Intake of fiber and nuts during adolescence and incidence of proliferative benign breast disease

Epidemiology and Risk Factors for Breast Cancer: 21st Century Advances, Gaps to Address through Interdisciplinary Science

Research methods to study risk factors and prevention of breast cancer have evolved rapidly. We focus on advances from epidemiologic studies reported over the past two decades addressing scientific discoveries, as well as their clinical and public health translation for breast cancer risk reduction. In addition to reviewing methodology advances such as widespread assessment of mammographic density and Mendelian randomization, we summarize the recent evidence with a focus on the timing of exposure and windows of susceptibility. We summarize the implications of the new evidence for application in risk stratification models and clinical translation to focus prevention-maximizing benefits and minimizing harm. We conclude our review identifying research gaps. These include: pathways for the inverse association of vegetable intake and estrogen receptor (ER)-ve tumors, prepubertal and adolescent diet and risk, early life adiposity reducing lifelong risk, and gaps from changes in habits (e.g., vaping, binge drinking), and environmental exposures.

"I haven't had that information, even though I think I'm really well-informed about most things": a qualitative focus group study on Australian women's understanding and views of potentially modifiable risk factors for breast cancer

BACKGROUND

Building health literacy about potentially modifiable risk factors for breast cancer may help to empower women to make more informed decisions about their breast health; however there has been limited qualitative research on this topic. This study aimed to explore current knowledge, understanding and experience of potentially modifiable risk factors for breast cancer, and views on current and future communication strategies for this information and related interventions.

METHODS

Qualitative study using online focus groups via Zoom in October-November 2022. A diverse sample of women from the Australian community aged 40-74 years were recruited.

RESULTS

Fifty-one women from a range of socioeconomic backgrounds took part in nine focus groups. General knowledge of risk factors for breast cancer in the community is limited, particularly in relation to modifiable factors such as alcohol consumption and postmenopausal obesity, with many women describing feelings of 'shock' following this information. Women overwhelming believed that information on modifiable risk factors for breast cancer should be communicated more widely, however communication preferences for receiving this information varied. There was a strong preference amongst the women for a cascade of information which they believed may then help target greater number of women of all ages and backgrounds. Despite worry about long-term compliance, women also supported various lifestyle interventions which may help them and other women to reduce their overall risk.

CONCLUSIONS

Findings from this study highlight the need for more widespread community communication and education about risk factors for breast, in particular potentially modifiable risk factors such as alcohol consumption and postmenopausal obesity. As breast screening programs in Australia and globally begin to evaluate the potential for risk-related screening this will provide an additional context for primary prevention, hence planning of messaging and piloting of lifestyle-related prevention strategies in breast cancer is needed now. Gaining an understanding of women's preferences for communication and forms of interventions is vital to ensure their engagement.

Investigating the Link between Early Life and Breast Anomalies

Several factors during childhood and adolescence are thought to be associated with the development of proliferative benign breast diseases and breast cancer in adulthood. In order to identify them, the authors conducted an extensive review of the literature up to October 2022, searching for clinical studies, reports, and guidelines in English. A thorough Medline/Pubmed and Google scholar database research was performed, investigating the link between diet, exercise, age of menarche, body mass index, ionizing radiation exposure during childhood and adolescence, and proliferative breast diseases and breast cancer in adulthood. A list of keywords, including breast disorders, adolescence, childhood, and breast cancer was included in our search algorithm. Numerous studies concede that the development of breast disease in adulthood is influenced by various risk factors, whose influence begins during early childhood and adolescence.

Adolescent alcohol, nuts, and fiber: combined effects on benign breast disease risk in young women

Adolescent drinking is associated with higher risks of proliferative benign breast disease (BBD) and invasive breast cancer (BC). Furthermore, adolescent nut and fiber consumptions are associated with lower risks of benign lesions and premenopausal BC. We hypothesize that diet (nuts, fiber) may mitigate the elevated BBD risk associated with alcohol. A prospective cohort of 9031 females, 9-15 years at baseline, completed questionnaires in 1996-2001, 2003, 2005, 2007, 2010, 2013, and 2014. Participants completed food frequency questionnaires in 1996-2001. In 2005, participants (>=18 years) began reporting biopsy-confirmed BBD (N = 173 cases). Multivariable logistic regression estimated associations between BBD and cross-classified intakes (14-17 years) of alcohol and peanut butter/nuts (separately, total dietary fiber). Only 19% of participants drank in high school; drinking was associated with elevated BBD risk (OR = 1.75, 95% CI: 1.20-2.56; p = 0.004) compared to nondrinkers. Participants consuming any nuts/butter had lower BBD risk (OR = 0.64, 95% CI: 0.45-0.90; p = 0.01) compared to those consuming none. Participants in top 75% fiber intake had lower risk (OR = 0.57, 95% CI: 0.40-0.81; p = 0.002) compared to bottom quartile. Testing our hypothesis that consuming nuts/butter mitigates the elevated alcohol risk, analyzing alcohol and nuts combined found that those who consumed both had lower risk (RR = 0.47, 95% CI: 0.24-0.89; p = 0.02) compared to drinkers eating no nuts. Our analysis of alcohol and fiber together did not demonstrate risk mitigation by fiber. For high school females who drink, their BBD risk may be attenuated by consuming nuts. Due to modest numbers, future studies need to replicate our findings in adolescent/adult females. However, high school students may be encouraged to eat nuts and fiber, and to avoid alcohol, to reduce risk of BBD and for general health benefits.

Legume and Nuts Consumption in Relation to Odds of Breast Cancer: A Case-Control Study

Previous studies on the association between legume and nuts intake and risk of breast cancer have mainly been focused on individual components of legume or nuts, rather than consumption of the whole food group. This study aimed to investigate the relation between legume and nuts intake in relation to breast cancer in Iranian women. In this population-based case-control study, we enrolled 350 pathologically confirmed new cases of breast cancer and 700 controls which were matched with cases in terms of age and socioeconomic status. Dietary intakes were assessed using a validated block-format 168-item semi-quantitative food frequency questionnaire. Legume intake was computed by summing up the consumption of lentils, peas, chickpeas, and different kinds of beans, including red beans and pinto beans. To calculate nuts consumption, we summed up intake of mixed nuts, almond, peanut, walnut and hazelnut. Data on potential confounding variables were also collected using pre-tested questionnaires. Mean consumption of legume and nuts among cases and controls were 14.7 ± 15.0 and 2.3 ± 5.6, respectively. A significant inverse association was found between legume intake and breast cancer (OR: 0.41, 95% CI: 0.30-0.57); such that after adjusting for confounders, participants in the top tertile of legume intake had 46% lower odds of breast cancer compared with those in the bottom tertile (OR: 0.54, 95% CI: 0.36-0.88). Such inverse association was seen among postmenopausal women (OR: 0.51, 95% CI: 0.31-0.85) and also among normal-weight participants (OR: 0.49, 95% CI: 0.29-0.82). In terms of nuts intake, it was inversely associated with odds of breast cancer (OR: 0.16, 95% CI: 0.11-0.23). This association remained significant even after taking potential confounders into account (OR: 0.15, 95% CI: 0.09-0.26). The same association was also seen in premenopausal women (OR: 0.21, 95% CI: 0.14-0.31), postmenopausal women (OR: 0.23, 95% CI: 0.13-0.42), normal-weight (OR: 0.15, 95% CI: 0.08-0.28), and overweight or obese people (OR: 0.27, 95% CI: 0.10-0.71). Our findings on the inverse association of legume and nuts intake with odds of breast cancer support the current recommendations on these foods. Prospective studies are needed to further examine this link.

Higher Dietary Inflammatory Index Scores are Associated with Increased Odds of Benign Breast Diseases in a Case-Control Study

Purpose

Dietary inflammatory index (DII) is a new tool for assessing the inflammatory potential of diet. Since there is no study that has investigated the association of DII and benign breast diseases (BBD), the aim of our study was to compare DII scores in patients with and without BBD.

Methods

One hundred and eleven (111) subjects with BBD and 104 healthy women attending the Iranian Center for Breast Cancer affiliated with the Academic Center for Education, Culture and Research were enrolled in a case–control study. Dietary data collected using a 168‑item validated food frequency questionnaire (FFQ). Energy-adjusted DII was calculated based on FFQ. Socio demographic data were collected by interview. In addition, physical activity was measured by the International Physical Activity Questionnaire (IPAQ). Weight, height and waist circumference were also measured.

Results

After adjustment for multiple confounding variables, participants at the highest tertile of DII had increased OR for BBD (OR=1.7, 95% CI=0.75–3.95) (P-trend =0.04).

Conclusion

The increased chance of BBD was suggested with a higher consumption of diets with inflammatory potential. However, this result should be interpreted with caution as OR was not statistically significant. Interventional studies are warranted to elucidate the role of inflammatory diets in the development of BBD.

Health Equity in National Cancer Control Plans: An Analysis of the Ontario Cancer Plan

BACKGROUND

National cancer control plans (NCCPs) are important documents that guide strategic priorities in cancer care and plan for the appropriate allocation of resources based on the social, geographic and economic needs of a population. Despite the emphasis on health equity by the World Health Organization (WHO), few NCCPs have a focus on health equity. The Ontario Cancer Plan (OCP) IV, (2015 to 2019) is an example of an NCCP with clearly defined health equity goals and objectives.

METHODS

This paper presents a directed-content analysis of the OCP IV health equity goals and objectives, in light of the synergies of oppression analytical framework.

RESULTS

The OCP IV confines equity to an issue of access-to-care. As a result, it calls for training, funding, and social support services to increase accessibility for high-risk population groups. However, equity has a broader definition. And as such, it also implies that systematic differences in health outcomes between social groups should be minimal. This is particularly significant given that socially disadvantaged cancer patients in Ontario have distinctly poorer cancer-related health outcomes.

CONCLUSION

Health systems are seeking ways to reduce the health equity gap. However, to reduce health inequities which are socially-based will require a recognition of the living and working conditions of patients which influence risk, mortality and survival. NCCPs represent a way to politically advocate for the determinants of health which profoundly influence cancer risk, outcomes and mortality.

Dietary intake from birth through adolescence in relation to risk of benign breast disease in young women

PURPOSE

Nutritional factors during different periods in life impact breast cancer risk. Because benign breast disease (BBD) is a well-established risk factor for breast cancer, we investigated childhood nutrition from birth through age 14 year and subsequent BBD.

METHODS

A prospective cohort study of 9031 females, 9-15 year at baseline, completed questionnaires (including heights, weights) annually from 1996 to 2001, in 2003, 2005, 2007, 2010, 2013 and 2014. In 1996, mothers reported infant feeding practices during their daughters first year of life. Beginning in 1996, participants completed annual food frequency questionnaires. In 2005, participants (18 year +) began reporting whether they had ever been diagnosed with biopsy-confirmed BBD (N = 173 cases). Multivariable logistic regression models estimated associations between childhood nutrition and BBD, adjusted for maternal breast disease and childhood body size factors.

RESULTS

Although no infant nutrition factors were associated with biopsy-confirmed BBD, certain adolescent dietary factors were. A multivariable model simultaneously included the most important diet and body size factors from different age periods: higher BBD risk was associated with greater age 10 year consumption of animal (non-dairy, energy-adjusted) fat (OR 2.27, p < .02, top vs. bottom quartiles) and with lower 14 year consumption of nuts/peanut butter (OR 0.60, p = .033, top vs. bottom quartiles).

CONCLUSION

Greater intake of animal (non-dairy) fat at 10 year and lower intake of nuts/peanut butter at 14 year were independently associated with higher BBD risk. These dietary factors appeared to operate on BBD risk independent of childhood growth (gestational weight gain, childhood BMI and height, adolescent height growth velocity), young adult height and BMI, and family history.

Intake of bean fiber, beans, and grains and reduced risk of hormone receptor-negative breast cancer: the San Francisco Bay Area Breast Cancer Study

High dietary fiber intake has been associated with reduced breast cancer risk, but few studies considered tumor subtypes defined by estrogen receptor (ER) and progesterone receptor (PR) status or included racial/ethnic minority populations who vary in their fiber intake. We analyzed food frequency data from a population-based case-control study, including 2135 breast cancer cases (1070 Hispanics, 493 African Americans, and 572 non-Hispanic Whites (NHWs)) and 2571 controls (1391 Hispanics, 557 African Americans, and 623 NHWs). Odds ratios (OR) and 95% confidence intervals (CI) for breast cancer associated with fiber intake were calculated using unconditional logistic regression. Breast cancer risk associated with high intake (high vs. low quartile) of bean fiber (p-trend = 0.01), total beans (p-trend = 0.03), or total grains (p-trend = 0.05) was reduced by 20%. Inverse associations were strongest for ER-PR- breast cancer, with risk reductions associated with high intake ranging from 28 to 36%. For bean fiber, risk was reduced among foreign-born Hispanics only, who had the highest fiber intake, whereas for grain intake, inverse associations were found among NHWs only. There was no evidence of association with fiber intake from vegetables and fruits or total intake of vegetables and fruits. A high dietary intake of bean fiber and fiber-rich foods such as beans and grains may lower the risk of ER-PR- breast cancer, an aggressive breast cancer subtype for which few risk factors have been identified.

Early Life Exposures and Adult Cancer Risk

Very little is known about the influence of early life exposures on adult cancer risk. The purpose of this narrative review was to summarize the epidemiologic evidence relating early life tobacco use, obesity, diet, and physical activity to adult cancer risk; describe relevant theoretical frameworks and methodological strategies for studying early life exposures; and discuss policies and research initiatives focused on early life. Our findings suggest that in utero exposures may indirectly influence cancer risk by modifying biological pathways associated with carcinogenesis; however, more research is needed to firmly establish these associations. Initiation of exposures during childhood and adolescence may impact cancer risk by increasing duration and lifetime exposure to carcinogens and/or by acting during critical developmental periods. To expand the evidence base, we encourage the use of life course frameworks, causal inference methods such as Mendelian randomization, and statistical approaches such as group-based trajectory modeling in future studies. Further, we emphasize the need for objective exposure biomarkers and valid surrogate endpoints to reduce misclassification. With the exception of tobacco use, there is insufficient evidence to support the development of new cancer prevention policies; however, we highlight existing policies that may reduce the burden of these modifiable risk factors in early life.

Tree nut, peanut, and peanut butter intake and risk of postmenopausal breast cancer: The Netherlands Cohort Study

PURPOSE

Nut intake has been associated with reduced mortality and risk of cardiovascular diseases, but there is only limited evidence on cancer. We investigated the relationship between nut intake and risk of postmenopausal breast cancer, and estrogen/progesterone receptor (ER/PR) subtypes.

METHODS

In The Netherlands Cohort Study, 62,573 women aged 55-69 years provided information on dietary and lifestyle habits in 1986. After 20.3 years of follow-up, 2,321 incident breast cancer cases and 1,665 subcohort members were eligible for multivariate case-cohort analyses.

RESULTS

Total nut intake was significantly inversely related to ER negative (ER -) breast cancer risk, with HR 0.55 (95% CI 0.33-0.93) for those consuming at least 10 g nuts/day versus non-consumers (p trend = 0.025). There were no significant inverse associations with ER + or total breast cancer. While there was no variation between PR subtypes, the ER-PR- subtype was also significantly inversely associated with nut intake, with HR 0.53 (95% CI 0.29-0.99), p trend = 0.037. Intake of peanuts and tree nuts separately was also inversely related to ER - breast cancer subtypes, while no associations were found with peanut butter intake.

CONCLUSIONS

Our findings suggest an inverse association between nut intake and ER - breast cancer, and no association with total or hormone receptor-positive subtypes.

Tree nut, peanut, and peanut butter intake and risk of postmenopausal breast cancer: The Netherlands Cohort Study

PURPOSE

Nut intake has been associated with reduced mortality and risk of cardiovascular diseases, but there is only limited evidence on cancer. We investigated the relationship between nut intake and risk of postmenopausal breast cancer, and estrogen/progesterone receptor (ER/PR) subtypes.

METHODS

In The Netherlands Cohort Study, 62,573 women aged 55-69 years provided information on dietary and lifestyle habits in 1986. After 20.3 years of follow-up, 2,321 incident breast cancer cases and 1,665 subcohort members were eligible for multivariate case-cohort analyses.

RESULTS

Total nut intake was significantly inversely related to ER negative (ER -) breast cancer risk, with HR 0.55 (95% CI 0.33-0.93) for those consuming at least 10 g nuts/day versus non-consumers (p trend = 0.025). There were no significant inverse associations with ER + or total breast cancer. While there was no variation between PR subtypes, the ER-PR- subtype was also significantly inversely associated with nut intake, with HR 0.53 (95% CI 0.29-0.99), p trend = 0.037. Intake of peanuts and tree nuts separately was also inversely related to ER - breast cancer subtypes, while no associations were found with peanut butter intake.

CONCLUSIONS

Our findings suggest an inverse association between nut intake and ER - breast cancer, and no association with total or hormone receptor-positive subtypes.

Physical activity, sedentary behaviour, diet, and cancer: an update and emerging new evidence

The lifestyle factors of physical activity, sedentary behaviour, and diet are increasingly being studied for their associations with cancer. Physical activity is inversely associated with and sedentary behaviour is positively (and independently) associated with an increased risk of more than ten types of cancer, including colorectal cancer (and advanced adenomas), endometrial cancers, and breast cancer. The most consistent dietary risk factor for premalignant and invasive breast cancer is alcohol, whether consumed during early or late adult life, even at low levels. Epidemiological studies show that the inclusion of wholegrain, fibre, fruits, and vegetables within diets are associated with reduced cancer risk, with diet during early life (age <8 years) having the strongest apparent association with cancer incidence. However, randomised controlled trials of diet-related factors have not yet shown any conclusive associations between diet and cancer incidence. Obesity is a key contributory factor associated with cancer risk and mortality, including in dose-response associations in endometrial and post-menopausal breast cancer, and in degree and duration of fatty liver disease-related hepatocellular carcinoma. Obesity produces an inflammatory state, characterised by macrophages clustered around enlarged hypertrophied, dead, and dying adipocytes, forming crown-like structures. Increased concentrations of aromatase and interleukin 6 in inflamed breast tissue and an increased number of macrophages, compared with healthy tissue, are also observed in women with normal body mass index, suggesting a metabolic obesity state. Emerging randomised controlled trials of physical activity and dietary factors and mechanistic studies of immunity, inflammation, extracellular matrix mechanics, epigenetic or transcriptional regulation, protein translation, circadian disruption, and interactions of the multibiome with lifestyle factors will be crucial to advance this field.

Adolescent fiber intake and mammographic breast density in premenopausal women

Background

To date, there is limited and inconsistent epidemiologic evidence for associations of adolescent diet with mammographic breast density, a strong and consistent predictor of breast cancer. We investigated the association of adolescent fiber intake with mammographic density in premenopausal women.

Methods

This study included 743 cancer-free premenopausal women (mean age, 44.9 years) within the Nurses’ Health Study II cohort. Percent breast density, absolute dense and non-dense areas were measured from digitized film mammograms using a computer-assisted thresholding technique. Adolescent and adult diet were assessed with a food frequency questionnaire; energy-adjusted nutrient intakes were estimated for each food item. Information regarding breast cancer risk factors was obtained from baseline or biennial questionnaires closest to the mammogram date. We used generalized linear regression to quantify associations between quartiles of adolescent fiber intake and each of the breast density measures, adjusted for potential confounders. Associations were examined separately for total fiber intake; fiber from fruits, vegetables, legumes, and cereal; and food sources of fiber (fruits, vegetables, and nuts).

Results

In multivariable analyses, total fiber intake during adolescence was not associated with percent breast density (p for trend = 0.64), absolute dense area (p for trend = 0.80), or non-dense area (p for trend = 0.75). Similarly, neither consumption of fiber from fruits, vegetables, legumes, or cereal nor specific sources of fiber intake (fruits, vegetables, or nuts) during adolescence were associated with any of the mammographic density phenotypes.

Conclusions

Our findings do not support the hypothesis that adolescent fiber intake is associated with premenopausal mammographic breast density.

Dietary Fiber Intake in Young Adults and Breast Cancer Risk

OBJECTIVE

We evaluated fiber intake during adolescence and early adulthood in relation to breast cancer (BC) risk in the Nurses' Health Study II.

METHODS

Among 90,534 premenopausal women who completed a dietary questionnaire in 1991, we documented 2833 invasive BC cases during 20 years of follow-up. In 1998, 44,263 of these women also completed a questionnaire about their diet during high school; among these women, we documented 1118 cases of BC by end of follow-up. Multivariable-adjusted Cox proportional hazards regression was used to model relative risks (RRs) and 95% confidence intervals (CIs) for BC across categories of dietary fiber.

RESULTS

Among all women, early adulthood total dietary fiber intake was associated with significantly lower BC risk (RR for highest versus lowest quintile 0.81; 95% CI 0.72-0.91; Ptrend = .002). Higher intakes of soluble fiber (RR for highest versus lowest quintile 0.86; 95% CI 0.77-0.97; Ptrend = .02) and insoluble fiber (RR for highest versus lowest quintile 0.80; 95% CI 0.71-0.90; Ptrend < .001) were each associated with lower BC risk. Total dietary fiber intake in adolescence was also associated with lower BC risk (RR for highest versus lowest quintile 0.84; 95% CI 0.70-1.01; Ptrend = .04). For the average of fiber intake during adolescence and early adult life, the RR comparing highest with lowest quintiles was 0.75 (95% CI 0.62-0.91, Ptrend = .004).

CONCLUSIONS

Our findings support the hypothesis that higher fiber intakes reduce BC risk and suggest that intake during adolescence and early adulthood may be particularly important.

Dietary approach to stop hypertension (DASH): diet components may be related to lower prevalence of different kinds of cancer: A review on the related documents

Background:

Dietary approaches to stop hypertension (DASH) eating plan is a healthy dietary pattern. Our object is to review surveys in the field of major components of DASH diet and different kinds of cancers.

Materials and Methods:

Our search result from PubMed search engine recruited to find related articles.

Results:

Adherence to the DASH diet components was significantly related to lower prevalence of various cancers due to their high content of fiber, nutrients, vitamins, mineral, and antioxidant capacity.

Conclusion:

In this review, positive association of DASH diet components and different cancers were observed. However, the exact association of DASH with cancers should be clarified in future longitudinal studies due to potential interaction among foods and nutrients.

Review of nut phytochemicals, fat-soluble bioactives, antioxidant components and health effects

The levels of phytochemicals (total phenols, proanthocyanidins, gallic acid + gallotannins, ellagic acid + ellagitannins, flavonoids, phenolic acids, stilbenes and phytates), fat-soluble bioactives (lipid, tocols, phytosterols, sphingolipids, carotenoids, chlorophylls and alkyl phenols) as well as natural antioxidants (nutrient and non-nutrient) present in commonly consumed twelve nuts (almond, Brazil nut, cashew, chestnut, hazelnut, heartnut, macadamia, peanut, pecan, pine nut, pistachio and walnut) are compared and reported. Recent studies adding new evidence for the health benefits of nuts are also discussed. Research findings from over 112 references, many of which have been published within last 10 years, have been compiled and reported.

Preventing breast cancer now by acting on what we already know

The age-specific rate of breast cancer rises rapidly through premenopausal years and significantly more slowly after menopause. Reproductive factors affect cell proliferation and the accumulation of genetic changes. Lifetime risk of breast cancer is linearly related to the length of the interval from menarche to first birth. Lifestyle changes that accompany industrialization, together with shifting reproductive patterns, drive up incidence rates. Prevention must begin early in the life as almost one-quarter of cases are diagnosed before age 50 in high-income countries. This requires greater emphasis on prevention across the life course to address the global burden of breast cancer.

Breast cancer risk associated with benign breast disease: systematic review and meta-analysis

Benign breast disease (BBD) is a broad category of diagnoses reported to convey a variable degree of increased risk of developing breast cancer. A meta-analysis of the existing literature was performed to quantify the risk estimate associated with BBD. Pubmed, Google Scholar, and EMBASE databases were searched in January 2011. English retrospective and prospective observational studies published from 1972 to 2010 evaluating BBD and the risk of breast cancer were included with data acquisition reported from 1930 to 2007. Eligibility was performed independently following a standardized protocol for full-text publication review by a single reviewer and reviewed by a second author. Of the 3,409 articles retrieved from the literature search, 32 studies met the selection criteria. Reported risk estimates, including relative risk, odds ratio, standardized incidence ratios, rate ratio, hazards ratio, and incidence rate ratio, were the primary outcomes extracted. The most commonly reported pathologies were decided prior to extraction and organized into the following categories for analysis of the extracted risk estimate: non-proliferative disease (NPD), proliferative disease without atypia, benign breast disease not otherwise specified (BBD), and atypical hyperplasia not otherwise specified (AHNOS). The mean age at benign breast biopsy was 46.1 years and the mean age of developing breast cancer was 55.9 years. The mean follow-up length was 12.8 years (range 3.3-20.6). The summary risk estimate of developing breast cancer for NPD was 1.17 (N = 8; 95% CI 0.94-1.47). Proliferative disease without atypia was associated with significantly increased risk of future breast cancer, summary relative risk 1.76 (N = 15; 95% CI 1.58-1.95). The summary risk estimate for AHNOS was 3.93 (N = 13; 95% CI 3.24-4.76). This meta-analysis demonstrates that proliferative benign breast disease with or without atypia is associated with a significant increase in risk of developing breast cancer. These data support management strategies for women with benign breast disease such as additional screening methods or chemoprevention.

Intakes of fat and micronutrients between ages 13 and 18 years and the incidence of proliferative benign breast disease

PURPOSE

Dietary exposures during adolescence may exert important effects on breast development and future breast cancer risk. This study evaluated the associations between high school intakes of fat and micronutrients and the incidence of proliferative benign breast disease (BBD), a marker of increased breast cancer risk.

METHODS

29,480 women (mean age 43.3 years, range 33.6-52.9) completed a high school food frequency questionnaire in 1998 in the Nurses' Health Study II. Between 1991 and 2001, 682 women (follow-up time: 259,828 person-years) were diagnosed with proliferative BBD whose biopsy slides were reviewed and confirmed by the study pathologists.

RESULTS

In multivariate Cox proportional hazards models, high school intakes of total fat and types of fat were not associated with proliferative BBD. Women in the highest quintile of total retinol activity equivalents (RAEs), which incorporate retinol, α- and β-carotene, and β-cryptoxanthin intakes, had a 17 % lower risk of proliferative BBD than those in the lowest quintile [multivariate hazard ratio (HR) 95 % CI 0.83 (0.64, 1.07), p trend = 0.01]; however, additional adjustment for high school dietary factors (vitamin D, nuts, and fiber) rendered the association nonsignificant [0.99 (0.73, 1.34), p trend = 0.32]. Results were similar with additional adjustment for adult RAE intake. Intakes of vitamin E and individual carotenoids were not associated with proliferative BBD, although an inverse association cannot be ruled out.

CONCLUSIONS

In this study, adolescent fat and micronutrient intakes were not associated with risk of proliferative BBD.

Cancer chemoprevention with nuts

It is well established that increased nut consumption is associated with a reduced risk of major chronic diseases, such as cardiovascular disease and type 2 diabetes mellitus. On the other hand, the association between nut consumption and cancer mortality is less clear. Recent studies have suggested that nut consumption is associated with reduced cancer mortality. This evidence reinforces the interest to investigate the chemopreventive properties of nuts, and it raises questions about the specific cancer type(s) and setting that can be more affected by nut consumption, as well as the cellular mechanisms involved in this protective effect. Here we discuss recent studies on the association of nut consumption and cancer, and we propose specific cellular mechanisms by which nut components can affect cancer progression.

Computerized database management system for breast cancer patients

Data analysis based on breast cancer risk factors such as age, race, breastfeeding, hormone replacement therapy, family history, and obesity was conducted on breast cancer patients using a new enhanced computerized database management system. My Structural Query Language (MySQL) is selected as the application for database management system to store the patient data collected from hospitals in Malaysia. An automatic calculation tool is embedded in this system to assist the data analysis. The results are plotted automatically and a user-friendly graphical user interface is developed that can control the MySQL database. Case studies show breast cancer incidence rate is highest among Malay women, followed by Chinese and Indian. The peak age for breast cancer incidence is from 50 to 59 years old. Results suggest that the chance of developing breast cancer is increased in older women, and reduced with breastfeeding practice. The weight status might affect the breast cancer risk differently. Additional studies are needed to confirm these findings.

Breast cancer risk accumulation starts early: prevention must also

Nearly one in four breast cancers is diagnosed before the age of 50, and many early-stage premalignant lesions are present but not yet diagnosed. Therefore, we review evidence to support the strategy that breast cancer prevention efforts must begin early in life. This study follows the literature review methods and format. Exposures during childhood and adolescence affect a woman's long-term risk of breast cancer, but have received far less research attention than exposures that occur later in life. Breast tissue undergoes rapid cellular proliferation between menarche and first full-term pregnancy, and risk accumulates rapidly until the terminal differentiation that accompanies first pregnancy. Evidence on childhood diet and growth in height, and adolescent alcohol intake, among other adolescent factors is related to breast cancer risk and risk of premalignant proliferative benign lesions. Breast cancer prevention efforts will have the greatest effect when initiated at an early age and continued over a lifetime. Gaps in knowledge are identified and deserve increase attention to inform prevention.

Adolescent carotenoid intake and benign breast disease

BACKGROUND

Carotenoids may reduce risk of benign breast disease (BBD), an independent risk factor for breast cancer, through antioxidative or antiproliferative mechanisms. Exposure to carotenoids may be most important during adolescence when breast tissue is still developing. We examined adolescent carotenoid intake in relation to BBD in young women.

METHODS

In 6593 adolescent girls in the prospective Growing Up Today Study cohort, intakes of α-carotene, β-carotene, β-cryptoxanthin, lutein/zeaxanthin, and lycopene were assessed by using the means from food-frequency questionnaires in 1996, 1997, and 1998. Girls reported biopsy-confirmed BBD on questionnaires in 2005, 2007, and 2010 (n = 122). We conducted logistic regression of energy-adjusted carotenoid intakes in relation to BBD, adjusted for age, family history of breast cancer or BBD, age at menarche, nulliparity, alcohol intake, BMI, and physical activity.

RESULTS

Mean (SD) age at baseline was 12.0 (1.6) years. β-Carotene intake was inversely associated with BBD; comparing the highest to lowest quartile, the multivariate-adjusted odds ratio was 0.58 (95% confidence interval: 0.34-1.00; P-trend = .03). α-Carotene and lutein/zeaxanthin were also inversely associated with BBD, but the associations were not statistically significant.

CONCLUSIONS

Adolescent carotenoid intake may be associated with lower BBD risk; these findings warrant further study.

Priorities for the primary prevention of breast cancer

Despite recent calls to intensify the search for new risk factors for breast cancer, acting on information that we already have could prevent thousands of cases each year. This article reviews breast cancer primary prevention strategies that are applicable to all women, discusses the underutilization of chemoprevention in high-risk women, highlights the additional advances that could be made by including young women in prevention efforts, and comments on how the molecular heterogeneity of breast cancer affects prevention research and strategies.

Adolescent dietary fiber, vegetable fat, vegetable protein, and nut intakes and breast cancer risk

The importance of early-life exposures in breast cancer development is increasingly recognized. However, limited research has evaluated the relationship between adolescent diet and subsequent risk of breast cancer and reported inconsistent results. This population-based case-control study investigated the associations of dietary fiber, vegetable protein, vegetable fat, and nuts consumed during adolescence with adult breast cancer risk. Women, ages 25-74 years, who were diagnosed with first primary breast cancer between 2002 and 2003, were identified using the Ontario Cancer Registry. Controls were identified through random-digit dialing and age-frequency matched to cases. Diet at ages 10-15 was assessed with a 55-item food frequency questionnaire among 2,865 cases and 3,299 controls. Logistic regression was performed to estimate odds ratios (ORs) and 95 % confidence intervals (CIs). Inverse associations were found between intakes of dietary fiber, vegetable protein, vegetable fat, and nuts during adolescence and breast cancer risk, which persisted after controlling for adult intakes. The ORs (95 % CI) for the highest versus the lowest quintile of intake were 0.66 (0.55-0.78; P trend < 0.0001) for fiber, 0.80 (0.68-0.95; P trend = 0.01) for vegetable protein, 0.74 (0.63-0.87; P trend = 0.002) for vegetable fat, and 0.76 (0.61-0.95 for ≥1 serving/day vs. <1 serving/month intake; P trend = 0.04) for nuts. The reduced risk for adolescent intakes of fiber, vegetable protein, and nuts was largely limited to postmenopausal women (P interaction ≤ 0.05). Dietary fiber, vegetable protein, vegetable fat, and nuts consumed during adolescence were associated with reduced breast cancer risk.

Adolescent dietary fiber, vegetable fat, vegetable protein, and nut intakes and breast cancer risk

The importance of early-life exposures in breast cancer development is increasingly recognized. However, limited research has evaluated the relationship between adolescent diet and subsequent risk of breast cancer and reported inconsistent results. This population-based case-control study investigated the associations of dietary fiber, vegetable protein, vegetable fat, and nuts consumed during adolescence with adult breast cancer risk. Women, ages 25-74 years, who were diagnosed with first primary breast cancer between 2002 and 2003, were identified using the Ontario Cancer Registry. Controls were identified through random-digit dialing and age-frequency matched to cases. Diet at ages 10-15 was assessed with a 55-item food frequency questionnaire among 2,865 cases and 3,299 controls. Logistic regression was performed to estimate odds ratios (ORs) and 95 % confidence intervals (CIs). Inverse associations were found between intakes of dietary fiber, vegetable protein, vegetable fat, and nuts during adolescence and breast cancer risk, which persisted after controlling for adult intakes. The ORs (95 % CI) for the highest versus the lowest quintile of intake were 0.66 (0.55-0.78; P trend < 0.0001) for fiber, 0.80 (0.68-0.95; P trend = 0.01) for vegetable protein, 0.74 (0.63-0.87; P trend = 0.002) for vegetable fat, and 0.76 (0.61-0.95 for ≥1 serving/day vs. <1 serving/month intake; P trend = 0.04) for nuts. The reduced risk for adolescent intakes of fiber, vegetable protein, and nuts was largely limited to postmenopausal women (P interaction ≤ 0.05). Dietary fiber, vegetable protein, vegetable fat, and nuts consumed during adolescence were associated with reduced breast cancer risk.

Calorie intake, olive oil consumption and mammographic density among Spanish women

High mammographic density (MD) is one of the main risk factors for development of breast cancer. To date, however, relatively few studies have evaluated the association between MD and diet. In this cross-sectional study, we assessed the association between MD (measured using Boyd's semiquantitative scale with five categories: <10%, 10–25%, 25–50%, 50–75% and >75%) and diet (measured using a food frequency questionnaire validated in a Spanish population) among 3,548 peri- and postmenopausal women drawn from seven breast cancer screening programs in Spain. Multivariate ordinal logistic regression models, adjusted for age, body mass index (BMI), energy intake and protein consumption as well as other confounders, showed an association between greater calorie intake and greater MD [odds ratio (OR) = 1.23; 95% confidence interval (CI) = 1.10-1.38, for every increase of 500 cal/day], yet high consumption of olive oil was nevertheless found to reduce the prevalence of high MD (OR = 0.86;95% CI = 0.76-0.96, for every increase of 22 g/day in olive oil consumption); and, while greater intake of whole milk was likewise associated with higher MD (OR = 1.10; 95%CI 1.00-1.20, for every increase of 200 g/day), higher consumption of protein (OR = 0.89; 95% CI 0.80-1.00, for every increase of 30 g/day) and white meat (p for trend 0.041) was found to be inversely associated with MD. Our study, the largest to date to assess the association between diet and MD, suggests that MD is associated with modifiable dietary factors, such as calorie intake and olive oil consumption. These foods could thus modulate the prevalence of high MD, and important risk marker for breast cancer.

Vegetable protein and vegetable fat intakes in pre-adolescent and adolescent girls, and risk for benign breast disease in young women

Previous investigations, of adolescent diet recalled in adulthood, found lower risk for benign breast disease (BBD) with higher intakes of vegetable fat and nuts during high school. We investigate whether vegetable protein and fat, derived from diets reported during pre-adolescence and adolescence, are associated with subsequent risk for BBD in young women. The Growing Up Today Study includes 9,039 females, 9-15 years in 1996, who completed questionnaires annually through 2001, and then in 2003, 2005, 2007, and 2010. Food frequency questionnaires (1996-2001) obtained intake data on a variety of foods. Beginning in 2005, women (18-30 years) reported whether they had ever been diagnosed with BBD that was confirmed by breast biopsy (n = 112 cases). Logistic regression estimated associations between intakes of vegetable protein and fat and biopsy-confirmed BBD. Those individual foods that were the largest contributors of protein and fat in this cohort were also investigated. In analyses of intakes from 1996 through 1998, when our cohort was youngest, vegetable fat (OR = 0.72/(10 gm/day), 95 % CI 0.53-0.98; p = 0.04) was inversely associated with BBD risk. The greatest sources of vegetable fat and protein in these girls were peanut butter, peanuts, nuts, beans (beans, lentils, and soybeans), and corn. A daily serving of any one of these was associated with lower risk (OR = 0.32/(serv/day), 95 % CI 0.13-0.79; p = 0.01). Peanut butter (and nuts) at age 11 years was inversely associated with risk (p = 0.01). In analyses of intakes at age 14 years, vegetable protein was associated with lower BBD risk (OR = 0.64/(10 gm/day), 95 % CI 0.43-0.95; p = 0.03). A daily serving at 14 years of any one of the foods was associated with lower risk (OR = 0.34, 95 % CI 0.16-0.75; p = 0.01), as was peanut butter (and nuts) (p = 0.02). Girls with a family history of breast cancer had significantly lower risk if they consumed these foods or vegetable fat. In conclusion, consumption of vegetable protein, fat, peanut butter, or nuts by older girls may help reduce their risk of BBD as young women.

Invited commentary: are dietary intakes and other exposures in childhood and adolescence important for adult cancers?

In this issue of the Journal, Nimptsch et al. (Am J Epidemiol. 2013;178(2):172-183) report significant associations between female adolescents' poultry consumption in high school and subsequent reduced risk of colorectal adenomas in adulthood. Consumption of red meat or fish was not related to risk, but replacement with poultry reduced the risk of later adenomas. Most epidemiologic studies of adult diseases lack exposure data from the distant past. By focusing on a cancer precursor lesion and using a variety of methods to assess data quality, the investigators address concerns about the quality of distant recall. These findings add to the growing evidence that links childhood and adolescent lifestyle and environmental exposures with subsequent risk of cancers arising in adulthood. Highlights of the literature on this topic and methodological challenges are summarized. Future studies would benefit from incorporating measures of lifestyle, diet, environmental exposures, and other risk factors from early in life and from validation and other data quality checks of such measurements. Sources of historical data on children's and adolescents' exposures should be sought and evaluated in conjunction with subsequent exposures in relationship to adult-onset cancers.

Association between diet during preadolescence and adolescence and risk for breast cancer during adulthood

It is increasingly evident that diet during preadolescence and adolescence has important consequences for breast cancer during adulthood. However, only a few epidemiologic studies have been conducted on the relationship between diet during preadolescence and adolescence, and cancer during adulthood. This situation is partly because of methodological challenges such as the long latency period, the complexity of breast cancer, the lack of validated diet assessment tools, and the large number of subjects that must be followed, all of which increase costs. In addition, funding opportunities are few for such studies. Results from the small number of epidemiologic studies are inconsistent, but evidence is emerging that specific aspects of the diet during preadolescence and adolescence are important. For example, during preadolescence and adolescence, severe calorie restriction with poor food quality, high total fat intake, and alcohol intake tend to increase risk, whereas high soy intake decreases risk. Research on preadolescent and adolescent diet is a paradigm shift in breast cancer investigations. This research paradigm has the potential to produce transformative knowledge to inform breast cancer prevention strategies through dietary intervention during preadolescence and adolescence, rather than later in life, as is current practice, when it is perhaps less effective. Methodological challenges that have plagued the field might now be overcome by leveraging several existing large-scale cohort studies in the U.S. and around the world to investigate the role of diet during preadolescence and adolescence in risk for adult breast cancer.

Preadolescent and adolescent risk factors for benign breast disease

PURPOSE

It is well established that exposures during childhood and adolescence affect breast cancer risk much later in life. Recently, studies have begun to evaluate whether early life exposures might also impact the risk of developing benign breast disease (BBD). A diagnosis of proliferative BBD independent of other breast cancer risk factors also increases the subsequent risk of breast cancer; therefore, understanding how to decrease the incidence of BBD may have important implications for primary breast cancer prevention.

METHODS

We reviewed several studies from prospective cohort studies that have investigated the relationship between risk factors during childhood and adolescence, such as anthropometric and reproductive characteristics as well as diet and other behaviors, and subsequent risk of BBD.

RESULTS

Higher intake of vegetable oils, nuts, vitamin E, and fiber and lower consumption of animal fat, red meat, and alcohol are associated with reduced risk of BBD. Childhood weight and adolescent body mass index are inversely associated with BBD risk, whereas a greater peak height velocity during adolescence is associated with a higher risk of BBD. There was no association between age of menarche and risk of BBD.

CONCLUSION

Early life exposures and behaviors appear to impact BBD risk. The current body of evidence further supports the importance of a life-course approach to breast cancer prevention.

Dietary intake of vitamin D during adolescence and risk of adult-onset systemic lupus erythematosus and rheumatoid arthritis

OBJECTIVE

Vitamin D has immunomodulatory properties with potential etiologic implications for autoimmune diseases. The relevant exposure time during which vitamin D may influence disease risk is unknown. Our objective was to examine the relationship between reported vitamin D intake during adolescence and adult-onset rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) incidence in prospective cohort studies of women, the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHSII).

METHODS

Food frequency questionnaires concerning high school diet completed by 73,629 NHS (1986) and 45,544 NHSII (1998) participants were used to calculate nutrient intakes during adolescence. Incident RA and SLE cases prior to 2006 (NHS) and 2007 (NHSII) were confirmed by medical record review. Cox proportional hazards models calculated relative risks and 95% confidence intervals of incident RA and SLE according to quintile cutoffs of vitamin D intake. Age- and calorie-adjusted and multivariable-adjusted (including sun exposure factors) analyses were completed. Random-effects models were used to meta-analyze estimates of association from the 2 cohorts.

RESULTS

Incident RA was confirmed in 652 NHS and 148 NHSII participants and SLE was confirmed in 122 NHS and 54 NHSII participants over a mean followup time of 351 months (NHS) and 209 months (NHSII). Age- and calorie-adjusted and multivariable-adjusted models did not show significant associations between adolescent vitamin D intake and risk of adult-onset RA or SLE.

CONCLUSION

We did not find associations between adolescent dietary vitamin D intake and adult RA or SLE risk among NHS and NHSII women, suggesting that other time periods during the life course should be studied.

Applying what we know to accelerate cancer prevention

More than half of the cancer occurring today is preventable by applying knowledge that we already have. Tobacco, obesity, and physical inactivity are the modifiable causes of cancer that generate the most disease. Cancer burden can be reduced by alterations in individual and population behaviors and by public health efforts as long as these changes are driven by sound scientific knowledge and social commitment to change. The obstacles to these efforts are societal and arise from the organization of institutions, including academia, and in the habits of daily life. To achieve maximal possible cancer prevention, we will need better ways to implement what we know and improved infrastructure that will better incentivize and support transdisciplinary, multilevel research and successful intervention.

Adolescent intakes of vitamin D and calcium and incidence of proliferative benign breast disease

Vitamin D and calcium have been shown to have protective effects against breast cancer development in animal studies. Vitamin D and calcium play important anticarcinogenic roles in animal studies. Exposures between menarche and first birth may be important in breast development and future breast cancer risk. However, the relations between adolescent vitamin D and calcium intake and the risk of proliferative benign breast disease (BBD), a marker of increased breast cancer risk, have not yet been evaluated. We examined these associations in the Nurses' Health Study II. Among the 29,480 women who completed an adolescent diet questionnaire in 1998, 682 proliferative BBD cases were identified and confirmed by centralized pathology review between 1991 and 2001. Hazard ratios (HRs) and 95 % confidence intervals (CIs) were estimated by Cox proportional hazards regression and adjusted for potential confounders. A suggestive inverse association was observed between adolescent total vitamin D intake and proliferative BBD. Women in the highest quintile of vitamin D intake during adolescence had a 21 % lower risk (multivariate HR (95 % CI): 0.79 (0.61, 1.01), p-trend = 0.07) of proliferative BBD than women in the lowest quintile. Results were essentially the same when the analysis was restricted to prospective cases (n = 142) diagnosed after return of the adolescent diet questionnaire and independent of adult vitamin D intake. Adolescent total milk intake was positively associated with proliferative BBD (≥3 servings/day vs. <1 serving/day HR (95 % CI): 1.41 (0.91, 2.17), p-trend = 0.03), after additional adjustment for total vitamin D. Calcium intake during adolescence was not associated with proliferative BBD (p-trend = 0.91). Vitamin D intake during adolescence may be important in the earlier stage of breast carcinogenesis. These findings, if corroborated, may suggest new pathways and strategies for breast cancer prevention.

Intakes of alcohol and folate during adolescence and risk of proliferative benign breast disease

OBJECTIVES

To examine the combined effect of alcohol and folate intake during adolescence on the risk of proliferative benign breast disease (BBD).

METHODS

We used data from 29 117 women in the Nurses' Health Study II who completed both adolescent alcohol consumption questions in 1989 and an adolescent diet questionnaire in 1998. A total of 659 women with proliferative BBD diagnosed between 1991 and 2001 were confirmed by central pathology review. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals (CIs), adjusted for established risk factors of breast cancer.

RESULTS

Adolescent alcohol consumption was dose-dependently associated with an increased risk of proliferative BBD (hazard ratio = 1.15 per 10 g/day consumption; 95% CI, 1.03-1.28). There was no significant association between adolescent folate intake and the risk of proliferative BBD. Stratified analyses showed that each 10-g/day alcohol intake during adolescence was associated with a 21% (95% CI, 1.01-1.45) increase in the risk of proliferative BBD among women with low folate intake during adolescence, which was not significantly different from the alcohol-associated risk among women with moderate and high folate intake during adolescence (P for interaction = 0.18).

CONCLUSIONS

Adolescent alcohol consumption is associated with increased risk of proliferative BBD, which may not be reduced by increased folate intake during adolescence.