Pregnancy and Lactation: Risk or Protective Factors for Breast Cancer?

A Clustering Study of Sociodemographic Data, Dietary Patterns, and Gut Microbiota in Healthy and Breast Cancer Women Participating in the MICROMA Study

SCOPE

This work is part of the clinical study NCT03885648 registered in ClinicalTrials.gov, aimed at studying the relationship among breast cancer, microbiota, and exposure to environmental pollutants. As a first step, we characterized and evaluated risk factors of the participants.

METHODS AND RESULTS

A case-control study was designed with breast cancer (cases, n = 122) and healthy women (controls, n = 56) recruited in two hospitals of Andalusia (Southern Spain). Participants answered questionnaires of Mediterranean diet adherence and food frequency. Data were collected from medical histories and microbiota was analyzed on stool samples. Most cases (78.2%) were diagnosed as stages I and II. Cases had higher age, body mass index (BMI), glucose, cholesterol, and potassium values than controls. Cases exhibited higher adherence to the Mediterranean diet and their food consumption was closer to that dietary pattern. A hierarchical cluster analysis revealed that the Bacillota/Bacteroidota ratio was the most relevant variable in women with breast cancer, which was higher in this group compared with controls.

CONCLUSION

Although cases exhibited higher adherence to the Mediterranean diet compared with controls, they presented features and microbiota alterations typical of the metabolic syndrome, probably due to their higher BMI and reflecting changes in their lifestyle around the time of diagnosis.

Dual role of pregnancy in breast cancer risk

Reproductive history is one of the strongest risk factors for breast cancer in women. Pregnancy can promote short-term breast cancer risk, but also reduce a woman's lifetime risk of breast cancer. Changes in hormone levels before and after pregnancy are one of the key factors in breast cancer risk. This article summarizes the changes in hormone levels before and after pregnancy, and the roles of hormones in mammary gland development and breast cancer progression. Other factors, such as changes in breast morphology and mammary gland differentiation, changes in the proportion of mammary stem cells (MaSCs), changes in the immune and inflammatory environment, and changes in lactation before and after pregnancy, also play key roles in the occurrence and development of breast cancer. This review discusses the dual effects and the potential mechanisms of pregnancy on breast cancer risk from the above aspects, which is helpful to understand the complexity of female breast cancer occurrence.

Breast Cancer Knowledge and Associated Behaviors in Northern Borders, Saudi Arabia: A Cross-Sectional Study

Background Breast cancer remains a significant public health issue globally and is notably pervasive within the female population, representing a leading cause of concern. It poses a challenge across different age groups and is influenced by diverse risk factors that include genetic predispositions and various elements of lifestyle. Saudi Arabia, mirroring the global situation, has also seen its share of this disease's impact, prompting a closer look at the factors contributing to its prevalence. Educating the public and advocating for lifestyle changes are crucial steps in cancer prevention. With early-stage diagnosis and screening, many lives can potentially be saved. Our research is focused on understanding the level of awareness and preventative practices among women in the Northern Border region of Saudi Arabia. It seeks to explore the influence of familial history on knowledge and perceptions surrounding breast cancer, which could guide future educational and screening programs. Methods This cross-sectional study engaged 643 female participants, aged 18 and above, from the Northern Border region of Saudi Arabia upon their informed consent. Data were compiled via a structured questionnaire encompassing sociodemographic information, breast cancer knowledge, and preventive practices. Results The data disclosed that a significant majority (86%) recognized breast lumps as indicative of breast cancer, with 69.1% cognizant of hereditary risks. Awareness about lactation as a preventative strategy was noted in 76.7% of the participants, followed by 70.6% acknowledging the merits of a healthy diet. The study unveiled no substantial awareness disparity between individuals with or without a family history of the disease. Alarmingly, 80.4% had never sought a breast examination, and a parallel 83.7% had not undergone mammography. Conclusion The study sheds light on the heterogeneity in breast cancer awareness among women in Saudi Arabia's Northern Border region. Although the recognition of lumps and the preventative role of lactation is relatively high, there remains a deficit in comprehending additional symptoms, signs, and risk factors. The conspicuously low rates of breast cancer examinations and mammography underscore an urgent need for enhanced educational initiatives and a strategic push toward bolstering participation in regular cancer screenings.

Association between breastfeeding and periodontitis in Korean women using Korea National Health and Nutrition Examination Survey (KNHANES): a cross-sectional study

OBJECTIVES

The effect of breastfeeding on periodontal disease in women remains unclear. This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey to explore the association between breastfeeding and periodontitis in Korean women using data from the Korean National Health and Nutrition Examination Survey (KNHANES VII).

MATERIALS AND METHODS

Cross-sectional data was analyzed from the KNHANES 2016-2018. The study population included 5,587 parous women aged ≥ 30 years. The outcome variable was the presence or absence of periodontitis. The explanatory variable, period of breastfeeding, was defined as "none", "1-11 months", and "more than 12 months". Confounder variables (socio-educational, personal healthcare practice, and systemic medical characteristics) were adjusted for in the logistic regression analysis.

RESULTS

Approximately 60% of the participants breastfed for ≥ 12 months. In all statistical models, the prevalence of periodontitis was approximately 60% greater in women that did not breastfeed compared to women that had breastfed for 12 months or longer. When adjusted for age, statistical significance was only present in the 50-59 years age group (adjusted odds ratio [aOR], 1.678; 95% confidence interval [CIs], 1.046-2.691).

CONCLUSION

Our study shows that women that breastfed for a relatively long duration had a lower risk of periodontitis. Therefore, breastfeeding may be beneficial for women's periodontal health. These results are expected to be helpful in oral health education for pregnant women.

The hormonal physiology of immune components in breast milk and their impact on the infant immune response

During pregnancy, the maternal body undergoes a considerable transformation regarding the anatomy, metabolism, and immune profile that, after delivery, allows for protection and nourishment of the offspring via lactation. Pregnancy hormones are responsible for the development and functionality of the mammary gland for breast milk production, but little is known about how hormones control its immune properties. Breast milk composition is highly dynamic, adapting to the nutritional and immunological needs that the infant requires in the first months of life and is responsible for the main immune modeling of breastfed newborns. Therefore, alterations in the mechanisms that control the endocrinology of mammary gland adaptation for lactation could disturb the properties of breast milk that prepare the neonatal immune system to respond to the first immunologic challenges. In modern life, humans are chronically exposed to endocrine disruptors (EDs), which alter the endocrine physiology of mammals, affecting the composition of breast milk and hence the neonatal immune response. In this review, we provide a landscape of the possible role of hormones in the control of passive immunity transferred by breast milk and the possible effect of maternal exposure to EDs on lactation, as well as their impacts on the development of neonatal immunity.

Human milk variation is shaped by maternal genetics and impacts the infant gut microbiome

Human milk is a complex mix of nutritional and bioactive components that provide complete nutrition for the infant. However, we lack a systematic knowledge of the factors shaping milk composition and how milk variation influences infant health. Here, we used multi-omic profiling to characterize interactions between maternal genetics, milk gene expression, milk composition, and the infant fecal microbiome in 242 exclusively breastfeeding mother-infant pairs. We identified 487 genetic loci associated with milk gene expression unique to the lactating mammary gland, including loci that impacted breast cancer risk and human milk oligosaccharide concentration. Integrative analyses uncovered connections between milk gene expression and infant gut microbiome, including an association between the expression of inflammation-related genes with IL-6 concentration in milk and the abundance of Bifidobacteria in the infant gut. Our results show how an improved understanding of the genetics and genomics of human milk connects lactation biology with maternal and infant health.

How Do Healthy Women Perceive the Risk of Breast Cancer? The Role of Illness Perceptions and Compared Risk between Portugal and the U.A.E

(1) Background: Breast cancer (BC) shows significant epidemiological differences between Eastern and Western countries. These may arise from socio-cultural factors influencing how healthy young women perceive this condition, their risk of getting cancer, and the implications for preventive screening behaviors. In this study, the illness perceptions, individual risk perception, compared risk, and beliefs about preventive behaviors for BC of female university students were compared using an anonymous online survey between a European country (Portugal) and the United Arab Emirates. (2) Method: A structural equation model (SEM) was developed to investigate the hypothetical relationship between illness perceptions and compared risk as predictors of perceived risk for BC. (3) Results: There were significant differences between the study variables. The SEM was invariant, but the differences between regression coefficients in both countries were highly statistically significant. Mediation analyses revealed a significant indirect effect of compared risk on individual risk and a significantly stronger direct effect for the Emirati sample. (4) Conclusions: These findings suggest that cultural research may help to explain factors that may shape social comparison of individual risk characteristics and influence perceived risk. Moreover, providing culturally appropriate strategies to be designed and implemented can promote early detection behaviors for BC.