Do insulin-like growth factors mediate the effect of alcohol on breast cancer risk?

Prognostic impact of tumor-specific insulin-like growth factor binding protein 7 (IGFBP7) levels in breast cancer: a prospective cohort study

The prognostic impact of insulin-like growth factor binding protein 7 (IGFBP7) in breast cancer is unclear. Host factors, including lifestyle, anthropometry and metabolic profile, might influence tumor-specific IGFBP7. This study aimed to investigate whether IGFBP7 levels and messenger ribonucleic acid (mRNA) expression are associated with the patient and tumor characteristics and prognosis in breast cancer. Patients with primary breast cancer in Lund, Sweden, were included preoperatively in the study between 2002 and 2012 (n = 1018). Tumor-specific IGFBP7 protein levels were evaluated with immunohistochemistry using tissue microarrays in tumors from 878 patients. IGFBP7 mRNA expression and its corresponding clinical data were obtained from The Cancer Genome Atlas and analyzed for 809 patients. Tumor-specific IGFBP7 protein levels were categorized based on Histo 300 scores into IGFBP7^low (6.2%), IGFBP7^intermediate (75.7%) and IGFBP7^high (18.1%). Both low IGFBP7 protein levels and mRNA expression were associated with less aggressive tumor characteristics. Overall, IGFBP7^low conferred low recurrence risk. The prognostic impact of IGFBP7^high varied according to any alcohol consumption and tamoxifen treatment. IGFBP7^high was associated with low recurrence risk in alcohol consumers but high recurrence risk in alcohol abstainers (P_interaction= 0.039). Moreover, the combination of IGFBP7^high and estrogen receptor-positive tumors was associated with low recurrence risk only in tamoxifen-treated patients (P_interaction= 0.029). To conclude, IGFBP7^low might be a good, independent prognosticator in breast cancer. The prognostic impact of IGFBP7^high depends on host factors and treatment. IGFBP7 merits further investigation to confirm whether it could be a suitable biomarker for treatment selection.

The relationship between different dimensions of alcohol use and the burden of disease-an update

BACKGROUND AND AIMS

Alcohol use is a major contributor to injuries, mortality and the burden of disease. This review updates knowledge on risk relations between dimensions of alcohol use and health outcomes to be used in global and national Comparative Risk Assessments (CRAs).

METHODS

Systematic review of reviews and meta-analyses on alcohol consumption and health outcomes attributable to alcohol use. For dimensions of exposure: volume of alcohol use, blood alcohol concentration and patterns of drinking, in particular heavy drinking occasions were studied. For liver cirrhosis, quality of alcohol was additionally considered. For all outcomes (mortality and/or morbidity): cause of death and disease/injury categories based on International Classification of Diseases (ICD) codes used in global CRAs; harm to others.

RESULTS

In total, 255 reviews and meta-analyses were identified. Alcohol use was found to be linked causally to many disease and injury categories, with more than 40 ICD-10 three-digit categories being fully attributable to alcohol. Most partially attributable disease categories showed monotonic relationships with volume of alcohol use: the more alcohol consumed, the higher the risk of disease or death. Exceptions were ischaemic diseases and diabetes, with curvilinear relationships, and with beneficial effects of light to moderate drinking in people without heavy irregular drinking occasions. Biological pathways suggest an impact of heavy drinking occasions on additional diseases; however, the lack of medical epidemiological studies measuring this dimension of alcohol use precluded an in-depth analysis. For injuries, except suicide, blood alcohol concentration was the most important dimension of alcohol use. Alcohol use caused marked harm to others, which has not yet been researched sufficiently.

CONCLUSIONS

Research since 2010 confirms the importance of alcohol use as a risk factor for disease and injuries; for some health outcomes, more than one dimension of use needs to be considered. Epidemiological studies should include measurement of heavy drinking occasions in line with biological knowledge.

The relationship between different dimensions of alcohol use and the burden of disease-an update

BACKGROUND AND AIMS

Alcohol use is a major contributor to injuries, mortality and the burden of disease. This review updates knowledge on risk relations between dimensions of alcohol use and health outcomes to be used in global and national Comparative Risk Assessments (CRAs).

METHODS

Systematic review of reviews and meta-analyses on alcohol consumption and health outcomes attributable to alcohol use. For dimensions of exposure: volume of alcohol use, blood alcohol concentration and patterns of drinking, in particular heavy drinking occasions were studied. For liver cirrhosis, quality of alcohol was additionally considered. For all outcomes (mortality and/or morbidity): cause of death and disease/injury categories based on International Classification of Diseases (ICD) codes used in global CRAs; harm to others.

RESULTS

In total, 255 reviews and meta-analyses were identified. Alcohol use was found to be linked causally to many disease and injury categories, with more than 40 ICD-10 three-digit categories being fully attributable to alcohol. Most partially attributable disease categories showed monotonic relationships with volume of alcohol use: the more alcohol consumed, the higher the risk of disease or death. Exceptions were ischaemic diseases and diabetes, with curvilinear relationships, and with beneficial effects of light to moderate drinking in people without heavy irregular drinking occasions. Biological pathways suggest an impact of heavy drinking occasions on additional diseases; however, the lack of medical epidemiological studies measuring this dimension of alcohol use precluded an in-depth analysis. For injuries, except suicide, blood alcohol concentration was the most important dimension of alcohol use. Alcohol use caused marked harm to others, which has not yet been researched sufficiently.

CONCLUSIONS

Research since 2010 confirms the importance of alcohol use as a risk factor for disease and injuries; for some health outcomes, more than one dimension of use needs to be considered. Epidemiological studies should include measurement of heavy drinking occasions in line with biological knowledge.

Alcohol Intake Among Breast Cancer Survivors: Change in Alcohol Use During a Weight Management Intervention

Background

Daily alcohol intake in quantities as small as half a drink/day significantly increases the risk of breast cancer recurrence for postmenopausal survivors. Interventions designed to modify alcohol use among survivors have not been studied; however, lifestyle interventions that target change in dietary intake may affect alcohol intake.

Objective

To evaluate change in alcohol use during a weight loss intervention for obese, rural-dwelling breast cancer survivors.

Methods

Data were derived from an 18-month trial that included a 6-month weight loss intervention delivered via group conference calls, followed by a 12-month randomized weight loss maintenance phase in which participants received continued group calls or mailed newsletters. Participants who reported regular alcohol use at baseline (N=37) were included in this study.

Results

Mean daily alcohol intake significantly decreased from baseline to 6 months during the weight loss intervention (19.6-2.3 g; P=.001). Mean alcohol intake did not significantly increase (b=0.99, P=.12) during the weight loss maintenance phase (months 6-18) and did not depend on randomization group (b=0.32, P=.799).

Conclusions

Findings provide preliminary evidence that a weight loss intervention may address obesity and alcohol use risk factors for cancer recurrence. Minimal mail-based contact post weight loss can maintain alcohol use reductions through 18 months, suggesting durability in these effects. These results highlight a possibility that lifestyle interventions for survivors may modify health behaviors that are not the main foci of an intervention but that coincide with intervention goals.

Trial Registration

Clinicaltrials.gov NCT01441011; https://clinicaltrials.gov/ct2/show/NCT01441011 (Archived by WebCite at http://www.webcitation.org/6lsJ9dMa9)

Alcohol Use and Breast Cancer: A Critical Review

The objective of this study was to outline the biological pathways of alcohol-attributable breast cancer, the epidemiological risk relationship between alcohol consumption and breast cancer, and the global burden of breast cancer incidence and mortality attributable to alcohol consumption, with a focus on light drinking. First, the literature regarding the biological mechanisms of how alcohol affects the risk of breast cancer was reviewed and summarized. Second, a search of meta-analyses that evaluated the risk relationship between alcohol consumption and breast cancer was conducted. Last, the burden of alcohol-attributable breast cancer incidence and mortality was estimated by means of a Population-Attributable Fraction methodology. Data on alcohol consumption were obtained from the Global Information System on Alcohol and Health, and data on cancer incidence and mortality were obtained from the GLOBOCAN database. Alcohol consumption affects breast cancer risk through the alteration in hormone levels and the associated biological pathways, the metabolism of ethanol resulting in carcinogens, and the inhibition of the one carbon metabolism pathway. The systematic review found 15 meta-analyses on the risk relationship between alcohol consumption (also light consumption) and the risk of breast cancer. All but 2 of these analyses showed a dose-response relationship between alcohol consumption and the risk of breast cancer. An estimated 144,000 (95% confidence interval [CI]: 88,000 to 200,000) breast cancer cases and 38,000 (95% CI: 2,400 to 53,000) breast cancer deaths globally in 2012 were attributable to alcohol, with 18.8% of these cases and 17.5% of these deaths affecting women who were light alcohol consumers. All levels of evidence showed a risk relationship between alcohol consumption and the risk of breast cancer, even at low levels of consumption. Due to this strong relationship, and to the amount of alcohol consumed globally, the incidence of and mortality from alcohol-attributable breast cancer is large.

Association of Mediterranean diet, dietary supplements and alcohol consumption with breast density among women in South Germany: a cross-sectional study

BACKGROUND

Effects of dietary factors, such as adherence to Mediterranean diet, multivitamin-multimineral supplements use and alcohol consumption on mammographic breast density, an important biomarker of breast cancer risk, are not sufficiently consistent to elaborate preventive recommendations. This study aims to investigate the association between current diet and mammographic density.

METHODS

We performed a cross-sectional study in 424 pre- and post-menopausal women aged 21 to 84 years. Current Mediterranean dietary pattern, multivitamin-multimineral supplements use, alcohol consumption and potential confounders were assessed with a self-administered questionnaire in the University Hospital Ulm (2007-2008). Radiologists evaluated mammographic density according to the American College of Radiology (ACR) classification, which was summarized in low = ACR1/2 and high = ACR3/4 mammographic density. Logistic regression models were used to assess the association between current diet and mammographic density.

RESULTS

Adherance to Mediterranean dietary pattern was inversely associated with mammographic density in the models adjusted for age and BMI (per 1 unit increase of score OR 0.95; 95%CI 0.90-0.997). Current use of multivitamin-multimineral supplements was also inversely associated with mammographic density (OR 0.53; 95%CI 0.34-0.83). Further adjustment revealed similar point estimates but the associations were no longer statistically significant. Compared to non-drinkers, excessive alcohol consumption (<10 g/d) was positively associated with mammographic density (OR 1.47; 95%CI 0.82-2.63).

CONCLUSIONS

Our results show that dietary factors are associated with mammographic density. Adherence to Mediterranean diet and current use of multivitamin-multimineral supplements could be inversely associated with mammographic density and may suggest a protective effect against breast cancer, whereas high alcohol consumption was associated with increased mammographic density.

Light alcohol drinking and cancer: a meta-analysis

BACKGROUND

There is convincing evidence that alcohol consumption increases the risk of cancer of the colorectum, breast, larynx, liver, esophagus, oral cavity and pharynx. Most of the data derive from studies that focused on the effect of moderate/high alcohol intakes, while little is known about light alcohol drinking (up to 1 drink/day).

PATIENTS AND METHODS

We evaluated the association between light drinking and cancer of the colorectum, breast, larynx, liver, esophagus, oral cavity and pharynx, through a meta-analytic approach. We searched epidemiological studies using PubMed, ISI Web of Science and EMBASE, published before December 2010.

RESULTS

We included 222 articles comprising ∼92 000 light drinkers and 60 000 non-drinkers with cancer. Light drinking was associated with the risk of oropharyngeal cancer [relative risk, RR = 1.17; 95% confidence interval (CI) 1.06-1.29], esophageal squamous cell carcinoma (SCC) (RR = 1.30; 95% CI 1.09-1.56) and female breast cancer (RR = 1.05; 95% CI 1.02-1.08). We estimated that ∼5000 deaths from oropharyngeal cancer, 24 000 from esophageal SCC and 5000 from breast cancer were attributable to light drinking in 2004 worldwide. No association was found for colorectum, liver and larynx tumors.

CONCLUSIONS

Light drinking increases the risk of cancer of oral cavity and pharynx, esophagus and female breast.

Epidemiology and pathophysiology of alcohol and breast cancer: Update 2012

AIMS

To update epidemiological data on alcohol and breast cancer, with special emphasis on light alcohol consumption, and to review mechanisms of alcohol mediated mammary carcinogenesis.

METHODS

For epidemiological data, in November 2011 we performed a literature search in various bibliographic databases, and we conducted a meta-analysis of data on light alcohol drinking. Relevant mechanistic studies were also reviewed to November 2011.

RESULTS

A significant increase of the order of 4% in the risk of breast cancer is already present at intakes of up to one alcoholic drink/day. Heavy alcohol consumption, defined as three or more drinks/day, is associated with an increased risk by 40-50%. This translates into up to 5% of breast cancers attributable to alcohol in northern Europe and North America for a total of approximately 50,000 alcohol-attributable cases of breast cancer worldwide. Up to 1-2% of breast cancers in Europe and North America are attributable to light drinking alone, given its larger prevalence in most female populations when compared with heavy drinking. Alcohol increases estrogen levels, and estrogens may exert its carcinogenic effect on breast tissue either via the ER or directly. Other mechanisms may include acetaldehyde, oxidative stress, epigenetic changes due to a disturbed methyl transfer and decreased retinoic acid concentrations associated with an altered cell cycle.

CONCLUSIONS

Women should not exceed one drink/day, and women at elevated risk for breast cancer should avoid alcohol or consume alcohol occasionally only.

The relation between different dimensions of alcohol consumption and burden of disease: an overview

AIMS

As part of a larger study to estimate the global burden of disease and injury attributable to alcohol: to evaluate the evidence for a causal impact of average volume of alcohol consumption and pattern of drinking on diseases and injuries; to quantify relationships identified as causal based on published meta-analyses; to separate the impact on mortality versus morbidity where possible; and to assess the impact of the quality of alcohol on burden of disease.

METHODS

Systematic literature reviews were used to identify alcohol-related diseases, birth complications and injuries using standard epidemiological criteria to determine causality. The extent of the risk relations was taken from meta-analyses.

RESULTS

Evidence of a causal impact of average volume of alcohol consumption was found for the following major diseases: tuberculosis, mouth, nasopharynx, other pharynx and oropharynx cancer, oesophageal cancer, colon and rectum cancer, liver cancer, female breast cancer, diabetes mellitus, alcohol use disorders, unipolar depressive disorders, epilepsy, hypertensive heart disease, ischaemic heart disease (IHD), ischaemic and haemorrhagic stroke, conduction disorders and other dysrhythmias, lower respiratory infections (pneumonia), cirrhosis of the liver, preterm birth complications and fetal alcohol syndrome. Dose-response relationships could be quantified for all disease categories except for depressive disorders, with the relative risk increasing with increased level of alcohol consumption for most diseases. Both average volume and drinking pattern were linked causally to IHD, fetal alcohol syndrome and unintentional and intentional injuries. For IHD, ischaemic stroke and diabetes mellitus beneficial effects were observed for patterns of light to moderate drinking without heavy drinking occasions (as defined by 60+ g pure alcohol per day). For several disease and injury categories, the effects were stronger on mortality compared to morbidity. There was insufficient evidence to establish whether quality of alcohol had a major impact on disease burden.

CONCLUSIONS

Overall, these findings indicate that alcohol impacts many disease outcomes causally, both chronic and acute, and injuries. In addition, a pattern of heavy episodic drinking increases risk for some disease and all injury outcomes. Future studies need to address a number of methodological issues, especially the differential role of average volume versus drinking pattern, in order to obtain more accurate risk estimates and to understand more clearly the nature of alcohol-disease relationships.

Alcohol intake over the life course and mammographic density

Alcohol intake is one of the few modifiable risk factors for breast cancer. Current alcohol intake has been associated with mammographic density, a strong intermediate marker of breast cancer risk, though few studies have examined the effect of both current and average lifetime alcohol intake. We interviewed 262 participants from a New York birth cohort (born 1959-1963) and obtained mammograms from 163 (71.5% of participants with a mammogram). We collected information on alcohol intake by beverage type separately for each decade of life. We used multivariable linear models to assess the associations between current and average lifetime alcohol intake and mammographic density using a quantitative measure of density from digitized images. Overall, current alcohol intake was more strongly associated with mammographic density than average lifetime alcohol intake; compared with nondrinkers, those with current intake of seven or more servings per week had on average 12.3% (95% CI: 4.3, 20.4) higher density, adjusted for average lifetime alcohol intake, age, and body mass index. We observed a consistent inverse association for red wine intake and mammographic density, suggesting that the positive association between mammographic density and overall alcohol intake was driven by other types of alcoholic beverages. Our findings support an association between current alcohol intake and increased mammographic density independent of the effect of average lifetime alcohol intake. If replicated, our study suggests that reducing current alcohol consumption, particularly beer and white wine intake, may be a means of reducing mammographic density regardless of intake earlier in life.

Effect of prediagnostic alcohol consumption on survival after breast cancer in young women

BACKGROUND

Alcohol consumption has been comprehensively investigated as an etiologic risk factor for breast cancer but has received little attention in terms of its effect on prognosis after breast cancer, particularly for young women.

METHODS

1,286 women diagnosed with invasive breast cancer at age < or =45 years from two population-based case-control studies in the Seattle-Puget Sound region were followed from their diagnosis of breast cancer (between January 1983 and December 1992) for survival through June 2002, during which time 364 women had died. Cox proportional hazards modeling was used to assess the effect of prediagnostic alcohol consumption on the risk of dying.

RESULTS

After adjusting for age and diagnosis year, compared with nondrinkers, women who consumed alcohol in the 5 years before diagnosis had a decreased risk of death [>0 to <3 drinks per week: hazard ratio, 0.7; 95% confidence interval (95% CI), 0.6-0.95; 3 to <7 drinks per week: risk ratio, 0.6; 95% CI, 0.4-0.8;7 drinks per week: risk ratio, 0.7; 95% CI, 0.5-0.9]. This association was unchanged on additional adjustment for potential confounders including most notably treatment, stage at diagnosis, and mammogram history.

CONCLUSION

These results suggest that women who consume alcohol before a diagnosis of breast cancer have improved survival, which does not appear to be attributable to differences in stage, screening, or treatment.

Meta-analysis of Studies of Alcohol and Breast Cancer with Consideration of the Methodological Issues

OBJECTIVE

To give an up-to-date assessment of the association of alcohol with female breast cancer, addressing methodological issues and shortfalls in previous overviews.

METHODS

Meta-analysis of studies (any language) providing original data on incidence of first primary breast cancer and alcohol. Two reviewers independently extracted data. Study quality assessed by objective criteria including degree of control for confounding; funnel plots examined for publication bias; meta-regression techniques to explore heterogeneity. Risks associated with drinking versus not drinking and dose-response not constrained through the origin estimated using random effects methods.

RESULTS

Ninety-eight unique studies were included, involving 75,728 and 60,653 cases in drinker versus non-drinker and dose-response analyses, respectively. Findings were robust to study design and analytic approaches in the meta-analyses. For studies judged high quality, controlled for appropriate confounders, excess risk associated with alcohol drinking was 22% (95% CI: 9-37%); each additional 10 g ethanol/day was associated with risk higher by 10% (95% CI: 5-15%). There was no evidence of publication bias. Risk did not differ significantly by beverage type or menopausal status. Estimated population attributable risks were 1.6 and 6.0% in USA and UK, respectively.

CONCLUSIONS

Taking account of shortcomings in the study base and methodological concerns, we confirm the alcohol-breast cancer association. We compared our results to those of an individual patient data analysis, with similar findings. We conclude that the association between alcohol and breast cancer may be causal.

Alcohol consumption and mammographic density in a multiethnic population

This report examined the association between alcohol intake and breast cancer risk as assessed by mammographic densities in a multiethnic population. Information for this analysis was available from 2 previous investigations: a nutritional intervention study (The Breast, Estrogens, and Nutrition Study; BEAN) with 217 premenopausal women and a nested case-control study within The Multiethnic Cohort (MEC) with 1,250 primarily postmenopausal women. On the basis of self-reported alcohol intake from a validated food frequency questionnaire, women were categorized into abstainers (<1 drink/month), low (<1 drink/day) and high (>or=1 drink/day) alcohol consumers. On average, 3 mammograms were available per woman. Using mixed models, we calculated mean percent densities for each alcohol consumption category while adjusting for covariates. Mean alcohol intakes for women in the BEAN study and for cases and controls in the MEC study were 2.0, 2.7 and 1.8 drinks/week, respectively. Overall, the difference in densities between abstainers and the highest alcohol intake category was only 1-2% and the differences were not statistically significant. However, the difference was 3-5% for women aged 55-65 years and for breast cancer cases. In postmenopausal women without hormone replacement therapy (HRT), breast density increased by 2% for each higher alcohol intake category. Breast densities were also elevated for high alcohol consumers on estrogen-only therapy as compared to abstainers and low consumers, whereas combined HRT use was associated with higher mammographic densities independent of alcohol use. In conclusion, despite the low alcohol intake in our population, alcohol consumers had higher percent breast densities than did abstainers. The larger difference in some subgroups suggests that women with certain characteristics may be more susceptible to the influence of alcohol on breast density than others.

Prospective study of alcohol consumption and breast cancer risk in Japanese women

Epidemiologic evidence is lacking for the association between alcohol consumption and the risk of breast cancer in Japanese women. We addressed this association in a prospective cohort study with an average follow-up of 7.6 years. At baseline (1988-1990), cohort participants completed a self-administered questionnaire that included alcohol use, reproductive history and hormone use. The women were followed up for breast cancer incidence through December 31, 1997. Cox proportional hazards models were used to calculate relative risks (RRs) and 95% confidence intervals (CIs) for breast cancer incidence and any association with alcohol consumption. During a follow-up of 271,412 person-years, we identified 151 women with breast cancer, of whom 45 were current drinkers and 11 drank > or =15 g of alcohol/day. After adjustment for age and other potential risk factors for breast cancer, the RR for current drinkers was 1.27 (95% CI 0.87-1.84) compared to nondrinkers. Average alcohol intake of <15 g/day did not significantly increase the risk for breast cancer. However, risk was significantly increased for women who consumed > or =15 g/day of alcohol (RR = 2.93, 95% CI 1.55-5.54). Age at starting drinking and frequency of consumption per week were not significantly associated with breast cancer risk. Our cohort study demonstrated that Japanese women who consume at least a moderate amount of alcohol have an increased risk of breast cancer.

No relations between breast cancer risk and fatty acids of erythrocyte membranes in postmenopausal women of the Malmö Diet Cancer cohort (Sweden)

OBJECTIVE

To examine the fatty acid composition of erythrocyte membranes, in relation to obesity indexes and breast cancer risk.

DESIGN

A nested case-control study.

SETTING

The Malmö Diet Cancer cohort, Sweden.

SUBJECTS

Among women 50 y or older at baseline (n=12 803), incident breast cancer cases (n=237) were matched to controls (n=673) on age and screening date.

METHODS

A diet history method, a structured questionnaire, anthropometrics and blood samples provided data. Analysis included partial correlation coefficients between dietary fatty acids (DFA) and fatty acids of erythrocyte membranes (EFA), and Spearman's rank order correlations between EFA and four obesity indexes. Conditional logistic regression examined breast cancer risks related to EFA.

RESULTS

DFA and EFA from fish and milk, and DFA and EFA linoleic acid, show significant positive associations. Relations are negative between indexes of obesity and "milk" EFA, but positive between indexes of obesity and indexes of delta9- and delta6-desaturase enzyme activity. No significant relations were observed between EFA and breast cancer risk.

CONCLUSIONS

Similar to other studies, dietary fish and milk fatty acids, and linoleic acid, are related to the corresponding EFA. Breast cancer risk was not significantly related to EFA in this study. However, the findings suggest positive relations between body mass index, body fat per cent and indexes of desaturase activity, and negative relations between central obesity and milk EFA.

SPONSORSHIP

The Swedish Cancer Society, the Swedish Medical Research Council, the European Commission, the Swedish Dairy Association and the City of Malmö.

Exposures in childhood, adolescence and early adulthood and breast cancer risk: a systematic review of the literature

A growing body of work indicates that exposures over the life course have important roles to play in the aetiology of breast cancer. This review synthesises the literature that has been published in the area of early life events and female breast cancer risk. The review finds some evidence, primarily from cohort studies on the relationship between birthweight and breast cancer, to suggest that in utero events are related to breast cancer risk in adulthood. Strong evidence to support a positive association between height and breast cancer exists. Postulated mechanisms for this relationship include the role of early diet in subsequent disease risk, and the influence of endogenous growth factors mediating the relationship. There is some evidence to suggest that leg length is the component of height which is generating the observed associations between height and breast cancer. There is no consistent pattern of association between relative weight in childhood or adolescence and risk of breast cancer. The evidence to suggest an association between physical activity in early life and breast cancer risk is convincing from case-control studies, but is not fully substantiated by the results of three cohort studies. There are inconsistent results regarding the association between smoking at a young age and breast cancer risk. There is little evidence for an association between passive smoking in early life and breast cancer risk. No clear association between early drinking and breast cancer risk exists. These results are discussed in relation to possible underlying mechanisms and health promotion strategies which could reduce breast cancer risk.

Role of estrogen in alcohol promotion of breast cancer and prolactinomas

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Dipak K. Sarkar. The presentations were (1) Dual role of estrogen as hormone and carcinogen in mammary carcinogenesis, by Joachim G. Liehr; (2) Alcohol and breast cancer: Studies using animals, by Keith W. Singletary; and (3) Evaluation of the role of estrogen in mediation of ethanol effect on prolactinoma: Studies using animals, by Dipak K. Sarkar.

Role of estrogen in alcohol promotion of breast cancer and prolactinomas

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Dipak K. Sarkar. The presentations were (1) Dual role of estrogen as hormone and carcinogen in mammary carcinogenesis, by Joachim G. Liehr; (2) Alcohol and breast cancer: Studies using animals, by Keith W. Singletary; and (3) Evaluation of the role of estrogen in mediation of ethanol effect on prolactinoma: Studies using animals, by Dipak K. Sarkar.