Risk factors for breast cancer in a population with high incidence rates

Mechanistic insight and structure activity relationship of isatin-based derivatives in development of anti-breast cancer agents

Breast cancer is most common in women and most difficult to manage that causes highest mortality and morbidity among all diseases and posing significant threat to mankind as well as burden on healthcare system. In 2020, 2.3 million women were diagnosed with breast cancer and it was responsible for 685,000 deaths globally, suggesting the severity of this disease. Apart from that, relapsing of cases and resistance among available anticancer drugs along with associated side effects making the situation even worse. Therefore, it is a global emergency to develop potent and safer antibreast cancer agents. Isatin is most versatile and flying one nucleus which is an integral competent and various anticancer agent in clinical practice and widely used by various research groups around the globe for development of novel, potent, and safer antibreast cancer agents. This review will shed light on the structural insights and antiproliferative potential of various isatin-based derivatives developed for targeting breast cancer in last three decades that will help researchers in design and development of novel, potent, and safer isatin-based antibreast cancer agents.

A Flexible Method for Identifying Spatial Clusters of Breast Cancer Using Individual-Level Data

Prior research has shown that cancer risk varies by geography, but scan statistics methods for identifying cancer clusters in case-control studies have been limited in their ability to identify multiple clusters and adjust for participant-level risk factors. We develop a method to identify geographic patterns of breast cancer odds using the Wisconsin Women's Health Study, a series of 5 population-based case-control studies of female Wisconsin residents aged 20-79 enrolled in 1988-2004 (cases=16,076, controls=16,795). We create sets of potential clusters by overlaying a 1 km grid over each county-neighborhood and enumerating a series of overlapping circles. Using a two-step approach, we fit a penalized binomial regression model to the number of cases and trials in each grid cell, penalizing all potential clusters by the least absolute shrinkage and selection operator (Lasso). We use BIC to select the number of clusters, which are included in a participant-level logistic regression model. We identify 15 geographic clusters, resulting in 23 areas of unique geographic odds ratios. After adjustment for known risk factors, confidence intervals narrowed but breast cancer odds ratios did not meaningfully change; one additional hotspot was identified. By considering multiple overlapping spatial clusters simultaneously, we discern gradients of spatial odds across Wisconsin.

The System of Belief Inventory: A Validation Study in Turkish Cancer Patients

This study was conducted with the purpose of assessing validity and reliability of the System of belief inventory, which was developed to evaluate the System of belief inventory of cancer patients in Turkish society. In the present study, the result of the KMO test was determined to be 0.71, and that of Bartlett's test was 988.269; both tests were observed to be significant at p < 0.001. The Cronbach α reliability coefficient of the System of belief inventory was determined to be 0.98, and the α values of the System of belief inventory subgroups were 0.98-0.93.

An Example from the Rural Areas of Turkey: Women Breast Cancer Risk Levels and Application and Knowledge Regarding Early Diagnosis-Scan of Breast Cancer

OBJECTIVE

This research has been conducted for the purpose of determining the cancer risk levels of women living in a small village of in Saraycık village of Ankara and their knowledge and application of breast cancer early diagnose-scan methods.

MATERIALS AND METHODS

317 women were taken as examples for the study. Data were collected by giving survey forms to women and conducting face-to-face interviews. In determining breast cancer risk, "the form to determine the breast cancer risk" has been used. For breast cancer informational questions, one point has been given for each correct answer. In evaluating the data, number, percentage calculations, average and standard deviation, Mann-Whitney U (MU), Kruskal-Wallis (KW), One-way analysis of variance (F) independent sample T (t) tests have been used.

RESULTS

It has been found that breast cancer risk is low, the knowledge level about cancer early recognition methods are medium among the women. It has been determined that 74.4% women didn't perform breast self-examination. 89.6% of women don't have mammography taken and 88.6% don't have their breast examined by health personnel.

CONCLUSION

In our study, it has been found that the risk levels of women are low, their knowledge about early diagnosis and cure are at a medium level and their use of these methods are inadequate. For this reason, we suggest that responsibility of healthcare professionals have to be increased in determining breast cancer risk among women and education and advisory services for this subject to be offered.

Prevalence of Known Risk Factors in Women Diagnosed with Breast Cancer at Inmol Hospital, Lahore, Punjab

BACKGROUND

Breast cancer is the most prevalent cancer in women worldwide and its frequency is increasing gradually in many countries. Over the last three decades an increase in the breast cancer has been witnessed in the earlier low-risk Asian countries including Pakistan.

PURPOSE

The objective of the current study was to assess the prevalence of known risk factors like early menarche, late menopause, socio economic, reproductive and demographic factors, among women diagnosed with breast cancer at INMOL hospital, Lahore, Punjab, as little information exists in this regard.

MATERIALS AND METHODS

A survey study was conducted on 200 women diagnosed with breast cancer who were seen at Institute of Nuclear Medicine and Oncology (INMOL) hospital, Lahore. A structured questionnaire was administered to these patients regarding the known risk factors through face to face interviews after obtaining appropriate consent.

RESULTS

Regarding non-modifiable risk factors, our study showed that majority of the breast cancer patients were diagnosed at 35-45 years (32.5%) or at older age (≤46) and experienced menarche at 12 years or older (66 %). Likewise, a large number of patients reached menopause at the age of 45 years (60%), had no family and personal history of breast cancer (80%) and hence fell in a low risk category. Regarding modifiable risk factors in women diagnosed with breast cancer, most of the patients fell in low risk strata as the majority were married (98%) at young age, breastfed their children for 12 months or more (88%) and bore two to three children (80%). Considering income criteria, the majority of the patients had a low risk profile as they belonged to middle class (70%), urban area (60%) and were house wives (80%). However, it was noted that a considerable number of women (34%) diagnosed with breast cancer experienced menarche at an early age (<12) and reached menopause after the age of 45 years. This situation is further augmented by environmental changes and dietary habits and places them in a high risk category.

Pathological profile of patients with breast diseases in Shiraz

BACKGROUND

Around 200,000 breast disorders are annually diagnosed all over the world. Fibrocystic changes are the most common breast disorder and fibroadenoma is the most prevalent benign breast tumor. The present study aimed to determine the spectrum, type and prevalence of breast masses in women referred to Shiraz University of Medical Sciences between 2004 and 2012 .

MATERIALS AND METHODS

A cross-sectional study was conducted on the diagnostic reports data.

RESULTS

A total of 640 samples were studied. Most 57.3% of masses were detected in the left breast, 65%, 28.2% and 6.1% of cases presenting with benign, malignant, and inflammatory lesions, respectively. Among all the samples the most prevalent diagnosis (37.7%) was fibroadenoma and fibrocystic lesions (17%). 174 samples (96% of the malignant cases) were invasive. 6.5% of the benign, and 37% of the malignant cases occurred in post menopause women and the differences were statistically significant. Among those with malignant tumors lymph nodes were involved in 25.6% of menopausal women and 44.2% of non-menopausal ones, and the difference was statistically significant.

CONCLUSIONS

Regular clinical breast examination beside mammographic follow-ups, especially during menopause, should be carried out as a priority and a national organized program should be designed for screening breast disorders.

A steroid metabolizing gene variant in a polyfactorial model improves risk prediction in a high incidence breast cancer population

Background

We have combined functional gene polymorphisms with clinical factors to improve prediction and understanding of sporadic breast cancer risk, particularly within a high incidence Caucasian population.

Methods

A polyfactorial risk model (PFRM) was built from both clinical data and functional single nucleotide polymorphism (SNP) gene candidates using multivariate logistic regression analysis on data from 5022 US Caucasian females (1671 breast cancer cases, 3351 controls), validated in an independent set of 1193 women (400 cases, 793 controls), and reassessed in a unique high incidence breast cancer population (165 cases, 173 controls) from Marin County, CA.

Results

The optimized PFRM consisted of 22 SNPs (19 genes, 6 regulating steroid metabolism) and 5 clinical risk factors, and its 5-year and lifetime risk prediction performance proved significantly superior (~ 2-fold) over the Gail model (Breast Cancer Risk Assessment Tool, BCRAT), whether assessed by odds (OR) or positive likelihood (PLR) ratios over increasing model risk levels. Improved performance of the PFRM in high risk Marin women was due in part to genotype enrichment by a CYP11B2 (-344T/C) variant.

Conclusions and general significance

Since the optimized PFRM consistently outperformed BCRAT in all Caucasian study populations, it represents an improved personalized risk assessment tool. The finding of higher Marin County risk linked to a CYP11B2 aldosterone synthase SNP associated with essential hypertension offers a new genetic clue to sporadic breast cancer predisposition.

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A polyfactorial breast cancer risk assessment model (PFRM) was built and validated.

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The optimized PFRM incorporates both genetic (22 SNPs/19 genes) and clinical risk factors.

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The PFRM was further validated in a high risk USA/Marin breast cancer population.

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This PFRM consistently performed significantly better than the BCRAT (Gail model).

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A functional aldosterone synthase SNP in PFRM improved predictive performance in Marin.

Residential mobility and breast cancer in Marin County, California, USA

Marin County (California, USA) has among the highest incidences of breast cancer in the U.S. A previously conducted case-control study found eight significant risk factors in participants enrolled from 1997–1999. These included being premenopausal, never using birth control pills, lower highest lifetime body mass index, having four or more mammograms from 1990–1994, beginning drinking alcohol after age 21, drinking an average two or more alcoholic drinks per day, being in the highest quartile of pack-years of cigarette smoking, and being raised in an organized religion. Previously conducted surveys provided residential histories; while Ǫ statistic accounted for participants’ residential mobility, and assessed clustering of breast cancer cases relative to controls based on the known risk factors. These identified specific cases, places, and times of excess breast cancer risk. Analysis found significant global clustering of cases localized to specific residential histories and times. Much of the observed clustering occurred among participants who immigrated to Marin County. However, persistent case-clustering of greater than fifteen years duration was also detected. Significant case-clustering among long-term residents may indicate geographically localized risk factors not accounted for in the study design, as well as uncertainty and incompleteness in the acquired addresses. Other plausible explanations include environmental risk factors and cases tending to settle in specific areas. A biologically plausible exposure or risk factor has yet to be identified.

Oral contraceptive use and risk of breast, cervical, colorectal, and endometrial cancers: a systematic review

Oral contraceptives may influence the risk of certain cancers. As part of the AHRQ Evidence Report, Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer, we conducted a systematic review to estimate associations between oral contraceptive use and breast, cervical, colorectal, and endometrial cancer incidence. We searched PubMed, Embase, and Cochrane Database of Systematic Reviews. Study inclusion criteria were women taking oral contraceptives for contraception or ovarian cancer prevention; includes comparison group with no oral contraceptive use; study reports quantitative associations between oral contraceptive exposure and relevant cancers; controlled study or pooled patient-level meta-analyses; sample size for nonrandomized studies ≥100; peer-reviewed, English-language; published from January 1, 2000 forward. Random-effects meta-analyses were conducted by estimating pooled ORs with 95% confidence intervals (CIs). We included 44 breast, 12 cervical, 11 colorectal, and 9 endometrial cancers studies. Breast cancer incidence was slightly but significantly increased in users (OR, 1.08; CI, 1.00-1.17); results show a higher risk associated with more recent use of oral contraceptives. Risk of cervical cancer was increased with duration of oral contraceptive use in women with human papillomavirus infection; heterogeneity prevented meta-analysis. Colorectal cancer (OR, 0.86; CI, 0.79-0.95) and endometrial cancer incidences (OR, 0.57; CI, 0.43-0.77) were significantly reduced by oral contraceptive use. Compared with never use, ever use of oral contraceptives is significantly associated with decreases in colorectal and endometrial cancers and increases in breast cancers. Although elevated breast cancer risk was small, relatively high incidence of breast cancers means that oral contraceptives may contribute to a substantial number of cases.

Religion, spirituality, and health: the research and clinical implications

This paper provides a concise but comprehensive review of research on religion/spirituality (R/S) and both mental health and physical health. It is based on a systematic review of original data-based quantitative research published in peer-reviewed journals between 1872 and 2010, including a few seminal articles published since 2010. First, I provide a brief historical background to set the stage. Then I review research on R/S and mental health, examining relationships with both positive and negative mental health outcomes, where positive outcomes include well-being, happiness, hope, optimism, and gratefulness, and negative outcomes involve depression, suicide, anxiety, psychosis, substance abuse, delinquency/crime, marital instability, and personality traits (positive and negative). I then explain how and why R/S might influence mental health. Next, I review research on R/S and health behaviors such as physical activity, cigarette smoking, diet, and sexual practices, followed by a review of relationships between R/S and heart disease, hypertension, cerebrovascular disease, Alzheimer's disease and dementia, immune functions, endocrine functions, cancer, overall mortality, physical disability, pain, and somatic symptoms. I then present a theoretical model explaining how R/S might influence physical health. Finally, I discuss what health professionals should do in light of these research findings and make recommendations in this regard.

Effect of body mass index on breast cancer during premenopausal and postmenopausal periods: a meta-analysis

OBJECTIVE

There is no universal consensus on the relationship between body mass index (BMI) and breast cancer. This meta-analysis was conducted to estimate the overall effect of overweight and obesity on breast cancer risk during pre- and post-menopausal period.

DATA SOURCES

All major electronic databases were searched until April 2012 including Web of Knowledge, Medline, Scopus, and ScienceDirect. Furthermore, the reference lists and related scientific conference databases were searched.

REVIEW METHODS

All prospective cohort and case-control studies investigating the association between BMI and breast cancer were retrieved irrespective of publication date and language. Women were assessed irrespective of age, race and marital status. The exposure of interest was BMI. The primary outcome of interest was all kinds of breast cancers confirmed pathologically. Study quality was assessed using the checklist of STROBE. Study selection and data extraction were performed by two authors separately. The effect measure of choice was risk ratio (RR(i)) and rate ratio (RR(a)) for cohort studies and odds ratio (OR) in case-control studies.

RESULTS

Of 9163 retrieved studies, 50 studies were included in meta-analysis including 15 cohort studies involving 2,104,203 subjects and 3,414,806 person-years and 35 case-control studies involving 71,216 subjects. There was an inverse but non-significant correlation between BMI and breast cancer risk during premenopausal period: OR = 0.93 (95% CI 0.86, 1.02); RR(i) = 0.97 (95% CI 0.82, 1.16); and RR(a) = 0.99 (95% CI 0.94, 1.05), but a direct and significant correlation during postmenopausal period: OR = 1.15 (95% CI 1.07, 1.24); RR(i) = 1.16 (95% CI 1.08, 1.25); and RR(a) = 0.98 (95% CI 0.88, 1.09).

CONCLUSION

The results of this meta-analysis showed that body mass index has no significant effect on the incidence of breast cancer during premenopausal period. On the other hand, overweight and obesity may have a minimal effect on breast cancer, although significant, but really small and not clinically so important.

Vitamin D receptor polymorphisms and breast cancer risk in a high-incidence population: a pilot study

BACKGROUND

Marin County, CA has very high incidence of breast cancer. Traditional risk factors, such as those included in the Gail model, do not effectively stratify breast cancer in this population. This retrospective case-control pilot study evaluates DNA from volunteers from a previous Marin County breast cancer epidemiology study. A polyfactorial risk model (OncoVue; InterGenetics Incorporated) that incorporates 22 polymorphisms in 19 genes and 5 clinical risk factors was used to stratify risk in Marin County women.

STUDY DESIGN

DNA genotyping was performed on 164 Caucasian women diagnosed with primary breast cancer in Marin County from 1997 to 1999 and 174 age- and ethnicity-matched control subjects. Individual lifetime risks were determined using the polyfactorial risk model and genotype frequencies in women at elevated risk were compared with the overall genotypes.

RESULTS

The vitamin D receptor VDR ApaI A2/A2 (rs7975232) homozygous polymorphism was present in high frequency in elevated-risk women. Sixty-four percent of elevated-risk women had the VDR Apa1 A2/A2 genotype compared with only 34% in the overall study, a statistically significant 1.9-fold difference (p = 0.0003). VDR Apa1 A2/a1 and a1/a1 genotypes were also present, but in lower frequencies.

CONCLUSIONS

The high frequency of the VDR Apa1 A2/A2 homozygous polymorphism in women designated as elevated risk for breast cancer by the polyfactorial risk model might be related to the high incidence rates of breast cancer in Marin County, CA. Vitamin D supplementation could modify risk of breast cancer in this population.

Risk factors for breast cancer for women aged 40 to 49 years: a systematic review and meta-analysis

BACKGROUND

Identifying risk factors for breast cancer specific to women in their 40s could inform screening decisions.

PURPOSE

To determine what factors increase risk for breast cancer in women aged 40 to 49 years and the magnitude of risk for each factor.

DATA SOURCES

MEDLINE (January 1996 to the second week of November 2011), Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (fourth quarter of 2011), Scopus, reference lists of published studies, and the Breast Cancer Surveillance Consortium.

STUDY SELECTION

English-language studies and systematic reviews of risk factors for breast cancer in women aged 40 to 49 years. Additional inclusion criteria were applied for each risk factor.

DATA EXTRACTION

Data on participants, study design, analysis, follow-up, and outcomes were abstracted. Study quality was rated by using established criteria, and only studies rated as good or fair were included. Results were summarized by using meta-analysis when sufficient studies were available or from the best evidence based on study quality, size, and applicability when meta-analysis was not possible. Data from the Breast Cancer Surveillance Consortium were analyzed with proportional hazards models by using partly conditional Cox regression. Reference groups for comparisons were set at U.S. population means.

DATA SYNTHESIS

Sixty-six studies provided data for estimates. Extremely dense breasts on mammography or first-degree relatives with breast cancer were associated with at least a 2-fold increase in risk for breast cancer. Prior breast biopsy, second-degree relatives with breast cancer, or heterogeneously dense breasts were associated with a 1.5- to 2.0-fold increased risk; current use of oral contraceptives, nulliparity, and age 30 years or older at first birth were associated with a 1.0- to 1.5-fold increased risk.

LIMITATIONS

Studies varied by measures, reference groups, and adjustment for confounders, which could bias combined estimates. Effects of multiple risk factors were not considered.

CONCLUSION

Extremely dense breasts and first-degree relatives with breast cancer were each associated with at least a 2-fold increase in risk for breast cancer in women aged 40 to 49 years. Identification of these risk factors may be useful for personalized mammography screening.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Risk factors for breast cancer for women aged 40 to 49 years: a systematic review and meta-analysis

BACKGROUND

Identifying risk factors for breast cancer specific to women in their 40s could inform screening decisions.

PURPOSE

To determine what factors increase risk for breast cancer in women aged 40 to 49 years and the magnitude of risk for each factor.

DATA SOURCES

MEDLINE (January 1996 to the second week of November 2011), Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (fourth quarter of 2011), Scopus, reference lists of published studies, and the Breast Cancer Surveillance Consortium.

STUDY SELECTION

English-language studies and systematic reviews of risk factors for breast cancer in women aged 40 to 49 years. Additional inclusion criteria were applied for each risk factor.

DATA EXTRACTION

Data on participants, study design, analysis, follow-up, and outcomes were abstracted. Study quality was rated by using established criteria, and only studies rated as good or fair were included. Results were summarized by using meta-analysis when sufficient studies were available or from the best evidence based on study quality, size, and applicability when meta-analysis was not possible. Data from the Breast Cancer Surveillance Consortium were analyzed with proportional hazards models by using partly conditional Cox regression. Reference groups for comparisons were set at U.S. population means.

DATA SYNTHESIS

Sixty-six studies provided data for estimates. Extremely dense breasts on mammography or first-degree relatives with breast cancer were associated with at least a 2-fold increase in risk for breast cancer. Prior breast biopsy, second-degree relatives with breast cancer, or heterogeneously dense breasts were associated with a 1.5- to 2.0-fold increased risk; current use of oral contraceptives, nulliparity, and age 30 years or older at first birth were associated with a 1.0- to 1.5-fold increased risk.

LIMITATIONS

Studies varied by measures, reference groups, and adjustment for confounders, which could bias combined estimates. Effects of multiple risk factors were not considered.

CONCLUSION

Extremely dense breasts and first-degree relatives with breast cancer were each associated with at least a 2-fold increase in risk for breast cancer in women aged 40 to 49 years. Identification of these risk factors may be useful for personalized mammography screening.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Incidence of breast cancer in fars province, southern iran: a hospital-based study

BACKGROUND

Breast cancer is still considered as one of the most common female cancers worldwide regardless of the countries' level of development. This study determines the incidence of breast cancer in Fars Province, Southern Iran.

METHODS

This study used patients' records from Shiraz University of Medical Sciences Cancer Registry Centre, which is a Hospital-Based Registry of Nemazee Hospital. Data were recorded based on International Classification of Diseases for Oncology (ICD-O) and compromised all invasive cancers in ICD-10 categories of C-00 to C-80. The findings were shown as the number of cases by site (ICD-10) and gender, with crude incidence (CRs), age-specific incidence and age-standardized incidence rates (ASRs) per 100,000 persons per year, performed by direct method using the world standard population.

RESULTS

The age group of 40-49 years had the highest rate of breast cancer and naturally most cases were post-menopause ones. Most cases were diagnosed in moderate differentiated state with an increasing trend. Early diagnosis of in situ neoplasms has not increased over time in comprised with malignant cases. The number of diagnosed cases has sharply increased after year 2004 especially during post-menopause period.

CONCLUSION

As the number of diagnosed cases has increased during post-menopausal period, screening and health programs seem necessary for menopause women.

An investigation of breast cancer risk factors in Cyprus: a case control study

BACKGROUND

Breast cancer is the most common form of malignancy affecting women worldwide. It is also the leading cancer in females in Cyprus, with approximately 400 new cases diagnosed annually. It is well recognized that genetic variation as well as environmental factors modulate breast cancer risk. The main aim of this study was to assess the strength of associations between recognized risk factors and breast cancer among Cypriot women. This is the first epidemiological investigation on risk factors of breast cancer among the Cypriot female population.

METHODS

We carried out a case-control study, involving 1,109 breast cancer patients and a group of 1,177 controls who were recruited while participating in the National screening programme for breast cancer. Information on demographic characteristics and potential risk factors were collected from both groups during a standardized interview. Logistic regression analysis was used to assess the strength of the association between each risk factor and breast cancer risk, before and after adjusting for the possible confounding effect of other factors.

RESULTS

In multivariable models, family history of breast cancer (OR 1.64, 95% CI 1.23, 2.19) was the strongest predictor of breast cancer risk in the Cypriot population. Late menarche (OR 0.64, 95% CI 0.45, 0.92 among women reaching menarche after the age of 15 vs. before the age of 12) and breastfeeding (OR 0.74, 95% CI 0.59, 0.92) exhibited a strong protective effect. In the case of breastfeeding, the observed effect appeared stronger than the effect of pregnancy alone. Surprisingly, we also observed an inverse association between hormone replacement therapy (HRT) although this may be a product of the retrospective nature of this study.

CONCLUSION

Overall the findings of our study corroborate with the results of previous investigations on descriptive epidemiology of risk factors for breast cancer. This investigation provides important background information for designing detailed studies that aim to improve our understanding of the epidemiology of breast cancer in the Cypriot population, including the study of gene-environment interactions. Furthermore, our study provides the first scientific evidence for formulating targeted campaigns for prevention and early diagnosis of breast cancer in Cyprus.

Recent trends in hormone therapy utilization and breast cancer incidence rates in the high incidence population of Marin County, California

Background

Recent declines in invasive breast cancer have been reported in the US, with many studies linking these declines to reductions in the use of combination estrogen/progestin hormone therapy (EPHT). We evaluated the changing use of postmenopausal hormone therapy, mammography screening rates, and the decline in breast cancer incidence specifically for Marin County, California, a population with historically elevated breast cancer incidence rates.

Methods

The Marin Women's Study (MWS) is a community-based, prospective cohort study launched in 2006 to monitor changes in breast cancer, breast density, and personal and biologic risk factors among women living in Marin County. The MWS enrolled 1,833 women following routine screening mammography between October 2006 and July 2007. Participants completed a self-administered questionnaire that included items regarding historical hormone therapy regimen (estrogen only, progesterone only, EPHT), age of first and last use, total years of use, and reason(s) for stopping, as well as information regarding complementary hormone use. Questionnaire items were analyzed for 1,083 non-Hispanic white participants ages 50 and over. Breast cancer incidence rates were assessed overall and by tumor histology and estrogen receptor (ER) status for the years 1990-2007 using data from the Northern California Surveillance, Epidemiology and End Results (SEER) cancer registry.

Results

Prevalence of EPHT use among non-Hispanic white women ages 50 and over declined sharply from 21.2% in 1998 to 6.7% by 2006-07. Estrogen only use declined from 26.9% in 1998 to 22.4% by 2006-07. Invasive breast cancer incidence rates declined 33.4% between 2001 and 2004, with drops most pronounced for ER+ cancers. These rate reductions corresponded to declines of about 50 cases per year, consistent with population attributable fraction estimates for EPHT-related breast cancer. Self-reported screening mammography rates did not change during this period. Use of alternative or complementary agents did not differ significantly between ever and never hormone users. Of women who reported stopping EPHT in the past 5 years, 60% cited "health risks" or "news reports" as their primary reasons for quitting.

Conclusion

A dramatic reduction in EPHT use was followed temporally by a significant reduction in invasive and ER+ breast cancer rates among women living in Marin County, California.

Use and perception of hormone therapy following media reports of the Women's Health Initiative: a survey of Australian WISDOM participants

OBJECTIVES

To investigate the impact of the Women's Health Initiative (WHI) on the use and perception of hormone therapy (HT) in well-informed and altruistic women who had volunteered for a similar long-term study of HT (Women's International Study of long Duration Oestrogen after Menopause, WISDOM).

METHODS

A total of 840 South Australian WISDOM participants were sent questionnaires asking about their source of information about the WHI, interpretation of the 2002 WHI findings, perception of HT as a risk factor for breast cancer, attitudes towards doctors and the media and intent to use HT in the future.

RESULTS

Altogether, 618 participants (74%) responded. Written and verbal information provided by WISDOM were rated as the most helpful sources of information about the WHI. Participants were aware of the increase in breast cancer and decrease in fractures seen with combined estrogen/progestogen hormone therapy (EPT) but were less convinced about the other major findings, including cardiovascular disease and dementia. HT was rated as an important risk factor for breast cancer. Participants valued medical research and were more likely to question therapies without evidence. After WHI and WISDOM, most were willing to participate in a subsequent trial and most past HT users resumed therapy.

CONCLUSIONS

There are sufficient recruits for future long-term HT studies if they are given sufficient quality information and individual counselling. Our study also suggests that women who are appropriately informed may choose to take long-term HT despite a more conservative approach advised by some agencies.

Differences in reproductive risk factors for breast cancer in middle-aged women in Marin County, California and a sociodemographically similar area of Northern California

Background

The Northern California county of Marin (MC) has historically had high breast cancer incidence rates. Because of MC's high socioeconomic status (SES) and racial homogeneity (non-Hispanic White), it has been difficult to assess whether these elevated rates result from a combination of established risk factors or other behavioral or environmental factors. This survey was designed to compare potential breast cancer risks and incidence rates for a sample of middle-aged MC women with those of a demographically similar population.

Methods

A random sample of 1500 middle-aged female members of a large Northern California health plan, half from Marin County (MC) and half from a comparison area in East/Central Contra Costa County (ECCC), were mailed a survey covering family history, reproductive history, use of oral contraceptives (OC) and hormone replacement therapy (HRT), behavioral health risks, recency of breast screening, and demographic characteristics. Weighted data were used to compare prevalence of individual breast cancer risk factors and Gail scores. Age-adjusted cumulative breast cancer incidence rates (2000–2004) were also calculated for female health plan members aged 40–64 residing in the two geographic areas.

Results

Survey response was 57.1% (n = 427) and 47.9% (n = 359) for MC and ECCC samples, respectively. Women in the two areas were similar in SES, race, obesity, exercise frequency, current smoking, ever use of OCs and HRT, age at onset of menarche, high mammography rates, family history of breast cancer, and Gail scores. However, MC women were significantly more likely than ECCC women to be former smokers (43.6% vs. 31.2%), have Ashkenazi Jewish heritage (12.8% vs. 7.1%), have no live births before age 30 (52.7% vs. 40.8%), and be nulliparous (29.2% vs. 15.4%), and less likely to never or rarely consume alcohol (34.4% vs. 41.9%). MC and ECCC women had comparable 2000–2004 invasive breast cancer incidence rates.

Conclusion

The effects of reproductive risks factors, Ashkenazi Jewish heritage, smoking history, and alcohol consumption with regard to breast cancer risk in Marin County should be further evaluated. When possible, future comparisons of breast cancer incidence rates between regions should adjust for differences in income and education in addition to age and race/ethnicity, preferably by using a sociodemographically similar comparison group.

Religion and reduced cancer risk: what is the explanation? A review

Several studies of members of Christian religious communities have shown significantly lower risks for certain cancers amongst members than in the general population. We identified 17 epidemiological studies of the risk for cancer amongst members of Christian communities published during the past 40 years. In the studies in which adjustment was made only for age and sex, reductions were observed in the risks for lifestyle-associated cancers, i.e. those associated with tobacco smoking, alcohol consumption, diet, physical activity and reproductive factors. In the studies in which adjustment was also made for healthy habits, no reduction in risk for cancer was observed. We conclude that the most important factor in the correlation between membership in a religious Christian community and risk for cancer is the healthy lifestyle inherent in religious practice in these communities. The epidemiological studies reviewed did not, however, differentiate the effect on cancer risk of the meaning that a certain lifestyle can give to an individual.

Inhibition of Caco-2 colon, MCF-7 and Hs578T breast, and DU 145 prostatic cancer cell proliferation by water-soluble black bean condensed tannins

The potential anti-angiogenic activities of water-soluble condensed tannins isolated from black beans were evaluated using HEL 299 normal human fibroblast lung cells, Caco-2 colon, MCF-7 and Hs578T breast, and DU 145 human prostatic cancer cells. Condensed tannins at 0.24-24 microM did not affect the growth of normal cells, but dose-dependently induced cancer cell death by apoptosis as shown by a concentration-dependent decrease in ATP and cell gross morphology. After 24h exposure to Caco-2, MCF-7, Hs578T, and DU 145 cancer cells, water-soluble black bean condensed tannins at 24 microM suppressed fetal bovine serum stimulated cell migration, the secretion of matrix metalloproteinase-2 (MMP-2 or gelatinase A), matrix metalloproteinase-9 (MMP-9 or gelatinase B), and vascular endothelial growth factor VEGF(165) receptor expression by the cancer cells in the conditioned media. The potential health enhancing properties of condensed tannins from black beans as inhibitors of angiogenesis is discussed.

Recent changes in breast cancer incidence and risk factor prevalence in San Francisco Bay area and California women: 1988 to 2004

Introduction

Historically, the incidence rate of breast cancer among non-Hispanic white women living in the San Francisco Bay area (SFBA) of California has been among the highest in the world. Substantial declines in breast cancer incidence rates have been documented in the United States and elsewhere during recent years. In light of these reports, we examined recent changes in breast cancer incidence and risk factor prevalence among non-Hispanic white women in the SFBA and other regions of California.

Methods

Annual age-adjusted breast cancer incidence and mortality rates (1988 to 2004) were obtained from the California Cancer Registry and analyzed using Joinpoint regression. Population-based risk factor prevalences were calculated using two data sources: control subjects from four case-control studies (1989 to 1999) and the 2001 and 2003 California Health Interview Surveys.

Results

In the SFBA, incidence rates of invasive breast cancer increased 1.3% per year (95% confidence interval [CI], 0.7% to 2.0%) in 1988–1999 and decreased 3.6% per year (95% CI, 1.6% to 5.6%) in 1999–2004. In other regions of California, incidence rates of invasive breast cancer increased 0.8% per year (95% CI, 0.4% to 1.1%) in 1988–2001 and decreased 4.4% per year (95% CI, 1.4% to 7.3%) in 2001–2004. In both regions, recent (2000–2001 to 2003–2004) decreases in invasive breast cancer occurred only in women 40 years old or older and in women with all histologic subtypes and tumor sizes, hormone receptor-defined types, and all stages except distant disease. Mortality rates declined 2.2% per year (95% CI, 1.8% to 2.6%) from 1988 to 2004 in the SFBA and the rest of California. Use of estrogen-progestin hormone therapy decreased significantly from 2001 to 2003 in both regions. In 2003–2004, invasive breast cancer incidence remained higher (4.2%) in the SFBA than in the rest of California, consistent with the higher distributions of many established risk factors, including advanced education, nulliparity, late age at first birth, and alcohol consumption.

Conclusion

Ongoing surveillance of breast cancer occurrence patterns in this high-risk population informs breast cancer etiology through comparison of trends with lower-risk populations and by highlighting the importance of examining how broad migration patterns influence the geographic distribution of risk factors.

Breast Cancer among Immigrants: A Systematic Review and New Research Directions

This paper highlights the relationship between migration and female breast cancer. A comprehensive review aimed at identifying risk and protective factors that cut across races and ethnicities was performed. A total of 79 studies (1971-2005) from 16 countries were reviewed. The findings are consistent with existing knowledge about the importance of potentially modifiable environmental and behavioral determinants of risk, acting both pre- and post-migration. While the acculturation-based risk transition model is strong, it is not always supported. As a new direction for migrant studies, we extrapolate the review findings to the experience of Eastern European (EE) immigrants. Health data on this population, typically characterized by low health motivation and passive receipt of preventive efforts, are largely unavailable. Based on relevant theory, empirical and qualitative studies, two breast cancer prevention models for the EE immigrant population are proposed and the need for future research using ethnically disaggregated data is discussed.

Effects of a telephone counseling intervention on sisters of young women with breast cancer

OBJECTIVE

Women that have a first-degree relative diagnosed with breast cancer at an early age are at increased risk of the disease, yet they often lack information about their personal risk of breast cancer and early detection measures. An intervention to provide objective risk information, reduce worries, and promote screening and healthy behaviors was developed.

METHOD

In 1999-2002, a randomized pre-post design was used to test a tailored telephone counseling intervention with a sample of 163 women whose sisters were diagnosed with breast cancer at age 50 or younger in the San Francisco Bay Area. Participants were interviewed by telephone regarding their breast cancer risk factors, perceived risk, worries, lifestyle factors, and screening behavior. A modified Gail model was used to compute an objective measure of individualized lifetime risk.

RESULTS

Risk overestimates averaged 25 percentage points. The intervention was effective in reducing overestimates in women age 50 and over but not in those under 50. The intervention was effective in increasing physical activity and reinforcing the conviction to maintain good breast health, but not in decreasing worries or increasing screening.

CONCLUSION

Telephone counseling appears to be a viable tool for reducing risk overestimates and promoting healthy behaviors among sisters of women with breast cancer.

Breast cancer incidence trends in deprived and affluent Scottish women

OBJECTIVE

Breast cancer is commoner in the affluent and breast cancer rates in many countries are rising; it remains unclear whether this incidence rise is consistent across the different socio-economic groups. The rising incidence of breast cancer may be related to changes in population risk factor profiles. This study aimed to determine breast cancer incidence trends in women of different socio-economic categories and whether these trends were related to breast cancer risk factor trends.

DESIGN

Data on breast cancer incidence rates by deprivation quintile in Scotland 1991-2000 were analysed using linear regression. Data on first births at late maternal age, BMI trends (based on the Scottish Health Surveys) and breast screening uptake trends in the different categories were also analysed and their relation to breast cancer incidence trends explored.

POPULATION AND SETTING

Breast cancer incidence data was based on all women in Scotland. BMI data was based on representative cross-sectional survey data from the Scottish Health Surveys-women in the 1995, 1998 and 2003 surveys were 16-64, 16-74 and aged 16 and over, respectively. First birth data was based on all women aged 35-39 in Scotland. Breast screening uptake data was studied in women of screening age, that is, aged 50-64.

RESULTS

Breast cancer incidence rates in Scottish women are rising in parallel across all socio-economic categories and the incidence gap between deprived and affluent still remains. Since the late 1980s, numbers of first birth in Scottish women aged 35-39 have risen dramatically, especially in the affluent, but numbers were stable before this. The prevalence of obesity and mean BMI has increased over time in all socio-economic classes but BMI continues to be higher in the deprived. Uptake of screening invitations has increased in all socio-economic groups.

CONCLUSIONS

Breast cancer is rising in women of all socio-economic status in Scotland and the deprived-affluent gap remains. Trends in late age at first pregnancy, prevalence of obesity and screening uptake do not fully explain the observed trends.

Population attributable risk of breast cancer in white women associated with immediately modifiable risk factors

BACKGROUND

Estrogen/progestin replacement therapy (EPRT), alcohol consumption, physical activity, and breast-feeding duration differ from other factors associated with breast cancer in being immediately modifiable by the individual, thereby representing attractive targets for future breast cancer prevention efforts. To justify such efforts, it is vital to quantify the potential population-level impacts on breast cancer considering population variations in behavior prevalence, risk estimate, and baseline incidence.

METHODS

For each of these four factors, we calculated population attributable risk percents (PARs) using population-based survey (2001) and cancer registry data (1998-2002) for 41 subpopulations of white, non-Hispanic California women aged 40-79 years, and ranges of relative risk (RR) estimates from the literature.

RESULTS

Using a single RR estimate, subpopulation PARs ranged from 2.5% to 5.6% for hormone use, from 0.0% to 6.1% for recent consumption of > or = 2 alcoholic drinks daily, and 4.6% to 11.0% for physical inactivity. Using a range of RR estimates, PARs were 2-11% for EPRT use, 1-20% for alcohol consumption and 2-15% for physical inactivity. Subpopulation data were unavailable for breastfeeding, but PARs using published RR estimates ranged from 2% to 11% for lifetime breastfeeding > or = 31 months. Thus, of 13,019 breast cancers diagnosed annually in California, as many as 1,432 attributable to EPRT use, 2,604 attributable to alcohol consumption, 1,953 attributable to physical inactivity, and 1,432 attributable to never breastfeeding might be avoidable.

CONCLUSION

The relatively feasible lifestyle changes of discontinuing EPRT use, reducing alcohol consumption, increasing physical activity, and lengthening breastfeeding duration could lower population breast cancer incidence substantially.

Breast Cancer Screening in Women Surviving Hodgkin Disease

OBJECTIVE

To inform female Hodgkin disease (HD) survivors, younger than 35 at diagnosis, of their increased risk for breast cancer and encourage them to seek breast cancer screening.

METHODS

An evidence-based intervention, telephone counseling, was used in a pre-post test design, randomized trial with the control group being offered the intervention following the post-test. Women treated at Stanford University who received thoracic irradiation before age 35, alive and HD-free at last contact, were referred to the project (n = 471). Of 261 eligible women who could be located, 157 completed the pretest and were randomized (60% response rate) and 133 completed the post-test (85% retention rate).

RESULTS

There was a positive intervention effect on mammography maintenance: the odds of being in maintenance at post-test compared with pretest were greater in the intervention group than in the control group [odds ratio (OR) = 3.6]. Women were more likely to be in mammography maintenance at pre- or post-test if at pretest they were married (OR = 5.7), employed (OR = 2.3), more worried about breast cancer (OR = 1.4 per unit of scale), or received an annual physical examination (OR = 2.2). Women under age 40 were much less likely to be in maintenance than were those age 45 and over (age 35-39, OR = 0.2; under age 35, OR = 0.07).

CONCLUSIONS

The findings indicate that providing risk information encourages cancer survivors to take health preventive actions. Telephone counseling is a method that can provide risk information and is easily transferable to settings where people seek health information, such as telephone information lines.

Influence of nativity status on breast cancer risk among US black women

Black women are at increased risk for breast cancer mortality. The black category is assumed to be homogeneous, an assumption that may be misleading. This study aims to examine the relationship between nativity and breast cancer risk factors among women identified as black. A sample of 236 black women over 18 years of age in Brooklyn, New York, was recruited. Data were collected on race/ethnicity, breast cancer risk factors, and other sociodemographic, behavioral, and early life experience factors. Logistic regression analyses were used to estimate prevalence ratios for association between nativity and breast cancer risk factors. US-born blacks were more likely to be unemployed, smoke, not breastfeed, and breastfeed for a shorter duration than foreign-born blacks (all p< or =0.01). Foreign-born blacks were more likely to have parents who achieved at least a high school education (p<0.05). After adjustment for smoking, employment, and parental education, US-born blacks were twice as likely to never breastfeed (PR 2.2, 95% CI: 1.1, 4.46) compared to foreign-born blacks. Among women who breastfed, US-born blacks were also less likely to breastfeed for 6-11 months or more than 12 months, but these associations were not statistically significant. Because lactation reduces breast cancer risk and is a leading modifiable risk factor, understanding its variation within black women will help physicians and public health practitioners to target patient counseling and education of breast cancer risk.

Science and society: the Long Island Breast Cancer Study Project

In the early 1990s, breast cancer advocates petitioned the United States Congress to investigate the high rates of breast cancer on Long Island in the state of New York. The resulting law led to the Long Island Breast Cancer Study Project (LIBCSP)--more than ten research projects designed to study the possible causes of this increased incidence of cancer. This project reported that there was no evidence that environmental exposures were responsible. Controversial from its start, the LIBCSP has had an important role in efforts to understand the reasons for the high rates of breast cancer in some regions of the United States.

Dietary patterns and the risk of postmenopausal breast cancer

The association between individual foods and breast cancer has been inconsistent. Therefore, we examined the association between diet and risk of postmenopausal breast cancer by the alternative approach of dietary patterns. Dietary patterns were identified with factor analysis from food consumption data collected from a food frequency questionnaire in 1984. Relative risks were computed using proportional hazard models and adjusted for known risk factors for breast cancer. Between 1984 and 2000, we ascertained 3,026 incident cases of postmenopausal breast cancer. We identified 2 major dietary patterns. The prudent pattern is characterized by higher intake of fruits, vegetables, whole grains, low-fat dairy products, fish and poultry, while the Western pattern is characterized by higher intake of red and processed meats, refined grains, sweets and desserts and high-fat dairy products. Neither of the patterns was associated with overall risk of postmenopausal breast cancer. However, a positive association between the Western pattern score was observed among smokers at baseline (relative risk = 1.44, comparing top to bottom quintiles; 95% CI = 1.02-2.03; p for trend = 0.03). An inverse association was observed between the prudent pattern and estrogen receptor-negative cancer (relative risk = 0.62; 95% CI = 0.45-0.88; p for trend = 0.006). Among the major food groups, higher consumptions of fruits (relative risk for 1 serving/day increase = 0.88; 95% CI = 0.80-0.97; p = 0.009) and vegetables (relative risk = 0.94; 95% CI = 0.88-0.99; p = 0.03) were significantly associated with decreased risk for ER(-) breast cancer. In conclusion, we did not observe an overall association between the prudent or Western pattern and overall breast cancer risk. However, a Western-type diet may elevate risk of breast cancer among smokers, and a prudent diet may protect against estrogen receptive-negative tumors.

Residential mobility in the California Teachers Study: implications for geographic differences in disease rates

BACKGROUND

Especially for cancers with long latency periods, such as breast cancer, the issue of residential mobility hinders ecologic analyses seeking to examine the role of environmental contaminants in chronic disease etiology. This study describes and evaluates characteristics associated with residential mobility in a sub-sample of the California Teachers Study (CTS) cohort.

METHODS

In 2000, lifetime residential histories were collected for a sub-sample of 328 women enrolled in the CTS; women's degree of residential mobility and associated factors were analyzed.

RESULTS

While most women moved many times during their lives (average = 8.9), the average number of years at their residence when they enrolled in the study was reasonably long (15.1 years). Age strongly predicted duration at current residence but was not related to the number of lifetime residences. After adjusting for age, California-born women and women living in high socioeconomic status (SES) neighborhoods were significantly more residentially stable. Agreement between self-reported urbanization of recent residences and that based on census data of the geocoded residences was very good (80% concordant). Among women currently living in urban areas, an average of 43.3 years, or 77%, of their lifetimes were spent in urban residences; among women currently living in a rural area, an average of 37.3 years, or 67% of their lifetimes were spent in rural residences.

CONCLUSIONS

This suggests that analyses of incidence rates based on current residence, while not capturing a woman's full exposure history, may reasonably reflect some aspect of longer term chronic exposures, especially those related to urbanization, at least in professional women.

Evaluation and outcome of behavioural changes in the rehabilitation of cancer patients: a review

The global increase in the number of newly diagnosed cancers has led in most affected countries to increased numbers of cancer survivors, who have specific needs for physical and psychosocial rehabilitation. In spite of recent progress, little is known about the specific rehabilitation measures that could increase the quality of life for cancer survivors. We reviewed published interventions that focussed on changing known risk factors for cancer recurrence and improving physical well-being; those we selected were exercise, smoking, alcohol consumption, diet and the use of sun screens. The published trials varied in the quality of the methods used, often had inadequate sample sizes and showed difficulty in validating outcomes. We conclude that there is still insufficient evidence to assess the importance of these behavioural risk factors in the rehabilitation of cancer patients. Future interventions should be designed to assess the separate effects of dietary changes, exercise and psychosocial interventions.

Origins and evolution of cell phenotypes in breast tumors

This study presents a stochastic model that correlates genomic instability with tumor formation. The model describes the time- and space-variant volumetric concentrations of cancer cells of various phenotypes in a breast tumor. The cells of epithelial origin in the cancerous breast tissue are classified into four different phenotypes, normal epithelial cells and the grade 1, grade 2 and grade 3 cancer cell types with increasing potential for growth and invasion. Equations governing the time course of volumetric concentrations of cell phenotypes are derived by using the principle of conservation of mass. Cell migration into and from the stroma is taken into account. The transformations between cell phenotypes are due to genetic inheritance and chromosome aberrations. These transformations are assumed to be stochastic functions of the local cell concentration. The simulations of the model for planar geometry replicate the shapes of human breast tumors and capture the time history of tumor growth in animal models. Simulations point to transformation of tumor cell population from heterogeneous compositions to a single phenotype at advanced stages of invasive tumors. Systematic variations of model parameters in the computations indicate the important roles the migration capacity, proliferation rate, and phenotype transition probability play in tumor growth. The model developed provides realistic simulations for standard breast cancer therapies and can be used in the optimization studies of chemotherapy, radiotherapy, hormone therapy and emerging individualized therapies for cancer.

Oligogenic combinations associated with breast cancer risk in women under 53 years of age

Common, but weakly penetrant, functional polymorphisms probably account for most of the genetic risk for breast cancer in the general population. Current polygenic risk models assume that component genes act independently. To test for potential gene-gene interactions, single nucleotide polymorphisms in ten genes with known or predicted roles in breast carcinogenesis were examined in a case-control study of 631 Caucasian women diagnosed with breast cancer under the age of 53 years and 1,504 controls under the age of 53 years. Association of breast cancer risk with individual genes and with two- and three-gene combinations was analyzed. Sixty-nine oligogenotypes from 37 distinct two- and three-gene combinations met stringent criteria for significance. Significant odds ratios (ORs) covered a 12-fold range: 0.5-5.9. Of the observed ORs, 17% differed significantly from the ORs predicted by a model of independent gene action, suggesting epistasis, i.e., that these genes interact to affect breast cancer risk in a manner not predictable from single gene effects. Exploration of the biological basis for these oligogenic interactions might reveal etiologic or therapeutic insights into breast cancer and other cancers.

Alcohol Exposure and Breast Cancer: Results of the Women's Contraceptive and Reproductive Experiences Study

Objectives: To explore associated biological outcomes and clarify the role of timing of exposure in the alcohol-breast cancer relationship.

Methods: In a population-based study of 4,575 women ages 35 to 64 years diagnosed with invasive breast cancer between 1994 and 1998 and 4,682 controls, we collected details of lifetime alcohol use and factors that could confound or modify the alcohol-breast cancer relationship. We used conditional logistic regression to compute the odds of breast cancer among drinkers relative to nondrinkers at all ages and at ages 35 to 49 and 50 to 64 years separately.

Results: Recent consumption (at reference age minus two) of ≥7 drinks per week was associated with increased risk [odds ratio (OR), 1.2; 95% CI, 1.01-1.3] and evidence of dose response was observed. Most of the excess was observed among women ages 50-64 years (OR 1.3; 95% CI, 1.1-1.6), although the test for age interaction was not statistically significant. Exposure later in life seemed more important than early exposure. Excess breast cancer associated with recent consumption was restricted to localized disease. When outcome was examined according to tumor hormone receptor status, highest risks were observed for estrogen receptor–positive/progesterone receptor–negative tumors (OR 1.6; 95% CI, 1.2-2.3).

Conclusions: The effect of timing of alcohol exposure on breast cancer risk is complicated and will require additional study focused on this one issue. Further work is needed to explain how alcohol exposure, sex hormones, and tumor receptor status interact.

Patterns of Alcohol Consumption and Breast Cancer Risk in the California Teachers Study Cohort

Alcohol consumption of approximately two drinks or more per day has been associated with elevated breast cancer risk in the California Teachers Study cohort as well as in many other populations. The objective of this analysis is to examine effects of age at drinking and drinking patterns and to identify effect modifiers. Of the 103,460 at-risk cohort members, age &lt;85, who resided in California and completed the baseline alcohol assessment, 1,742 were diagnosed with invasive breast cancer after joining the cohort and before January 2001. Incident breast cancers were identified through the California Cancer Registry and follow-up for death and confirmation of continued California residence used various sources. Multivariate Cox proportional hazards regression models were used to estimate relative risks (RRs). Elevated breast cancer risk was most evident for recent drinking [RR = 1.28, 95% confidence interval (CI): 1.06–1.54 for ≥20 g/day versus nondrinkers], with no clear pattern for consumption during earlier periods of life. This elevation in risk was 32% among postmenopausal women (95% CI: 1.06–1.63) and 21% among pre/perimenopausal women (95% CI: 0.76–1.92). Highest risks associated with heavy alcohol consumption were observed among postmenopausal women with a history of biopsy-diagnosed benign breast disease (RR = 1.97, 95% CI: 1.39–2.79 compared to nondrinkers without benign breast disease) or who had used combination hormone replacement therapy (HRT) (RR = 2.24, 95% CI: 1.59–3.14 compared to nondrinkers who never used HRT). Recent alcohol consumption equivalent to two or more drinks per day increases the risk of invasive breast cancer, with the greatest RRs observed among heavy drinkers who are also postmenopausal and have a history of benign breast disease or who use HRT.

Breast cancer in Marin County

Two articles previously published in Breast Cancer Research illustrate the high rates of breast cancer in Marin County, a wealthy, urban county immediately northwest of the city of San Francisco. I herein comment on these articles, and on the political/psychological/scientific dilemma presented by regions with high cancer rates, such as Marin County. I discuss possible causes for such cancer 'clusters', and conclude with some thoughts about the future.