Breastfeeding and the risk of ovarian cancer: a meta-analysis

Paradigm Shift: A Comprehensive Review of Ovarian Cancer Management in an Era of Advancements

Ovarian cancer (OC) is the female genital malignancy with the highest lethality. Patients present a poor prognosis mainly due to the late clinical presentation allied with the common acquisition of chemoresistance and a high rate of tumour recurrence. Effective screening, accurate diagnosis, and personalised multidisciplinary treatments are crucial for improving patients' survival and quality of life. This comprehensive narrative review aims to describe the current knowledge on the aetiology, prevention, diagnosis, and treatment of OC, highlighting the latest significant advancements and future directions. Traditionally, OC treatment involves the combination of cytoreductive surgery and platinum-based chemotherapy. Although more therapeutical approaches have been developed, the lack of established predictive biomarkers to guide disease management has led to only marginal improvements in progression-free survival (PFS) while patients face an increasing level of toxicity. Fortunately, because of a better overall understanding of ovarian tumourigenesis and advancements in the disease's (epi)genetic and molecular profiling, a paradigm shift has emerged with the identification of new disease biomarkers and the proposal of targeted therapeutic approaches to postpone disease recurrence and decrease side effects, while increasing patients' survival. Despite this progress, several challenges in disease management, including disease heterogeneity and drug resistance, still need to be overcome.

Mammographic Breast Density and Risk of Ovarian Cancer in Korean Women

BACKGROUND

This study aimed to investigate the potential association between mammographic breast density and ovarian cancer risk.

METHODS

This retrospective cohort study included women ≥40 years of age who underwent a mammography screening from 2009 to 2014. Breast density was assessed using the Breast Imaging-Reporting and Data System. The primary outcome was ovarian cancer development, and the cases were recorded until 2020. Cox proportional hazards regression was used to assess the association between breast density and ovarian cancer development. Subgroup analyses stratified by age, menopausal status, and body mass index (BMI) were conducted.

RESULTS

Of the 8,556,914 women included in this study, 9,246 ovarian cancer events were recorded during a median follow-up period of 10 years (interquartile range, 8.1-11.0 years). Compared with women with almost entirely fat density, those with scattered fibroglandular density, heterogeneous density, and extreme density had an increased risk of ovarian cancer with adjusted HRs of 1.08 [95% confidence interval (CI), 1.02-1.15], 1.16 (95% CI, 1.09-1.24), and 1.24 (95% CI, 1.15-1.34), respectively. The strongest association was observed in the ≥60 years age group; subgroup analysis indicated a significant increase in association between the higher-density category and ovarian cancer risk, regardless of BMI or menopausal status.

CONCLUSIONS

Higher levels of breast density are associated with an increased risk of ovarian cancer.

IMPACT

Breast density may have a relationship with ovarian cancer risk and could be used to assess future risk.

Predicting intention and maintenance of breastfeeding up to 2-years after birth in primiparous and multiparous women

OBJECTIVES

Breastfeeding up to 2-years has been associated with short and long-term health benefits for both newborns and mothers. However, few women breastfeed up to 2-years after birth. This study extends previous research on the theory of planned behaviour (TPB) examining the predictors of intention and maintenance of breastfeeding up to 2-years in both primiparous and multiparous women.

DESIGN

155 pregnant women participated in this longitudinal study.

METHODS

Expectant mothers completed a questionnaire and then 2-years after the child's birth were asked to report breastfeeding behaviour. Interactions among parity and TPB constructs were examined.

RESULTS

Attitudes, descriptive and injunctive norms, and perceived behavioural control (PBC) explained 58% of the variance in mothers' intention to breastfeed. Attitudes were the strongest predictor, followed by PBC, descriptive norms and parity. A significant interaction was found between parity and PBC, showing that PBC was only a significant predictor of intention to breastfeed at 2-years in multiparous women. Intentions predicted breastfeeding behaviour at 2-years.

CONCLUSION

Promoting intentions may be a useful way to increase breastfeeding duration to 2-years and targeting attitudes and norms may be one way to increase intentions. Further, targeting PBC may also be useful to increase intentions, but only in multiparous women.

No such thing as a free lunch: The direct marginal costs of breastfeeding

Understanding costs associated with breastfeeding is critical to developing maximally effective policy to support breastfeeding by addressing financial barriers. Breastfeeding is not without cost; direct costs include those of equipment, modified nutritional intake, and time (opportunity cost). Breastfeeding need not require more equipment than formula feeding, though maternal equipment use varies by maternal preference. Meeting increased nutritional demands requires increased spending on food and potentially dietary supplementation, the marginal cost of which depends on a mother's baseline diet. The opportunity cost of the three to four hours per day breastfeeding demands may be prohibitively high, particularly to low-income workers. These costs are relatively highest for low-income individuals, a group disproportionately comprising racial and ethnic minorities, and who demonstrate lower rates of breastfeeding than their white and higher-income peers. Acknowledging and addressing these costs and their regressive nature represents a critical component of effective breastfeeding policy and promotion.

Technical Report: Breastfeeding and the Use of Human Milk

Breastfeeding and human milk are the normative standards for infant feeding and nutrition. The short- and long-term medical and neurodevelopmental advantages of breastfeeding make breastfeeding or the provision of human milk a public health imperative. The American Academy of Pediatrics (AAP) recommends exclusive breastfeeding for approximately 6 months after birth. Furthermore, the AAP supports continued breastfeeding, along with appropriate complementary foods introduced at about 6 months, as long as mutually desired by mother and child for 2 years or beyond. These recommendations are consistent with those of the World Health Organization (WHO). Medical contraindications to breastfeeding are rare. The AAP recommends that birth hospitals or centers implement maternity care practices shown to improve breastfeeding initiation, duration, and exclusivity. The Centers for Disease Control and Prevention and The Joint Commission monitor breastfeeding practices in United States hospitals. Pediatricians play a critical role in hospitals, their practices, and communities as advocates of breastfeeding and, thus, need to be trained about the benefits of breastfeeding for mothers and children and in managing breastfeeding. Efforts to improve breastfeeding rates must acknowledge existing disparities and the impact of racism in promoting equity in breastfeeding education, support, and services.

Breastfeeding and the risk of epithelial ovarian cancer among women with a BRCA1 or BRCA2 mutation

OBJECTIVE

BRCA mutation carriers face a high lifetime risk of developing ovarian cancer. The strong inverse association between breastfeeding and the risk of ovarian cancer is established in the general population but is less well studied among women with a germline BRCA1 or BRCA2 mutation.

METHOD

Thus, we conducted a matched case-control analysis to evaluate the association between breastfeeding history and the risk of developing ovarian cancer. After matching for year of birth, country of residence, BRCA gene and personal history of breast cancer, a total of 1650 cases and 2702 controls were included in the analysis. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI) associated with various breastfeeding exposures.

RESULTS

A history of ever-breastfeeding was associated with a 23% reduction in risk (OR = 0.77; 95%CI 0.66-0.90; P = 0.001). The protective effect increased with breastfeeding from one month to seven months after which the association was relatively stable. Compared to women who never breastfed, breastfeeding for seven or more months was associated with a 32% reduction in risk (OR = 0.68; 95%CI 0.57-0.81; P < 0.0001) and did not vary by BRCA gene or age at diagnosis. The combination of breastfeeding and oral contraceptive use was strongly protective (0.47; 95%CI 0.37-0.58; P < 0.0001).

CONCLUSIONS

These findings support a protective effect of breastfeeding for at least seven months among women with a BRCA1 or BRCA2 mutation, that is independent of oral contraceptive use.

The Role of Perinatal Anxiety and Depression in Breastfeeding Practices

Objective: Maternal mental health difficulties are common during the perinatal period and have a negative impact on breastfeeding practices. Most research has focused on the role of postpartum depression, whereas maternal anxiety has been less studied, despite its high prevalence. A better understanding of the mental health variables that impact breastfeeding practices is necessary to support maternal and infant health and well-being. The aim of this study is to explore the association between breastfeeding practices and maternal mental health, with an emphasis on maternal anxiety. Materials and Methods: Two hundred twenty-nine women were followed from the third trimester of gestation to 3 and 6 months postpartum. The participants provided self-reports of depression, anxiety, and breastfeeding practices. Mental health symptoms were compared between participants who reported exclusive versus mixed breastfeeding at 3 months postpartum, and between mothers who maintained breastfeeding versus those who had weaned their infants at 6 months postpartum. Logistic regression analysis was used to explore the variables contributing to breastfeeding practices. Results: High levels of depressive symptoms during pregnancy were associated to nonexclusive breastfeeding at 3 months postpartum. At 3 months postpartum, both high levels of anxiety and depression were associated with nonexclusive breastfeeding at that time. Logistic regression analyses revealed that exclusive breastfeeding at 3 months postpartum predicted breastfeeding continuation at 6 months after childbirth. Conclusion: Both maternal depression and anxiety negatively impact breastfeeding practices. Early identification of maternal mental health problems during the perinatal period is relevant to promote maternal emotional well-being and to prevent breastfeeding difficulties.

A systematic review and meta-analysis of interventions incorporating behaviour change techniques to promote breastfeeding among postpartum women

The benefits of exclusive breastfeeding are well documented, yet few women adhere to recommendations. We report the Behaviour Change Techniques (BCTs) within interventions trialled internationally after pregnancy to promote exclusive and mixed breastfeeding as well as evidence of effectiveness. PsycINFO, EMBASE and MEDLINE databases were screened. Twenty-three (n = 23) studies met inclusion criteria. Three authors independently extracted data, coded interventions using the BCT v.1 taxonomy, and assessed study quality. There was a moderate significant effect of the interventions promoting exclusive breastfeeding up to four weeks postpartum (OR 1.77, [95% CI: 1.47-2.13]) but this effect slightly declined beyond thirteen weeks (OR 1.63, [95% CI: 1.07-2.47]). Twenty-nine BCTs were identified within interventions. 'Credible source' and 'instruction on how to perform the behaviour' were the most prevalent and 'social support (unspecified)' contributed to the effectiveness of exclusive breastfeeding interventions five to eight weeks postpartum. Using BCTs with cognitive and behavioural aspects may help women develop coping mechanisms promoting exclusive breastfeeding. Further trials are needed in countries with low breastfeeding rates such as the UK. The use of programme theory during intervention development and clear description of intervention components is recommended. This meta-analysis provides guidance for trials evaluating postpartum breastfeeding interventions.

Stress-Induced Suppression of Milk Protein Is Involved in a Noradrenergic Mechanism in the Mammary Gland

Stress decreases milk components such as milk protein and milk yield. The objective of this study was to investigate whether noradrenaline (NA) in milk constituted a factor associated with stress-induced changes in milk proteins such as β-casein. Breast milk obtained from eight healthy, nursing women contained NA at concentrations ranging from 12.7 to 115.5 nM. The expression of tyrosine hydroxylase (TH), a rate-limiting enzyme of NA synthesis, was observed in primary normal human mammary epithelial cells (HMECs), and in MCF-12A and MCF-10A cell lines. The mean NA concentration in culture medium used by MCF-12A transfected with TH small interfering RNA (siRNA) was significantly lower than that of cells transfected with control siRNA. NA concentration in milk in restraint-stressed nursing mice was significantly higher than that in nonstressed nursing mice, owing to elevated TH expression in the mammary epithelium. The mean β-casein concentration in milk in restraint-stressed mice was significantly lower than that in nonstressed mice. NA treatment resulted in a concentration-dependent decrease in β-casein expression in HMECs. β2 adrenergic receptor (ADRB2) expression was observed in HMECs, MCF-12A, and MCF-10A, and immunohistochemical analysis of ADRB2 using mammary epithelium sections obtained from mice at day 10 of lactation showed that ADRB2 was expressed at the apical membrane of mammary epithelium. Treatment with salbutamol, an ADRB2 stimulant, decreased β-casein expression in a concentration-dependent manner in MCF-12A. Our results showed that endogenous NA derived from mammary epithelial cells likely comprises one of the factors involved in stress-induced changes in milk proteins such as β-casein.

Exploring the Role of Fallopian Ciliated Cells in the Pathogenesis of High-Grade Serous Ovarian Cancer

High-grade serous epithelial ovarian cancer (HGSOC) is the fifth leading cause of cancer death in women and the first among gynecological malignancies. Despite an initial response to standard chemotherapy, most HGSOC patients relapse. To improve treatment options, we must continue investigating tumor biology. Tumor characteristics (e.g., risk factors and epidemiology) are valuable clues to accomplish this task. The two most frequent risk factors for HGSOC are the lifetime number of ovulations, which is associated with increased oxidative stress in the pelvic area caused by ovulation fluid, and a positive family history due to genetic factors. In the attempt to identify novel genetic factors (i.e., genes) associated with HGSOC, we observed that several genes in linkage with HGSOC are expressed in the ciliated cells of the fallopian tube. This finding made us hypothesize that ciliated cells, despite not being the cell of origin for HGSOC, may take part in HGSOC tumor initiation. Specifically, malfunction of the ciliary beat impairs the laminar fluid flow above the fallopian tube epithelia, thus likely reducing the clearance of oxidative stress caused by follicular fluid. Herein, we review the up-to-date findings dealing with HGSOC predisposition with the hypothesis that fallopian ciliated cells take part in HGSOC onset. Finally, we review the up-to-date literature concerning genes that are located in genomic loci associated with epithelial ovarian cancer (EOC) predisposition that are expressed by the fallopian ciliated cells.

[Endogenous Serotonin and Milk Production Regulation in the Mammary Gland]

　Intrinsic serotonin (5-hydroxytryptamine; 5-HT) synthesized within the mammary epithelium has an important physiological role in milk volume homeostasis in many species including mice, cows, and humans. During lactation, mammary epithelial cells activate 5-HT synthesis by tryptophan hydroxylase 1 (TPH1). TPH1 catalyzes the rate-limiting step in 5-HT biosynthesis within mammary glands. 5-HT synthesized in mammary glands is released into both the apical (milk) and basolateral spaces by a vesicular monoamine transporter. 5-HT released into milk is incorporated by the apical membrane-expressed serotonin reuptake transporter and degraded by the monoamine oxidase A enzyme. Suckling maintains 5-HT at low levels in milk. When the mammary gland becomes filled with milk, 5-HT provides a negative feedback signal that suppresses further milk synthesis in the mammary epithelium. Our research, using human mammary epithelial MCF-12A cells, shows that the expression of β-casein, a differentiation marker, is suppressed via 5-HT-mediated inhibition of signal transducer and activator of transcription 5. Additionally, our results show that reduced β-casein expression in MCF-12A cells is associated with 5-HT₇ receptor expression. Furthermore, we show that 5-HT₇ receptor-mediated suppression of β-casein expression is involved in the activation of protein kinase A and protein-tyrosine phosphatase 1B. Thus, this mechanism might be associated with the feedback signals by 5-HT within the mammary epithelium. Hence, further research that builds on our findings should include the elucidation of the physiological roles of 5-HT present in milk synthesized by mammary epithelial cells in vivo and its effects on nursing infants.

Breastfeeding and the Benefits of Lactation for Women's Health

The offer of the maternal breast to the baby is an unquestionable right of mothers and their children, and all efforts should be made to promote, follow and maintain exclusive breastfeeding for up to 6 months and supplement it until the child completes 2 years of age. Many publications are available in the literature about the qualities of breast milk, its benefits and health repercussions, stimulating the practice of breastfeeding and supporting campaigns for its implementation. However, although it is widely known that breastfeeding is an important step in the reproductive process of women and its practice offers benefits to both mother and child, most of the available information highlights the benefits of breast milk for children, while mention of the effects of breastfeeding on the health of the mother is usually neglected. Thus, the objective of the present study is to highlight the multiple benefits of breastfeeding for the physical and emotional health of the nursing mother. The authors consulted articles published in the databases PubMed, Virtual Health Library and Web of Science using the keywords breastfeeding, breast milk, lactation and maternal health.

Socio-economic status and maternal BMI are associated with duration of breast-feeding of Norwegian infants

Objective

To explore whether there is an association between socio-economic status and maternal BMI and duration of any breast-feeding/exclusive breast-feeding among Norwegian infants at 4 and 5 months of age in 2016.

Design

Cross-sectional design. Baseline data from a randomized controlled trial. Data concerning breast-feeding were collected by FFQ.

Setting

Recruitment was done at child health-care centres and through Facebook in 2016. In total, 960 infants/parents registered for participating in the study Early Food for Future Health.

Subjects

A total of 715 infant/mother dyads completed the questionnaire when the child was between 5 and 6 months old.

Results

At 5 months of age, 81·0 % of infants were breast-fed and 16·4 % were exclusively breast-fed. Infants of highly educated mothers had higher odds of being breast-fed at 5 months compared with infants of mothers with less education. Infants of multiparous mothers had higher odds of being exclusively breast-fed for the first 5 months compared with infants of mothers with one child. Infants of mothers with overweight/obesity had reduced odds of both being breast-fed at all and being exclusively breast-fed at 4 months of age compared with infants of mothers with normal BMI.

Conclusions

Our results show that duration of breast-feeding varies with socio-economic status and maternal BMI in Norway. Targeting groups with low socio-economic status and mothers with overweight or obesity is important, as they are less likely to breast-feed according to recommendations.

Cancer Risk-Reducing Opportunities in Gynecologic Surgery

This review article discusses cancer risk-reducing opportunities in gynecologic surgery. We cover strategies to reduce ovarian and uterine cancer risk by presenting general practice guidelines and expanding on the literature behind clinical decision points. We address populations of women at increased hereditary risk and those at population risk. We specifically discuss risk-reducing salpingo-oophorectomy, prophylactic salpingectomy with delayed oophorectomy, concomitant hysterectomy, opportunistic salpingectomy, bilateral tubal ligation, and hysterectomy. For clinical scenarios in which data are limited or conflicting, we detail the studies on which clinicians' decisions hinge to allow the reader to weigh the available evidence.

A meta-analysis of breastfeeding and osteoporotic fracture risk in the females

Our meta-analysis included 12 studies from PubMed, Embase, and Web of Science. Finding indicated breastfeeding may well reduce the risk of osteoporotic fracture.

INTRODUCTION

Several epidemiologic studies have investigated that breastfeeding is associated with short-term bone loss in the women, but the long-term effect on osteoporotic fracture risk remains unclear. Thus, we conducted this meta-analysis to explore the potential association between breastfeeding and osteoporotic fracture risk in the females and possible dose-response relationship between them.

METHODS

We searched PubMed, Embase, and Web of Science (ISI) up to April 2016 for relevant articles associated between breastfeeding and osteoporotic fracture. Pooled relative risks (RRs) with 95 % confidence intervals (CIs) were calculated with a random-effects model. Dose-response analysis was performed by restricted cubic spline.

RESULTS

Twelve articles including 14,954 participants were identified. The pooled RRs of osteoporotic hip and forearm fracture for the highest vs lowest duration of breastfeeding were 0.84 (95 % CI 0.67-1.05), 0.72 (95 % CI 0.52-0.99), and 0.82 (95 % CI 0.56-1.19), respectively. In subgroup analysis, breastfeeding was associated with a decreased risk of osteoporotic fracture in case-control study (RR = 0.70, 95 % CI 0.49-0.99) and postmenopausal women (RR = 0.66, 95 % CI 0.47-0.93). In dose-response analysis, osteoporotic and hip fracture risk decreased by 0.9 and 1.2 % for each month increment of breastfeeding, respectively.

CONCLUSIONS

Our meta-analysis revealed that breastfeeding may well reduce the risk of osteoporotic fracture. More cohort studies with large sample sizes are needed to confirm the conclusion.

Lifestyle changes and the risk of developing endometrial and ovarian cancers: opportunities for prevention and management

Modifiable lifestyle factors, such as obesity, lack of physical activity, and smoking, contribute greatly to cancer and chronic disease morbidity and mortality worldwide. This review appraises recent evidence on modifiable lifestyle factors in the prevention of endometrial cancer (EC) and ovarian cancer (OC) as well as new evidence for lifestyle management of EC and OC survivors. For EC, obesity continues to be the strongest risk factor, while new evidence suggests that physical activity, oral contraceptive pills, and bariatric surgery may be protective against EC. Other medications, such as metformin and nonsteroidal anti-inflammatory drugs, may be protective, and interventional research is ongoing. For OC, we find increasing evidence to support the hypothesis that obesity and hormone replacement therapy increase the risk of developing OC. Oral contraceptive pills are protective against OC but are underutilized. Dietary factors such as the Mediterranean diet and alcohol consumption do not seem to affect the risk of either OC or EC. For EC and OC survivors, physical activity and weight loss are associated with improved quality of life. Small interventional trials show promise in increasing physical activity and weight maintenance for EC and OC survivors, although the impact on long-term health, including cancer recurrence and overall mortality, is unknown. Women's health providers should integrate counseling about these modifiable lifestyle factors into both the discussion of prevention for all women and the management of survivors of gynecologic cancers.

Acculturation and Intention to Breastfeed among a Population of Predominantly Puerto Rican Women

BACKGROUND

Latinas have high overall breastfeeding initiation rates, yet Puerto Ricans have among the lowest exclusive breastfeeding rates. This study sought to determine if acculturation was associated with intent to breastfeed in a predominantly Puerto Rican population.

METHODS

A cohort of Latina women were enrolled in Proyecto Buena Salud, and provided information on infant feeding intent (n = 1,323). Acculturation was assessed via the Psychological Acculturation Scale (PAS), language preference, and generation in the United States.

RESULTS

Increasing acculturation as measured by English language preference (aOR 0.61 [95% CI 0.42-0.88]) and second or third generation in the United States (aOR 0.70 [95% CI 0.52-0.95)] was inversely associated with odds of intending to exclusively breastfeed. Similarly, women with higher levels of acculturation as measured by the PAS (aOR 0.67 [95% CI 0.45-0.99]), English language preference (aOR 0.48 [95% CI 0.33-0.70]) and second or third generation in the United States (aOR 0.42 [95% CI 0.31-0.58]) were less likely to report intent to combination feed as compared with women with lower acculturation.

CONCLUSIONS

Acculturation was inversely associated with intent to exclusively breastfeed and intent to combination feed in this predominantly Puerto Rican sample.

Predictors of breastfeeding initiation in Hong Kong and Mainland China born mothers

BACKGROUND

In recent years there has been a steady influx of immigrants into Hong Kong from Mainland China, where breastfeeding patterns differ. Studies in other regions have found substantial differences in breastfeeding rates between native-born and immigrant mothers. The purpose of this study was to examine factors associated with breastfeeding initiation in Hong Kong born and Mainland China born mothers living in Hong Kong.

METHODS

We used a multi-center cross-sectional study design and recruited 2761 new mothers from the postnatal wards of all eight public hospitals in Hong Kong that offer obstetric services. We assessed breastfeeding status as well as various socio-demographic, maternal and birth characteristics. Chi-square tests and multivariable logistic regression were used to identify the predictors of breastfeeding initiation in Hong Kong born and Mainland China born participants.

RESULTS

80.3 % of Hong Kong and 81.1 % of Mainland Chinese born women initiated breastfeeding. In the fully adjusted models, multiparity (Odds Ratio [OR] 0.53, 95 % CI 0.43-0.66) and maternal smoking (OR 0.29, 95 % CI 0.18-0.45) were strongly associated with failure to initiate breastfeeding in both Hong Kong and Mainland China born participants. In Hong Kong born mothers, participants with lower maternal education and those who had a cesarean section were significantly less likely to breastfeed. For Mainland China born mothers, paternal smoking (OR 0.70, 95 % CI 0.49-0.99) and having a pregnancy-related health problem (OR 0.60, 95 % CI 0.38-0.94) were both additional risk factors for not breastfeeding.

CONCLUSION

This study has identified predictors of breastfeeding initiation in Hong Kong and Mainland China born mothers. Given the current high breastfeeding initiation rates among both groups, antenatal breastfeeding education and promotion programmes need to specifically intervene with sub-groups of pregnant women at risk for not breastfeeding so that their efforts are more strategic and cost-effective.