Association of Diet Quality and Breast Cancer Incidence in the Multiethnic Cohort (MEC)

Abstract Objectives Healthy eating patterns assessed by diet quality indexes (DQIs) have been related to lower risk of cancer incidence and mortality; however, the association between DQIs and breast cancer risk is still unclear. This study investigated the relation of DQIs with breast cancer incidence among diverse women from the Multiethnic Cohort (MEC). Methods At baseline (1993–1996), 101,291 female participants of five major racial/ethnic groups (African Americans, Native Hawaiians, Japanese Americans, Latinos and whites) aged 45–75 years completed a survey including a validated food frequency questionnaire. Scores for Healthy Eating Index 2015 (HEI-2015), Alternate Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean diet score (aMED), and Dietary Approaches to Stop Hypertension (DASH) score were calculated and divided into quintiles (Q1-Q5). Cox regression was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between DQIs and breast cancer risk, with adjustment for known risk factors including body mass index (BMI) among others. Results During a mean follow-up of 17.4 years, 7769 breast cancer cases were identified through linkage to tumor registries. The respective HRs for Q5 vs. Q1 were: 1.06 (95% CI, 0.98–1.14) for HEI-2015, 0.96 (95% CI, 0.90–1.04) for AHEI-2010, 1.01 (95% CI, 0.94–1.09) for aMED, and 0.95 (95% CI, 0.88–1.02) for DASH. No significant dose-response relations of DQIs with breast cancer risk were observed (all Ptrend ≥ 0.07). HRs analyzed by ethnic group also resulted in null findings with no significant dose-response relations and no significant Q5 vs. Q1 associations of DQIs with breast cancer risk (all Ptrend ≥ 0.14). For example, the respective HRs for the HEI-2015 by race/ethnicity were: 0.96 (95% CI, 0.81–1.14) for African Americans, 1.15 (95% CI, 0.90–1.46) for Native Hawaiians, 1.02 (95% CI, 0.89–1.17) for Japanese, 1.08 (95% CI, 0.88–1.33) for Latinas, and 1.08 (95% CI, 0.92–1.27) for whites. Conclusions Although adherence to DQIs was not associated with breast cancer risk overall or within racial/ethnic groups, nutrition remains important in breast cancer prevention as obesity, a strong modifiable risk factor, may be influenced by diet quality. Funding Sources This work was supported by grants from the National Cancer Institute.

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Aromatase and breast cancer susceptibility.

Endocrine Related Cancer ◽

10.1677/erc.0.0060165 ◽

1999 ◽

pp. 165-173 ◽

Cited By ~ 108

Author(s):

N M Probst-Hensch ◽

S A Ingles ◽

A T Diep ◽

R W Haile ◽

F Z Stanczyk ◽

...

Keyword(s):

Breast Cancer ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Latina Women ◽

Repeat Polymorphism ◽

Cyp19 Gene ◽

Functional Relevance

Based on experimental and epidemiological evidence it is hypothesized that estrogen increases breast cancer risk by increasing mitotic activity in breast epithelial cells. Aromatase is crucial to the biosynthesis of estrogens and may therefore play a role in breast cancer development. Supporting data for an etiological role of aromatase in breast tumor biology are several-fold. First, the association between weight and postmenopausal breast cancer risk may be mediated by aromatase. Secondly, a pilot study found a higher aromatase expression in normal breast adipose tissue from breast cancer cases as opposed to healthy women. Thirdly, experimental data in animals suggest that aromatase activity predisposes mammary tissue to preneoplastic and neoplastic changes. In a multiethnic cohort study conducted in Los Angeles and on Hawaii we investigated (i) whether the plasma estrone to androstenedione (E1/A) ratio in different ethnic groups was associated with ethnic differences in breast cancer incidence, and (ii) whether genetic variation in the CYP19 gene encoding the P450 aromatase protein was associated with breast cancer risk. The age- and weight-adjusted ethnic specific E1/A ratios x 100 among women without oophorectomy were 7.92 in African-Americans, 8.22 in Japanese, 10.73 in Latinas and 9.29 in non-Latina Whites (P=0.09). The high E1/A ratio in Latina women was not associated with a high breast cancer incidence; in fact Latina women had the lowest breast cancer incidence in the cohort observed so far. We found no consistent association of an intronic (TTTA)n repeat polymorphism with breast cancer risk in different ethnic groups. This polymorphism was not associated with differences in the plasma E1/A ratio in a way that would predict its functional relevance. We describe a newly identified TTC deletion in intron 5 of the CYP19 gene that is associated with the (TTTA)n repeat polymorphism. Neither this polymorphism, nor a polymorphism at codon 264 in exon VII of the CYP19 gene, was associated with breast cancer. We did not identify any genetic variation in exon VIII in 54 African-American subjects. We identified rare genetic variants of unknown functional relevance in the promoter 1.4 of the CYP19 gene in 3 out of 24 Latina women. Further investigation into the role of aromatase in breast cancer etiology is important, given that the potential use of aromatase inhibitors as breast cancer chemopreventives depends on these results.

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Could Recent Decreases in Breast Cancer Incidence Really Be Due to Lower HRT Use? Trends in Attributable Risk for Modifiable Breast Cancer Risk Factors in Canadian Women

Can J Public Health ◽

10.1007/bf03404862 ◽

2010 ◽

Vol 101 (5) ◽

pp. 405-409 ◽

Cited By ~ 18

Author(s):

C. Ineke Neutel ◽

Howard Morrison

Keyword(s):

Breast Cancer ◽

Risk Factors ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Attributable Risk ◽

Cancer Risk Factors ◽

Breast Cancer Risk Factors

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Sleep duration and breast cancer incidence: results from the Million Women Study and meta-analysis of published prospective studies

SLEEP ◽

10.1093/sleep/zsaa166 ◽

2020 ◽

Author(s):

Angel T Y Wong ◽

Alicia K Heath ◽

Tammy Y N Tong ◽

Gillian K Reeves ◽

Sarah Floud ◽

...

Keyword(s):

Breast Cancer ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Sleep Duration ◽

Cancer Incidence ◽

Prospective Studies ◽

Average Duration ◽

Meta Analysis ◽

Breast Cancer Incidence ◽

Weighted Average

Abstract Study Objectives To investigate the association between sleep duration and breast cancer incidence, we examined the association in a large UK prospective study and conducted a meta-analysis of prospective studies. Methods In the Million Women Study, usual sleep duration over a 24-h period was collected in 2001 for 713,150 participants without prior cancer, heart problems, stroke, or diabetes (mean age = 60 years). Follow-up for breast cancer was by record linkage to national cancer registry data for 14.3 years on average from the 3-year resurvey. Cox regression models yielded multivariable-adjusted breast cancer relative risks (RR) and 95% confidence intervals (CIs) for sleep duration categories. Published prospective studies of sleep duration and breast cancer risk were included in a meta-analysis, which estimated the inverse-variance weighted average of study-specific log RRs for short and for long versus average duration sleep. Results After excluding the first 5 years to minimize reverse causation bias in the Million Women Study, 24,476 women developed breast cancer. Compared with 7–8 h of sleep, the RRs for <6, 6, 9, and >9 h of sleep were 1.01 (95% CI, 0.95–1.07), 0.99 (0.96–1.03), 1.01 (0.96–1.06), and 1.03 (0.95–1.12), respectively. In a meta-analysis of 14 prospective studies plus the Million Women Study, including 65,410 breast cancer cases, neither short (RR < 7 h = 0.99 [0.98–1.01]) nor long (RR > 8 h = 1.01 [0.98–1.04]) versus average duration sleep was associated with breast cancer risk. Conclusions The totality of the prospective evidence does not support an association between sleep duration and breast cancer risk.

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Risk-Reducing Salpingo-Oophorectomy and Breast Cancer Risk Reduction in the Gynecologic Oncology Group Protocol-0199 (GOG-0199)

JNCI Cancer Spectrum ◽

10.1093/jncics/pkz075 ◽

2019 ◽

Vol 4 (1) ◽

Cited By ~ 2

Author(s):

Phuong L Mai ◽

Austin Miller ◽

Mitchell H Gail ◽

Steven Skates ◽

Karen Lu ◽

...

Keyword(s):

Breast Cancer ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Incidence Rates ◽

Pathogenic Variant ◽

Risk Reducing ◽

Cancer Risk Reduction

Abstract Background Risk-reducing salpingo-oophorectomy (RRSO) has been associated with approximately 50% breast cancer risk reduction among women with a pathogenic variant in BRCA1 or BRCA2 (BRCA1/2), a finding that has recently been questioned. Methods We estimated incidence rates of breast cancer and all cancers combined during 5 years of follow-up among participants selecting RRSO or ovarian cancer screening (OCS) among women with a BRCA1/2 pathogenic variant or strong breast and/or ovarian cancer family history. Ovarian or fallopian tube or peritoneal cancer incidence rates were estimated for the OCS group. Breast cancer hazard ratios (HRs) for time-dependent RRSO were estimated using Cox regression with age time-scale (4943 and 4990 women-years in RRSO and OCS cohorts, respectively). All statistical tests were two-sided. Results The RRSO cohort included 925 participants, and 1453 participants were in the OCS cohort (381 underwent RRSO during follow-up), with 88 incident breast cancers diagnosed. Among BRCA1/2 pathogenic variant carriers, a non-statistically significant lower breast cancer incidence was observed in the RRSO compared with the OCS cohort (HR = 0.86, 95% confidence interval = 0.45 to 1.67; P = .67). No difference was observed in the overall population or among subgroups stratified by prior breast cancer history or menopausal status. Seven fallopian tube and four ovarian cancers were prospectively diagnosed in the OCS cohort, and one primary peritoneal carcinoma occurred in the RRSO cohort. Conclusions These data suggest that RRSO might be associated with reduced breast cancer incidence among women with a BRCA1/2 pathogenic variant, although the effect, if present, is small. This evolving evidence warrants a thorough discussion regarding the impact of RRSO on breast cancer risk with women considering this intervention.

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Metformin and breast cancer risk: A meta-analysis and critical literature review.

Journal of Clinical Oncology ◽

10.1200/jco.2012.30.27_suppl.25 ◽

2012 ◽

Vol 30 (27_suppl) ◽

pp. 25-25

Author(s):

Nananda Col ◽

Leslie Ochs ◽

Vicky Springmann ◽

Aaron K Aragaki ◽

Rowan T. Chlebowski

Keyword(s):

Breast Cancer ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Literature Review ◽

Cancer Incidence ◽

Invasive Breast Cancer ◽

Meta Analysis ◽

Breast Cancer Incidence ◽

Cochrane Library ◽

Study Quality

25 Background: Observational studies have suggested that metformin, commonly used for diabetes treatment that increases insulin sensitivity and improves glycemic control, decreases the incidence of several common cancers. However, findings regarding metformin and breast cancer incidence have been mixed. To explore this issue, a systematic literature review and meta-analysis were performed with a focus on potential biases. Methods: We conducted a comprehensive literature search for all pertinent studies addressing metformin use and breast cancer risk by searching Pub Med, Cochrane Library, Scopus (which includes Embase, ISI Web of Science) using the Mesh terms: "metformin" or "biguanides" or "diabetes mellitus, type 2/therapy" and "cancer" or "neoplasms". When multiple hazard ratios (HR) or odds ratio (OR) were reported, the most adjusted estimate was used in the base-case analysis. We pooled the adjusted HR using and performed sensitivity analyses on duration of metformin use (> or < 3 years use), study quality (assessed using the GRADE system), and initial observation year of the cohort (before vs after 1997). Results: From a total of 421 citations, 13 full-text articles were considered, and 7 independent studies were included. All were observational (4 cohort and 3 case control). Our combined OR for metformin association with invasive breast cancer of all 7 studies was 0.83 (95% CI, 0.71-0.97). Funnel plot analyses did not suggest publication bias. Stronger associations were found when analyses were limited to studies estimating the impact of longer metformin duration (OR = 0.75. 95% CI, 0.62-0.91) or among studies that began observing their cohort before 1997 (OR=0.68. 95% CI, 0.55-0.84). Stratification according to study quality did not affect the combined OR but higher quality studies had smaller CI and achieved statistical significance. Interpretation is limited by the observational nature of reports and different comparison groups. Conclusions: Our analyses support a protective effect of metformin on invasive breast cancer incidence among postmenopausal women with diabetes. Clinical trials are needed to determine whether metformin reduces breast cancer risk.

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Arsenic Exposure and Breast Cancer Risk: A Re-Evaluation of the Literature

Nutrients ◽

10.3390/nu12113305 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3305

Author(s):

Katherine Pullella ◽

Joanne Kotsopoulos

Keyword(s):

Breast Cancer ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Arsenic Exposure ◽

Epidemiologic Studies ◽

Environmental Toxins ◽

The Public

Arsenic is a widespread environmental contaminant and recognized carcinogen for the skin, bladder and lungs. In recent years, there has been an increasing number of studies that have investigated the effects of arsenic exposure and cancer risk at other sites, including the breast. However, to date, the association between arsenic exposure and breast cancer risk remains unclear. This article will provide an overview of arsenic metabolism, the clinically important biomarkers commonly used to assess arsenic exposure, and review the epidemiologic studies examining the role of arsenic exposure on breast cancer risk. Given the large burden of disease associated with breast cancer, it is of the upmost importance to identify risk factors and preventative strategies that could reduce cancer incidence. Limiting exposure to endemic environmental toxins, such as arsenic, represents one such strategy. More studies are required to better ascertain this relationship and to develop the public policy necessary to significantly reduce breast cancer incidence.

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Physical activity and risk of postmenopausal breast cancer defined by hormone receptor status and histology: A large prospective cohort study with 18 years of follow up

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.1002 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 1002-1002 ◽

Cited By ~ 1

Author(s):

A. Bardia ◽

A. H. Wang ◽

L. C. Hartmann ◽

J. E. Olson ◽

C. M. Vachon ◽

...

Keyword(s):

Breast Cancer ◽

Physical Activity ◽

Risk Factors ◽

Cohort Study ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Histological Subtypes

1002 Background: Physical activity is a modifiable breast cancer risk factor, perhaps mediating risk reduction through regulation of estrogen metabolism. Evidence regarding effect of physical activity is conflicting partly because breast cancer is a heterogenous constellation of different tumor subtypes with differing etiologies. No prospective study has examined the relationship between physical activity and breast cancer incidence based on ER/PR status or histological subtype. Objective: Examine effect of physical activity on breast cancer incidence based on ER/PR status and histological subtypes of breast cancer. Methods: The Iowa Women’s Health Study is a prospective cohort study of postmenopausal women (N=41,837). Physical activity was self-reported on baseline questionnaire, and three levels (high, medium and low) were defined. Breast cancer incidence, histologic subtype and ER/PR status, through 18 years of follow-up, were ascertained by linkage with the Iowa SEER Cancer Registry. Cox proportional hazards models were used to estimate multivariate relative risks (RRs) and 95% confidence intervals (CIs) of breast cancer, adjusting for other breast cancer risk factors. Results: During 554,819 person-years of follow-up, 2548 incident cases of breast cancer were observed. High physical activity was associated with decreased risk for breast cancer (RR 0.91, 95 % CI 0.81–1.01) compared to low activity. The protective effect was most marked in ER+/PR− (RR 0.66, CI 0.46–0.94), intermediate in ER−/PR− (RR 0.80, CI 0.56–1.15), weakest in ER+/PR+ (RR 0.94, CI 0.81–1.08), and elevated in ER-/PR+ (RR 1.42, CI 0.67–3.01) tumors. Higher physical activity was also associated with a decreased risk of invasive ductal/lobular carcinoma (RR 0.90, CI 0.80–1.02), but not with invasive breast cancer with a favorable histology (RR 1.19, CI 0.78–1.81). Conclusions: Higher physical activity was associated with a 10% decreased risk of breast cancer. Unexpectedly, risk reduction was most marked in PR- tumors, particularly ER+/PR-, and the more aggressive histologic forms. Further studies are needed to confirm these findings, and also evaluate other risk factors based on ER/PR status and histological subtypes. No significant financial relationships to disclose.

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Redefining the impact of nutrition on breast cancer incidence: is epigenetics involved?

Nutrition Research Reviews ◽

10.1017/s0954422411000199 ◽

2012 ◽

Vol 25 (1) ◽

pp. 68-95 ◽

Cited By ~ 29

Author(s):

Dorothy Teegarden ◽

Isabelle Romieu ◽

Sophie A. Lelièvre

Keyword(s):

Breast Cancer ◽

Gene Expression ◽

Dna Methylation ◽

Breast Cancer Risk ◽

Cancer Risk ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Dietary Factors ◽

Transcription Control ◽

The Impact

Breast cancer incidence is rising worldwide with an increase in aggressive neoplasias in young women. Possible factors involved include lifestyle changes, notably diet that is known to make an impact on gene transcription. However, among dietary factors, there is sufficient support for only greater body weight and alcohol consumption whereas numerous studies revealing an impact of specific diets and nutrients on breast cancer risk show conflicting results. Also, little information is available from middle- and low-income countries. The diversity of gene expression profiles found in breast cancers indicates that transcription control is critical for the outcome of the disease. This suggests the need for studies on nutrients that affect epigenetic mechanisms of transcription, such as DNA methylation and post-translational modifications of histones. In the present review, a new examination of the relationship between diet and breast cancer based on transcription control is proposed in light of epidemiological, animal and clinical studies. The mechanisms underlying the impact of diets on breast cancer development and factors that impede reaching clear conclusions are discussed. Understanding the interaction between nutrition and epigenetics (gene expression control via chromatin structure) is critical in light of the influence of diet during early stages of mammary gland development on breast cancer risk, suggesting a persistent effect on gene expression as shown by the influence of certain nutrients on DNA methylation. Successful development of breast cancer prevention strategies will require appropriate models, identification of biological markers for rapid assessment of preventive interventions, and coordinated worldwide research to discern the effects of diet.

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