Alcohol consumption and the risk of breast cancer among BRCA1 and BRCA2 mutation carriers

A 14-Year Analysis of Breast Cancer Risk Factors and Its Determinants of Mortality in Rural Southwestern Nigeria

Background

Research on breast cancer risk factors and mortality is gaining recognition and attention globally; there is need to add more information on its determinants among patients admitted in hospital. Some studies on risk factors and mortality of breast cancer in Nigeria hospitals conducted in the urban and suburban areas have been documented. Therefore, an addition of a study conducted in the setting of a rural health institution is necessary. This study assessed the risk factors and determinants of mortality among patients admitted for breast cancer in rural Southwestern Nigeria.

Methods

A retrospective observational study was conducted on 260 patients who were admitted for breast cancer between January 2010 and December 2023 using a data form and a standardized information form. The data were analyzed using SPSS version 22.0. The risk factors and the determinants of mortality of patients with breast cancer were identified using multivariate regression model.

Results

The breast cancer risk factors were old age, family history, tobacco smoking, combined oral contraceptives, and hormonal therapy use. The case fatality rate was 38.1%, and its determinants of mortality were patients who were older (adjusted odds ratio [AOR], 1.956; 95% confidence interval [CI]:1.341-4.333), obese (AOR, 2.635; 95% CI: 1.485-6.778), stage IV (AOR, 1.895; 95% CI: 1.146-8.9742), mastectomy (AOR, 2.512; 95% CI: 1.003-6.569), discontinued adjuvant chemotherapy (AOR, 1.785; 95% CI: 1.092-4.6311), and yet to commence adjuvant chemotherapy (AOR, 2.568; 95% CI: 1.367-5.002).

Conclusion

The study revealed that patients with breast cancer were associated with high mortality. Sustained health education to promote early diagnosis, managed co-morbidities, and access to treatment may contribute to reduction in breast cancer mortality in rural Nigeria.

Lifestyle Factors and Breast Cancer in Females with PTEN Hamartoma Tumor Syndrome (PHTS)

Females with PTEN Hamartoma Tumor Syndrome (PHTS) have breast cancer risks up to 76%. This study assessed associations between breast cancer and lifestyle in European female adult PHTS patients. Data were collected via patient questionnaires (July 2020-March 2023) and genetic diagnoses from medical files. Associations between lifestyle and breast cancer were calculated using logistic regression corrected for age. Index patients with breast cancer before PHTS diagnosis (breast cancer index) were excluded for ascertainment bias correction. In total, 125 patients were included who completed the questionnaire at a mean age of 44 years (SD = 13). This included 21 breast cancer indexes (17%) and 39 females who developed breast cancer at 43 years (SD = 9). Breast cancer patients performed about 1.1 times less often 0-1 times/week physical activity than ≥2 times (ORtotal-adj = 0.9 (95%CI 0.3-2.6); consumed daily about 1.2-1.8 times more often ≥1 than 0-1 glasses of alcohol (ORtotal-adj = 1.2 (95%CI 0.4-4.0); ORnon-breastcancer-index-adj = 1.8 (95%CI 0.4-6.9); were about 1.04-1.3 times more often smokers than non-smokers (ORtotal-adj = 1.04 (95%CI 0.4-2.8); ORnon-breastcancer-index-adj = 1.3 (95%CI 0.4-4.2)); and overweight or obesity (72%) was about 1.02-1.3 times less common (ORtotal-adj = 0.98 (95%CI 0.4-2.6); ORnon-breastcancer-index-adj = 0.8 (95%CI 0.3-2.7)). Similar associations between lifestyle and breast cancer are suggested for PHTS and the general population. Despite not being statistically significant, results are clinically relevant and suggest that awareness of the effects of lifestyle on patients' breast cancer risk is important.

Modifiable risk factors in women at high risk of breast cancer: a systematic review

BACKGROUND

Modifiable risk factors (alcohol, smoking, obesity, hormone use, and physical activity) affect a woman's breast cancer (BC) risk. Whether these factors affect BC risk in women with inherited risk (family history, BRCA1/2 mutations, or familial cancer syndrome) remains unclear.

METHODS

This review included studies on modifiable risk factors for BC in women with inherited risk. Pre-determined eligibility criteria were used and relevant data were extracted.

RESULTS

The literature search resulted in 93 eligible studies. For women with family history, most studies indicated that modifiable risk factors had no association with BC and some indicated decreased (physical activity) or increased risk (hormonal contraception (HC)/menopausal hormone therapy (MHT), smoking, alcohol). For women with BRCA mutations, most studies reported no association between modifiable risk factors and BC; however, some observed increased (smoking, MHT/HC, body mass index (BMI)/weight) and decreased risk (alcohol, smoking, MHT/HC, BMI/weight, physical activity). However, measurements varied widely among studies, sample sizes were often small, and a limited number of studies existed.

CONCLUSIONS

An increasing number of women will recognize their underlying inherited BC risk and seek to modify that risk. Due to heterogeneity and limited power of existing studies, further studies are needed to better understand how modifiable risk factors influence BC risk in women with inherited risk.

Bewertung des Rotweinkonsums im Rahmen der mediterranen Ernährung – Eine systematische Literaturanalyse

Hintergrund Die mediterrane Ernährung (MedE) zeigte in mehreren Studien einen präventiven Effekt hinsichtlich Typ 2 Diabetes, kardiovaskulären Erkrankungen und Tumorerkrankungen. Zur MedE wird in der Regel ein mäßiger Konsum von Wein, speziell Rotwein, empfohlen, dem selbst ein kardioprotektiver Effekt zugesprochen wird. Jedoch zeigen zahlreiche Studien, dass schon kleine Mengen Alkohol das Krebsrisiko erhöhen können. In der vorliegenden Arbeit soll eine Übersicht zur aktuellen Datenlage zum Zusammenhang zwischen dem Alkoholkonsum im Rahmen einer MedE, dem Krebsrisiko sowie dem Risiko für kardiovaskuläre Erkrankungen erstellt werden.

Methoden Im Rahmen einer systematischen Literaturrecherche in den Datenbanken PubMed und Scopus wurde nach den Schlagwörtern „diet, mediterranean“ und „alcohol drinking“ gesucht. Voraussetzung war, dass Angaben zur Art und Menge des konsumierten Alkohols im Rahmen der MedE vorlagen.

Ergebnisse Die Umsetzung der MedE kann sowohl das Risiko kardiometabolischer Erkrankungen als auch das Krebsrisiko u. a. für Brustkrebs senken. Moderater Alkoholkonsum zeigt protektive Effekte auf das Herz-Kreislauf-System, ist jedoch mit einem erhöhten Risiko für diverse Krebserkrankungen assoziiert. Mehrere Studien beschreiben eine Assoziation zwischen Alkoholkonsum und Brustkrebsinzidenz, wobei die Ergebnisse zwischen den Studien nicht einheitlich waren. Dabei kommt dem täglichen Glas Rotwein mit ca. 10–15 g Ethanol als vorherrschendem alkoholischen Getränk der Mittelmeerregion eine risikosenkende Wirkung zu.

Schlussfolgerung Moderater Konsum von Rotwein hat nach der vorliegenden systematischen Literaturanalyse, anders als andere alkoholische Getränke, einen protektiven Effekt auf kardiometabolische Erkrankungen und möglicherweise auch auf genetisch bedingten Brustkrebs, während der Konsum von anderen Alkoholgetränken die schützende Wirkung einer MedE möglicherweise reduziert.

Diet, weight management, physical activity and Ovarian & Breast Cancer Risk in women with BRCA1/2 pathogenic Germline gene variants: systematic review

Introduction

Women with pathogenic germline gene variants in BRCA1 and/or BRCA2 are at increased risk of developing ovarian and breast cancer. While surgical and pharmacological approaches are effective for risk-reduction, it is unknown whether lifestyle approaches such as healthful dietary habits, weight management, and physical activity may also contribute to risk-reduction. We conducted a systematic review of evidence related to dietary habits, weight status/change, and physical activity on ovarian and breast cancer risk among women with BRCA1/2 pathogenic variants.

Methods

We searched Medline, EMBASE, CENTRAL, PubMed, and clinicaltrials.gov up to October 3, 2019. We identified 2775 records and included 21.

Results

There is limited evidence related to these factors and ovarian cancer risk. For breast cancer risk, evidence suggests higher diet quality, adulthood weight-loss of ≥10 pounds, and activity during adolescence and young-adulthood may be linked with decreased risk. Higher meat intake and higher daily energy intake may be linked with increased risk.

Conclusions

There is not enough evidence to suggest tailored recommendations for dietary habits or weight management among women with BRCA1/2 pathogenic variants compared to the general population for ovarian and breast cancer risk-reduction, and physical activity recommendations should remain the same.

Alcohol Consumption, Cigarette Smoking, and Risk of Breast Cancer for BRCA1 and BRCA2 Mutation Carriers: Results from The BRCA1 and BRCA2 Cohort Consortium

BACKGROUND

Tobacco smoking and alcohol consumption have been intensively studied in the general population to assess their effects on the risk of breast cancer, but very few studies have examined these effects in BRCA1 and BRCA2 mutation carriers. Given the high breast cancer risk for mutation carriers and the importance of BRCA1 and BRCA2 in DNA repair, better evidence on the associations of these lifestyle factors with breast cancer risk is essential.

METHODS

Using a large international pooled cohort of BRCA1 and BRCA2 mutation carriers, we conducted retrospective (5,707 BRCA1 mutation carriers and 3,525 BRCA2 mutation carriers) and prospective (2,276 BRCA1 mutation carriers and 1,610 BRCA2 mutation carriers) analyses of alcohol and tobacco consumption using Cox proportional hazards models.

RESULTS

For both BRCA1 and BRCA2 mutation carriers, none of the smoking-related variables was associated with breast cancer risk, except smoking for more than 5 years before a first full-term pregnancy (FFTP) when compared with parous women who never smoked. For BRCA1 mutation carriers, the HR from retrospective analysis (HRR) was 1.19 [95% confidence interval (CI), 1.02-1.39] and the HR from prospective analysis (HRP) was 1.36 (95% CI, 0.99-1.87). For BRCA2 mutation carriers, smoking for more than 5 years before an FFTP showed an association of a similar magnitude, but the confidence limits were wider (HRR = 1.25; 95% CI, 1.01-1.55 and HRP = 1.30; 95% CI, 0.83-2.01). For both carrier groups, alcohol consumption was not associated with breast cancer risk.

CONCLUSIONS

The finding that smoking during the prereproductive years increases breast cancer risk for mutation carriers warrants further investigation.

IMPACT

This is the largest prospective study of BRCA mutation carriers to assess these important risk factors.

The Mediterranean Diet and Breast Cancer: A Personalised Approach

There have been many original and review articles summarizing the impact of nutrition and diet on breast cancer risk. However, very few consider the implication of genetic background and the effect of personalised nutrition on the risk and prognosis of breast cancer. A literature search was performed using the following databases: MEDLINE (Ovid), PubMed, Scopus and EMBASE (Ovid). The ensuing search terms were selected: genomics, nutrigenomics, breast cancer, breast neoplasms, cancer, nutrigenetics, diet-gene interaction, and Mediterranean, nutrition, polyphenols and diet. In this review, we discuss the Mediterranean-style diet and associated nutrients, evidence of benefit, impact on gene expression and evidence of interactions with genotype and how this interaction can modify breast cancer risk and progression. In addition, the impact of nutrients commonly associated with a Mediterranean-style diet, on breast cancer treatment, and synergistic effects are mentioned when modified by genotype. Some evidence exists around the benefit of a gene-based personalised diet based on a Mediterranean-style dietary pattern, but further evidence in the form of clinical trials is required before such an approach can be comprehensively implemented.

BRCA Mutations and Breast Cancer Prevention

Women who inherit a deleterious BRCA1 or BRCA2 mutation face substantially increased risks of developing breast cancer, which is estimated at 70%. Although annual screening with magnetic resonance imaging (MRI) and mammography promotes the earlier detection of the disease, the gold standard for the primary prevention of breast cancer remains bilateral mastectomy. In the current paper, I review the evidence regarding the management of healthy BRCA mutation carriers, including key risk factors and protective factors, and also discuss potential chemoprevention options. I also provide an overview of the key findings from the literature published to date, with a focus on data from studies that are well-powered, and preferably prospective in nature.

Epidemiology of Moderate Alcohol Consumption and Breast Cancer: Association or Causation?

Epidemiological studies have been used to show associations between modifiable lifestyle habits and the incidence of breast cancer. Among such factors, a history of alcohol use has been reported in multiple studies and meta-analyses over the past decades. However, associative epidemiological studies that were interpreted as evidence that even moderate alcohol consumption increases breast cancer incidence have been controversial. In this review, we consider the literature on the relationship between moderate or heavy alcohol use, both in possible biological mechanisms and in variations in susceptibility due to genetic or epigenetic factors. We argue that there is a need to incorporate additional approaches to move beyond the associations that are reported in traditional epidemiological analyses and incorporate information on molecular pathologic signatures as a requirement to posit causal inferences. In particular, we point to the efforts of the transdisciplinary field of molecular pathological epidemiology (MPE) to evaluate possible causal relationships, if any, of alcohol consumption and breast cancer. A wider application of the principles of MPE to this field would constitute a giant step that could enhance our understanding of breast cancer and multiple modifiable risk factors, a step that would be particularly suited to the era of "personalized medicine".

Dose-Dependent Associations between Wine Drinking and Breast Cancer Risk - Meta-Analysis Findings

PURPOSE

To investigate any potential association between wine and breast cancer risk.

MATERIALS AND METHODS

We quantitatively assessed associations by conducting a meta-analysis based on evidence from observational studies. In May 2014, we performed electronic searches in PubMed, EmBase and the Cochrane Library to identify studies examining the effect of wine drinking on breast cancer incidence. The relative risk (RR) or odds ratio (OR) were used to measure any such association.

RESULTS

The analysis was further stratified by confounding factors that could influence the results. A total of twenty-six studies (eight case-control and eighteen cohort studies) involving 21,149 cases were included in our meta-analysis. Our study demonstrated that wine drinking was associated with breast cancer risk. A 36% increase in breast cancer risk was observed across overall studies based on the highest versus lowest model, with a combined RR of 1.0059 (95%CI 0.97-1.05) in dose-response analysis. However, 5 g/d ethanol from wine seemed to have protective value from our non-linear model.

CONCLUSIONS

Our findings indicate that wine drinking is associated with breast cancer risk in a dose-dependent manner. High consumption of wine contributes to breast cancer risk with protection exerted by low doses. Further investigations are needed for clarification.

Prospective evaluation of alcohol consumption and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

Given the adverse effect of alcohol in the development of breast cancer among women in the general population, we evaluated whether a similar association exists among women with a BRCA1 or BRCA2 mutation. Information regarding baseline daily alcohol consumption was abstracted from a research questionnaire for 3067 BRCA mutation carriers enrolled in a prospective cohort study. Women were followed biennially until the date of the last follow-up questionnaire, date of breast cancer diagnosis, date of prophylactic bilateral mastectomy, or date of death. Cox proportional hazards models were used to estimate relative risks (RRs) and 95 % confidence intervals (CIs) for invasive breast cancer associated with alcohol consumed at or prior to completion of the baseline questionnaire. After a mean of 5.4 years of follow-up, we observed 259 incident cases of primary invasive breast cancer. Compared with non-users, the adjusted RRs were 1.06 (95 % CI 0.78-1.44) for ever use and 1.08 (0.79-1.47) for current alcohol use. For women in the highest versus lowest quintile of cumulative alcohol consumption, the RR was 0.94 (95 % CI 0.63-1.40; P trend = 0.65). Our findings suggest that alcohol consumption is not a risk factor for breast cancer among women with a BRCA1 or BRCA2 mutation.

Alcohol and breast cancer: reconciling epidemiological and molecular data

Breast cancer is the most diagnosed cancer in women worldwide. Epidemiological studies have suggested a possible causative role of alcohol consumption as a risk factor for breast cancer. However, such conclusions should be interpreted with considerable caution for several reasons. While epidemiological studies can help identify the roots of health problems and disease incidence in a community, they are by necessity associative and cannot determine cause and effect relationships. In addition, all these studies rely on self-reporting to determine the amount and type of alcoholic beverage consumed, which introduces recall bias. This is documented in a recent study which stated that the apparent increased risk of cancer among light-moderate drinkers may be "substantially due to underreporting of intake." Another meta-analysis about alcohol and breast cancer declared "the modest size of the association and variation in results across studies leave the causal role of alcohol in question." Furthermore, breast cancer develops over decades; thus, correlations between alcohol consumption and breast cancer cannot be determined in epidemiological studies with windows of alcohol exposure that captures current or recent alcohol intake, after clinical diagnosis. Numerous risk factors are involved in breast carcinogenesis; some are genetic and beyond the control of a woman; others are influenced by lifestyle factors. Breast cancer is a heterogeneous and polygenic disease which is further influenced by epigenetic mechanisms that affect the transciptomes, proteomes and metabolomes, and ultimately breast cancer evolution. Environmental factors add another layer of complexity by their interactions with the susceptibility genes for breast cancer and metabolic diseases. The current state-of-knowledge about alcohol and breast cancer association is ambiguous and confusing to both a woman and her physician. Confronting the huge global breast cancer issue should be addressed by sound science. It is advised that women with or without a high risk for breast cancer should avoid overconsumption of alcohol and should consult with their physician about risk factors involved in breast cancer. Since studies associating moderate alcohol consumption and breast cancer are contradictory, a woman and her physician should weigh the risks and benefits of moderate alcohol consumption.

Modifiers of cancer risk in BRCA1 and BRCA2 mutation carriers: systematic review and meta-analysis

BACKGROUND

There is substantial variability in cancer risk in women who have inherited a BRCA1 or BRCA2 (BRCA1/2) mutation. Numerous factors have been hypothesized to modify these risks, but studies are of variable quality, and it remains unclear which of these may be of value in clinical risk assessment.

METHODS

PubMed and Web of Science databases were searched for articles published through September 2013. Fixed effects meta-analysis was done using the hazard ratios and/or odds ratios to estimate the pooled effect estimates (ES) and 95% confidence intervals (CIs) to identify factors that are associated with cancer risk modification in BRCA1/2 mutation carriers.

RESULTS

We identified 44 nonoverlapping studies that met predefined quality criteria. Sufficient evidence is available to make clinically relevant inferences about a number of cancer risk modifiers. The only variable examined that produced a probable association was late age at first live birth, a meta-analysis showed a decrease in the risk of breast cancer in BRCA1 mutation carriers with women aged 30 years or older vs. women younger than 30 years (ES = 0.65; 95% CI =0.42 to 0.99). The same was shown for women aged 25 to 29 years versus those aged less than 25 years (ES = 0.69; 95% CI = 0.48 to 0.99). Breastfeeding and tubal ligation were associated with reduced ovarian cancer risk in BRCA1 mutation carriers; oral contraceptives were associated with reduced risk among BRCA1/2 mutation carriers. Smoking was associated with increased breast cancer risk in BRCA2 mutation carriers only.

CONCLUSIONS

Data assessing many potential risk modifiers are inadequate, and many have not been externally validated. Although additional studies are required to confirm some associations, sufficient information is available for some risk factors to be used in risk counseling or lifestyle modification to minimize cancer risk in BRCA1/2 mutation carriers

Alcohol Intake and Breast Cancer Risk: Weighing the Overall Evidence

Moderate alcohol consumption has been linked to an approximate 30-50% increased risk in breast cancer. Case-control and cohort studies have consistently observed this modest increase. We highlight recent evidence from molecular epidemiologic studies and studies of intermediate markers like mammographic density that provide additional evidence that this association is real and not solely explained by factors/correlates of the exposure and outcome present in non-randomized studies. We also review evidence from studies of higher risk women including BRCA1 and BRCA2 mutation carriers. Given the incidence of heart disease is higher than breast cancer and modest alcohol consumption is associated with reduced risk of heart disease, we examine the latest evidence to evaluate if alcohol reduction should be targeted to women at high risk for breast cancer. We also review the most recent evidence on the effect of alcohol use on tumor recurrence and survival for those diagnosed with breast cancer.

Breast cancer risk factors differ between Asian and white women with BRCA1/2 mutations

The prevalence and penetrance of BRCA1 and BRCA2 (BRCA1/2) mutations may differ between Asians and whites. We investigated BRCA1/2 mutations and cancer risk factors in a clinic-based sample. BRCA1/2 mutation carriers were enrolled from cancer genetics clinics in Hong Kong and California according to standardized entry criteria. We compared BRCA mutation position, cancer history, hormonal and reproductive exposures. We analyzed DNA samples for single-nucleotide polymorphisms reported to modify breast cancer risk. We performed logistic regression to identify independent predictors of breast cancer. Fifty Asian women and forty-nine white American women were enrolled. BRCA1 mutations were more common among whites (67 vs. 42 %, p = 0.02), and BRCA2 mutations among Asians (58 vs. 37 %, p = 0.04). More Asians had breast cancer (76 vs. 53 %, p = 0.03); more whites had relatives with breast cancer (86 vs. 50 %, p = 0.0003). More whites than Asians had breastfed (71 vs. 42 %, p = 0.005), had high BMI (median 24.3 vs. 21.2, p = 0.04), consumed alcohol (2 drinks/week vs. 0, p < 0.001), and had oophorectomy (61 vs. 34 %, p = 0.01). Asians had a higher frequency of risk-associated alleles in MAP3K1 (88 vs. 59 %, p = 0.005) and TOX3/TNRC9 (88 vs. 55 %, p = 0.0002). On logistic regression, MAP3K1 was associated with increased breast cancer risk for BRCA2, but not BRCA1 mutation carriers; breast density was associated with increased risk among Asians but not whites. We found significant differences in breast cancer risk factors between Asian and white BRCA1/2 mutation carriers. Further investigation of racial differences in BRCA1/2 mutation epidemiology could inform targeted cancer risk-reduction strategies.

Diet and breast cancer: understanding risks and benefits

BACKGROUND

Breast cancer is the most commonly diagnosed cancer among women in the United States. Extensive research has been completed to evaluate the relationship between dietary factors and breast cancer risk and survival after breast cancer; however, a summary report with clinical inference is needed. Materials and

METHODS

This review summarizes the current epidemiological and clinical trial evidence relating diet to breast cancer incidence, recurrence, survival, and mortality. The review includes emerging epidemiological studies that assess risk within breast cancer subtypes as well as a summary of previous and ongoing dietary intervention trials designed to modify breast cancer risk.

RESULTS

The available literature suggests that both low-fat and high-fiber diets may be weakly protective against breast cancer, whereas total energy intake and alcohol appear to be positively associated. Fiber may be weakly protective possibly through modulation of estrogen, whereas fruit and vegetable intake is not clearly associated with risk. Obesity is a risk factor for postmenopausal disease, and adult weight gain should be avoided to reduce risk. In survivors, diet has the greatest potential influence on overall mortality rather than breast cancer-specific events.

CONCLUSION

Diet is modestly associated with breast cancer risk; associations appear more pronounced for postmenopausal disease, and healthy choices after diagnosis and treatment likely support longevity more so than reduced risk for recurrent disease.

Breast cancer in the Arctic--changes over the past decades

The purpose of this study is to review the current literatures on breast cancer (BC) in the Arctic, especially the trends in incidence during the last decades and the possible explanations. The design of this study is a literature review. The scientific literature concerning BC were reviewed, especially focusing on the Arctic and the special conditions that exist in this region. Breast cancer incidence is increasing all over the world, including in the Arctic. The enormous transition in health conditions and lifestyle in the Arctic might be contributing to the known risk factors. In Greenland, the age at menarche has diminished by 3 years during the course of 100 years, and the number of children per women as well as the duration of breastfeeding is decreasing. Obesity and intake of saturated fat is increasing and the intake of traditional food rich in unsaturated fat and vitamin D decreasing. Smoking and alcohol consumption in the Arctic has been relatively high but is now decreasing. More focus on genetic susceptibility in relation to BC has identified the specific BRCA1 founder mutation in the Greenlandic population, which might appear to be an important risk factor. However, the known established risk factors alone cannot account for the increasing trend observed. Studies suggest that environmental contaminants such as persistent organic pollutants (POPs) including perfluorinated compounds increase the risk of BC possibly in conjunction with certain genetic polymorphisms involved in carcinogen activation. The lipophilic POPs such as polychlorinated biphenyls and organochlorine pesticides are found at very high levels in the Arctic population. Several factors can explain the increasing incidence of BC in the Arctic. The transition in lifestyle and health conditions unfortunately increases the known risk factors of BC. Moreover, the population of the Arctic might show up to be especially vulnerable because of the contemporary high burden of POPs and genetic susceptibility.

A bayesian translational framework for knowledge propagation, discovery, and integration under specific contexts

The immense corpus of biomedical literature existing today poses challenges in information search and integration. Many links between pieces of knowledge occur or are significant only under certain contexts-rather than under the entire corpus. This study proposes using networks of ontology concepts, linked based on their co-occurrences in annotations of abstracts of biomedical literature and descriptions of experiments, to draw conclusions based on context-specific queries and to better integrate existing knowledge. In particular, a Bayesian network framework is constructed to allow for the linking of related terms from two biomedical ontologies under the queried context concept. Edges in such a Bayesian network allow associations between biomedical concepts to be quantified and inference to be made about the existence of some concepts given prior information about others. This approach could potentially be a powerful inferential tool for context-specific queries, applicable to ontologies in other fields as well.

Alcohol intake and mammographic density in postmenopausal Norwegian women

Mammographic density is a strong risk factor for breast cancer. While alcohol intake has been associated with increased breast cancer risk, the association between alcohol consumption and mammographic density is not clear. We assessed the association between alcohol consumption and mammographic density among women who participated in the Norwegian Breast Cancer Screening Program in 2004. Mammographic density was assessed on digitized mammograms from 2,251 postmenopausal women aged 50-69 years, using a computer assisted method. Current intake of beer, wine (red and white), and liquor was assessed using a validated food frequency questionnaire. Non-drinkers were defined as complete abstainers (i.e., those who reported no intake of any type of alcohol). We used multivariate linear regression models to estimate least square means of percent mammographic density by categories of alcohol intake with adjustment for potential confounders. We also checked for possible effect modification by stratifying the analyses by age, body mass index, and hormone therapy. The mean percent mammographic density was almost similar for drinkers 18.3% (95% CI: 17.6-18.9%) and non-drinkers 17.8% (95% CI: 16.1-19.4%) (P = 0.59). There was no indication that amount of alcohol consumed was associated with percent mammographic density, with a mean percent density among women with the highest intake (>90 g of alcohol per week) of 18.2% (95% CI: 16.9-19.0%), only slightly different from that of non-drinkers 18.3% (17.3-19.6%) (P for trend = 0.99). There was no association between any type of alcohol consumed and mammographic density.There was no effect modification by body mass index, age, or hormone therapy use. We found no evidence of an association between alcohol intake and percent mammographic density.