial flushing, vaginal atrophy, and osteoporosis. Although hormone replacement therapy is utilized to treat menopausal symptoms, it is associated with a risk of breast cancer development. We aimed to evaluate the estrogenic activities of Spartina anglica (SA) and its compounds and identify potential candidates for the treatment of estrogen reduction without the risk of breast cancer. We evaluated the estrogenic and anti-proliferative effects of extracts of SA and its compounds in MCF-7 breast cancer cells. We performed an uterotrophic assay using an immature female rat model. Among extracts of SA, belowground part (SA-bg-E50) had potent estrogenic activity. In the immature female rat model, the administration of SA-bg-E50 increased uterine weight compared with that in the normal group. Among the compounds isolated from SA, 1,3-di-O-trans-feruloyl-(-)-quinic acid (1) had significant estrogenic activity and induced phosphorylation at serine residues of estrogen receptor (ER)α. All extracts and compounds from SA did not increase MCF-7 cell proliferation. Compound 1 is expected to act as an ERα ligand and have estrogenic effects, without side effects, such as breast cancer development.

Hormone Therapy and Breast Cancer: Emerging Steroid Receptor Mechanisms

Although hormone therapy is widely used by millions of women to relieve symptoms of menopause, it has been associated with several side-effects such as coronary heart disease, stroke and increased invasive breast cancer risk. These side-effects have caused many women to seek alternatives to conventional hormone therapy, including the controversial custom-compounded bioidentical hormone therapy suggested to not increase breast cancer risk. Historically estrogens and the estrogen receptor were considered the principal factors promoting breast cancer development and progression, however, a role for other members of the steroid receptor family in breast cancer pathogenesis is now evident, with emerging studies revealing an interplay between some steroid receptors. In this review, we discuss examples of hormone therapy used for the relief of menopausal symptoms, highlighting the distinction between conventional hormone therapy and custom-compounded bioidentical hormone therapy. Moreover, we highlight the fact that not all hormones have been evaluated for an association with increased breast cancer risk. We also summarize the current knowledge regarding the role of steroid receptors in mediating the carcinogenic effects of hormones used in menopausal hormone therapy, with special emphasis on the influence of the interplay or crosstalk between steroid receptors. Unraveling the intertwined nature of steroid hormone receptor signaling pathways in breast cancer biology is of utmost importance, considering that breast cancer is the most prevalent cancer among women worldwide. Moreover, understanding these mechanisms may reveal novel prevention or treatment options, and lead to the development of new hormone therapies that does not cause increased breast cancer risk.

Cardiac autonomic modulation impairments in advanced breast cancer patients

AIM

To compare cardiac autonomic modulation in early- versus advanced-stage breast cancer patients before any type of cancer treatment and investigate associated factors.

METHODS AND RESULTS

This cross-sectional study included women (30-69 years old) with primary diagnosis of breast cancer and women with benign breast tumors. We evaluated cardiac modulation by heart rate variability and assessed factors of anxiety, depression, physical activity, and other relevant medical variables. Patients were divided into three groups based on TNM staging of cancer severity: early-stage cancer (n = 42), advanced-stage cancer (n = 37), or benign breast tumors to serve as a control (n = 37). We analyzed heart rate variability in time and frequency domains. The advanced-stage cancer group had lower vagal modulation than early-stage and benign groups; also, the advance-stage group had lower overall heart rate variability when compared to benign conditions. Heart rate variability was influenced by age, menopausal status, and BMI.

CONCLUSIONS

Heart rate variability seems to be a promising, non-invasive tool for early diagnosis of autonomic dysfunction in breast cancer and detection of cardiovascular impairments at cancer diagnosis. Cardiac autonomic modulation is inversely associated with breast cancer staging.

Estrogen preserves split renal function in a chronic complete unilateral ureteral obstruction animal model

Estrogen may help to preserve renal function in chronic kidney disease. This study examined whether estrogen administration or deprivation affected the split renal function in rats subjected to chronic unilateral ureteral obstruction (UUO). Fifteen adult female Sprague-Dawley rats were randomly divided into three groups. Low- and high-estrogen groups were modeled by female castration or estrogen intraperitoneal injection, respectively, and the rats in the normal-estrogen group were untreated. Intermittent split renal function [glomerular filtration rate (GFR)] examination was performed on rats on days 2, 6 and 16 after UUO surgery via single-photon emission computed tomography (SPECT/CT). Routine hematoxylin and eosin (H&E) staining, immunohistochemistry, pathology examination and electron microscopy were performed to compare the histological differences. Low-, normal- and high-estrogen groups were successfully established (P<0.001). In the acute stage, the GFR of the contralateral healthy kidney showed a greater compensatory rise in the normal- and high-estrogen groups than in the low-estrogen group (P<0.05). In the chronic stage, the GFR of the obstructed kidney continued to decrease with the GFR of the high-estrogen group being significantly better preserved than that of the low-estrogen group (P<0.05). The GFR of the contralateral kidney compensated to the greatest extent in the high-estrogen group (P=0.01), and the total GFR was significantly superior (P<0.05). Routine H&E examination showed significant histological changes following surgery. The low-estrogen group had significant renal interstitial fibrosis compared with the normal- and high-estrogen groups (P<0.05), as observed by immunohistochemical (IHC) examination of transforming growth factor-β (TGF-β) and α-smooth muscle actin (α-SMA). Electron-microscopic (EM) examination also differentiated between groups. In conclusion, estrogen administration and deprivation significantly affected renal function. Estrogen may preserve the split renal function (GFR) in rats with chronic UUO.

Bias in breast cancer research in the screening era

Screening aims to detect breast cancer at an earlier stage than would occur if symptoms developed. The characteristics of breast cancer that are detectable at screening depend on both the physical properties of the screening test and specific anatomical features of breast cancer. As a result, breast cancer detected by screening is a select subset of all breast cancer existing in the population. Therefore, biomedical, clinical and epidemiological research into breast cancer using populations with access to screening can result in major bias. The biases, with examples, are explained.

Progesterone--promoter or inhibitor of breast cancer

Based on the results of a French cohort of postmenopausal women, it has been claimed that micronized progesterone does not enhance breast cancer risk. The impact of reproductive factors on breast cancer risk and a high prevalence of occult breast carcinomas at the time of menopause suggest an involvement of endogenous progesterone in the development of breast cancer. High mammographic density in the luteal phase and during treatment with estrogen/progestogen combinations reflect a change in the composition of mammary stroma and an increased water accumulation in the extracellular matrix which is caused by hygroscopic hyaluronan-proteoglycan aggregates. Proteoglycans are also involved in the regulation of proliferation, migration, and differentiation of epithelial cells and angiogenesis, and may influence malignant transformation of breast cells and progression of tumors. Reports on a lack of effect of estrogen/progesterone therapy on breast cancer risk may be rooted in a selective prescription to overweight women and/or to the very low progesterone serum levels after oral administration owing to a strong inactivation rate. The contradictory results concerning the proliferative effect of progesterone may be associated with a different local metabolism in normal compared to malignant breast tissue. Similar to other progestogens, hormone replacement therapy with progesterone seems to promote the development of breast cancer, provided that the progesterone serum levels have reached the threshold for endometrial protection.

Population-based hormone receptor-specific incidence trends of breast cancer in Germany

OBJECTIVES

Several countries reported a drop in prescription of hormone replacement therapy (HRT) in the 2000s, followed by decreases in breast cancer incidence among postmenopausal women aged 50-69 years. The aim of this study was to provide hormone receptor specific incidence rates of breast cancer in Germany.

METHODS

Breast cancer data were extracted from the cancer registries of the Federal States of Brandenburg and Saarland and the area of Munich for the period from 1998 to 2007. We obtained nationwide data on HRT prescription in 1998-2007 from health insurances. Multiple imputation was used on missing values for the receptor status. Age-standardized (European standard population) and age-specific rates were calculated.

RESULTS

The age-standardized incidence rates in breast cancer were virtually constant over the entire period in all regions. In particular, no substantial changes over time occurred within the age- and receptor-specific analyses. In the same period we observed a drop in HRT use, starting in 1999 and leveling off in 2004. The incidence trends of carcinoma in situ of the female breast increased during the study period.

CONCLUSIONS

In our data, we did not observe an association between the decline in HRT prescription and breast cancer incidence among women aged from 50 to 69 years. The lack of temporal changes in breast cancer incidence may be explained by introduction of opportunistic and organized mammography screening and low absolute levels of HRT prescription in Germany.

Effects of herbal and dietary supplements on cognition in menopause: a systematic review

OBJECTIVE

Many postmenopausal women use herbal remedies and dietary supplements to counteract menopausal symptoms, including the decline in cognitive function. The aim of this systematic review is to evaluate the evidence regarding the efficacy of herbal and dietary supplements on cognition in menopause.

DESIGN

Randomized clinical trials (RCTs) of herbal medicines and dietary supplements were identified using the Medline, EMBASE, AMED, PsycINFO, CINAHL and The Cochrane Library 2010 (Issue 2) electronic databases and by hand searches. Data were independently extracted and evaluated by two reviewers. Risk of bias was assessed by two independent reviewers using the Cochrane Collaboration tool.

RESULTS

Twelve RCTs were included and five of these suggest that isoflavone, soy and Gingko biloba supplementation may improve cognition in postmenopausal women. However, most of the included studies had serious methodological flaws which demand a cautious interpretation of these findings.

CONCLUSIONS

The evidence that herbal and dietary supplements might positively affect the cognitive decline during the menopause is not compelling.

Soy intake in association with menopausal symptoms during the first 6 and 36 months after breast cancer diagnosis

It has been suggested that soy food and its components may relieve menopausal symptoms (MPS) including hot flashes, night sweats, and vaginal dryness in healthy women. However, little is known about the effect of soy food intake on MPS in women with breast cancer. We examined associations of occurrence of MPS with soy food intake in 4,842 Chinese women aged 20-75 years who had non-metastatic breast cancer and had not used hormone replacement therapy. MPS were assessed at 6 and 36 months after cancer diagnosis using a standardized questionnaire, and associations with soy food intake were evaluated in multivariate regression analyses. Daily soy food intake was assessed at 6 months postdiagnosis and over the first 36 months postdiagnosis using a validated food frequency questionnaire. The prevalence of MPS was 56% at 6 months and 63% at 36 months postdiagnosis with the hotflash being the most common MPS (~44-55%). Hot flashes occurred mainly in premenopausal breast cancer patients who were in the highest quartile of isoflavone intake at 6 months postdiagnosis (OR = 1.20, 95% CI: 0.98-1.59) compared with the lowest quartile. This association was stronger at 36 months postdiagnosis (OR = 1.59, 95% CI: 1.02-2.48). We found no significant associations for any MPS, night sweats, or vaginal dryness. Neither tamoxifen use nor BMI modified the association between MPS and isoflavone intake. There was no evidence that soy food consumption reduced MPS among breast cancer patients. High soy intake may increase the prevalence of hotflashes among premenopausal patients. Our study suggests that soy acts as an estrogen antagonist in breast cancer patients.