Risk factors of breast cancer: a systematic review and meta-analysis

Non-genetic factors and breast cancer: an umbrella review of meta-analyses

BACKGROUND

Previous research has found associations between various non-genetic factors and breast cancer (BrCa) risk. This study summarises and appraises the credibility of the available evidence on the association between non-genetic factors and BrCa risk.

METHODS

We conducted an umbrella review of meta-analyses. Medline, Scopus, and the Cochrane databases were systematically searched for meta-analyses examining non-genetic factors and BrCa incidence or mortality. The strength of the evidence was graded in four categories (i.e., weak, suggestive, highly suggestive, convincing).

RESULTS

A total of 781 meta-analyses from 280 publications were evaluated and graded. We included exposures related to anthropometric measurements, biomarkers, breast characteristics and diseases, diet and supplements, environment, exogenous hormones, lifestyle and social factors, medical history, medication, reproductive history, and pregnancy. The largest number of examined associations was found for the category of diet and supplements and for exposures such as aspirin use and active smoking. The statistically significant (P-value < 0.05) meta-analyses were 382 (49%), of which 204 (53.4%) reported factors associated with increased BrCa risk. Most of the statistically significant evidence (n = 224, 58.6%) was graded as weak. Convincing harmful associations with heightened BrCa risk were found for increased body mass index (BMI), BMI and weight gain in postmenopausal women, oral contraceptive use in premenopausal women, increased androstenedione, estradiol, estrone, and testosterone concentrations, high Breast Imaging Reporting and Data System (BIRADS) classification, and increased breast density. Convincing protective factors associated with lower BrCa risk included high fiber intake and high sex hormone binding globulin (SHBG) levels while highly suggestive protective factors included high 25 hydroxy vitamin D [25(OH)D] levels, adherence to healthy lifestyle, and moderate-vigorous physical activity.

CONCLUSIONS

Our findings suggest some highly modifiable factors that protect from BrCa. Interestingly, while diet was the most studied exposure category, the related associations failed to reach higher levels of evidence, indicating the methodological limitations in the field. To improve the validity of these associations, future research should utilise more robust study designs and better exposure assessment techniques. Overall, our study provides knowledge that supports the development of evidence-based BrCa prevention recommendations and guidance, both at an individual level and for public health initiatives.

TRIAL REGISTRATION

PROSPERO CRD42022370675.

Glucagon-Like Peptide 1 Receptor Agonists and 13 Obesity-Associated Cancers in Patients With Type 2 Diabetes

Importance

Thirteen human malignant neoplasms have been identified as obesity-associated cancers (OACs), ie, the presence of excess body fat is associated with increased risk of developing cancer and worse prognosis in patients with these specific tumors. The glucagon-like peptide receptor agonist (GLP-1RA) class of pharmaceuticals are effective agents for the treatment of type 2 diabetes (T2D) and for achieving weight loss, but the association of GLP-1RAs with the incident risk of 13 OACs is unclear.

Objective

To compare the incident risk of each of the 13 OACs in patients with T2D who were prescribed GLP-1RAs vs insulins or metformin.

Design, Setting, and Participants

This retrospective cohort study was based on a nationwide multicenter database of electronic health records (EHRs) of 113 million US patients. The study population included 1 651 452 patients with T2D who had no prior diagnosis of OACs and were prescribed GLP-1RAs, insulins, or metformin during March 2005 to November 2018. Data analysis was conducted on April 26, 2024.

Exposures

Prescription of GLP-1RAs, insulins, or metformin.

Main Outcomes and Measures

Incident (first-time) diagnosis of each of the 13 OACs occurring during a 15-year follow-up after the exposure was examined using Cox proportional hazard and Kaplan-Meier survival analyses with censoring applied. Hazard ratios (HRs), cumulative incidences, and 95% CIs were calculated. All models were adjusted for confounders at baseline by propensity-score matching baseline covariates.

Results

In the study population of 1 651 452 patients with T2D (mean [SD] age, 59.8 [15.1] years; 827 873 [50.1%] male and 775 687 [47.0%] female participants; 5780 [0.4%] American Indian or Alaska Native, 65 893 [4.0%] Asian, 281 242 [17.0%] Black, 13 707 [0.8%] Native Hawaiian or Other Pacific Islander, and 1 000 780 [60.6%] White participants), GLP-1RAs compared with insulin were associated with a significant risk reduction in 10 of 13 OACs, including in gallbladder cancer (HR, 0.35; 95% CI, 0.15-0.83), meningioma (HR, 0.37; 95% CI, 0.18-0.74), pancreatic cancer (HR, 0.41; 95% CI, 0.33-0.50), hepatocellular carcinoma (HR, 0.47; 95% CI, 0.36-0.61), ovarian cancer (HR, 0.52; 95% CI, 0.03-0.74), colorectal cancer (HR, 0.54; 95% CI, 0.46-0.64), multiple myeloma (HR, 0.59; 95% CI, 0.44-0.77), esophageal cancer (HR, 0.60; 95% CI, 0.42-0.86), endometrial cancer (HR, 0.74; 95% CI, 0.60-0.91), and kidney cancer (HR, 0.76; 95% CI, 0.64-0.91). Although not statistically significant, the HR for stomach cancer was less than 1 among patients who took GLP-1RAs compared with those who took insulin (HR, 0.73; 95% CI, 0.51-1.03). GLP-1RAs were not associated with a reduced risk of postmenopausal breast cancer or thyroid cancer. Of those cancers that showed a decreased risk among patients taking GLP-1RAs compared with those taking insulin, HRs for patients taking GLP-1RAs vs those taking metformin for colorectal and gallbladder cancer were less than 1, but the risk reduction was not statistically significant. Compared with metformin, GLP-1RAs were not associated with a decreased risk of any cancers, but were associated with an increased risk of kidney cancer (HR, 1.54; 95% CI, 1.27-1.87).

Conclusions and Relevance

In this study, GLP-1RAs were associated with lower risks of specific types of OACs compared with insulins or metformin in patients with T2D. These findings provide preliminary evidence of the potential benefit of GLP-1RAs for cancer prevention in high-risk populations and support further preclinical and clinical studies for the prevention of certain OACs.

Breast Cancer Risk Factors among Women with Solid Breast Lesions

BACKGROUND

Breast cancer is the most frequent malignancy in women worldwide and one of the most curable cancers if diagnosed at an early stage. Female patients presenting solid breast lesions are greatly predisposed to breast cancer development, and as such, effective screening of high-risk patients is valuable in early-stage breast cancer detection.

OBJECTIVES

The aim of our study was to identify the most relevant demographic, reproductive and lifestyle risk factors for breast cancer among women with solid breast lesions living in western Romania, namely the urban region consisting of Timisoara and the rural surrounding regions.

METHODS

From January 2017 to December 2021, 1161 patients with solid breast lesions, as detected by sonoelastography, were divided into two groups: patients with benign lesions (1019, 87.77%) and patients with malignant nodules (142, 12.23%). The malignancy group was confirmed by a histopathological result. Variables including age, BMI, menarche, menopause, years of exposure to estrogen, number of births, breastfeeding period, use of oral combined contraceptives, smoker status, family medical history and living area (rural-urban) were recorded.

RESULTS

It was evidenced by our study that the main risk factors for malignancy were elevated age (OR = 1.07, 95% CI 1.05-1.08), BMI (OR = 1.06, 95% CI 1.02-1.10), living area (rural) (OR = 1.86, 95% CI 1.13-2.85) and family medical history (negative) (OR 3.13, 95% CI 1.43-8.29). The other proposed risk factors were not found to be statistically significant.

CONCLUSIONS

Age and BMI were observed to be the most significant factors for breast cancer risk increase, followed by living in a rural area. A family history of breast cancer was shown to be inversely correlated with cancer risk increase.

Oncogenic BRCA1,2 Mutations in the Human Lineage-A By-Product of Sexual Selection?

In this review, we discuss the long-known problem of tissue-specific carcinogenesis in BRCA1 and BRCA2 mutation carriers: while the genes are expressed ubiquitously, increased cancer risk is observed mostly in the breast and ovaries, and to a much lesser extent, in some other tissues such as the prostate or pancreas. We reevaluate hypotheses on the evolutionary origin of these mutations in humans. Also, we align together the reports that at least some great apes have much lower risks of epithelial cancers in general and breast cancer in particular with the fact that humans have more voluminous breast tissue as compared to their closest extant relatives, particularly chimpanzees and bonobos. We conjecture that this disparity may be a consequence of sexual selection, augmented via selection for enhanced lactation. Further, we argue that there is an organ-specific enigma similar to the Peto paradox: breast cancer risk in humans is only minimally correlated with breast size. These considerations lead to the hypothesis that, along with the evolutionary development of larger breasts in humans, additional changes have played a balancing role in suppressing breast cancer. These yet-to-be-discovered mechanisms, while purely speculative, may be valuable to understanding human breast cancer, though they may not be exclusive to the mammary gland epithelial cells. Combining these themes, we review some anti-carcinogenesis preventive strategies and prospects of new interventions against breast cancer.

Australian, Irish, and Swedish women's comfort levels when breastfeeding in public

BACKGROUND

Despite a flux of global initiatives to increase and sustain breastfeeding rates, challenges persist. The decision to commence and sustain breastfeeding is influenced by multiple, complex factors. Feelings of social embarrassment, shame, fear of judgement, and lack of confidence when breastfeeding in public, compound women's decisions to breastfeed and may result in formula feeding or early cessation of breastfeeding. A greater understanding of where and how women feel most comfortable when breastfeeding in public can assist in designing interventions to support the initiation and continuation of breastfeeding.

METHODS

A cross-sectional survey was conducted with women living in Australia (n = 10,910), Sweden (n = 1,520), and Ireland (n = 1,835), who were currently breastfeeding or who had breastfed within the previous two years. Our aim was to explore where, and how often women breastfeed in public and to compare their levels of comfort when breastfeeding in public. Data were collected in 2018 using an anonymous online survey over a four-week period in Ireland, Australia, and Sweden, and were analyzed using SPSS Version 25.

RESULTS

Most respondents were highly educated, with over 70% in each country reporting having a university or college degree. Observing women breastfeeding in public was more commonly reported to be a weekly or daily occurrence in Sweden (24.5%) and Australia (28%), than in Ireland (13.3%). Women in the participating countries reported breastfeeding in public most commonly whenever their babies needed feeding. Very few women never or rarely breastfed publicly. Coffee shops/cafes, restaurants, and parks were the most popular locations. In all three countries, partners were reported to be very supportive of breastfeeding in public, which enhanced breastfeeding women's comfort levels. When asked to score out of a maximum comfort level of 10, women reported higher mean levels of comfort when breastfeeding in front of strangers (Ireland M = 7.33, Australia M = 6.58, Sweden M = 6.75) than with those known to them, particularly in front of their father-in-law (Ireland M = 5.44, Australia M = 5.76, Sweden M = 6.66 out of 10), who scored lowest in terms of women's comfort levels.

CONCLUSION

This study offers important insights into the experiences and comfort levels of women breastfeeding in public. Limitations include the anonymous nature of the surveys, thus preventing follow-up, and variances in terminology used to describe locations across the three settings. Recommendations are made for research to determine the relationships between the frequency of breastfeeding in public and breastfeeding women's perceived comfort levels, the influence of family members' perceptions of breastfeeding in public and women's experiences, and the experience of women who feel uncomfortable while breastfeeding in public, with a view to developing support measures.

Association between estimated cardiorespiratory fitness and breast cancer: a prospective cohort study

OBJECTIVE

To examine the association between cardiorespiratory fitness (CRF) and the risk of breast cancer in postmenopausal women.

METHODS

This study used data from 17 840 cancer-free postmenopausal women with a CRF assessment from the UK Biobank. High estimated CRF (eCRF) was categorised as being >80th percentile within 10-year age bands. Fine and Gray regression was used to examine the association between eCRF and breast cancer risk, accounting for both non-breast cancer diagnoses and all-cause mortality as competing risks. Age was used as the time scale. Several different models were produced, including those adjusting for known breast cancer risk factors, and stratified by measures of body fat (body mass index and per cent body fat).

RESULTS

Over a median follow-up of 11.0 years there were 529 cases of invasive breast cancer, 1623 cases of non-breast cancer disease and 241 deaths. With adjustment for breast cancer risk factors, high eCRF was associated with a 24% (subdistribution HR (SDHR) 0.76, 95% CI 0.60 to 0.97) lower risk of breast cancer. When stratified by measures of body fat, we found evidence of effect measure modification. Mainly, having high eCRF was only associated with a lower risk of breast cancer among those classified as having overweight/obesity (SDHR 0.33, 95% CI 0.11 to 1.01) or percentage body fat above the 1st quintile (SDHR 0.65, 95% CI 0.45 to 0.94).

CONCLUSION

Having higher CRF may be a protective factor against breast cancer in postmenopausal women but only for women with elevated body fat.

Breast Cancer: Clinical-Epidemiological Profile and Toxicities of Women Receiving Treatment with Taxanes in the Amazon Region

Breast cancer is the most common malignant disease and the leading cause of mortality among women worldwide. Antineoplastic chemotherapy is one of its primary treatments, typically based on the class of drugs known as taxanes. Despite their proven therapeutic efficacy, these drugs can induce severe toxicities, leading to dose limitations or even treatment discontinuation. The objective of this study was to describe the clinical-epidemiological profile, risk factors, and toxicities of taxane-based chemotherapy treatment in women with breast cancer in the Amazon region. This is a cross-sectional, quantitative, and descriptive study conducted with 300 women diagnosed with breast cancer undergoing taxane treatment. Most patients were in the 40-49 age range, of brown ethnicity, and had completed elementary school. The majority of patients had risk factors such as alcoholism and a sedentary lifestyles. Most women had their first pregnancy between the ages of 18 and 21, breastfed their children, had menarche between the ages of 12 and 13, and were pre-menopausal and with a family history of cancer. The most frequent histological type was non-special invasive carcinoma and the Luminal B subtype. Most participants in this study showed taxane toxicity, with neurotoxicity being the most frequent. These findings reveal the importance of early detection, comprehensive risk factors, and effective management of treatment toxicities to improve patient outcomes in breast cancer care in the Amazon region.

Estrogens and the risk of breast cancer: A narrative review of literature

In female mammals, the development and regulation of the reproductive system and non-reproductive system are significantly influenced by estrogens (oestrogens). In addition, lipid metabolism is another physiological role of estrogens. Estrogens act through different types of receptors to introduce signals to the target cell by affecting many estrogen response elements. Breast cancer is considered mostly a hormone-dependent disease. Approximately 70% of breast cancers express progesterone receptors and/or estrogen receptors, and they are a good marker for cancer prognosis. This review will discuss estrogen metabolism and the interaction of estrogen metabolites with breast cancer. The carcinogenic role of estrogen is discussed in light of both conventional and atypical cancers susceptible to hormones, such as prostate, endometrial, and lung cancer, as we examine how estrogen contributes to the formation and activation of breast cancer. In addition, this review will discuss other factors that can be associated with estrogen-driven breast cancer.

Practice, confidence and continuity of breast self-examination among women in Thailand during COVID-19 pandemic: a cross-sectional study

OBJECTIVE

Breast self-examination (BSE) is the most feasible screening tool compared with clinical breast examination and mammography. It is crucial to address the associated factors of practising BSE to develop a targeted BSE promotion programme and improve the BSE quality in Thai women, particularly during the COVID-19 pandemic.

DESIGN AND SETTING

We conducted a cross-sectional study in Thailand's north and northeast region from March 2020 to November 2022.

PARTICIPANTS

This study involved 405 women aged 30-70 years old.

VARIABLES AND OUTCOMES

Demographic information, health status and BSE were collected using a modified questionnaire based on the Champion Health Belief Model. The outcomes were ever-practising BSE, BSE practice within the last 6 months, continuity of BSE and confidence in doing BSE. Logistic regression and decision tree analysis identified the associated factors.

RESULTS

75.55% of participants ever performed BSE. Around 74.18% did BSE within the last 6 months. Diploma graduates (adjusted OR (aOR) 25.48, 95% CI 2.04 to 318.07), 21-40 reproductive years (aOR 4.29, 95% CI 1.22 to 15.08), ever pregnant (aOR 3.31, 95% CI 1.05 to 10.49), not drinking alcohol (aOR 2.1, 95% CI 1.04 to 4.55), not receiving hormone replacement (aOR 5.51, 95% CI 2.04 to 14.89), higher knowledge (aOR 1.29, 95% CI 1.09 to 1.52), attitude (aOR 1.15, 95% CI 1.05 to 1.26) and practice/cues of action towards BSE were associated with ever-practising BSE. Frequent high-fat diet, high awareness of breast cancer, lower knowledge of BSE and lower attitude toward BSE were associated with not practising BSE within 6 months and BSE discontinuation. Only high knowledge of BSE was associated with absolute confidence in BSE (p<0.05).

CONCLUSION

Despite having a higher percentage than other studies in different countries prior to the pandemic, it is still crucial to improve knowledge of BSE to encourage BSE practice, confidence and continuity of BSE in Thai women. Moreover, the BSE campaign should target women with prolonged exposure to oestrogen and sedentary lifestyle.

Descriptive Study and Surgical Management Among Infiltrating Lobular Carcinoma Patients Admitted to King Abdulaziz Medical City From 2000 to 2017: A Retrospective Cross-Sectional Study

INTRODUCTION

Invasive lobular carcinoma (ILC) is the second most common histologic type of breast carcinoma. The etiology of ILC is unknown; however, many contributing risk factors have been suggested. Treatment of ILC can be divided into local and systemic. Our objectives were to assess the clinical presentations, risk factors, radiological findings, pathological types, and surgical options for patients with ILC treated at the national guard hospital. Identify the factors associated with metastasis and recurrence.

METHODS

Retrospective cross-sectional descriptive study at a tertiary care center in Riyadh. All adult patients aged 16 years and above, from different nationalities, and both genders, were diagnosed with ILC from 2000 to 2017 and followed up at KAMC. The sampling technique was a non-probability consecutive technique. Among 1066 patients identified, 91 patients were diagnosed with ILC over seventeen years study period.

RESULTS

The median age at the primary diagnosis was 50. On the clinical examination, 63 (71%) cases were found to have palpable masses which was the most suspicious finding. On radiology, the most encountered finding was speculated masses which were seen in 76 (84%). Regarding the pathology, unilateral breast cancer was seen in 82 while bilateral breast cancer was found only in eight. For the biopsy, a core needle biopsy was the most commonly used in 83 (91%) patients. The most documented surgery for ILC patients was a modified radical mastectomy. Metastasis in different organs was identified with the musculoskeletal system being the commonest site. Different significant variables were compared between patients with or without metastasis. Skin changes, post-operative invasion, estrogen, progesterone, and HER2 receptors were significantly associated with metastasis. Patients with metastasis were less likely to have conservative surgery. Regarding the Recurrence and five years survival, out of 62 cases, 10 had recurrence within five years, which was more prevalent in patients who had fine needle aspiration, excisional biopsy, and nulliparous patients.

CONCLUSION

To our knowledge, this is the first study to exclusively describe ILC in Saudi Arabia. The results of this current study are highly important, as these results provide baseline data of ILC in the capital city of Saudi Arabia.

Clusters of high-risk, low-risk, and temporal trends of breast and cervical cancer-related mortality in São Paulo, Brazil, during 2000-2016

PURPOSE

Studying breast and cervical cancers in space and time and verifying divergences of different territorially established socioeconomic profiles.

METHODS

Ecological study using spatial scanning (with socioeconomic characterization), space-time, and spatial variation of temporal trends, in order to identify significant clusters of high- and low-risk or temporal trends, of deaths from breast cancer and cervical cancer, in the city of São Paulo, Brazil, during 2000-2016.

RESULTS

High-risk spatial clusters were identified in the central areas, and low-risk clusters were identified in the peripheral areas, which were associated with better and worse socioeconomic conditions, respectively. As for cervical cancer, the pattern was the opposite. High-risk space-time clusters occurred in the early years of the study, whereas low-risk clusters occurred in the most recent years. For breast cancer, the central areas showed a temporal trend of decreasing mortality and the peripheral areas showed an increasing trend. While for cervical cancer, in general, the temporal trend was for the identified clusters to fall.

CONCLUSIONS

It is expected that this study will provide insights for the formulation of public policies to implement prevention and control measures, in order to reduce mortality and inequalities related to breast and cervical cancers.

Intra-urban spatial variability of breast and cervical cancer mortality in the city of São Paulo: analysis of associated factors

OBJECTIVE

To identify spatial variability of mortality from breast and cervical cancer and to assess factors associated in the city of São Paulo.

METHODS

Between 2009 and 2016, 10,124 deaths from breast cancer and 2,116 deaths from cervical cancer were recorded in the Mortality Information System among women aged 20 years and over. The records were geocoded by address of residence and grouped according to Primary Health Care coverage areas. A spatial regression modeling was put together using the Bayesian approach with a Besag-York-Mollié structure to verify the association of deaths with selected indicators.

RESULTS

Mortality rates from these types of cancer showed inverse spatial patterns. These variables were associated with breast cancer mortality: travel time between one and two hours to work (RR - relative risk: 0.97; 95%CI - credible interval: 0.93-1.00); women being the head of the household (RR 0.97; 95%CI 0.94-0.99) and deaths from breast cancer in private health institutions (RR 1.04; 95%CI 1.00-1.07). The following variables were associated with mortality from cervical cancer: travel time to work between half an hour and one hour (RR 0.92; 95%CI 0.87-0.98); per capita household income of up to 3 minimum wages (RR 1.27; 95%CI 1.18-1.37) and ratio of children under one year of age related to the female population aged 15 to 49 years (RR 1.09; 95%CI 1.01-1.18).

CONCLUSION

The predicted RR for mortality from these cancers were calculated and associated with the socioeconomic conditions of the areas covered.

Intra-urban spatial variability of breast and cervical cancer mortality in the city of São Paulo: analysis of associated factors

ABSTRACT Objective: To identify spatial variability of mortality from breast and cervical cancer and to assess factors associated in the city of São Paulo. Methods: Between 2009 and 2016, 10,124 deaths from breast cancer and 2,116 deaths from cervical cancer were recorded in the Mortality Information System among women aged 20 years and over. The records were geocoded by address of residence and grouped according to Primary Health Care coverage areas. A spatial regression modeling was put together using the Bayesian approach with a Besag-York-Mollié structure to verify the association of deaths with selected indicators. Results: Mortality rates from these types of cancer showed inverse spatial patterns. These variables were associated with breast cancer mortality: travel time between one and two hours to work (RR – relative risk: 0.97; 95%CI – credible interval: 0.93–1.00); women being the head of the household (RR 0.97; 95%CI 0.94–0.99) and deaths from breast cancer in private health institutions (RR 1.04; 95%CI 1.00–1.07). The following variables were associated with mortality from cervical cancer: travel time to work between half an hour and one hour (RR 0.92; 95%CI 0.87–0.98); per capita household income of up to 3 minimum wages (RR 1.27; 95%CI 1.18–1.37) and ratio of children under one year of age related to the female population aged 15 to 49 years (RR 1.09; 95%CI 1.01–1.18). Conclusion: The predicted RR for mortality from these cancers were calculated and associated with the socioeconomic conditions of the areas covered.

Increasing importance of breast cancer in Nepal

Recently, breast cancer cases in Nepal are on the rise, accounting for approximately 16% of all cancer cases, making it the second most common malignancy. Given the dependence of the Nepalese on agriculture, the rampant use of pesticides as well as the presence of arsenic in water supplies might be contributing to this huge rise in cancer cases. Herein, we provide a brief overview of the status of breast cancer, its burden, risk factors, screening and modes of treatment in Nepal.

Promote Community Engagement in Participatory Research for Improving Breast Cancer Prevention: The P.I.N.K. Study Framework

Breast cancer (BC) has overtaken lung cancer as the most common cancer in the world and the projected incidence rates show a further increase. Early detection through population screening remains the cornerstone of BC control, but a progressive change from early diagnosis only-based to a personalized preventive and risk-reducing approach is widely debated. Risk-stratification models, which also include personal lifestyle risk factors, are under evaluation, although the documentation burden to gather population-based data is relevant and traditional data collection methods show some limitations. This paper provides the preliminary results from the analysis of clinical data provided by radiologists and lifestyle data collected using self-administered questionnaires from 5601 post-menopausal women. The weight of the combinations of women's personal features and lifestyle habits on the BC risk were estimated by combining a model-driven and a data-driven approach to analysis. The weight of each factor on cancer occurrence was assessed using a logistic model. Additionally, communities of women sharing common features were identified and combined in risk profiles using social network analysis techniques. Our results suggest that preventive programs focused on increasing physical activity should be widely promoted, in particular among the oldest women. Additionally, current findings suggest that pregnancy, breast-feeding, salt limitation, and oral contraception use could have different effects on cancer risk, based on the overall woman's risk profile. To overcome the limitations of our data, this work also introduces a mobile health tool, the Dress-PINK, designed to collect real patients' data in an innovative way for improving women's response rate, data accuracy, and completeness as well as the timeliness of data availability. Finally, the tool provides tailored prevention messages to promote critical consciousness, critical thinking, and increased health literacy among the general population.

Anticancer potential of cryptotanshinone on breast cancer treatment; A narrative review

Breast cancer has recently been known as the first lethal malignancy in women worldwide. Despite the existing treatments that have improved the patients’ prognosis, some types of breast cancer are serious challenges to treat. Therefore, efforts are underway to provide more efficient therapy. Cryptotanshinone (CPT) is a liposoluble diterpenoid derivation of a traditional Chinese herbal medicine called Salvia miltiorrhiza Bunge. It has been considered in the past decades due to its vast therapeutic properties, including anti-tumor, anti-inflammatory, and anti-fibrosis. Recently, studies have found that CPT showed a significant anti-breast cancer effect in vivo and in vitro through different physiological and immunological mechanisms. This study summarized the latest research findings on the antitumor effect of CPT in breast cancer. Further, the main molecular mechanisms based on breast cancer types and combination with other drugs were reviewed to provide essential evidence for future longitudinal research and its clinical application in breast cancer treatment.

The burden and risks of emerging complications of diabetes mellitus

The traditional complications of diabetes mellitus are well known and continue to pose a considerable burden on millions of people living with diabetes mellitus. However, advances in the management of diabetes mellitus and, consequently, longer life expectancies, have resulted in the emergence of evidence of the existence of a different set of lesser-acknowledged diabetes mellitus complications. With declining mortality from vascular disease, which once accounted for more than 50% of deaths amongst people with diabetes mellitus, cancer and dementia now comprise the leading causes of death in people with diabetes mellitus in some countries or regions. Additionally, studies have demonstrated notable links between diabetes mellitus and a broad range of comorbidities, including cognitive decline, functional disability, affective disorders, obstructive sleep apnoea and liver disease, and have refined our understanding of the association between diabetes mellitus and infection. However, no published review currently synthesizes this evidence to provide an in-depth discussion of the burden and risks of these emerging complications. This Review summarizes information from systematic reviews and major cohort studies regarding emerging complications of type 1 and type 2 diabetes mellitus to identify and quantify associations, highlight gaps and discrepancies in the evidence, and consider implications for the future management of diabetes mellitus.

Genome-wide interaction analysis of menopausal hormone therapy use and breast cancer risk among 62,370 women

Use of menopausal hormone therapy (MHT) is associated with increased risk for breast cancer. However, the relevant mechanisms and its interaction with genetic variants are not fully understood. We conducted a genome-wide interaction analysis between MHT use and genetic variants for breast cancer risk in 27,585 cases and 34,785 controls from 26 observational studies. All women were post-menopausal and of European ancestry. Multivariable logistic regression models were used to test for multiplicative interactions between genetic variants and current MHT use. We considered interaction p-values < 5 × 10-8 as genome-wide significant, and p-values < 1 × 10-5 as suggestive. Linkage disequilibrium (LD)-based clumping was performed to identify independent candidate variants. None of the 9.7 million genetic variants tested for interactions with MHT use reached genome-wide significance. Only 213 variants, representing 18 independent loci, had p-values < 1 × 105. The strongest evidence was found for rs4674019 (p-value = 2.27 × 10-7), which showed genome-wide significant interaction (p-value = 3.8 × 10-8) with current MHT use when analysis was restricted to population-based studies only. Limiting the analyses to combined estrogen-progesterone MHT use only or to estrogen receptor (ER) positive cases did not identify any genome-wide significant evidence of interactions. In this large genome-wide SNP-MHT interaction study of breast cancer, we found no strong support for common genetic variants modifying the effect of MHT on breast cancer risk. These results suggest that common genetic variation has limited impact on the observed MHT-breast cancer risk association.

Increasing Breastfeeding Rates Through Continuity of Care

Background

Continuity of care is important in many aspects of medicine, as evidenced by the patient-centered medical home model. The newborn period is an especially important time for continuity of care, as this time sets the stage for lifelong health. Breastfeeding, which is known for its positive health benefits for both mother and child, is the gold standard for infant feeding. While inpatient lactation support is a common amenity available during hospital admission, support can be more difficult to obtain once a patient is discharged. To help eliminate this barrier, a process was put in place within an Eastern Pennsylvania health network’s seven office locations to standardize outreach to the mother-infant dyad.

Methods

A quality improvement retrospective chart review comparing pre- and post-intervention rates of exclusive and non-exclusive breastfeeding was completed using one health system’s Electronic Health Record (EHR). A referral process was established to capture dyads born within the health network’s hospital who were going to be followed at one of the seven pediatric offices outpatient. Mothers were called and followed to see how they were progressing with their breastfeeding goals. Any problems were addressed by the health network’s International Board-Certified Lactation Consultants (IBCLCs) and Certified Lactation Counselor (CLC).

Results

Lactation rates at the pediatric practice were observed to have increased at both 6 months and 12 months post-intervention compared to pre-intervention.

Conclusion

Proactively scheduling and providing outreach immediately following birth may promote increased breastfeeding rates.

Exploring the effects of genetic variation on gene regulation in cancer in the context of 3D genome structure

Background

Numerous genome-wide association studies (GWAS) conducted to date revealed genetic variants associated with various diseases, including breast and prostate cancers. Despite the availability of these large-scale data, relatively few variants have been functionally characterized, mainly because the majority of single-nucleotide polymorphisms (SNPs) map to the non-coding regions of the human genome. The functional characterization of these non-coding variants and the identification of their target genes remain challenging.

Results

In this communication, we explore the potential functional mechanisms of non-coding SNPs by integrating GWAS with the high-resolution chromosome conformation capture (Hi-C) data for breast and prostate cancers. We show that more genetic variants map to regulatory elements through the 3D genome structure than the 1D linear genome lacking physical chromatin interactions. Importantly, the association of enhancers, transcription factors, and their target genes with breast and prostate cancers tends to be higher when these regulatory elements are mapped to high-risk SNPs through spatial interactions compared to simply using a linear proximity. Finally, we demonstrate that topologically associating domains (TADs) carrying high-risk SNPs also contain gene regulatory elements whose association with cancer is generally higher than those belonging to control TADs containing no high-risk variants.

Conclusions

Our results suggest that many SNPs may contribute to the cancer development by affecting the expression of certain tumor-related genes through long-range chromatin interactions with gene regulatory elements. Integrating large-scale genetic datasets with the 3D genome structure offers an attractive and unique approach to systematically investigate the functional mechanisms of genetic variants in disease risk and progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-021-01021-x.

Women’s breast cancer risk factors in Kinshasa, Democratic Republic of the Congo

Purpose: Breast cancer (BC) is the most common malignancy and the leading cause of cancer-related deaths among women worldwide. Risk factors for this disease are numerous and their prevalence varies according to racial and ethnic groups and geographical regions. Therefore, we sought to identify BC risk factors in the Congolese population. Methods: A case-control study was conducted at the Nganda Hospital Center in Kinshasa, Democratic Republic of the Congo. One hundred and sixty patients with breast cancer (cases) were compared to 320 women who did not have BC (controls). STATA version 16 was used to analyze data with statistical significance considered at p < 0.05. Results: There is a strong association between BC in Congolese women and early menarche age (adjusted odds ratio [aOR] = 2.3; 95% CI: 1.2-4.3), family history of BC (aOR = 2.5; 95% CI: 1.2-5.5), overweight (aOR = 1.8; 95% CI: 1.1-2.7), and obesity (aOR = 7.3; 95% CI: 4.0-13.4). Conclusion: Our results indicate the presence of certain conventional risk factors. Thus, these results will be of great value in establishing adequate evidence-based awareness and preventive measures among the Congolese population.

Terminal differentiation and anti-tumorigenic effects of prolactin in breast cancer

Breast cancer is a major disease affecting women worldwide. A woman has 1 in 8 lifetime risk of developing breast cancer, and morbidity and mortality due to this disease are expected to continue to rise globally. Breast cancer remains a challenging disease due to its heterogeneity, propensity for recurrence and metastasis to distant vital organs including bones, lungs, liver and brain ultimately leading to patient death. Despite the development of various therapeutic strategies to treat breast cancer, still there are no effective treatments once metastasis has occurred. Loss of differentiation and increased cellular plasticity and stemness are being recognized molecularly and clinically as major derivers of heterogeneity, tumor evolution, relapse, metastasis, and therapeutic failure. In solid tumors, breast cancer is one of the leading cancer types in which tumor differentiation state has long been known to influence cancer behavior. Reprograming and/or restoring differentiation of cancer cells has been proposed to provide a viable approach to reverse the cancer through differentiation and terminal maturation. The hormone prolactin (PRL) is known to play a critical role in mammary gland lobuloalveolar development/remodeling and the terminal differentiation of the mammary epithelial cells promoting milk proteins gene expression and lactation. Here, we will highlight recent discoveries supporting an anti-tumorigenic role for PRL in breast cancer as a "pro/forward-differentiation" pathway restricting plasticity, stemness and tumorigenesis.

The distribution of reproductive risk factors disclosed the heterogeneity of receptor-defined breast cancer subtypes among Tanzanian women

Background

Recent epidemiological studies suggest that reproductive factors are associated with breast cancer (BC) molecular subtypes. However, these associations have not been thoroughly studied in the African populations. The present study aimed to investigate the prevalence of BC molecular subtypes and assess their association with reproductive factors in Tanzanian BC patients.

Methods

This hospital-based case-only cross-sectional study consisted of 263 histologically confirmed BC patients in Tanzania. Clinico-pathological data, socio-demographic characteristics, anthropometric measurements, and reproductive risk factors were examined using the Chi-square test and one-way ANOVA. The association among reproductive factors and BC molecular subtypes was analyzed using multinomial logistic regression. The heterogeneity of the associations was assessed using the Wald test.

Results

We found evident subtype heterogeneity for reproductive factors. We observed that post-menopausal status was more prevalent in luminal-A subtype, while compared to luminal-A subtype, luminal-B and HER-2 enriched subtypes were less likely to be found in post-menopausal women (OR: 0.21, 95%CI 0.10–0.41, p = 0.001; OR: 0.39, 95%CI 0.17–0.89, p = 0.026, respectively). Also, the luminal-B subtype was more likely to be diagnosed in patients aged ≤ 40 years than the luminal-A subtype (OR: 2.80, 95%CI 1.46–5.32, p = 0.002). Women who had their first full-term pregnancy at < 30 years were more likely to be of luminal-B (OR: 2.71, 95%CI 1.18–4.17, p = 0.018), and triple-negative (OR: 2.28, 95%CI 1.02–4.07, p = 0.044) subtypes relative to luminal-A subtype. Furthermore, we observed that breastfeeding might have reduced odds of developing luminal-A, luminal-B and triple-negative subtypes. Women who never breastfed were more likely to be diagnosed with luminal-B and triple-negative subtypes when compared to luminal-A subtype (OR: 0.46, 95%CI 0.22–0.95, p = 0.035; OR: 0.41, 95%CI 0.20–0.85, p = 0.017, respectively).

.

Conclusion

Our results are the first data reporting reproductive factors heterogeneity among BC molecular subtypes in Tanzania. Our findings suggest that breast-feeding may reduce the likelihood of developing luminal-A, luminal-B, and triple-negative subtypes. Meanwhile, the first full-term pregnancy after 30 years of age could increase the chance of developing luminal-A subtype, a highly prevalent subtype in Tanzania. More interventions to promote modifiable risk factors across multiple levels may most successfully reduce BC incidence in Africa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01536-6.

Fertility and breast cancer: A literature review of counseling, preservation options and outcomes

Fertility preservation is an important issue in breast cancer patients undergoing oncological treatment. Fertility counseling is a crucial need given the physical and psychological stress experienced by patients. Cryopreservation of mature oocytes is currently the standard fertility-preserving procedure. Other options such as ovarian tissue preservation or gonadal protection during chemotherapy are still experimental, but have proven effectiveness. Prompt referral to a fertility unit is highly recommended in order to ensure quality of care. In this article, we focus on the different strategies to preserve fertility in breast cancer patients, assessing also the safety of pregnancy and breastfeeding after cancer. A systemic literature review was performed for research articles published in English in PubMed, or as abstracts from the European Society for Medical Oncology (ESMO), San Antonio Breast Cancer Symposium (SABCS) and American Society of Clinical Oncology (ASCO) annual meetings, using the search terms "breast cancer" and "fertility".

Mortality due to breast cancer in a region of high socioeconomic vulnerability in Brazil: Analysis of the effect of age-period and cohort

INTRODUCTION

Breast cancer is an important public health problem worldwide, with important disparities in incidence, mortality, and survival rates between developed and developing countries due to inequalities regarding access to measures for the prevention and treatment of the disease. In Brazil, there are higher rates of incidence and a downward trend in mortality in regions of greater socioeconomic development.

OBJECTIVE

To evaluate the effect of age, period, and birth cohort on breast cancer mortality in women aged 20 years and older in the states of the Northeast Region of Brazil, an area of high socioeconomic vulnerability, from 1980 to 2019.

METHODS

The death records were extracted from the DATASUS Mortality Information System website (Department of National Health Informatics) from the Ministry of Health of Brazil. Estimable functions were used to estimate the age-period and cohort models (APC) using the Epi library from the R statistical software version 6.4.1.

RESULTS

The average breast cancer mortality rate for the period was 20.45 deaths per 100,000 women. The highest coefficients per 100,000 women were observed in the states of Pernambuco (21.09 deaths) and Ceará (20.85 deaths), and the lowest in Maranhão (13.58 deaths) and Piauí (15.43 deaths). In all of the locations, there was a progressive increase in mortality rates in individuals over 40 years of age, with higher rates in the last five-year period (2015-2019). There was an increase in the risk of death for the five-year period of the 2000s in relation to the reference period (1995-1999) in the Northeast region and in the states of Alagoas, Bahia, Maranhão, Paraíba, and Piauí. In addition, there was an increased risk of death for women born after the 1950s in all locations.

CONCLUSION

The highest mortality rates in all five-year periods analyzed were observed in states with greater socioeconomic development, with an increase in mortality rates in the 2000s, and a higher risk of death in the younger cohorts.

Menopausal hormone therapy and women's health: An umbrella review

BACKGROUND

There remains uncertainty about the impact of menopausal hormone therapy (MHT) on women's health. A systematic, comprehensive assessment of the effects on multiple outcomes is lacking. We conducted an umbrella review to comprehensively summarize evidence on the benefits and harms of MHT across diverse health outcomes.

METHODS AND FINDINGS

We searched MEDLINE, EMBASE, and 10 other databases from inception to November 26, 2017, updated on December 17, 2020, to identify systematic reviews or meta-analyses of randomized controlled trials (RCTs) and observational studies investigating effects of MHT, including estrogen-alone therapy (ET) and estrogen plus progestin therapy (EPT), in perimenopausal or postmenopausal women in all countries and settings. All health outcomes in previous systematic reviews were included, including menopausal symptoms, surrogate endpoints, biomarkers, various morbidity outcomes, and mortality. Two investigators independently extracted data and assessed methodological quality of systematic reviews using the updated 16-item AMSTAR 2 instrument. Random-effects robust variance estimation was used to combine effect estimates, and 95% prediction intervals (PIs) were calculated whenever possible. We used the term MHT to encompass ET and EPT, and results are presented for MHT for each outcome, unless otherwise indicated. Sixty systematic reviews were included, involving 102 meta-analyses of RCTs and 38 of observational studies, with 102 unique outcomes. The overall quality of included systematic reviews was moderate to poor. In meta-analyses of RCTs, MHT was beneficial for vasomotor symptoms (frequency: 9 trials, 1,104 women, risk ratio [RR] 0.43, 95% CI 0.33 to 0.57, p < 0.001; severity: 7 trials, 503 women, RR 0.29, 95% CI 0.17 to 0.50, p = 0.002) and all fracture (30 trials, 43,188 women, RR 0.72, 95% CI 0.62 to 0.84, p = 0.002, 95% PI 0.58 to 0.87), as well as vaginal atrophy (intravaginal ET), sexual function, vertebral and nonvertebral fracture, diabetes mellitus, cardiovascular mortality (ET), and colorectal cancer (EPT), but harmful for stroke (17 trials, 37,272 women, RR 1.17, 95% CI 1.05 to 1.29, p = 0.027) and venous thromboembolism (23 trials, 42,292 women, RR 1.60, 95% CI 0.99 to 2.58, p = 0.052, 95% PI 1.03 to 2.99), as well as cardiovascular disease incidence and recurrence, cerebrovascular disease, nonfatal stroke, deep vein thrombosis, gallbladder disease requiring surgery, and lung cancer mortality (EPT). In meta-analyses of observational studies, MHT was associated with decreased risks of cataract, glioma, and esophageal, gastric, and colorectal cancer, but increased risks of pulmonary embolism, cholelithiasis, asthma, meningioma, and thyroid, breast, and ovarian cancer. ET and EPT had opposite effects for endometrial cancer, endometrial hyperplasia, and Alzheimer disease. The major limitations include the inability to address the varying effects of MHT by type, dose, formulation, duration of use, route of administration, and age of initiation and to take into account the quality of individual studies included in the systematic reviews. The study protocol is publicly available on PROSPERO (CRD42017083412).

CONCLUSIONS

MHT has a complex balance of benefits and harms on multiple health outcomes. Some effects differ qualitatively between ET and EPT. The quality of available evidence is only moderate to poor.

The impact of left truncation of exposure in environmental case-control studies: evidence from breast cancer risk associated with airborne dioxin

In epidemiology, left-truncated data may bias exposure effect estimates. We analyzed the bias induced by left truncation in estimating breast cancer risk associated with exposure to airborne dioxins. Simulations were run with exposure estimates from a Geographic Information System (GIS)-based metric and considered two hypotheses for historical exposure, three scenarios for intra-individual correlation of annual exposures, and three exposure-effect models. For each correlation/model combination, 500 nested matched case-control studies were simulated and data fitted using a conditional logistic regression model. Bias magnitude was assessed by estimated odds-ratios (ORs) versus theoretical relative risks (TRRs) comparisons. With strong intra-individual correlation and continuous exposure, left truncation overestimated the Beta parameter associated with cumulative dioxin exposure. Versus a theoretical Beta of 4.17, the estimated mean Beta (5%; 95%) was 73.2 (67.7; 78.8) with left-truncated exposure and 4.37 (4.05; 4.66) with lifetime exposure. With exposure categorized in quintiles, the TRR was 2.0, the estimated OR_{Q5 vs. Q1} 2.19 (2.04; 2.33) with truncated exposure versus 2.17 (2.02; 2.32) with lifetime exposure. However, the difference in exposure between Q5 and Q1 was 18× smaller with truncated data, indicating an important overestimation of the dose effect. No intra-individual correlation resulted in effect dilution and statistical power loss. Left truncation induced substantial bias in estimating breast cancer risk associated with exposure with continuous and categorical models. With strong intra-individual exposure correlation, both models detected associations, but categorical models provided better estimates of effect trends. This calls for careful consideration of left truncation-induced bias in interpreting environmental epidemiological data.

The causal effect and impact of reproductive factors on breast cancer using super learner and targeted maximum likelihood estimation: a case-control study in Fars Province, Iran

OBJECTIVES

The relationship between reproductive factors and breast cancer (BC) risk has been investigated in previous studies. Considering the discrepancies in the results, the aim of this study was to estimate the causal effect of reproductive factors on BC risk in a case-control study using the double robust approach of targeted maximum likelihood estimation.

METHODS

This is a causal reanalysis of a case-control study done between 2005 and 2008 in Shiraz, Iran, in which 787 confirmed BC cases and 928 controls were enrolled. Targeted maximum likelihood estimation along with super Learner were used to analyze the data, and risk ratio (RR), risk difference (RD), andpopulation attributable fraction (PAF) were reported.

RESULTS

Our findings did not support parity and age at the first pregnancy as risk factors for BC. The risk of BC was higher among postmenopausal women (RR = 3.3, 95% confidence interval (CI) = (2.3, 4.6)), women with the age at first marriage ≥20 years (RR = 1.6, 95% CI = (1.3, 2.1)), and the history of oral contraceptive (OC) use (RR = 1.6, 95% CI = (1.3, 2.1)) or breastfeeding duration ≤60 months (RR = 1.8, 95% CI = (1.3, 2.5)). The PAF for menopause status, breastfeeding duration, and OC use were 40.3% (95% CI = 39.5, 40.6), 27.3% (95% CI = 23.1, 30.8) and 24.4% (95% CI = 10.5, 35.5), respectively.

CONCLUSIONS

Postmenopausal women, and women with a higher age at first marriage, shorter duration of breastfeeding, and history of OC use are at the higher risk of BC.

Dietary Methyl-Group Donor Intake and Breast Cancer Risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)

(1) Background: Methyl-group donors (MGDs), including folate, choline, betaine, and methionine, may influence breast cancer (BC) risk through their role in one-carbon metabolism; (2) Methods: We studied the relationship between dietary intakes of MGDs and BC risk, adopting data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort; (3) Results: 318,686 pre- and postmenopausal women were followed between enrolment in 1992-2000 and December 2013-December 2015. Dietary MGD intakes were estimated at baseline through food-frequency questionnaires. Multivariable Cox proportional hazards regression models were used to quantify the association between dietary intake of MGDs, measured both as a calculated score based on their sum and individually, and BC risk. Subgroup analyses were performed by hormone receptor status, menopausal status, and level of alcohol intake. During a mean follow-up time of 14.1 years, 13,320 women with malignant BC were identified. No associations were found between dietary intakes of the MGD score or individual MGDs and BC risk. However, a potential U-shaped relationship was observed between dietary folate intake and overall BC risk, suggesting an inverse association for intakes up to 350 µg/day compared to a reference intake of 205 µg/day. No statistically significant differences in the associations were observed by hormone receptor status, menopausal status, or level of alcohol intake; (4) Conclusions: There was no strong evidence for an association between MGDs involved in one-carbon metabolism and BC risk. However, a potential U-shaped trend was suggested for dietary folate intake and BC risk. Further research is needed to clarify this association.

Breast cancer in sub-Saharan Africa: The current state and uncertain future

Breast cancer is the commonest cause of global cancer-related deaths in women and a public health burden in sub-Saharan Africa (SSA). Although the disease incidence in SSA seems lower, mortality rates are disproportionately high in comparison to high-income countries. The global disease burden is growing, with SSA reporting the majority of cases; however, the dearth of information results in insufficient data which is barely representative of the actual disease burden in this population. Future incidence predictions assign the subregion with a majority of the cases and associated deaths. Breast cancer presents with racial and ethnic variations, and available evidence suggests geographical diversity and persistent risk factors that have barely been explored in SSA. Breast cancer is a complex genetic disease, but the genetic risk factors in the extant African population, which is the most genetically diverse population, is scant and of low quality. This review focuses on the burden, prevalence, detection, treatment, survival, biology, as well as risk factors, and reinforces the need for breast cancer-associated risk factor investigation and population-specific studies in SSA.

Defining breast cancer awareness and identifying barriers to breast cancer awareness for women with an intellectual disability: A review of the literature

INTRODUCTION

Incidence rates for developing breast cancer are similar for women regardless of intellectual ability. However, women with an intellectual disability present with advanced breast cancers, which often have a poor prognosis.

METHOD

A structured narrative review of the literature was performed to explore the concepts of breast awareness and breast cancer awareness and subsequently, identify barriers to breast cancer awareness encountered by women with an intellectual disability.

RESULTS

A total of 22 studies involving people with varying levels of intellectual disability informed this review. The barriers to breast cancer awareness encountered by women with an intellectual disability include: lack of their understanding, the role of the carer and literacy issues.

CONCLUSION

Identifying the barriers to breast cancer awareness for women with an intellectual disability will help to facilitate breast cancer awareness which has the potential to result in better long-term outcomes through an early diagnosis of breast cancer.

The mammographic breast density distribution of Finnish women with breast cancer and comparison of breast density reporting using the 4th and 5th editions of the Breast Imaging-Reporting and Data System

PURPOSE

To examine the breast density distribution in patients diagnosed with breast cancer in an eastern Finnish population and to examine the changes in breast density reporting patterns between the 4^th and 5^th editions of the Breast Imaging-Reporting and Data System (BI-RADS).

METHOD

821 women (mean age 62.8 ± 12.2 years, range 28-94 years) with breast cancer were included in this retrospective study and their digital mammographic examinations were assessed semi-automatically and then visually by two radiologists in accordance with the 4^th and 5^th editions of the BI-RADS. Intraclass correlation coefficients (ICCs) were used to evaluate interobserver reproducibility. Chi-square tests were used to examine the associations between the breast density distribution and age or body mass index (BMI).

RESULTS

Interobserver reproducibility of the visual assessment was excellent, with an ICCr = 0.93. The majority of breast cancers occurred in fatty breasts (93.8 %) when density was assessed according to the 4^th edition of the BI-RADS. The distributions remained constant after correction for age and BMI. Using the 5^th edition, there was an overall 50.2 % decrease in almost entirely fatty (p <  0.001), 19.4 % increase in scattered fibroglandular (p <  0.001), 28.7 % increase in heterogeneously dense (p <  0.001), and 2.1 % increase in extremely dense (p <  0.001) categories.

CONCLUSIONS

Most breast cancers in eastern Finland occur in fatty breasts with an area density of < 50 %. Assessing breast density using the 5^th edition of the BI-RADS greatly increased denser assessments.

DOK7 Inhibits Cell Proliferation, Migration, and Invasion of Breast Cancer via the PI3K/PTEN/AKT Pathway

Recently, increasing attention has been paid to the correlation between the expression of downstream of kinase 7 (DOK7) and the occurrence and development of various tumors. In this study, we clarified the effects of DOK7 in breast cancer. First, we showed that DOK7 expression was obviously reduced in the breast cancer tissues and lower levels of DOK7 linked to more aggressive behaviors and worse prognosis of patients. Furthermore, DOK7 expression of various breast cancer cell lines was lower than that of human noncancerous MCF-10A cells. Overexpression of DOK7 inhibited proliferation, migration, and invasion, while silencing DOK7 expression promoted the malignancy of breast cancer. In addition, overexpression of DOK7 suppressed tumor proliferation and lung metastasis in animal models. Finally, to investigate the possible signaling mechanism, we first found that the level of p-AKT protein was extremely downregulated and the level of PTEN protein was remarkably upregulated after overexpressing DOK7 in breast cancer cells. Repression of PTEN expression using PTEN siRNA or SF1670 (PTEN inhibitor) rescued the tumor-inhibiting effect induced by DOK7 overexpression, suggesting that DOK7 inhibits proliferation, migration, and invasion of breast cancer cells though the PI3K/PTEN/AKT pathway. These results suggest that the downregulation of DOK7 may become a novel breast cancer therapeutic target.

The impact of oral contraceptive use on breast cancer risk: State of the art and future perspectives in the era of 4P medicine

Breast cancer is the most commonly occurring cancer in women, the second most frequent cancer overall, and it causes the greatest number of cancer-related deaths among women. The significant increased concern of breast cancer worldwide may be attributed to the prolonged life expectancy and the adoption of the western lifestyle with its related risks factors. A woman's risk for breast cancer is linked to her reproductive history and with her lifetime hormonal exposure. Among the known risk factors for breast cancer, several studies investigated the possible role of the assumption of hormonal "pills" in both breast cancer incidence and development. Nevertheless, data about the association between the assumption of oral contraceptives and breast cancer incidence are still controversial and not conclusive. Given the public health importance of breast cancer and the popularity of hormonal "pills" as contraceptive, the impact of oral contraceptive use on breast cancer risk assumes relevance from both a clinical and a social point of view. Therefore, in this review we wanted to illustrate this issue by addressing the following major themes: a) the role of sex steroid hormones in female breast development and carcinogenesis; b) the clinical impact of hormonal oral contraception according to the state of the art literature; c) the actual scientific debate and future perspectives.

Age at diagnosis of cancer in 185delAG BRCA1 mutation carriers of diverse ethnicities: tentative evidence for modifier factors

Germline pathogenic sequence variants (PSVs) in BRCA1 substantially increase risk for developing breast (BC) and ovarian cancer (OvC). Yet, incomplete penetrance suggests that modifier factors affect phenotypic expression of mutant BRCA1 alleles. Analysis of identical BRCA1 PSV carriers of diverse ethnicities may provide further evidence for modifier factors. Female carriers of the 185delAG BRCA1 PSV identified through high-risk clinics in Israel, and Manchester England from 1998-2018 were eligible. Data were retrieved from patients records and confirmed (in Israel) by cross referencing with the Israeli National Cancer Registry. Overall, 2503 female carriers were included: 1715 (71.4%) Ashkenazi Jews (AJ), 201 (8.3%) Iraqi Jews and 383 (15.9%) of mixed ethnicity. In 102 (4.2%) cases ethnicity could not be ascertained. Of Israeli AJ carriers 649 (37.8%), 256 (14.9%) and 62 (3.6%) were diagnosed with BC, OvC or both cancers, respectively. For the Iraqi Jews these frequencies were 76 (37.8%), 43 (21.4%), and 8 (3.98%), respectively. Age at diagnosis of BC in AJ and Iraqi Jews was 46.7 ± 12.3 years and 52.8 ± 12.2 years, respectively (p = 0.001). For OvC age at diagnosis for AJ was 53.5 ± 10.7 years and for Iraqi Jews 50.1 ± 8.8 years (p = 0.0027). No differences in these parameters were noted between English Jews (n = 110) and non-Jews (n = 32). Age at diagnosis of BC and OvC differs between AJ and Iraqi Jews who carry an identical BRCA1 PSV. This finding supports the existence of modifier factors that may be ethnic specific.

Breast cancer risk factors in Iran: a systematic review & meta-analysis

OBJECTIVES

Breast cancer is known as one of the deadliest forms of cancer, and it is increasing globally. There are a variety of proven and controversial risk factors for this malignancy. Herein, we aimed to undertake a systematic review and meta-analysis focus on the epidemiology of breast cancer risk factors in Iran.

METHODS

We performed a systematic search via PubMed, Scopus, Web of Science, and Persian databases for identifying studies published on breast cancer risk factors up to March 2019. Meta-analyses were done for risk factors reported in more than one study. We calculated odds ratios (ORs) with corresponding 95% confidence intervals (CIs) using a fixed/random-effects models.

RESULTS

Thirty-nine studies entered into the meta-analysis. Pooling of ORs showed a significant harmful effect for risk factors including family history (OR: 1.80, 95%CI 1.47-2.12), hormonal replacement therapy (HRT) (OR: 5.48, 95%CI 0.84-1.74), passive smokers (OR: 1.68, 95%CI 1.34-2.03), full-term pregnancy at age 30 (OR: 3.41, 95%CI 1.19-5.63), abortion (OR: 1.84, 95%CI 1.35-2.33), sweets consumption (OR: 1.71, 95%CI 1.32-2.11) and genotype Arg/Arg (crude OR: 1.59, 95%CI 1.07-2.10), whereas a significant protective effect for late menarche (OR: 0.58, 95%CI 0.32-0.83), nulliparity (OR: 0.68, 95%CI 0.39-0.96), 13-24 months of breastfeeding (OR: 0.68, 95%CI 0.46-0.90), daily exercise (OR: 0.59, 95%CI 0.44-0.73) and vegetable consumption (crude OR: 0.28, 95%CI 0.10-0.46).

CONCLUSIONS

This study suggests that factors such as family history, HRT, passive smokers, late full-term pregnancy, abortion, sweets consumption and genotype Arg/Arg might increase risk of breast cancer development, whereas late menarche, nulliparity, 13-24 months breastfeeding, daily exercise and vegetable consumption had an inverse association with breast cancer development.

Exploring the effects of genetic variation on gene regulation in cancer in the context of 3D genome structure.. [DOI: 10.1101/2020.10.06.328567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Numerous genome-wide association studies (GWAS) conducted to date revealed genetic variants associated with various diseases, including breast and prostate cancers. Despite the availability of these large-scale data, relatively few variants have been functionally characterized, mainly because the majority of single-nucleotide polymorphisms (SNPs) map to the non-coding regions of the human genome. The functional characterization of these non-coding variants and the identification of their target genes remain challenging. In this communication, we explore the potential functional mechanisms of non-coding SNPs by integrating GWAS with the high-resolution chromosome conformation capture (Hi-C) data for breast and prostate cancers. We show that more genetic variants map to regulatory elements through the 3D genome structure than the 1D linear genome lacking physical chromatin interactions. Importantly, the association of enhancers, transcription factors, and their target genes with breast and prostate cancers tends to be higher when these regulatory elements are mapped to high-risk SNPs through spatial interactions compared to simply using a linear proximity. Finally, we demonstrate that topologically associating domains (TADs) carrying high-risk SNPs also contain gene regulatory elements whose association with cancer is generally higher than those belonging to control TADs containing no high-risk variants. Our results suggest that many SNPs may contribute to the cancer development by affecting the expression of certain tumor-related genes through long-range chromatin interactions with gene regulatory elements. Integrating large-scale genetic datasets with the 3D genome structure offers an attractive and unique approach to systematically investigate the functional mechanisms of genetic variants in disease risk and progression.

Prognostic biomarkers related to breast cancer recurrence identified based on Logit model analysis

BACKGROUND

This study intended to determine important genes related to the prognosis and recurrence of breast cancer.

METHODS

Gene expression data of breast cancer patients were downloaded from TCGA database. Breast cancer samples with recurrence and death were defined as poor disease-free survival (DFS) group, while samples without recurrence and survival beyond 5 years were defined as better DFS group. Another gene expression profile dataset (GSE45725) of breast cancer was downloaded as the validation data. Differentially expressed genes (DEGs) were screened between better and poor DFS groups, which were then performed function enrichment analysis. The DEGs that were enriched in the GO function and KEGG signaling pathway were selected for cox regression analysis and Logit regression (LR) model analysis. Finally, correlation analysis between LR model classification and survival prognosis was analyzed.

RESULTS

Based on the breast cancer gene expression profile data in TCGA, 540 DEGs were screened between better DFS and poor DFS groups, including 177 downregulated and 363 upregulated DEGs. A total of 283 DEGs were involved in all GO functions and KEGG signaling pathways. Through LR model screening, 10 important feature DEGs were identified and validated, among which, ABCA3, CCL22, FOXJ1, IL1RN, KCNIP3, MAP2K6, and MRPL13, were significantly expressed in both groups in the two data sets. ABCA3, CCL22, FOXJ1, IL1RN, and MAP2K6 were good prognostic factors, while KCNIP3 and MRPL13 were poor prognostic factors.

CONCLUSION

ABCA3, CCL22, FOXJ1, IL1RN, and MAP2K6 may serve as good prognostic factors, while KCNIP3 and MRPL13 may be poor prognostic factors for the prognosis of breast cancer.

Risk Prediction Model Development for Late On-Set Breast Cancer Screening in Low- and Middle-Income Societies: A Model Study for North Cyprus

Background: Early detection of breast cancer alters the prognosis and tools that can predict the risk for breast cancer in women will have a significant impact on healthcare systems in low- and middle-income regions, such as North Cyprus. Objective: In this study, we developed a simple breast cancer risk model for the women of North Cyprus. Methods: Data from 655 women, consisting of 318 breast cancer cases and 337 hospital-based controls, was used to develop and internally validate the model, external validation was carried out using, 653 women consisting of 126 cases and 527 controls. Data were obtained from medical records and interviews after informed consent. Results: A model was derived that consisted of age ≥50 years and <50 years and the presence and absence of >1 first-degree relatives (FDR) with breast cancer. From internal and external validations the model’s AUCs were, 0.66 (95% CI = 0.62–0.70) and 0.69 (95% CI = 0.63–0.74) respectively. Conclusions: A unique model for risk prediction of breast cancer was developed to aid in identifying high-risk women from North Cyprus that can benefit from mammogram screening. Further study on a large scale that includes environmental risk factors is warranted.

History of Diabetes Mellitus and Risk of Breast Cancer in Asian Women: A Meta-Epidemiological Analysis of Population-Based Cohort Studies

Objectives

Previous quantitative systematic reviews conducting subgroup analyses by race have reported that the association between diabetes and breast cancer in Asian women was inconclusive. The aim of this meta-epidemiological study (MES) was to evaluate this association from additional population-based cohort studies.

Methods

The potential subjects of this MES were six Asian cohort studies selected by previous systematic reviews. Additional reports were found from the selected articles using citation discovery tools. The study with the longest follow-up period was selected among prospective studies of the same cohorts. A summary relative risk (sRR) and its 95% confidence intervals (CI) were calculated using random effect models.

Results

Four cohort studies on Asian women were finally selected. The participants were from the women population of Korea, Japan, China, and Taiwan and included a total of 1,448,254 women. The sRR (95% CI) (I-squared value) was 1.20 (0.98–1.46) (63.1%).

Conclusions

This MES found that the history of diabetes mellitus was not associated with the risk of breast cancer in Asian women. As breast cancer in this population develops at a younger age, additional cohort studies are necessary to conduct a subgroup analysis by menopausal status at diagnosis of breast cancer in Asian women.

Mediation analysis of the alcohol-postmenopausal breast cancer relationship by sex hormones in the EPIC cohort

Alcohol consumption is associated with higher risk of breast cancer (BC); however, the biological mechanisms underlying this association are not fully elucidated, particularly the extent to which this relationship is mediated by sex hormone levels. Circulating concentrations of estradiol, testosterone, their free fractions and sex-hormone binding globulin (SHBG), were examined in 430 incident BC cases and 645 matched controls among alcohol-consuming postmenopausal women nested within the European Prospective Investigation into Cancer and Nutrition. Mediation analysis was applied to assess whether individual hormone levels mediated the relationship between alcohol intake and BC risk. An alcohol-related hormonal signature, obtained by partial least square (PLS) regression, was evaluated as a potential mediator. Total (TE), natural direct and natural indirect effects (NIE) were estimated. Alcohol intake was positively associated with overall BC risk and specifically with estrogen receptor-positive tumors with respectively TE = 1.17(95%CI: 1.01,1.35) and 1.36(1.08,1.70) for a 1-standard deviation (1-SD) increase of intake. There was no evidence of mediation by sex steroids or SHBG separately except for a weak indirect effect through free estradiol where NIE = 1.03(1.00,1.06). However, an alcohol-related hormonal signature negatively associated with SHBG and positively with estradiol and testosterone was associated with BC risk (odds ratio [OR] = 1.25 [1.07,1.47]) for a 1-SD higher PLS score, and had a statistically significant NIE accounting for a mediated proportion of 24%. There was limited evidence of mediation of the alcohol-BC association by individual sex hormones. However, a hormonal signature, reflecting lower levels of SHBG and higher levels of sex steroids, mediated a substantial proportion of the association.

Identification of key molecular targets that correlate with breast cancer through bioinformatic methods

BACKGROUND

The present study aimed to identify key molecular targets of breast cancer for targeted treatment and to improve the survival rate.

METHODS

Overlapped difference expression genes in three datasets were identified in a weighted gene co-expression network analysis (WGCNA) module and MetaDE.ES analysis. Combined with the prognosis information [time, death, status and relative survival (RS)] in GSE42568, single-factor Cox regression analysis was used to screen the genes that were significantly related to the prognosis in the target gene set.

RESULTS

In total, 13 optimal gene combinations with a significantly correlated prognosis were obtained, including SSPN, NELL2, AGTR1, NRIP3, IKZF2, NAT1, CXCL12, NPY1R, PRAME, PPP1R1B, CRISP3, NMU and GSTP1. In addition, there was a significant correlation between the samples given by the prognostic prediction system and the validation dataset (GSE20685 and TCGA), with p values of 0.0299 in GSE20685 and 1.461 × 10^-5 in TCGA, and an area under the receiver operating characteristic of 0.942 and 0.923, respectively. RS-related differentially expressed genes between high- and low-risk groups were significantly related to biological processes such as cell period and the hormone stimulation response, and were also significantly involved in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways such as cell period, the peroxisome proliferator-activated receptor signaling pathway and the cancer pathway.

CONCLUSIONS

By predicting the survival risk of breast cancer patients based on the 13 optimal genes, high-risk patients would be detected early. Accordingly, this would help in the formulation of an appropriate treatment plan for patients.

Diabetes and Cancer: Cancer Should Be Screened in Routine Diabetes Assessment

Cancer incidence appears to be increased in both type 1 and type 2 diabetes mellitus (DM). DM represents a risk factor for cancer, particularly hepatocellular, hepatobiliary, pancreas, breast, ovarian, endometrial, and gastrointestinal cancers. In addition, there is evidence showing that DM is associated with increased cancer mortality. Common risk factors such as age, obesity, physical inactivity and smoking may contribute to increased cancer risk in patients with DM. Although the mechanistic process that may link diabetes to cancer is not completely understood yet, biological mechanisms linking DM and cancer are hyperglycemia, hyperinsulinemia, increased bioactivity of insulin-like growth factor 1, oxidative stress, dysregulations of sex hormones, and chronic inflammation. However, cancer screening rate is significantly lower in people with DM than that in people without diabetes. Evidence from previous studies suggests that some medications used to treat DM are associated with either increased or reduced risk of cancer. However, there is no strong evidence supporting the association between the use of anti-hyperglycemic medication and specific cancer. In conclusion, all patients with DM should be undergo recommended age- and sex appropriate cancer screenings to promote primary prevention and early detection. Furthermore, cancer should be screened in routine diabetes assessment.

Diabetes and cancer: A comprehensive review

Diabetes mellitus (DM) is a common worldwide endocrine disorder characterized by hyperglycemia resulting from defects in insulin secretion and insulin action or both. A number of clinical studies have investigated diabetes and its causal relation with neoplasm. Several epidemiological studies have found that diabetic patients have an increased risk of different types of cancers, for example liver, pancreas, gastric (stomach), colorectum, kidney, and breast, and it is predicted that hyperglycemic state observed in diabetic milieu enhances the cancer risk in prediabetic and diabetic individuals. To explore the strength of evidence and biases in the claimed associations between type 2 DM (T2DM) and risk of developing cancer, an umbrella review of the evidence across published meta-analyses or systematic reviews is performed. The concurrence of T2DM with the growing burden of cancer globally has generated interest in defining the epidemiological and biological relationships between these medical conditions. Through this review, it was found that diabetes could be related to cancer. Yet, the results from most of the studies are obscure and conflicting and need a robust research so that the link between diabetes and cancer could be firmly and impeccably documented.

Moderating Role of Demographic Characteristics in Breast Cancer Awareness and the Behavioural Disposition of Women in Ogun State, Nigeria

BACKGROUND

Breast cancer incidence is fast increasing, posing a significant threat to the health of women of all races globally. In Nigeria, breast cancer causes the most cancer-related deaths among women each year as a result of inadequate awareness.

AIM

This study is aimed at examining the moderating role of demographic characteristics in facilitating breast cancer awareness among women, and how it relates to their behavioural disposition to the disease.

METHODS

The study adopted the descriptive (survey) and cross-sectional research designs to elicit information from women of adult age selected across five Local Government Areas in Ogun state. The data, collected through questionnaire were analysed through the use of a variance-based SEM Partial Least Square (PLS).

RESULTS

The result shows that demographic characteristics (age and education) has a significant positive effect and jointly explain 74.9% of the variance in the breast cancer awareness and behavioural disposition among women in the study area. The findings revealed that a significant number of women with breast cancer had not acquired useful knowledge that could potentially be used to diagnose, prevent, and manage the disease. Unfortunately, the practice of Breast Self-Examination is grossly low among Nigerian women, as a consequence, only 20-30% of the women in study areas, including professionals, are aware of the benefits of BSE and only a smaller percentage practice BSE.

CONCLUSION

There is, therefore, a need to educate women on the benefits of this simple life-saving procedure through the consistent use of media platforms.

Immunohistochemistry for diagnosis and prognosis of breast cancer: a review

Breast cancer is the most prevalent malignant tumor and main oncologic cause of mortality in women. Although most diagnosis of breast pathology is accomplished using hematoxylin and eosin stained sections, some cases require immunohistochemistry for proper evaluation. We investigated the latter cases including distinctions between ductal and lobular carcinoma, in situ and invasive carcinoma, typical ductal hyperplasia and atypical ductal hyperplasia/ductal carcinoma in situ, papillary and spindle cell lesion assessment, metastasis evaluation, and assessment of prognostic and therapy markers. E-cadherin is used to differentiate ductal and lobular carcinoma; 34βE12, CK8, p120 catenin and β-catenin also produce consistent results. Myoepithelial cell (MEC) stains are used to evaluate in situ and invasive carcinoma; calponin, smooth muscle myosin heavy chain and p63 are sensitive/specific markers. 34βE12 and CK5/6 are positive in ductal hyperplasia, which enables its differentiation from atypical ductal hyperplasia and ductal carcinoma in situ. CK 5/6, ER and MEC markers are consistent options for evaluating papillary lesions. Spindle cell lesions can be assessed using β-catenin, SMA, CD34, p63, CKs and hormone receptors. It is important to differentiate primary carcinomas from metastases; the most commonly used markers to identify breast origin include mammaglobin, GCDFP-15, GATA3 and ER, although none of these is completely sensitive or specific. Immunohistochemistry can be used to evaluate central prognostic and predictive factors including molecular subtypes, HER2, hormone receptors, proliferation markers (Ki-67) and lymph-vascular invasion markers including ERG, CD31, CD34, factor VIII and podoplanin. Owing to the complexity of mammary lesions, diagnosis also depends on each particular situation, evaluation of cytological characteristics revealed by immunochemistry and correlation with histological findings.

Association of PARP1 rs4653734, rs907187 and rs1136410 variants with breast cancer risk among Iranian women

BACKGROUND

Breast cancer (BC) is the highest cause of mortality among female cancer patients. In some cases, BC is due to Poly [ADP-ribose] polymerase 1 (PARP1) gene dysregulation, which has been involved in various important cellular processes. Among Iranian women, the association between PARP1 polymorphisms and BC was never studied before so in this case-control study, the genetic association of three SNPs (rs1136410, rs907187 and rs4653734) was analyzed with susceptibility to BC.

METHODS

The study subjects were 386 Iranian females divided into 186 patients and 200 healthy controls. The genotypes of PARP1 variants were detected using ARMS and a combined ARMS-RFLP PCR method.

RESULTS

The results showed that Carriers of CG and GG genotypes of the variant rs4653734 were at higher risk of BC compared with wild-type carriers (CC) and this variant was statistically significant under a recessive model of inheritance. Moreover, rs907187 was related to increased BC risk in the CC and GG genotypes under dominant and recessive models of inheritance. The G allele frequency of rs4653734 and rs907187 was higher in breast cancer patients than in normal subjects. No association was detected between rs1136410 and susceptibility to BC among studied groups. Furthermore, A-G-C haplotype was linked to an increased BC risk, whereas A-C-C and A-C-G haplotypes were related to a decreased risk of BC. In Silico predictions suggested that rs907187 affects E2F and E2F-4 transcription factors binding site.

CONCLUSIONS

The current study suggests that rs907187 and rs4653734 have remarkable associations with BC risk among Iranian women.

A retrospective study on breast cancer presentation, risk factors, and protective factors in patients with a positive family history of breast cancer

Women with a positive family history of breast cancer are greatly predisposed to breast cancer development. From January 2007 to December 2016, 1101 patients with a histologically confirmed breast cancer were divided into two groups: patients with and without a positive family history of breast cancer. Variables including age at presentation, ethnicity, tumor size, age at menarche, age at menopause, oral contraceptive pill (OCP) use, hormone replacement therapy (HRT), alcohol intake, smoking, body mass index (BMI), diabetes mellitus, parity, and breastfeeding were recorded. One hundred and fifty-nine out of 1101 (14.4%) of the patients had a family history of breast cancer. There was no significant difference in the incidence of breast cancer among Malays, Chinese, and Indians. Both patient groups presented at a mean age of about 60 years (+FH 60; -FH 61.2 P-value = .218). Significantly higher prevalence of history of benign breast disease (11.3%, P .018), nulliparity (13.2%, P .014), tumor size at presentation of more than 5 cm (47.3%, P 0.001), and bilateral site presentation (3.1%, P 0.029) were noted among respondents with a positive family history of breast cancer compared to those with a negative family history of breast cancer. The odds of having a tumor size larger than 5cm at presentation were almost two times higher in patients with a positive family history as compared to those without a family history (adjusted OR = 1.786, 95% CI 1.211-2.484) (P-value .003). Women in Malaysia, despite having a positive family history of breast cancer, still present late at a mean age of 60 with a large tumor size of more than 5 cm, reflecting a lack of awareness. Breastfeeding does not protect women with a family history from developing breast cancer.