Workshop Report: Identification of Research Needs in Breast Cancer Etiology

Volume 22, No. 2
2001

[Table of Contents]

Workshop Report: Identification of Research Needs in Breast Cancer Etiology

Christine Friedenreich, Loraine D Marrett, Members of the Canadian Breast Cancer Initiative Working Group on Primary Prevention of Breast Cancer and an Expert Panel

Abstract

A workshop to evaluate the scientific evidence for the etiologic associations between modifiable lifestyle and environmental risk factors and to identify areas for future research in breast cancer etiology was sponsored jointly by the Canadian Breast Cancer Initiative and the Canadian Breast Cancer Research Initiative in May, 2001. Reviews of the scientific evidence in these topics were commissioned and an expert panel was convened to consider the reviews and make recommendations for research. The panel concluded that there was substantial evidence to proceed with additional research in several areas of breast cancer etiology. Particular support for future research for several lifestyle and environmental risk factors including alcohol, diet, physical activity, anthropometric factors, hormonally active agents and occupational exposures was identified. Several emerging hypotheses for breast cancer etiology were also considered and recommendations made in these areas. Specific areas for future consideration included: insulin-like growth factors, pharmaceuticals, viruses, psychosocial factors, and functional polymorphisms. The panel also identified common themes for future research including: studies of exposures across the life cycle; research in populations with unusual exposure levels; consideration of effect modification; development of improved exposure assessment methods and use of intermediate endpoints; separation of disease subtypes by hormone receptor status, stage and tumour markers; and consideration of biological mechanisms in breast cancer etiology.

Key words: breast cancer etiology; environment; lifestyle; primary prevention; risk factors

Introduction

Breast cancer in Canada

Breast cancer is the most common cancer in Canadian women: an estimated 19,500 Canadian women will be diagnosed with breast cancer in 2001, and 5,500 will die from the disease.¹ About one in every 10 women in Canada can expect to develop breast cancer in her lifetime. Canada, along with Australia, Western Europe and the United States, has the highest incidence in the world, with rates more than four times those in low-incidence countries in Asia and Africa.²

Furthermore, incidence has been increasing over at least the past 20 years in Canada; it is now about 25% higher than that in the early 1980s.³ Fortunately, mortality has been declining in recent years, probably because of intensive efforts to implement organized mammographic screening programs in most provinces and territories and improvements in treatment.

Despite the importance of the disease and substantial international research into its etiology, only about 25-40% of breast cancer incidence in Canadian women can be attributed to identifiable risk factors.⁴Unfortunately, many of these factors are not directly modifiable (e.g., family history of breast cancer, menstrual characteristics, age at first pregnancy).

The Canadian Breast Cancer Initiative Working Group on Primary Prevention

In 1993, Health Canada established the Canadian Breast Cancer Initiative (CBCI) with a mandate to reduce breast cancer morbidity and mortality. One component of the CBCI is the Canadian Breast Cancer Research Initiative (CBCRI). The CBCRI is a separate alliance of the public, private and charitable sectors, including the major funders of medical and cancer research, fundraisers, breast cancer survivors and advocates who have worked collaboratively to promote and fund breast cancer research in Canada.

In February 2000, the CBCI established the Working Group on Primary Prevention to provide advice on priority areas for research and prevention initiatives. Given the urgent need to identify means of reducing breast cancer incidence and the lack of etiologic information that would allow such primary prevention initiatives to occur, the Working Group decided to begin by identifying research needs around modifiable risk factors. “Modifiable” includes those risk factors and behaviours that individuals as well as public health policies might be able to modify or control in some way. The Working Group explicitly excluded chemoprevention because this issue is being addressed by another CBCI component. The limited time and resources available to the Working Group also prevented the review of exogenous hormone use.

Identification of Priority Research Needs for Modifiable Breast Cancer Risk Factors

Goal, objectives and approach

The Working Group established as its first goal the identification of gaps in knowledge and research needs for breast cancer in women that will inform primary prevention research (excluding research about chemoprevention).

It identified two specific objectives, namely:

To evaluate scientific data on the etiology of breast cancer;
To provide recommendations for future research on modifiable risk factors, with particular emphasis on lifestyle and environmental risk factors and the underlying biological mechanisms involved in the etiology of breast cancer.

The Working Group adopted a two-step approach to accomplish these objectives:

Literature reviews covering specific topics;
An expert workshop.

Literature Reviews

Reviews were conducted by members of the Working Group and two additional scientists on the topics shown in Table 1.^5-15 Most of the reviews related to known or suspected modifiable lifestyle or environmental risk factors for breast cancer. A separate review considered new hypotheses and methodologic approaches in breast cancer etiology.¹³ This review included topics that were not covered by the other reviews but which may warrant further research. Two special reviews were conducted on the biological aspects of breast cancer to provide background relevant to the identification of additional fruitful avenues of research.^14,15

TABLE 1 Topics of literature reviews
General area	Reviews conducted
Known or suspected modifiable lifestyle and environmental risk factors	Smoking (active and passive) Alcohol Diet Physical activity Anthropometric factors Electromagnetic fields (EMF) Organochlorines Occupation
New etiologic hypotheses	New and emerging hypotheses and methodologic approaches
Biology	Biological mechanisms Evolutionary aspects of etiology

Each review summarized the literature and made recommendations on substantive and methodological research needs for that topic. In making their recommendations, the authors tried to identify areas that might not have traditionally received adequate or complete research attention, as these might prove particularly valuable in terms of preventive potential.

The literature reviews were presented to and critiqued by other members of the Working Group, then revised accordingly. A summary report¹⁶was prepared to provide the highlights of each literature review and its main research recommendations. The summary report and the more detailed reviews were provided as background material for the second step of the process, the expert workshop.

Expert Workshop on Primary Prevention of Breast Cancer

Nine American and Canadian experts in various areas related to breast cancer etiology were invited to attend a workshop in Quebec City on May 3, 2001. The workshop immediately preceded the Canadian Breast Cancer Research Initiative’s “Reasons for Hope 2001” Second Scientific Breast Cancer Research Conference. Members of the Working Group also attended the workshop. The names of the workshop participants are listed in the appendix.

Goal

The goal of the workshop was to develop consensus recommendations for etiologic research needs that might ultimately lead to the primary prevention of breast cancer.

Process

The workshop process is outlined in Table 2. The experts received the literature reviews prior to the workshop and were asked to

read the reviews and consider the research recommendations in them;
recommend needed revisions to these recommendations; and,
identify additional recommendations for both substantive and methodological research.

TABLE 2 Workshop process
Pre-Workshop	Literature reviews conducted by Working Group members, with research recommendations Experts read reviews and revise/identify additional research recommendations
Workshop	Small group review and consolidation of research recommendations for specific topic areas (excluding new hypotheses and approaches) Full group discussion of consolidated recommendations in specific topic areas Full group brainstorming regarding recommendations for new hypotheses and approaches Full group review of all recommendations and development of consensus for inclusion/exclusion

Each expert was individually asked to pay particular attention to three specific topics and to provide his or her recommendations for research on these prior to the workshop. The experts were not expected to critique the reviews.

At the workshop, participants were initially asked to meet in small groups focused on a set of related topics (smoking and alcohol; diet, physical activity and anthropometric factors; EMF, organochlorines and occupation; and biological mechanisms and evolutionary aspects of etiology). Each group was asked to discuss and consolidate the recommendations made by the original reviewers and by the experts. The consolidated recommendations on each topic were then presented to the remaining workshop participants and discussed. New hypotheses and methodological approaches were discussed by all workshop participants in a plenary session. Finally, workshop participants reviewed all research recommendations and agreed on areas and topics worthy of further consideration.

Workshop Results

General Discussion

There were some general issues of clarification that required discussion and resolution at the start of the workshop (Table 3).

There was also discussion of the criteria that should be used for recommending an area as worthy of consideration for future research. The criteria selected are shown in Table 4; not all need to be satisfied simultaneously.

Research Recommendations Resulting from the Workshop

The recommendations and discussion identified a number of common methodologic themes, such as suggestions for types of research or approaches to research that were considered relevant for several of the specific risk factors or exposures (Table 5). Many of these themes are expanded upon in the topic-specific recommendations.

TABLE 3 General discussion areas
Issue	Resolution
Lack of review of hormone replacement therapy as a modifiable risk factor	To be discussed as part of “new hypotheses and approaches”
Etiology of breast cancer vs. other chronic diseases	Although overlap of risk factors with those of other chronic diseases, stay focused on breast cancer
Role of multidisciplinary research	To be encouraged
Human vs. animal research into mechanistic pathways	Human studies favoured

TABLE 4
Criteria for recommending priorities
for future research

Biological plausibility

Potential for modifiability

Magnitude of the problem (i.e. strength of the association and exposure prevalence)

Feasibility to conduct research in the short term with limited budget

Level of current supportive evidence

Ability to study or measure

Unique opportunity or need within Canada

TABLE 5 Common methodologic research recommendations for studies of breast cancer etiology
Recommendation	Rationale
Consideration/study of effect modification of lifestyle/environmental exposures by: Genetic predisposition (polymorphisms, specific mutations, etc) Race/ethnicity Menopausal status Other lifestyle/environmental exposures	Effects might vary across subgroups of the population or in conjunction with other exposures.
Research in specific populations with “unusual” exposure levels or “unusual” disease risks	Populations with particularly high levels of exposure might provide more power to detect effects and might help extend the dose-response curve. Populations at high or low risk of breast cancer might also be informative.
Study of exposures across the life cycle, particularly: In “susceptible” periods (e.g., puberty, pregnancy) In utero (i.e., intergenerational studies) Early in life	Response of breast tissue to exposures must vary over the life cycle, as do exposures themselves. There might be some periods of particular susceptibility.
Improved exposure assessment: Better questionnaires Use of biomarkers Objective measures Statistical methods for measurement error	Poor assessment of exposure and lack of consideration of measurement error might mask true effects.
Development and use of intermediate endpoints as indicators of breast cancer risk: Mammographic breast density Early thelarche (start of breast development)	Often, longitudinal and mechanistic studies cannot wait for breast cancers to develop, so relevant short-term endpoints are needed. This type of research can lead to a better understanding of the natural history of the disease.
Separation into disease subtypes according to: Hormone receptor status Stage Tumour markers	Exposures might relate to risk differentially by tumour characteristics.
Consideration/study of biological mechanisms Determinants of steroid hormones, prolactin and insulin-like growth factor (IGF)-related growth factors across the life cycle	Understanding the biological mechanisms for various risk factors may lead to more fruitful avenues for etiologic research.
Use of all types of study designs where appropriate: Longitudinal Case-control Cross-sectional Descriptive Interventions with intermediate endpoints	Each design will have some limitations, thus, the most appropriate designs need to be considered and used.

Table 6 summarizes the recommendations for each of the specific topics for which background literature reviews were prepared. It includes recommendations from both the reviews and the workshop. Table 7 identifies recommendations for research in emerging topic areas. Many of these topics have not been fully investigated. Although some areas may be more speculative, most are supported by suggestive evidence and/or biological plausibility.

An examination of the biological mechanisms and evolutionary aspects of breast cancer etiology was included in the workshop discussions because understanding these areas will enhance the development and testing of relevant hypotheses on the etiology of breast cancer. For example, the importance of reproductive hormones in the etiology of breast cancer is accepted yet the relationship between levels of hormones and breast cancer is not well understood. It may be important to improve understanding of how hormones are regulated through the complex internal feedback loops, and how these loops are affected by exogenous hormonally active agents. Furthermore, it will be important to consider simultaneously effects on breast cancer risk of the range of hormones in a given metabolic pathway. These mechanisms are intrinsic to establishing biological plausibility (Table 8).

Conclusions

Although the Working Group’s focus is primary prevention, the research needs identified were actually in the area of etiology, rather than primary prevention interventions. The Working Group felt that additional research into etiologic factors with potential for primary prevention was required before large-scale intervention prevention research could be recommended. Even for those risk factors where strong evidence of association exists, much information essential to the application of practical risk reduction interventions remains unknown.

A large number of areas for potentially fruitful research into the etiology of breast cancer were identified through the background reviews and the workshop. There was no attempt to prioritize these, other than to identify those for which the need for research was considered very low. This decision was made because the Working Group wanted to stimulate innovative research in a broad range of topics potentially relevant for breast cancer etiology.

The overlap of modifiable risk factors for breast cancer with those for other common chronic diseases was noted (e.g., body weight and diabetes; physical activity and heart disease), and the resultant importance of societal change and public health policy in effecting behaviour modification that would have multiple benefits was stressed. It was agreed that general directions for public health policies that may promote breast cancer risk reduction can be developed at this time despite the fact that only limited scientific evidence regarding specific interventions for the primary prevention of breast cancer at the population or individual clinical level currently exists.

Next Steps: Stimulating Innovative Breast Cancer Etiology Research in Canada

One of the key strategic areas identified by the CBCRI is breast cancer etiology research. In its 1998 Strategic Research Agenda CBCRI identified both primary prevention and environmental agents as breast cancer risk factors of special concern. CBCRI has closely followed the progress and work of the CBCI’s Working Group on Primary Prevention of Breast Cancer since its inception. Following the workshop, on May 4, 2001, a draft request for applications for research in breast cancer etiology was approved in principle by the CBCRI Board of Directors and announced at its “Reasons for Hope 2001” conference. This major initiative in breast cancer research is intended to respond to the gaps in breast cancer etiology research identified through the literature reviews and the workshop. These literature reviews and recommendations for future research will be used as the basis for a special competition in breast cancer etiology research in Canada that the CBCRI hopes to launch in the near future.

TABLE 6 Summary of research recommendations for specific modifiable risk factors
Risk factor	Summary consensus of evidence	Specific recommendations
Smoking	Little evidence of effect. Weak biological rationale. Methodological problems with assessment of passive smoking.	Overall, low priority for research Studies in genetically defined susceptible sub-populations Assessment of in utero and early life exposures where data exist to perform efficient studies (e.g., by record linkage)
Alcohol	Risks well known and quantified for moderate levels of drinking. More research needed for high consumption and to assist in developing appropriate primary prevention strategies (e.g., identification of high-risk subgroups). Full understanding of the biological mechanisms underlying the association still needed.	Gene-exposure interaction studies Genotypes involved in alcohol metabolism Pooling across studies/centres to gain power Mechanistic studies Effect on endogenous hormones and proteins, including those not well examined (e.g., progesterone, prolactin, IGF, androgens) Effect on target tissue Study of populations with high levels of consumption Effect modification by diet, particularly folate, body mass, and physical activity More comprehensive exposure assessment Exposures early in life and over the lifecycle Role of binge drinking Study of effect modification by ethnicity Association with intermediate endpoints (e.g., breast density) Effect in relation to tumour stage and hormone receptor status
Diet, physical activity and anthropometry*	Weight control and physical activity probably linked to breast cancer. Evidence specific enough to plan interventions on weight control but not yet adequate for physical activity interventions. Evidence for a link with diet less strong. More research needed to clarify interrelationships between diet, physical activity and anthropometry and breast cancer risk.	Clinical metabolic studies of effects of specific diet, physical activity and weight control interventions on sex hormones, prolactin and IGFs Intervention trials of specific changes in these risk factors, using both intermediate and long term endpoints, that examine the relative contribution of each risk factor to breast cancer risk reduction Incorporation of high quality measures of all three factors, including relevant parameters such as frequency, intensity and duration of physical activity Characterization and effects of patterns of exposure (vs. individual, specific exposures) within and between the three factors Effects of exposures at different periods of life, particularly during fetal development and juvenile development before first pregnancy Gene-environment interactions for physical activity and anthropometric measures Study of effects of weight change during different periods of life Role of some specific dietary constituents, such as phytoestrogens
Electromagnetic fields (EMF)	Little solid evidence of a link with breast cancer, but studies to date had serious methodological flaws, limiting ability to draw firm conclusions. Since EMF exposure is ubiquitous, some additional research desirable.	Study of populations with high levels of exposure, such as in occupational settings (although assessment of non-occupational exposures also needed) High quality exposure assessment Mechanistic approaches Large studies needed so that small excess risks detectable
Hormonally active agents/environmental chemicals (HAAs)†	Although some chemicals in this class (e.g., DDT/DDE or total PCBs) are not associated with increased breast cancer risk, many others not studied are potentially important. Since exposure prevalence could be high, particularly in some population subgroups, more research needed. Particular attention to agents well recognized as highly estrogenic, e.g., atrazine.	Development of screening methods to select agents for further study Development of good exposure assessment methods Low level exposures Interrelations between compounds Measurement during critical life periods Development of analytic methods (computation models) for examining effects of complex mixtures of exposures Study in populations with very high potential exposure levels (e.g., Inuit, those living close to toxic waste sites) Studies to characterize exposure levels, susceptibility and interactions Surveillance of population exposure levels Longitudinal exposure characterization (e.g., through blood and human milk banks) Understudied HAA exposures (including individual PCB congeners) Toxic equivalency approach Identification of modifiers of HAA metabolism (polymorphisms, etc.) Effects on possible intermediate endpoints such as premature puberty or thelarche Effect modification by body mass, parity, lactation
Occupational exposures	Methodological flaws common in studies conducted to date. High quality studies needed. Possible effects of women’s work on breast cancer risk understudied. The female workforce traditionally concentrated in administrative, teaching, clerical and other indoor occupations. Some of these groups have an excess of breast cancer. Further study of exposures and other less traditional jobs relevant to breast cancer in this group may be useful.	Studies employing “best practices” in terms of specificity of exposure (e.g., active ingredients vs. job title) occupational exposure assessment power measurement and control of non-occupational exposures and potential confounders such as menopausal status examination of dose-response relationships Explore use of biomarkers such as DNA adducts in nipple aspirates or breast milk Focus on substances with a biological rationale Animal bioassays indicate potential for mammary carcinogenesis (e.g., dyes, solvents, metal oxides) Study of occupations with high proportions of women, including homemakers and administrative/clerical workers Solvents and other household chemicals Indoor air quality or other possible explanations for high breast cancer risk in some of these groups (occupational exposures vs. lifestyle or other factors)
* These risk factors were considered together because of their very strong interrelationships † The topic organochlorines was expanded to hormonally active agents/environmental carcinogens during the workshop discussions.

TABLE 7
Summary of research recommendations for new and emerging hypotheses and methodologic approaches

Risk factor

Summary consensus of evidence

Specific recommendations

Insulin-like growth factors

Growing area of research; much literature on the mechanistic relationship between IGF and ovarian function but not yet on the epidemiological side. Multidisciplinary research will be required.

Relation of tissue levels to circulating levels
Relation to mammographic density
Effects pre- vs. post-menopause
Determination if associations independent of steroid hormone levels
Relation to steroid hormone levels
Role of genetic polymorphisms
Study of how other risk factors influence IGF levels, e.g., physical activity
Study to determine what affects binding proteins and receptors

Hormone replacement therapy (HRT)

Potentially an important modifiable risk factor to study, given the large number of women using various forms of HRT. Evidence that the addition of progestin to HRT further increases breast cancer risk.

Effect of very low dosage HRT on breast cancer risk
Effect on breast tissue of delivery by patch and other methods (e.g., intravaginal), cyclical and continuous
use biomarkers and intermediate endpoints (serum levels, pharmacokinetic studies, mammographic density)
Effect modification in relation to other risk factors, particularly physical activity and body mass
Evaluation of interventions that might beneficially affect hormone levels

Other pharmaceuticals

Suggestive evidence of association with breast cancer for some classes of drugs. Further investigation needed that establishes biological plausibility.

Study of tranquilizers for possible causal mechanisms through hormonal or hormone-receptor effects
Study of cholesterol-lowering drugs because they have been shown to affect IGF receptors
Study of ovulation-stimulating drugs (e.g., clomiphene) because it might induce premature thelarche
Drug studies must include:
Control for other risk factors, including HRT, and the condition for which the drug is prescribed
Duration of use

Early life exposure

Considerable interest in this area of research, as indicated in the common research themes and specific modifiable risk factors.

Use existing national (or other) longitudinal studies of children
add biological sample collection
measure important risk factors (physical activity, diet, etc.)
use biomarkers (e.g., hormone levels) and intermediate endpoints (e.g., mammographic breast density)
Breast cancer in children born from pre-eclampsic pregnancies
record linkage studies
Effect of feeding with soy formula on age at menarche and other indicators
Effect of birth weight, being a twin on hormone levels, breast density

Viruses

Possible fruitful area for future research. Study of viruses found in tumour tissue not recommended.

Epstein-Barr virus and mouse mammary tumour virus are leading viral candidates for research currently
Investigations using stored serum samples

Functional polymorphisms and gene-gene interactions

Polymorphisms and mutations are likely to be important in identifying susceptible and non-susceptible individuals and the potential for gene-environment and gene-gene interactions. Area will be exploratory, initially, and iterative.

Development of methods to identify functional polymorphisms for study
Interaction between epidemiologists and laboratory scientists will be important
Improved statistical methods for analysing multiple markers
Establishment of banks of biological material for use once relevant markers have been identified
Need for studies with large sample sizes

Other diseases

Number of diseases might be associated with altered androgen levels that might be involved in breast cancer etiology.

Incorporation of high quality diagnostic data into studies of other diseases
record linkage studies
consider possible underlying mechanisms linking the diseases

Psychosocial factors/Stress

Stress been shown to induce immune suppression that might be linked to breast cancer. However, study in this area is methodologically challenging.

Use of high quality measures of stress, including objective ones
Role of chronic vs. acute stress
Relation of acute stress to tumour progression
Role of pregnancy as a major immune-system suppressor

TABLE 8
Summary of research recommendations for biological mechanisms and evolutionary aspects of breast cancer etiology

Biological Mechanisms:

Study of risk factors in relation to mutation rate, mitotic indices and mammary tissue differentiation

Study of known mutagens and carcinogens in human mammary epithelial cells

Study of molecular and cellular mechanisms in humans

Methods of distinguishing parous versus nulliparous breast tissue

Role of apoptosis in breast cell cultures

Evolutionary Aspects:

Meta-analyses of existing studies that examine data from an evolutionary perspective including factors such as mutation rate, number of cell divisions that occur during menarche, pregnancy, menopause

Translation of known risk factors into shared biological mechanisms (e.g., estrogen/cell division/ life span to date)

Multidisciplinary collaborations to apply basic science models to human data of breast cancer

Health Canada Representatives
Chantale Charbonneau Cancer Division Centre for Chronic Disease Prevention and Control Public Health Agency of Canada Ottawa, ON Marielle Demers Cancer Division Centre for Chronic Disease Prevention and Control Public Health Agency of Canada Ottawa, ON	Howard Njoo Cancer Division Centre for Chronic Disease Prevention and Control Public Health Agency of Canada Ottawa, ON Carol Silcoff Research and Knowledge Development Division Information Analysis and Connectivity Branch Ottawa, ON
Facilitator	Workshop proceedings
Loraine Marrett Division of Preventive Oncology Cancer Care Ontario Toronto, ON	Sheila Penney St. John’s, NF
*Authors of literature reviews but not Working Group members

Acknowledgements

This workshop and the commissioned reviews written for the workshop were supported by Health Canada’s Canadian Breast Cancer Initiative (CBCI). The workshop was also supported, in part, by the Canadian Breast Cancer Research Initiative, an alliance of the Avon Flame Foundation, Canadian Breast Cancer Foundation, Canadian Breast Cancer Network, Canadian Cancer Society, Canadian Institutes of Health Research, Health Canada, and the National Cancer Institute of Canada. The CBCI’s Working Group on the Primary Prevention of Breast Cancer extends its gratitude to the invited scientists who participated as members of the expert panel. Their willingness to participate, share their knowledge and vision and to help formulate recommendations was greatly appreciated by those present and all those with an interest in breast cancer etiology and primary prevention. Sheila Penney’s excellent workshop notes greatly facilitated preparation of this report.

For further information on the workshop and its recommendations, please contact Dr. Christine Friedenreich at the Alberta Cancer Board.

References

National Cancer Institute of Canada. Canadian Cancer Statistics 2001. Toronto: April, 2001.
GLOBOCAN 2000. Cancer Incidence, Mortality and Prevalence Worldwide. Lyon: International Agency for Research on Cancer. (www.iarc.fr), 2000.
Cancer Bureau. Breast Cancer in Canada 2000. Laboratory Centre for Disease Control, Health Canada, Ottawa, 1999.
Rockhill B, Weinberg CR, Newman B. Population attributable fraction estimation for established breast cancer risk factors: considering the issues of high prevalence and unmodifiability. Am J Epidemiol 1998;147:826-33.
Friedenreich CM. Review of diet and breast cancer. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, November 2000.
Friedenreich CM. Review of physical activity and breast cancer. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, November 2000.
Friedenreich CM. Review of anthropometric risk factors and breast cancer. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, November 2000.
Goldberg M, Faith J, Campbell S, Valois M-F. Review: The association between breast cancer and active smoking and exposure to environmental tobacco smoke. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, December 2000.
Goldberg M, Lenz S, Campbell S, Valois M-F. Review: The association between breast cancer and alcohol consumption. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, December 2000.
Goldberg M, Hollm M-G. Review: The association between breast cancer and extremely low frequency electromagnetic fields. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, December 2000.
Labrèche F. Literature review of associations between breast cancer and occupational exposures. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, December 2000.
Woolcott CG, Aronson KJ. Association between breast cancer and organochlorines: Review of epidemiologic studies and biologic mechanisms. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, February 2001.
Aronson KJ, Woolcott CG. Emerging hypotheses and methodologic approaches in breast cancer etiology. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, March 2001.
Mandeville R. Review on the mechanisms of action of some etiologic risk factors for breast cancer. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, September 2000.
Wynne-Edwards K. Breast cancer etiology and prevention from an evolutionary perspective. Report prepared for the Working Group on Primary Prevention of Breast Cancer, Canadian Breast Cancer Initiative, November 2000.
Working Group on the Primary Prevention of Breast Cancer. Summary Report: Review of Lifestyle and Environmental Risk Factors for Breast Cancer. Health Canada, Ottawa 2001.

APPENDIX
Participants: Canadian Breast Cancer Initiative (CBCI) Workshop
on the Primary Prevention of Breast Cancer, May 3, 2001

Expert Panel

Christine Ambrosone
Derald H. Ruttenberg Cancer Center
Mount Sinai School of Medicine
New York, NY

Pierre Ayotte
Université Laval
Santé environmentale
Centre de Santé publique de Québec
Beauport, QC

Rachel Ballard-Barbash
Applied Research Program
National Cancer Institute
Bethesda, MD

Louise Brinton
Environmental Epidemiology Branch
Division of Cancer Epidemiology and Genetics
National Cancer Institute
Bethesda, MD

Jo Freudenheim
Department of Social & Preventive Medicine
State University of New York
Buffalo, NY

Susan Hankinson
Harvard Medical School
Department of Medicine
Brigham and Women’s Hospital
Boston, MA

Anne McTiernan (written comments only)
Fred Hutchinson Cancer Research Center
Seattle, WA

Malcolm Pike
Keck School of Medicine
University of Southern California
Los Angeles, CA

Suzanne Snedeker
Program on Breast Cancer and Environmental Risk Factors in New York State (BCERF)
Center for the Environment
Cornell University
Ithaca, NY

Working Group Members

Kristan Aronson
Department of Community Health and Epidemiology
Queen’s University
Kingston, ON

Christine Friedenreich, Chair
Division of Epidemiology, Prevention and Screening
Alberta Cancer Board
Calgary, AB

Mark Goldberg
Department of Epidemiology and Biostatistics
McGill University
Montréal, QC

Ruth Heisey
College of Family Physicians of Canada
University of Toronto
Toronto, ON

Valerie Hepburn
Toronto Public Health
Toronto, ON

Karen DeKoning
Canadian Breast Cancer Network
Chatham, ON

France Labrèche*
Montreal Public Health Department
Joint Departments of Epidemiology and
Biostatistics and Occupational Health
McGill University
Montréal, QC

Rosemonde Mandeville
Biotech Research Institute
Montréal, QC

Carolyn Pim
Division of Epidemiology, Prevention and Screening
Alberta Cancer Board
Calgary, AB

Christy Woolcott*
Department of Community Health Sciences
University of Calgary
Calgary, AB

Katherine Wynne-Edwards
Department of Biology
Queen’s University
Kingston, ON

Author References

Christine Friedenreich, Division of Epidemiology, Prevention and Screening, Alberta Cancer Board

Loraine D Marrett, Division of Preventive Oncology, Cancer Care Ontario

Members of the Canadian Breast Cancer Initiative Working Group on Primary Prevention of Breast Cancer listed in Appendix

Members of the Expert Panel listed in Appendix

Correspondence: Dr. Christine Freidenreich, Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, 1331–29 St. NW, Calgary, Alberta T2N 4N2; Fax: (403) 270-8003; E-mail: chrisf@cancerboard.ab.ca

[Previous] [Table of Contents] [Next]


	Last Updated: 2002-09-30		Important Notices