Alcohol intake, type of beverage, and risk of breast cancer in pre- and postmenopausal women

Breast cancer subtype and clinical characteristics in women from Peru

Introduction

Breast cancer is a heterogeneous disease, and the distribution of the different subtypes varies by race/ethnic category in the United States and by country. Established breast cancer-associated factors impact subtype-specific risk; however, these included limited or no representation of Latin American diversity. To address this gap in knowledge, we report a description of demographic, reproductive, and lifestyle breast cancer-associated factors by age at diagnosis and disease subtype for The Peruvian Genetics and Genomics of Breast Cancer (PEGEN-BC) study.

Methods

The PEGEN-BC study is a hospital-based breast cancer cohort that includes 1943 patients diagnosed at the Instituto Nacional de Enfermedades Neoplásicas in Lima, Peru. Demographic and reproductive information, as well as lifestyle exposures, were collected with a questionnaire. Clinical data, including tumor Hormone Receptor (HR) status and Human Epidermal Growth Factor Receptor 2 (HER2) status, were abstracted from electronic medical records. Differences in proportions and mean values were tested using Chi-squared and one-way ANOVA tests, respectively. Multinomial logistic regression models were used for multivariate association analyses.

Results

The distribution of subtypes was 52% HR+HER2-, 19% HR+HER2+, 16% HR-HER2-, and 13% HR-HER2+. Indigenous American (IA) genetic ancestry was higher, and height was lower among individuals with the HR-HER2+ subtype (80% IA vs. 76% overall, p=0.007; 152 cm vs. 153 cm overall, p=0.032, respectively). In multivariate models, IA ancestry was associated with HR-HER2+ subtype (OR=1.38,95%CI=1.06-1.79, p=0.017) and parous women showed increased risk for HR-HER2+ (OR=2.7,95%CI=1.5-4.8, p<0.001) and HR-HER2- tumors (OR=2.4,95%CI=1.5-4.0, p<0.001) compared to nulliparous women. Multiple patient and tumor characteristics differed by age at diagnosis (<50 vs. >=50), including ancestry, region of residence, family history, height, BMI, breastfeeding, parity, and stage at diagnosis (p<0.02 for all variables).

Discussion

The characteristics of the PEGEN-BC study participants do not suggest heterogeneity by tumor subtype except for IA genetic ancestry proportion, which has been previously reported. Differences by age at diagnosis were apparent and concordant with what is known about pre- and post-menopausal-specific disease risk factors. Additional studies in Peru should be developed to further understand the main contributors to the specific age of onset and molecular disease subtypes in this population and develop population-appropriate predictive models for prevention.

Evaluation of Feature Selection Techniques for Breast Cancer Risk Prediction

This study evaluates several feature ranking techniques together with some classifiers based on machine learning to identify relevant factors regarding the probability of contracting breast cancer and improve the performance of risk prediction models for breast cancer in a healthy population. The dataset with 919 cases and 946 controls comes from the MCC-Spain study and includes only environmental and genetic features. Breast cancer is a major public health problem. Our aim is to analyze which factors in the cancer risk prediction model are the most important for breast cancer prediction. Likewise, quantifying the stability of feature selection methods becomes essential before trying to gain insight into the data. This paper assesses several feature selection algorithms in terms of performance for a set of predictive models. Furthermore, their robustness is quantified to analyze both the similarity between the feature selection rankings and their own stability. The ranking provided by the SVM-RFE approach leads to the best performance in terms of the area under the ROC curve (AUC) metric. Top-47 ranked features obtained with this approach fed to the Logistic Regression classifier achieve an AUC = 0.616. This means an improvement of 5.8% in comparison with the full feature set. Furthermore, the SVM-RFE ranking technique turned out to be highly stable (as well as Random Forest), whereas relief and the wrapper approaches are quite unstable. This study demonstrates that the stability and performance of the model should be studied together as Random Forest and SVM-RFE turned out to be the most stable algorithms, but in terms of model performance SVM-RFE outperforms Random Forest.

ROS Signaling-Mediated Novel Biological Targets: Brf1 and RNA Pol III Genes

Biomolecule metabolism produces ROS (reactive oxygen species) under physiological and pathophysiological conditions. Dietary factors (alcohol) and carcinogens (EGF, DEN, and MNNG) also induce the release of ROS. ROS often causes cell stress and tissue injury, eventually resulting in disorders or diseases of the body through different signaling pathways. Normal metabolism of protein is critically important to maintain cellular function and body health. Brf1 (transcript factor II B-related factor 1) and its target genes, RNA Pol III genes (RNA polymerase III-dependent genes), control the process of protein synthesis. Studies have demonstrated that the deregulation of Brf1 and its target genes is tightly linked to cell proliferation, cell transformation, tumor development, and human cancers, while alcohol, EGF, DEN, and MNNG are able to induce the deregulation of these genes through different signaling pathways. Therefore, it is very important to emphasize the roles of these signaling events mediating the processes of Brf1 and RNA Pol III gene transcription. In the present paper, we mainly summarize our studies on signaling events which mediate the deregulation of these genes in the past dozen years. These studies indicate that Brf1 and RNA Pol III genes are novel biological targets of ROS.

The significance of Runx2 mediating alcohol-induced Brf1 expression and RNA Pol III gene transcription

Runx2 (Runt-related transcription factor 2) is a key transcription factor which is associated with osteoblast differentiation and expressed in ER+ (estrogen receptor positive) human breast cancer cell lines. Runx2 also participates in mammary gland development. Deregulation of RNA Pol III genes (polymerase III-dependent genes) is tightly linked to tumor development, while Brf1 (TFIIB-related factor 1) specifically regulates these gene transcription. However, nothing is known about the effect of Runx2 on Brf1 expression and Pol III gene transcription. Expression of Runx2, Brf1 and Pol III genes from the samples of human breast cancer and cell culture model were determined by the assays of RT-qPCR, immunoblot, luciferase reporter activity, immunohistochemistry, chromatin immunoprecipitation and Immunofluorescence. High expression of Runx2 is observed in the cases of breast cancer. The patients of high Runx2 expression at early stages display longer survival period, whereas the cases of high Runx2 at advanced stages reveal faster recurrence. The identification of signaling pathway indicates that JNK1 and c-Jun mediate Runx2 transcription. Repression of Runx2 reduces Brf1 expression and Pol III gene transcription. Further analysis indicates that Runx2 is colocalized with Brf1 in nucleus of breast cancer tissue. Both Runx2 and Brf1 synergistically modulate Pol III gene transcription. These studies indicate that Brf1 overexpression is able to be used as an early diagnosis biomarker of breast cancer, while high Runx2 expression indicates long survival period and faster recurrence. Runx2 mediates the deregulation of Brf1 and Pol III genes and its abnormal expression predicts the worse prognosis of breast cancer.

Binge Drinking and Risk of Breast Cancer: Results from the SUN ('Seguimiento Universidad de Navarra') Project

Alcohol intake is associated with the risk of breast cancer. Different patterns of alcohol-drinking may have different effects on breast cancer even when keeping constant the total amount of alcohol consumed. We aimed to assess the association between binge drinking and breast cancer risk. The SUN Project is a Spanish dynamic prospective cohort of university graduates initiated in 1999. In the 556-item lifestyle baseline questionnaire a validated food-frequency questionnaire was embedded. Participants completed biennial follow-up questionnaires. Cox regression models were used to estimate the hazard ratio (HR) for breast cancer associated with the exposure to binge drinking. A stratified analysis was performed according to menopausal status. We included 9577 women (mean age = 34 years, SD = 10 years), with a median follow-up of 11.8 years. Among 104,932 women-years of follow-up, we confirmed 88 incident cases of breast cancer. Women in the binge drinking group showed a higher risk of breast cancer (HR = 1.76; 95% CI: 1.03–2.99) compared to women in the non-binge drinking category. In the stratified analysis, a 2-fold higher risk for premenopausal breast cancer was associated with binge drinking habit (HR = 2.06; 95% CI: 1.11–3.82). This study adds new evidence on the association of binge drinking with breast cancer risk.

The influences of red wine in phenotypes of human cancer cells

Alcohol intake increases the risk of cancer development. Approximately 3.6% human cancers worldwide derive from chronic alcohol drinking, including oral, liver, breast and other organs. Our studies in vivo and in vitro have demonstrated that diluted ethanol increase RNA Pol III gene transcription and promotes cell proliferation and transformation, as well as tumor formation. However, it is unclear about the effect of red wines on the human cancer cells. In present study, we investigated the roles of red wine in human cancer cell growth, colony formation and RNA Pol III gene transcription. Low concentration (12.5 mM to 25 mM) of ethanol enhances cell proliferation of breast and esophageal cancer lines, whereas its higher concentration (100 mM to 200 mM) slightly decreases the rates. In contrast, red wines significantly repress cell proliferation of different human cancer lines from low dose to high dose. The results reveal that the red wine also inhibits colony formation of human breast cancer and esophageal carcinoma cells. The effects of repression on different human cancer lines are in a dose-dependent manner. Further analysis indicates that ethanol increases RNA Pol III gene transcription, whereas the red wines significantly reduce transcription of the genes. Interestingly, the effects of mature wine (brick red) on cancer cell phenotypes are much stronger than young wine (intense violet). Together, these new findings suggest that red wines may contain some bioactive components, which are able to inhibit human cancer cell growth and colony formation.

Alcohol Intake and Abnormal Expression of Brf1 in Breast Cancer

Breast cancer is the most common malignant disease of females. Overall, one woman in every nine will get breast cancer at some time in her life. Epidemiological studies have indicated that alcohol consumption has most consistently been associated with breast cancer risk. However, the mechanism of alcohol-associated breast cancer remains to be addressed. Little is known about the effects of alcohol consumption on Brf1 (TFIIIB-related factor 1) expression and RNA Pol III gene (RNA polymerase III-dependent gene) transcription, which are responsible for protein synthesis and tightly linked to cell proliferation, cell transformation, and tumor development. Emerging evidences have indicated that alcohol induces deregulation of Brf1 and Pol III genes to cause the alterations of cell phenotypes and tumor formation. In this paper, we summarize the progresses regarding alcohol-caused increase in the expression of Brf1 and Pol III genes and analysis of its molecular mechanism of breast cancer. As the earlier and accurate diagnosis approach of breast cancer is not available yet, exploring the molecular mechanism and identifying the biomarker of alcohol-associated breast cancer are especially important. Recent studies have demonstrated that Brf1 is overexpressed in most ER+ (estrogen receptor positive) cases of breast cancer and the change in cellular levels of Brf1 reflects the therapeutic efficacy and prognosis of this disease. It suggests that Brf1 may be a potential diagnosis biomarker and a therapeutic target of alcohol-associated breast cancer.

Dietary inflammatory index and incidence of breast cancer in the SUN project

BACKGROUND & AIMS

Breast cancer (BC) is the most commonly diagnosed cancer, and diet is suspected to play a role in its development. Dietary factors may mediate this process through modulation of inflammation, though findings from previous studies have not been consistent. We aimed to longitudinally assess the association between the dietary inflammatory index (DII^®), a frequently used method to assess the inflammatory potential of the diet, and incident BC.

METHODS

We included 10,713 middle-aged, Spanish female university graduates from the SUN cohort. DII^® scores were derived from a validated 136-item food-frequency questionnaire, and it was based on scientific evidence on the relationship between diet and inflammatory biomarkers. Diagnosis of BC was reported by the participant or, if deceased, by the next of kin or identified from death certificates. Self-reports of BC were confirmed by revision of medical reports by an experienced oncologist. Cox proportional hazard models were used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for the association between quartiles of DII^® and incident BC.

RESULTS

After 10.3 years of median follow-up, we identified 100 confirmed and 168 probable incident BC cases. The multivariable-adjusted HR for participants in the 4th quartile to the 1st quartile was 1.44 (95% CI 0.76-2.72; p-trend: 0.339) when confirmed cases were analyzed, and 1.20 (95% CI 0.72-1.99; p-trend: 0.757) for the probable cases. We neither observed statistically significant differences in regard to menopausal status.

CONCLUSIONS

The apparent increase in risk between DII^® scores and BC in our cohort was not statistically significant, which could be partly explained by the small number of observed cases.

Examining Nonparticipation in the Maternal Follow-up Within the Danish National Birth Cohort

A follow-up questionnaire on maternal health was distributed within the Danish National Birth Cohort (established in 1996-2002) 14 years after the index birth. Responses were obtained from 41,466 (53.2%) of 78,010 eligible mothers. To ensure the appropriate use of these data, the possibility of selection bias due to nonparticipation had to be evaluated. We estimated 4 selected exposure-outcome associations (prepregnancy weight-depression; exercise-degenerative musculoskeletal conditions; smoking-heart disease; and alcohol consumption-breast cancer). We adjusted for several factors associated with participation and applied inverse probability weighting. To estimate the degree of selection bias, we calculated relative odds ratios for the relationship between the baseline cohort and the subset participating in the Maternal Follow-up. Participating women were generally healthier, of higher social status, and older than the baseline cohort. However, selection bias in the chosen scenarios was limited; ratios of the odds ratios ranged from -14% to 5% after adjustment for age, parity, social status, and, if the variable was not the exposure variable, prepregnancy body mass index, exercise, smoking, and alcohol consumption. Applying inverse probability weighting did not further reduce bias. In conclusion, while participants differed somewhat from the baseline cohort, selection bias was limited after factors associated with participation status were accounted for.

Alcohol Consumption as a Risk Factor for Breast Cancer Development: A Case-Control Study in Brazil

Background:

Alcohol consumption is a well-established risk factor for breast cancer, but the evidence is mostly from developed countries. Brazil is going through a rapid demographic expansion, and studies of this relationship are also needed in such unexplored settings.

Methods:

We assessed the relationship between alcohol consumption and breast cancer risk among 1,506 Brazilian women (406 cases and 1,100 controls). Regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI). All statistical tests were two-tailed.

Results:

The mean age of the 1,506 women was 42.0 (standard deviation, ±15.0) years. There was a significant association between breast cancer and age, body mass index, age at menarche, menstrual flow and menstrual cycle. Multivariate analysis showed an increased risk of invasive breast cancer in regular alcohol consumers (<50 years old: OR 4.7; 95% CI 1.4–16.2; ≥50 years old: OR 3.9; 95% CI 1.2–13.4) compared with abstainers or occasional drinkers. Women with a regular alcohol intake for 10 years or more who were less than 50 years old had a threefold higher risk of developing breast cancer (OR 3.0; 95% CI 1.2–7.6).

Conclusion:

Regular alcohol consumption increases the risk of breast cancer mainly among women less than 50 years old.

Role of Brf1 interaction with ERα, and significance of its overexpression, in human breast cancer

TFIIB-related factor 1 (Brf1) modulates the transcription of RNA Pol III genes (polymerase-dependent genes). Upregulation of Pol III genes enhances tRNA and 5S RNA production and increases the translational capacity of cells to promote cell transformation and tumor development. However, the significance of Brf1 overexpression in human breast cancer (HBC) remains to be investigated. Here, we investigate whether Brf1 expression is increased in the samples of HBC, and we explore its molecular mechanism and the significance of Brf1 expression in HBC. Two hundred and eighteen samples of HBC were collected to determine Brf1 expression by cytological and molecular biological approaches. We utilized colocalization, coimmunoprecipitation, and chromatin immunoprecipitation methods to explore the interaction of Brf1 with estrogen receptor alpha (ERα). We determined how Brf1 and ERα modulate Pol III genes. The results indicated that Brf1 is overexpressed in most cases of HBC, which is associated with an ER-positive status. The survival period of the cases with high Brf1 expression is significantly longer than those with low levels of Brf1 after hormone treatment. ERα mediates Brf1 expression. Brf1 and ERα are colocalized in the nucleus. These results indicate an interaction between Brf1 and ERα, which synergistically regulates the transcription of Pol III genes. Inhibition of ERα by its siRNA or tamoxifen reduces cellular levels of Brf1 and Pol III gene expression and decreases the rate of colony formation of breast cancer cells. Together, these studies demonstrate that Brf1 is a good biomarker for the diagnosis and prognosis of HBC. This interaction of Brf1 with ERα and Brf1 itself are potential therapeutic targets for this disease.

Exploring a common mechanism of alcohol-induced deregulation of RNA Pol III genes in liver and breast cells

Alcohol intake is associated with numbers of different human cancers, such as hepatocellular carcinoma (HCC) and breast cancer. However, the molecular mechanism remains to be elucidated. RNA polymerase III-dependent genes (Pol III genes) deregulation elevates cellular production of tRNAs and 5S rRNA, resulting in an increase in translational capacity, which promote cell transformation and tumor formation. To explore a common mechanism of alcohol-associated human cancers, we have comparably analyzed that alcohol causes deregulation of Pol III genes in liver and breast cells. Our results reveal that alcohol enhances RNA Pol III gene transcription in both liver and breast cells. The induction of Pol III genes caused by alcohol in ER+ breast cancer lines or liver tumor lines are significantly higher than in their non-tumor cell lines. Alcohol increases cellular levels of Brf1 mRNA and protein, (which depeted) Brf1 is a key transcription factor and specifically regulate Pol III gene activity. Alcohol activates JNK1 to upregulate transcription of Brf1 and Pol III genes, whereas inhibition of JNK1 by SP600125 or its siRNA significantly decreases the induction of these genes. Furthermore, alcohol increases the rates of transformation of liver and breast cells, repressed JNK1 and Brf1 expression decrease transcription of Pol III genes and reduce the rates of colony formation of AML-12 and MCF-10 cells. Together, these studies support the idea that alcohol induces deregulation of Brf1 and RNA Pol III genes in liver and breast cells, which share a common signaling pathway to promote cell transformation. Through the common mechanism, alcohol-induced deregulation of RNA Pol III genes brings about greater phenotypic changes.

Alcohol and Cancer: Mechanisms and Therapies

Several scientific and clinical studies have shown an association between chronic alcohol consumption and the occurrence of cancer in humans. The mechanism for alcohol-induced carcinogenesis has not been fully understood, although plausible events include genotoxic effects of acetaldehyde, cytochrome P450 2E1 (CYP2E1)-mediated generation of reactive oxygen species, aberrant metabolism of folate and retinoids, increased estrogen, and genetic polymorphisms. Here, we summarize the impact of alcohol drinking on the risk of cancer development and potential underlying molecular mechanisms. The interactions between alcohol abuse, anti-tumor immune response, tumor growth, and metastasis are complex. However, multiple studies have linked the immunosuppressive effects of alcohol with tumor progression and metastasis. The influence of alcohol on the host immune system and the development of possible effective immunotherapy for cancer in alcoholics are also discussed here. The conclusive biological effects of alcohol on tumor progression and malignancy have not been investigated extensively using an animal model that mimics the human disease. This review provides insights into cancer pathogenesis in alcoholics, alcohol and immune interactions in different cancers, and scope and future of targeted immunotherapeutic modalities in patients with alcohol abuse.

Alcohol-associated cancer and deregulation of Pol III genes

Emerging evidence indicates that alcohol intake is associated with human cancers in different organs. However, the molecular mechanism of alcohol-associated human cancers remains to be elucidated. Here, this paper aimed to clarify a novel mechanism of alcohol-promoted cell transformation and tumor development. Alcohol induces JNK1 activation and increases cellular levels of c-Jun to upregulate Brf1 expression and Pol III gene transcription, leading to an enhancement of rates of cell transformation and tumor formation.

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.

Dietary patterns and the risk of female breast cancer among participants of the Canadian National Enhanced Cancer Surveillance System

OBJECTIVES

The role of diet in the etiology of breast cancer is not well understood despite extensive research. In the majority of this work, a single nutrient-based approach has been used which does not take into account combinations of food that are consumed. An alternative to the single nutrient approach is to identify patterns in the dietary intake information and relate these patterns to disease incidence. This investigation characterized dietary patterns among participants of a Canadian case-control study and related these dietary patterns to the incidence of breast cancer.

METHODS

Dietary and other risk factor data from cases and controls of the Canadian National Enhanced Cancer Surveillance System were collected using self-administered questionnaires. Principal component factor analysis was used to classify individuals based on their dietary patterns. The relationship between these dietary patterns and breast cancer was evaluated using logistic regression. The derived odds ratios and their 95% confidence limits were adjusted for several factors, such as smoking, alcohol intake, environmental tobacco smoke exposure and obesity.

RESULTS

In the 2,009 cases and 2,086 controls, three dietary patterns were identified: western, healthy and vitamin. The highest quartile of the "healthy" dietary pattern was related to a 22% decrease in breast cancer risk (95% CI: 0.61-1.00), relative to the lowest quartile. The fourth quartile of the "vitamin" dietary pattern was associated with a 14% decrease in breast cancer risk (95% CI: 0.70-1.04) relative to the first. No statistically significant associations between the "western" dietary pattern and breast cancer were found. These associations were neither confounded nor modified by menopausal status.

CONCLUSION

Our analyses reveal that individual dietary items tend to cluster together in such a way that there are three distinct dietary patterns in this sample of Canadian women. Some of these patterns, in turn, were associated with the risk of breast cancer.

Effects of the lifestyle habits in breast cancer transcriptional regulation

Through research carried out in the last 25 years about the breast cancer etiology, it has been possible to estimate that less than 10 % of patients who are diagnosed with the condition are carriers of some germline or somatic mutation. The clinical reports of breast cancer patients with healthy twins and the development of disease in women without high penetrance mutations detected, warn the participation more factors in the transformation process. The high incidence of mammary adenocarcinoma in the modern woman and the urgent need for new methods of prevention and early detection have demanded more information about the role that environment and lifestyle have on the transformation of mammary gland epithelial cells. Obesity, alcoholism and smoking are factors that have shown a close correlation with the risk of developing breast cancer. And although these conditions affect different cell regulation levels, the study of its effects in the mechanisms of transcriptional and epigenetic regulation is considered critical for a better understanding of the loss of identity of epithelial cells during carcinogenesis of this tissue. The main objective of this review was to establish the importance of changes occurring to transcriptional level in the mammary gland as a consequence of acute or chronic exposure to harmful products such as obesity-causing foods, ethanol and cigarette smoke components. At analyze the main studies related to topic, it has concluded that the understanding of effects caused by the lifestyle factors in performance of the transcriptional mechanisms that determine gene expression of the mammary gland epithelial cells, may help explain the development of this disease in women without genetic propensity and different phenotypic manifestations of this cancer type.

Links between alcohol consumption and breast cancer: a look at the evidence

Alcohol consumption by adult women is consistently associated with risk of breast cancer. Several questions regarding alcohol and breast cancer need to be addressed. Menarche to first pregnancy represents a window of time when breast tissue is particularly susceptible to carcinogens. Youth alcohol consumption is common in the USA, largely in the form of binge drinking and heavy drinking. Whether alcohol intake acts early in the process of breast tumorigenesis is unclear. This review aims to focus on the influences of timing and patterns of alcohol consumption and the effect of alcohol on intermediate risk markers. We also review possible mechanisms underlying the alcohol-breast cancer association.

Alteration of BRCA1 expression affects alcohol-induced transcription of RNA Pol III-dependent genes

Emerging evidence has indicated that alcohol consumption is an established risk factor for breast cancer. Deregulation of RNA polymerase III (Pol III) transcription enhances cellular Pol III gene production, leading to an increase in translational capacity to promote cell transformation and tumor formation. We have reported that alcohol intake increases Pol III gene transcription to promote cell transformation and tumor formation in vitro and in vivo. Studies revealed that tumor suppressors, pRb, p53, PTEN and Maf1 repress the transcription of Pol III genes. BRCA1 is a tumor suppressor and its mutation is tightly related to breast cancer development. However, it is not clear whether BRCA1 expression affects alcohol-induced transcription of Pol III genes. At the present studies, we report that restoring BRCA1 in HCC 1937 cells, which is a BRCA1 deficient cell line, represses Pol III gene transcription. Expressing mutant or truncated BRCA1 in these cells does not affect the ability of repression on Pol III genes. Our analysis has demonstrated that alcohol induces Pol III gene transcription. More importantly, overexpression of BRCA1 in estrogen receptor positive (ER+) breast cancer cells (MCF-7) decreases the induction of tRNA(Leu) and 5S rRNA genes by alcohol, whereas reduction of BRCA1 by its siRNA slightly increases the transcription of the class of genes. This suggests that BRCA1 is associated with alcohol-induced deregulation of Pol III genes. These studies for the first time demonstrate the role of BRCA1 in induction of Pol III genes by alcohol and uncover a novel mechanism of alcohol-associated breast cancer.

Tamoxifen represses alcohol-induced transcription of RNA polymerase III-dependent genes in breast cancer cells

Alcohol consumption in women has been associated with an increased risk of breast cancer, particular in estrogen receptor positive (ER+) cases. Deregulation of RNA polymerase III-dependent (Pol III) transcription enhances cellular tRNAs and 5S rRNA production, leading to an increase in translational capacity to promote cell transformation and tumor formation. Our recent studies demonstrated that alcohol induces Brf1 expression and Pol III gene transcription via ER. Here, we report that Tamoxifen (Tam) inhibits the induction of Brf1 and Pol III genes in ER+ breast cancer cells. Further analysis indicates that alcohol increases c-Jun expression to upregulate the transcription of Brf1 and Pol III genes, whereas Tam reduces c-Jun expression to repress the transcription of Brf1. Repression of cJun decreases cellular levels of ERα and Brf1. Alcohol-dependent increased occupancy of Brf1 in Pol III gene promoters is reduced by Tam. The repression of Brf1 and Pol III genes by Tam reduces alcohol-induced cell proliferation and colony formation. Together, these results indicate that Tam inhibits alcohol-induced Brf1 expression through c-Jun and ERα to downregulate Pol III gene transcription. Our studies uncover a new mechanism of Tam-treated ER+ breast cancer, by which Tam inhibits tumor growth through repressing Pol III gene transcription.

Female breast cancer and alcohol consumption: a review of the literature

CONTEXT

Consumption of alcoholic beverages is one of the single most important known and modifiable risk factor for human cancer. Among women, breast cancer is the most common cancer worldwide and the leading cause of cancer-related mortality. Consumption of alcoholic beverages is causally associated with female breast cancer and the association shows a linear dose-response relationship. The role of heavy drinking has been long recognized and even a moderate intake is associated with an increased risk for breast cancer. The present review is an update of the current evidence on the association between alcohol consumption and breast cancer risk. The aim is to gain further insight into this association and to improve our current understanding of the effects of the major modifying factors.

EVIDENCE ACQUISITION

Epidemiologic and experimental studies published since the most recent International Agency for Research on Cancer (IARC) Monograph on alcoholic beverages were identified in PubMed using a combination of keywords such as alcohol, breast cancer, polymorphisms, menopausal status.

EVIDENCE SYNTHESIS

Cumulative lifetime consumption, drinking frequency, drinking patterns and timing of exposure each modulate the association between alcohol consumption and breast cancer. Hormonal status, genetic polymorphisms, and nutritional factors may interact with ethanol metabolism and further influence breast cancer risk.

CONCLUSIONS

Better standardization among experimental and epidemiologic designs in assessing alcohol intake and timing of exposure may improve our understanding of the heterogeneity observed across studies, possibly allowing the quantification of the effects of occasional heavy drinking and the identification of a window of higher susceptibility to breast cancer development.

Elk1 and AP-1 sites in the TBP promoter mediate alcohol-induced deregulation of Pol III-dependent genes

The major risk factors for hepatocellular carcinoma (HCC) are chronic liver diseases that include hepatitis B, hepatitis C, alcoholic liver disease and non-alcoholic steatohepatitis. However, the mechanisms of alcohol-associated HCC remain to be elucidated. The products of RNA Pol III (RNA polymerase III) dependent genes are elevated in both transformation cells and tumor cells. TBP (TATA-box binding protein) is a central transcription factor, which regulates Pol I, Pol II and Pol III gene activity. Our studies have demonstrated that alcohol increases TBP expression and Pol III gene transcription to promote liver tumor formation. We continue to investigate how ethanol mediates TBP expression. Here, we report that ethanol induces TBP promoter activity and the induction is ethanol dose dependent. Blocking the JNK1 pathway by a chemical inhibitor and siRNA reduces this ethanol-induced activity. Furthermore, mutating G>A at a -46 bp Elk1 binding site of the TBP promoter or mutating AP-1 binding site at -37 bp (A>G) and -38 bp (C>T) reduces the TBP promoter activity. Mutation of both Elk1 and AP-1 binding sites dramatically represses this induction. Together, these studies demonstrate that, for the first time, alcohol increases Pol III gene transcription through a response element, which is composed of the overlapping Elk1 and AP-1 binding sites of the TBP promoter and affected by alcohol. It suggests that these binding sites may play a critical role in alcohol-induced deregulation of Pol III genes in liver tumor development.

ERα mediates alcohol-induced deregulation of Pol III genes in breast cancer cells

The association of alcohol consumption and breast cancer is more pronounced in cases that are positive for estrogen receptor (ER+) than in cases that are negative (ER-). Its mechanism remains to be determined. Deregulation of RNA polymerase III (Pol III) transcription enhances cellular tRNAs and 5S rRNA production, increasing translational capacity to promote cell transformation and tumor formation. Here, we report that alcohol increases Pol III gene transcription in both normal and cancer breast cell lines. The induction in ER+ breast cancer cells (MCF-7) is significantly higher than in ER- normal breast cells (MCF-10A, MCF-10F and MCF-12A) and is correlated with ER expression. E2 causes <2-fold increase in Pol III gene transcription. The addition of ethanol to this system now produces a 10-15-fold increase. Ethanol increases ERα expression, resulting in an increase in Brf1 protein and mRNA levels. In addition, ethanol markedly stimulates phosphorylation of JNK1, but not JNK2. Inhibition of JNK1 decreases ERE-Luc reporter activity and represses expression of ERα, Brf1 and Pol III genes. Reduction of ERα by its small interfering RNA represses Brf1 and Pol III gene transcription. Ethanol with E2 produces larger and more numerous colonies. Repression of ERα or Brf1 inhibits alcohol-induced cell transformation. Together, these results support the idea that alcohol increases ERα expression through JNK1 to elevate Brf1 expression and Pol III gene transcription to bring about greater phenotypic changes. These studies demonstrate that ERα mediates Pol III gene transcription through Brf1, suggesting that ERα may play a critical role in alcohol-induced deregulation of Pol III genes in ER+ breast cancer development.

Alcohol consumption in relation to aberrant DNA methylation in breast tumors

The mechanism for the observed association of alcohol consumption breast cancer risk is not known; understanding that mechanism could improve understanding of breast carcinogenesis and optimize prevention strategies. Alcohol may impact breast malignancies or tumor progression by altering DNA methylation. We examined promoter methylation of three genes, the E-cadherin, p16, and retinoic acid-binding receptor-β2 (RAR-β2) genes in archived breast tumor tissues from participants in a population-based case-control study. Real time methylation-specific PCR was performed on 803 paraffin-embedded samples, and lifetime alcohol consumption was queried. Unordered polytomous and unconditional logistic regression were used to derive adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RAR-β2 methylation was not associated with drinking. Among premenopausal women, alcohol consumption was also not associated with promoter methylation for E-cadherin and p16 genes. In case-case comparisons of postmenopausal breast cancer, compared with lifetime never drinkers, promoter methylation likelihood was increased for higher alcohol intake for E-cadherin (OR=2.39; 95% CI, 1.15-4.96), in particular for those with estrogen receptor-negative tumors (OR=4.13; 95% CI, 1.16-14.72), and decreased for p16 (OR=0.52; 95% CI, 0.29-0.92). There were indications that the association with p16 was stronger for drinking at younger ages. Methylation was also associated with drinking intensity independent of total consumption for both genes. We found alcohol consumption was associated with DNA methylation in postmenopausal breast tumors, suggesting that the association of alcohol and breast cancer may be related, at least in part, to altered methylation, and may differ by drinking pattern.

Breast clinic and life style study BLLISS

Background

Independent, strong and unequivocal evidence suggests that life style factors such as obesity and lack of physical activity along with certain reproductive choices can increase the risk of breast cancer. There are no studies measuring the effectiveness of guidelines from the Department of Health regarding life style choices made by women presenting to breast clinics. The aim of this audit was to study the prevalence of obesity, physical activity and reproductive factors in women referred to breast clinic.

Patients and methods

All patients attending the Breast clinic as new referrals were invited to complete a life style questionnaire. The data was analysed for prevalence of various risk factors for breast cancer. Three hundred and 73 patients completed the questionnaire.

Results

Final analyses of 373 patients demonstrated that 42% of women performed no exercise and only 24% of patients met Department of Health guideline of 30 minutes of exercise for 5 days a week. Overall 50% of patients were either obese or overweight and 22% of patients had BMI of > 30 kg/m². The median age of menarche was 13 and 18% of women started their period below the age 12. Twenty one percent of women were nulliparous and 14% had their first live birth after the age of 30. Fourteen percent of patients were on the hormone replacement therapy of which 57% have used hormones for more than 5 years. Twenty two percent of women smoked and 9% of women consumed alcohol 5 days a week of which 13% had more than 4 glasses of alcohol in a day.

Conclusion

There is preponderance of high risk life style choices in women attending breast clinic. If these life style options are not modified, there could potentially be a significant rise in the number of breast cancer in West Midlands.

The positive and negative health effects of alcohol- and the public health implications

In this paper, the negative and the positive effects of alcohol on health are reviewed. It is first of all established facts that a high alcohol intake implies an increased risk of a large number of health outcomes, such as dementia, breast cancer, colorectal cancer, cirrhosis, upper digestive tract cancer and alcohol dependency. Second, it is justified that alcohol has beneficial effects for some individuals, especially with regard to prevention of thrombosis of the heart. The public health relevance of these results is considered. The sensible drinking limits, used in both the UK and Denmark, of a maximum of 21 drinks per week for men and 14 drinks per week for women seem valid. A broader public health message of the beneficial effects of alcohol does not seem to be of interest in Western societies, where only a very small fraction of the population are non drinkers and may have very good reasons therefore.

An assessment of potential cancer risk following occupational exposure to ethanol

Recognition of the carcinogenic properties of ethanol has resulted from comprehensive evidence regarding the effect of consumption of alcohol; indeed, ethanol in alcoholic beverages is now considered a Group 1 carcinogen by the International Agency for Research on Cancer. However, there is little information on the effects of ethanol following exposure via the occupationally relevant routes of inhalation and dermal exposure. This review therefore focuses on these exposure routes, to assess potential carcinogenic risk associated with occupational exposure to ethanol. Inhalatory exposure at the current occupational exposure limit (OEL) for the United Kingdom (1000 ppm ethanol over an 8-h shift) was estimated to be equivalent to ingestion of 10 g ethanol (approximately 1 glass of alcohol) per day. However, in the occupational setting the dose-rate delivery of this amount of ethanol is low, allowing for its rapid and effective elimination, for the majority of individuals. Similarly, while dermal absorption in an occupational setting could potentially add to overall body ethanol burden, additional carcinogenic risk of such exposure is considered negligible. Thus, on balance, there appears little cause to suppose occupational exposure at or below the current OEL associates with any appreciable increase in risk of cancer. However, available occupational exposure data to confirm this view are currently limited. It is also suggested that adoption of a more flexible classification regime, considering risk in the context of hazard and exposure (such as that adopted by the German MAK commission), would represent an improvement over traditional occupational risk assessment practices.

Association between alcohol intake and serum sex hormones and peptides differs by tamoxifen use in breast cancer survivors

OBJECTIVE

To measure the association between alcohol intake and 11 hormones and peptides in postmenopausal breast cancer survivors and to evaluate whether this association differs by tamoxifen use.

METHODS

Self-reported alcohol intake was assessed via food frequency questionnaire on average 30 months post-breast cancer diagnosis in 490 postmenopausal women from three western states. Concurrently, a fasting blood sample was obtained for assay of estrone, estradiol, free estradiol, testosterone, free testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), leptin, C-peptide, insulin-like growth factor-I (IGF-I), and IGF-binding protein-3. Adjusted means of these hormones and peptides were calculated for categories of alcohol intake, overall and stratified by tamoxifen use.

RESULTS

The association between alcohol intake and serum hormone and peptide levels differed by tamoxifen use. We found statistically significant inverse associations between alcohol intake and both leptin and SHBG values but only among tamoxifen users. In women not using tamoxifen, we found a positive association between alcohol intake and DHEAS but no association in tamoxifen users.

CONCLUSION

Tamoxifen may modify the association between alcohol intake and serum hormones and peptides. The significant associations found for DHEAS and SHBG are in a direction considered unfavorable for breast cancer prognosis. Postmenopausal breast cancer survivors may benefit from decreasing their alcohol intake.

Interactions between intakes of alcohol and postmenopausal hormones on risk of breast cancer

Alcohol and postmenopausal hormone use are well-established modifiable risk factors for breast cancer. Alcohol may decrease the metabolic clearance of estradiol, whereby the risk of breast cancer associated with hormone use may depend on blood alcohol levels. The objective is to determine whether alcohol interacts with hormone use on risk of breast cancer. The 5,035 postmenopausal women who participated in the Copenhagen City Heart Study were asked about their alcohol intake and hormone use at baseline in 1981-1983 and were followed until 2002 in the Danish cancer registry, with <0.1% loss to follow-up. Proportional hazard models were used to analyze data. During follow-up, 267 women developed breast cancer. Alcohol consumption was associated with a small increased risk of breast cancer (hazard ratio = 1.11 per drink/day, 95% CI: 0.99-1.25). Women who used hormones also had a higher risk of breast cancer (HR = 2.00, 95% CI: 1.52-2.61) compared to nonhormone users. We found an interaction between these 2 factors; those who had an intake of more than 2 drinks per day and took hormones had a risk of 4.74 (95% CI: 2.61-8.59) for breast cancer compared to abstainers who did not use hormones. Alcohol was not associated with breast cancer among women who did not use hormones (HR = 0.98 per drink/day, 95% CI: 0.82-1.78). In conclusion, the interaction between alcohol and hormone use should, if confirmed in other studies, have an impact both on the prescription of hormones and on sensible drinking limits for postmenopausal women.

Alcohol intake and breast cancer risk among young women

INTRODUCTION

Alcohol intake has been consistently associated with breast cancer risk, but the importance of timing of intake and the impact of beverage type are unclear.

METHODS

We evaluated whether early, lifetime or recent alcohol intake was associated with breast cancer risk, and whether risk varied by type of alcoholic drinks in 1,728 newly diagnosed population-based breast cancer patients and 435 control subjects aged 20-49 years. We used multivariable logistic regression models to estimate odds ratios (OR) and 95% confidence intervals (CI) as measures of the relative risk of breast cancer associated with intake of alcoholic drinks.

RESULTS

Intake of alcoholic drinks during the recent five year period before the breast cancer diagnosis was associated with increased breast cancer risk (P (trend) = 0.04). Intake of two or more alcoholic drinks per day during this five year period was associated with an 82% increase in breast cancer risk relative to never drinkers (OR = 1.82, 95% CI = 1.01-3.28). No risk increase was observed for alcohol intake at ages 15-20 years or for lifetime alcohol intake. Risk did not vary by type of alcohol consumed.

CONCLUSIONS

Our results suggest that recent alcohol consumption may be associated with increased breast cancer risk in young women.

Alcohol dehydrogenase genetic polymorphisms, low-to-moderate alcohol consumption, and risk of breast cancer

BACKGROUND

In vitro, human isoenzymes encoded by genes homozygous for the ADH1C*1 or ADH1B*2 alleles metabolize ethanol to acetaldehyde at a faster rate than those homozygous for the ADH1C*2 or ADH1B*1 allele. Because alcohol is a known risk factor for breast cancer, we evaluated the joint association of genetic variants in ADH and alcohol consumption in relation to breast cancer.

METHODS

A nested case-control study of 321 cases and matched controls was conducted. Five single nucleotide polymorphisms (SNPs) in the ADH1C and ADH1B genes were genotyped. Logistic regression was used to assess odds ratios (ORs) and 95% confidence limits (CIs) for each SNP. Haplotype analysis of all 5 SNPs was also undertaken.

RESULTS

Among drinkers, the median intake of total alcohol was 13 g/wk (10th-90th percentiles; 4.5-135.9) in cases and 18 g/wk (10th-90th percentiles; 4.5-104.1) in controls. Women who drank alcohol tended to be at an increased risk of developing breast cancer compared with those who did not drink (OR=1.40%, 95% CI 0.97-2.03), particularly those who were premenopausal at the time of breast cancer diagnosis (OR=2.69%, 95% CI: 1.00-7.26). Of the known functional alleles, breast cancer risk was not significantly increased among carriers of at least 1 ADH1C*1 or ADH1B*2 allele, when compared with those homozygous for the genotype at each locus. However, breast cancer risk tended to be lower among women who inherited the G allele at ADH1B IVS1+896A>G (OR=0.62, 95% CI 0.37-1.04). Overall haplotype frequencies were not significantly different between cases and controls.

CONCLUSIONS

In this study low levels of alcohol are associated with a modest increase in breast cancer risk that is not altered by known functional allelic variants of the ADH1B and 1C gene. The protective association conferred by the G allele at ADH1B IVS1+896A>G needs further evaluation.

"Not getting tanked": definitions of moderate drinking and their health implications

BACKGROUND

People encounter large amounts of sometimes-inconsistent information about risks and benefits of alcohol consumption, and about what constitutes "low-risk" or "moderate" drinking.

METHODS

We used 150 in-depth interviews linked to questionnaire data to learn how people define moderate drinking and to describe the relationships between definitions, attitudes, and beliefs about moderate drinking and individuals' drinking patterns.

RESULTS

People adhere to definitions of moderate alcohol consumption that could put them, or others, at risk for short- or long-term negative consequences of drinking. Definitions that confused increased tolerance of alcohol with moderate drinking, and those that defined moderate drinking by the absence of short-term negative consequences or ability to maintain control over drinking, ignore long-term risks of heavy consumption. Individuals with risky attitudes were also more likely to report at-risk drinking practices.

CONCLUSIONS

Americans have complex beliefs about benefits and risks of alcohol consumption, and public health officials have not succeeded in conveying strong or clear messages about what constitutes low-risk drinking or about dose-response effects. Different (but more consistent) approaches to public education may be needed to increase knowledge about drinking-related risks. The prevalence of diverse norm-based definitions suggests that alternative normative information could help people reassess their own consumption.

Diet quality and BRCA-associated breast cancer risk

Although it has been suggested that dietary energy intake restriction may be related to reduced BRCA-associated breast cancer (BC) risk, it is currently not known whether overall diet quality could predict the BC risk among women with deleterious mutations in BRCA1 and BRCA2 (BRCA) genes who already have an elevated BC risk. To assess possible relationships between diet quality, reflected by the Alternate Healthy Eating Index (AHEI), the Diet Quality Index-Revised (DQI-R), the alternate Mediterranean Diet Index (aMED), the Canadian Healthy Eating Index (CHEI), and BRCA-associated BC risk, a case-control study was carried out within a cohort of 80 French-Canadian families with 250 members involving 89 carriers of BRCA genes affected by BC, 48 non-affected carriers and 46 non-affected non-carriers. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in unconditional logistic regression models. After adjustment for age, physical activity and total energy intake, we did not detect any association between the AHEI or aMED and BC. However, a strong and significant inverse relationship was apparent between the DQI-R and CHEI and BRCA-associated BC risk. ORs comparing the highest and lowest tertiles of diet quality scores were 0.35 (95%CI = 0.12-1.02; p ( )= 0.034 for trend) for the DQI-R and 0.18 (95%CI = 0.05-0.68; p = 0.006 for trend) for the CHEI, respectively. These inverse associations were not the result of a link with any specific component of the diet quality indexes. These results suggest that dietary guidelines reflected by the DQI-R and CHEI may constitute preventive strategies for reducing BRCA-associated BC risk.

Development in incidence of breast cancer in non-screened Danish women, 1973-2002--a population-based study

The authors report on the incidence rates of breast cancer overall and by histology in a population of unscreened women constituting approximately 80% of the total population of women in Denmark from 1973-2002, utilizing the files of the nationwide Danish Cancer Registry. The age-specific incidence rates of breast cancer increased throughout the period, and further, marked changes in the age-specific incidence pattern were observed, where the plateau and change of slope around the age of 46-48 in 1973-1981 shifted to around age 64-66 years in 1994-2002. Age-period-cohort modeling indicated that these changes were not attributable to a birth cohort effect. Although lobular breast cancer incidence increased more than ductal breast cancer incidence, this was only observed in the first decade after the introduction of the ICD-O system in Denmark and probably is attributable to this, whereas we observed no disproportionate changes by histology in any age group from 1988-2002. Thus, previous reports of a disproportionate increase in lobular breast cancer could not be confirmed in a non-screened population, whereas important changes over the past decade in the age-specific incidence pattern of breast cancer particular around the time of menopause were indicated.

Moderate acute intake of de-alcoholized red wine, but not alcohol, is protective against radiation-induced DNA damage ex vivo -- results of a comparative in vivo intervention study in younger men

Moderate intake of wine is associated with reduced risk of cardiovascular disease and possibly cancer however it remains unclear whether the potential health benefits of wine intake are due to alcohol or the non-alcoholic fraction of wine. We therefore tested the hypothesis that the non-alcoholic fraction of wine protects against genome damage induced by oxidative stress in a crossover intervention study involving six young adult males aged 21-26 years. The participants adhered to a low plant phenolic compound diet for 48 h prior to consuming 300 mL of complete red wine, de-alcoholized red wine or ethanol on separate occasions 1 week apart. Blood samples were collected 0.5, 1.0 and 2.0 h after beverage consumption. Baseline and radiation-induced genome damage was measured using the cytokinesis-block micronucleus assay and total plasma catechin concentration was measured. Consumption of de-alcoholized red wine significantly decreased the gamma radiation-induced DNA damage at 1 and 2 h post-consumption by 20%. In contrast alcohol tended to increase radiation-induced genome damage and complete wine protected against radiation-induced genome damage relative to alcohol. The observed effects were only weakly correlated with the concentration of total plasma catechin (R=-0.23). These preliminary data suggest that only the non-alcoholic fraction of red wine protects DNA from oxidative damage but this effect cannot be explained solely by plasma catechin.

The etiology of alcohol-induced breast cancer

Breast cancer is the most common cancer in women in the United States, and it is second among cancer deaths in women. Results of most epidemiologic studies, as well as of most experimental studies in animals, have shown that alcohol intake is associated with increased breast cancer risk. Alcohol consumption may cause breast cancer through different mechanisms, including through mutagenesis by acetaldehyde, through perturbation of estrogen metabolism and response, and by inducing oxidative damage and/or by affecting folate and one-carbon metabolism pathways. Alcohol-metabolizing enzymes are present in human breast tissue. Acetaldehyde is a known, although weak, mutagen. However, results of some studies with human subjects implicate this agent in the context of genetic susceptibilities to increased ethanol metabolism. Reactive oxygen species, resulting from ethanol metabolism, may be involved in breast carcinogenesis by causing damage, as well as by generating DNA and protein adducts. Alcohol interferes with estrogen pathways in multiple ways, influencing hormone levels and effects on the estrogen receptors. With regard to one-carbon metabolism, alcohol can negatively affect folate levels, and the folate perturbation affects DNA methylation and DNA synthesis, which is important in carcinogenesis. Some study results indicate that genetic variants of one-carbon metabolism genes might increase alcohol-related breast cancer risk. For all these pathways, genetic polymorphisms might play a role in increasing further a woman's risk for breast cancer. Additional studies are needed to determine the relative importance of these pathways, as well as the modifying influence by genetic variation.

College Students Lack Knowledge of Standard Drink Volumes: Implications for Definitions of Risky Drinking Based on Survey Data

BACKGROUND

College students tend to pour single servings of beer and liquor that are larger than commonly used standards. The reasons for this are unknown. Students might overpour because they lack knowledge of standard serving sizes. Alternatively, they might know how much alcohol to pour but simply have difficulty pouring the correct amounts. Misperceptions of standard serving sizes could lead to inaccuracies in self-reported consumption. If this is the case, then the validity of students' responses on alcohol surveys and the definitions of risky drinking that are based on them would be called into question. This study examined how college students define standard drinks, whether their definitions are similar to the definitions commonly used by alcohol researchers and government agencies, and whether their definitions of standard drinks are related to the sizes of the drinks that they pour. The study also examined whether feedback regarding the accuracy of their definitions of standard drinks leads students to alter their self-reported levels of consumption.

METHODS

Students (N = 133) completed an alcohol survey and performed tasks that required them to free-pour a single beer, glass of wine, shot of liquor, or the amount of liquor in a mixed drink. Roughly half of the students received feedback regarding their definitions of standard drinks. All students then were resurveyed about their recent levels of consumption.

RESULTS

With the exception of beer, students incorrectly defined the volumes of standard servings of alcohol, overestimating the appropriate volumes. They also overestimated appropriate volumes when asked to free-pour drinks. Positive relationships existed between students' definitions of standard drinks and the sizes of the drinks that they free-poured. Feedback regarding misperceptions of standard drink volumes led to an increase in levels of self-reported consumption, suggesting that students' original estimates of their alcohol consumption were too low.

CONCLUSIONS

Despite the recent focus on alcohol education and prevention at the college level, college students have not been taught how to define standard drinks accurately. They tend to overstate the appropriate volumes, leading them to overpour drinks and underreport levels of consumption. Self-reported consumption levels are altered by feedback regarding the accuracy of students' definitions of standard drinks. The findings raise important questions about the validity of students' responses on alcohol surveys and the definitions of risky drinking that are based them.