Alcohol Intake and Risk of Breast Cancer by Histologic Subtype and Estrogen Receptor Status Among Women Aged 55 to 74 Years

Metabolites in the Dance: Deciphering Gut-Microbiota-Mediated Metabolic Reprogramming of the Breast Tumor Microenvironment

Breast Cancer (BC) is an important disease causing death of many women worldwide. Here the relationship between gastroenteral microbionta and metabolism in the context of BC is investigated and described in detail. The interrelation between BC, metabolite abnormalities and reprogramming, and micronenvironment is described. All information about the various mechanisms by which these bacterial residents may influence disease initiation, progression, and treatment response is collected and summarized. We will see that gut-based biomarkers, and synergy between conventional therapies and microbiome interventions, together will soon be able to open-up new gates for breast cancer therapy.

Breast cancer (BC), a major cause of death among women worldwide, has traditionally been linked to genetic and environmental factors. However, emerging research highlights the gut microbiome’s significant role in shaping BC development, progression, and treatment outcomes. This review explores the intricate relationship between the gut microbiota and the breast tumor microenvironment, emphasizing how these microbes influence immune responses, inflammation, and metabolic pathways. Certain bacterial species in the gut either contribute to or hinder BC progression by producing metabolites that affect hormone metabolism, immune system pathways, and cellular signaling. An imbalance in gut bacteria, known as dysbiosis, has been associated with a heightened risk of BC, with metabolites like short-chain fatty acids (SCFAs) and enzymes such as β-glucuronidase playing key roles in this process. Additionally, the gut microbiota can impact the effectiveness of chemotherapy, as certain bacteria can degrade drugs like gemcitabine and irinotecan, leading to reduced treatment efficacy. Understanding the complex interactions between gut bacteria and BC may pave the way for innovative treatment approaches, including personalized microbiome-targeted therapies, such as probiotics and fecal microbiota transplants, offering new hope for more effective prevention, diagnosis, and treatment of BC.

Invasive lobular breast cancer: Focus on prevention, genetics, diagnosis, and treatment

Invasive lobular cancer (ILC) is the most common of the breast cancer special types, accounting for up to 15% of all breast malignancies. The distinctive biological features of ILC include the loss of the cell adhesion molecule E-cadherin, which drives the tumor's peculiar discohesive growth pattern, with cells arranged in single file and dispersed throughout the stroma. Typically, such tumors originate in the lobules, are more commonly bilateral compared to invasive ductal cancer (IDC) and require a more accurate diagnostic examination through imaging. They are luminal in molecular subtype, and exhibit estrogen and progesterone receptor positivity and HER2 negativity, thus presenting a more unpredictable response to neoadjuvant therapies. There has been a significant increase in research focused on this distinctive breast cancer subtype, including studies on its pathology, its clinical and surgical management, and the high-resolution definition of its genomic profile, as well as the development of new therapeutic perspectives. This review will summarize the heterogeneous pattern of this unique disease, focusing on challenges in its comprehensive clinical management and on future insights and research objectives.

Host, reproductive, and lifestyle factors in relation to quantitative histologic metrics of the normal breast

BACKGROUND

Emerging data indicate that variations in quantitative epithelial and stromal tissue composition and their relative abundance in benign breast biopsies independently impact risk of future invasive breast cancer. To gain further insights into breast cancer etiopathogenesis, we investigated associations between epidemiological factors and quantitative tissue composition metrics of the normal breast.

METHODS

The study participants were 4108 healthy women ages 18-75 years who voluntarily donated breast tissue to the US-based Susan G. Komen Tissue Bank (KTB; 2008-2019). Using high-accuracy machine learning algorithms, we quantified the percentage of epithelial, stromal, adipose, and fibroglandular tissue, as well as the proportion of fibroglandular tissue that is epithelium relative to stroma (i.e., epithelium-to-stroma proportion, ESP) on digitized hematoxylin and eosin (H&E)-stained normal breast biopsy specimens. Data on epidemiological factors were obtained from participants using a detailed questionnaire administered at the time of tissue donation. Associations between epidemiological factors and square root transformed tissue metrics were investigated using multivariable linear regression models.

RESULTS

With increasing age, the amount of stromal, epithelial, and fibroglandular tissue declined and adipose tissue increased, while that of ESP demonstrated a bimodal pattern. Several epidemiological factors were associated with individual tissue composition metrics, impacting ESP as a result. Compared with premenopausal women, postmenopausal women had lower ESP [β (95% Confidence Interval (CI)) = -0.28 (- 0.43, - 0.13); P < 0.001] with ESP peaks at 30-40 years and 60-70 years among pre- and postmenopausal women, respectively. Pregnancy [β (95%CI) vs nulligravid = 0.19 (0.08, 0.30); P < 0.001] and increasing number of live births (P-trend < 0.001) were positively associated with ESP, while breastfeeding was inversely associated with ESP [β (95%CI) vs no breastfeeding = -0.15 (- 0.29, - 0.01); P = 0.036]. A positive family history of breast cancer (FHBC) [β (95%CI) vs no FHBC = 0.14 (0.02-0.26); P = 0.02], being overweight or obese [β (95%CI) vs normal weight = 0.18 (0.06-0.30); P = 0.004 and 0.32 (0.21-0.44); P < 0.001, respectively], and Black race [β (95%CI) vs White = 0.12 (- 0.005, 0.25); P = 0.06] were positively associated with ESP.

CONCLUSION

Our findings revealed that cumulative exposure to etiological factors over the lifespan impacts normal breast tissue composition metrics, individually or jointly, to alter their dynamic equilibrium, with potential implications for breast cancer susceptibility and tumor etiologic heterogeneity.

Alcohol consumption, smoking, and invasive breast cancer risk after ductal carcinoma in situ

PURPOSE

Alcohol is an established risk factor for invasive breast cancer, and women with a prior ductal carcinoma in situ diagnosis are at higher risk of invasive breast cancer than the general population. However, for women with a prior ductal carcinoma in situ diagnosis, few studies have evaluated the association between alcohol and smoking and risk of subsequent invasive breast cancer.

METHODS

Utilizing a population-based case-control design nested among women diagnosed with a ductal carcinoma in situ between 1995 and 2013, we compared 243 cases diagnosed with a subsequent invasive breast cancer and 423 individually matched controls never diagnosed with a subsequent breast cancer.

RESULTS

Compared with never to occasional drinkers, drinkers consuming at least 7 alcoholic drinks per week on average at ductal carcinoma in situ diagnosis had a higher risk of invasive breast cancer that was borderline significant (OR 1.79, 95% CI 1.01-3.17, P value = 0.04). Smoking was not significantly associated with risk of developing an invasive breast cancer after adjustment for alcohol consumption.

CONCLUSIONS

These findings suggest that consuming at least one alcoholic drink per day on average is positively associated with invasive breast cancer for women with a prior ductal carcinoma in situ diagnosis. If confirmed, modulating alcohol consumption could be one strategy for women with a history of ductal carcinoma in situ to impact their risk of invasive breast cancer.

Risk factors for breast cancer and their association with molecular subtypes in a population of Northeast Brazil

BACKGROUND

The risk factors for breast cancer (BC) among women in Brazilian populations are poorly understood. To date, few Brazilian studies have addressed the potential association between risk factors and molecular BC subtypes. This case-control study aimed to identify risk factors for BC in a population of Northeast Brazil.

METHODS

Data from 313 patients with invasive BC and 321 healthy controls were obtained from medical records from two cancer treatment centres and personal interviews. Of the 313 BC patients, 224 (71.6%) had reached menopause. The following distribution of subtypes was found among 301 patients: (1) Luminal A: 54 (17.9%); (2) Luminal B: 175 (58.1%); (3) HER2/neu: 29 (9.7%); and (4) triple-negative breast cancer (TNBC): 43 (14.3%). Odds ratios (ORs) and confidence intervals (CIs) were determined using regression analysis.

RESULTS

Regression modelling indicated that family history, obesity (≥ 30.0 kg/m²), alcohol consumption and contraceptive use increased the overall risk of BC 1.78 (95% CI: 1.22-2.59), 1.69 (95% CI: 1.08-2.63), 2.21 (95% CI: 1.44-3.39) and 2.99 (95% CI: 2.09-4.28) times, respectively. After stratification for menopausal status, alcohol consumption increased the risk of BC 4.15 (95% CI: 2.13-8.11) times, and obesity, as a single variable, increased the risk of BC 2.02 (95% CI: 1.22-3.37) times, only among postmenopausal women. In a case-control analysis, the risk of TNBC and Luminal B breast cancer were 4.06 (95% CI: 1.58-10.42) and 1.87 times (95% CI: 1.13-3.11) higher, respectively, in obese women than in non-obese women. Furthermore, alcohol consumption increased the risk of Luminal A and B subtypes 7.08 (3.40-14.73) and 1.77 (1.07-2.92) times, respectively.

CONCLUSION

Family history, contraceptive use, obesity and alcohol consumption increased the risk of BC. Obesity and alcohol consumption differentially increased risk of TNBC and Luminal molecular subtypes.

Causes of death among women with breast cancer: A follow-up study of 50 481 women with breast cancer in Finland

Our study aims to assess mortality from causes other than breast cancer among women with breast cancer with focus on indications of joint aetiology. Data on female breast cancer patients were obtained from the Finnish Cancer Registry and their underlying causes of death in 54 categories from the Statistics Finland. Standardised mortality ratios (SMR) and their 95% confidence intervals (CIs) were calculated for 50 481 patients diagnosed between 1971 and 2000 and followed until December 2012, stratified by histology, age at diagnosis and time since diagnosis. The expected numbers of deaths were based on respective mortality rates among the Finnish general population. Hazard ratio (HR) was estimated from Poisson regression model to compare risks of cause of death by histology. 41% of 30 841 deaths were due to causes other than breast cancer. Significant excess mortality was observed for stomach cancer (SMR 1.43, 95% CI 1.26-1.62), circulatory system diseases (SMR 1.17, 95% CI 1.14-1.20) and suicide (SMR 1.51, 95% CI 1.28-1.78). In an age-adjusted analysis, significantly higher relative risk of stomach cancer mortality was observed for lobular vs ductal subtype (HR 2.00, 95% CI 1.32-3.02). Significantly increased SMRs were observed for cancers of respiratory organs among premenopausal women, and for other respiratory system diseases, dementia and Alzheimer disease among postmenopausal women. We conclude that female breast cancer patients are at increased risk of death from causes other than the breast cancer diagnosis including circulatory and respiratory system diseases and cancer of stomach, ovary and respiratory systems. The excess mortality because of different causes varies based on menopausal status and histology. There might be shared aetiological factors between the diagnosis of breast cancer and the causes of death among these patients.

Alcohol Consumption by Beverage Type and Risk of Breast Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies

AIMS

Alcohol intake has been shown to increase the risk of breast cancer. However, the dose-response analysis of different alcoholic beverages (spirits, wine and beer) is not clear. Our meta-analysis aims to provide a dose-response estimation between different alcohols and breast cancer risk.

METHODS

Search of PubMed and Web of Science and manual searches were conducted up to 1 December 2018, and summary relative risks (RRs) and attributable risk percentage (ARP) for alcohol intake on the development of breast cancer were calculated. Dose-response meta-analysis modeled relationships between drinking type and breast cancer risk. Sources of heterogeneity were explored, and sensitivity analyses were conducted to test the robustness of findings.

RESULTS

In total, 22 cohort studies and 45,350 breast cancer cases were included. Current drinkers for ER+ had an increased risk compared with never drinkers. In dose-response analysis, there was a statistically significant linear trend with breast cancer risk increasing gradually by total alcohol and wine dose: when adding 10 g per day, the risk increased by 10.5% (RR = 1.10, 95%CI = 1.08-1.13) in total alcohol and 8.9% (RR = 1.08, 95%CI = 1.04-1.14) in wine. For postmenopausal women, the risk increases by 11.1% (RR = 1.11, 95%CI = 1.09-1.13) with every 10 g of total alcohol increase. Furthermore, the breast cancer alcohol-attributed percentage is higher in Europe than in North America and Asia.

CONCLUSIONS

The effect of drinking on the incidence of breast cancer is mainly manifested in ER+ breast cancer. Quantitative analysis showed total drinking had a significant risk for breast cancer, especially for postmenopausal women. However, for different alcohols, just wine intake has the similar results.

Role of betaine in inhibiting the induction of RNA Pol III gene transcription and cell growth caused by alcohol

Alcohol has been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). Studies have demonstrated that alcohol intake increases the risk of breast cancer, and alcohol also stimulates breast cancer cell growth. Deregulation of Pol III genes is tightly associated with tumour development. Transcription factor II-B (TFIIB)-related factor 1 (Brf1) is a transcription factor that specifically regulates Pol III gene transcription. Our in vivo and in vitro studies have indicated that alcohol enhances the transcription of Pol III genes to cause an alteration of cellular phenotypes, which is closely related with human breast cancer. Betaine is a vegetable alkaloid and has antitumor functions. Most reports about betaine show that the consumption level of betaine is inversely associated with a risk of breast cancer. Although different mechanisms of betaine against tumour have been investigated, nothing has been reported on the effect of betaine on the deregulation of Brf1 and Pol III genes. In this study, we determine the role of betaine in breast cancer cell growth and colony formation and explore its mechanism. Our results indicate that alcohol increases the rates of growth and colony formation of breast cancer cells, whereas betaine is able to significantly inhibit the effects of alcohol on these cell phenotypes. Betaine decreases the induction of Brf1 expression and Pol III gene transcription caused by ethanol to reduce the rates of cell growth and colony formation. Together, these studies provide novel insights into the role of betaine in alcohol-caused breast cancer cell growth and deregulation of Brf1 and Pol III genes. These results suggest that betaine consumption is able to prevent alcohol-associated human cancer development.

Epidemiological characteristics of and risk factors for breast cancer in the world

AIM

Breast cancer is the most common cancer among women and one of the most important causes of death among them. This review aimed to investigate the incidence and mortality rates of breast cancer and to identify the risk factors for breast cancer in the world.

MATERIALS AND METHODS

A search was performed in PubMed, Web of Science, and Scopus databases without any time restrictions. The search keywords included the following terms: breast cancer, risk factors, incidence, and mortality and a combination of these terms. Studies published in English that referred to various aspects of breast cancer including epidemiology and risk factors were included in the study. Overall, 142 articles published in English were included in the study.

RESULTS

Based on the published studies, the incidence rate of breast cancer varies greatly with race and ethnicity and is higher in developed countries. Results of this study show that mortality rate of breast cancer is higher in less developed regions. The findings of this study demonstrated that various risk factors including demographic, reproductive, hormonal, hereditary, breast related, and lifestyle contribute to the incidence of breast cancer.

CONCLUSION

The results of this study indicated that incidence and mortality rates of breast cancer is rising, so design and implementation of screening programs and the control of risk factors seem essential.