MBCW Research

MBCW is an established leader in conducting breast cancer research and has redefined the way community organizations can participate in scientific studies. With a commitment to look at potential environmental causes of breast cancer, MBCW has created a unique and effective approach to breast cancer research.

MBCW has a simple belief: the people who live in a particular community can be invaluable contributors to the research process. That is why MBCW created an innovative way to conduct breast cancer research:

LISTEN > PARTNER > RESEARCH > COMMUNICATE > ACTION

We LISTEN to the concerns of our community, then PARTNER with scientists and researchers from established institutions to conduct original breast cancer RESEARCH. Once scientific research is completed, we COMMUNICATE the findings back to the community to help prompt ACTION – either for more research studies or to impact public policy.

MBCW has collaborated with scientific researchers from the University of California, San Francisco; Lawrence Berkeley Laboratories; Kaiser Permanente; the Marin County Health Department, and many other partners to conduct breast cancer research in Marin.

What is community-based research?

Community-based research is a process by which members of a community identify a problem, engage outside researchers in a collaborative that promotes co-learning, and achieve a balance between research and action.

Bay Area Breast Cancer and the Environment Research Center

In October 2003, the National Institute of Environmental Health Sciences funded a breast cancer research center in the Bay Area that will look at breast cancer and the environment.

The Bay Area Breast Cancer and the Environment Research Center is one of four research centers created by the National Institute of Environmental Health Sciences (NIEHS) and the National Cancer Institute (NCI) to investigate potential environmental factors that could lead to breast cancer.

The Center is a collaborative effort among Bay Area institutions, researchers, scientists and advocacy groups to harness the expertise in the region and work together to better understand the causes of breast cancer and what can be done to prevent it.

Initially, there will be two main areas of research focus. One project will study how the developmental steps of the mammary gland and use mouse models to test the effects of exposure to potential environmental stressors. The second project will be to conduct an epidemiological study of the determinants of puberty in girls. Attention will be paid to understanding the shift toward earlier puberty among adolescent girls, the identification of environmental exposures in young girls, and the interplay between genetic polymorphisms and environmental exposures that may put them at risk for future breast cancer.

One of the strengths of the Center will be its commitment to communicate its efforts with the local community. Marin Breast Cancer Watch will lead the Community Outreach and Translational Core (COTC), which seeks to facilitate two-way communication between scientists and the community.

The effort to a secure a Center in the Bay Area started last year after Marin Breast Cancer Watch co-hosted a town hall meeting with the UC Berkeley NIEHS Center titled: “Voices for a Healthy Community: Breast Cancer and the Environment.” The town hall created a dialogue between scientists and the community on breast cancer, identified areas of future breast cancer research, and created opportunities for further collaboration among cancer groups, concerned health professionals, scientists, public policy advocates, government officials and community members.

At the town hall, NIEHS Director Dr. Kenneth Olden announced the agency would award funding for centers in the coming year. A Bay Area group soon formed and began drafting a proposal. Shortly thereafter, Rep. Lynn Woolsey (D-Calif.) helped secure a commitment from four federal health agencies to study Marin County’s breast cancer rate and allocate resources for the effort.

The Research Center and the other centers in a national network supported by the NIH will focus attention on adolescence, a vulnerable period of breast development thought to play a critical role in the future development of breast cancer.

The BABCERC has a broad group of collaborators, including the University of California, San Francisco; Lawrence Berkeley National Laboratories; Kaiser Permanente; California DHS; Marin Breast Cancer Watch; San Francisco DHHS; the Marin County Health Department; and Roswell Park Cancer Institute.

Completed Research Studies:

The Adolescent Risk Factors Study (ARFS)

Authors: Margaret Wrensch, Terri Chew, Georgianna Farren, Janice Barlow, Flavia Belli, Christina Clarke,
Christine A. Erdmann, Marion Lee, Michelle Moghadassi, Roni Peskin-Mentzer, Charles P. Quesenberry Jr,
Virginia Souders-Mason, Linda Spence, Marisa Suzuki and Mary Gould.
Institutions: University of California, San Francisco
Marin Breast Cancer Watch
Northern California Cancer Center
Lawrence Berkeley National Laboratory
Kaiser Foundation Research Institute
Funding: California Breast Cancer Research Programs

The Adolescent Risk Factors Study was designed to understand if adolescent and pre-adolescent exposures and experiences differ between women with and without breast cancer in Marin County.

Interviews were conducted with approximately 300 Marin County women diagnosed between July 1, 1998 and June 30, 1999 with breast cancer (cases), and 300 Marin County women without breast cancer (controls), matched for age and ethnicity.

Factors used for comparison between cases and controls included:

  • Physical development and changes
  • Adolescent stress, family and social connections
  • Detailed adolescent and contemporary socioeconomic factors
  • Passive and active smoking
  • Alcohol use
  • Residency and migration
  • Standard breast cancer risk factors

Results of the study found striking similarities between the cases and controls as well as several differences that were significant.

Resulting Similarities

  • Lifetime number of years lived in Marin was 24.2 years for both groups
  • The mean age first lived in Marin was 28.8 for controls and 29.6 for cases

Other factors that were not found to be significantly different between controls and cases:

  • Having a first degree relative with breast cancer (20 percent of controls and 18 percent of cases)
  • History of a non-cancerous breast biopsy
  • Current socioeconomic status
  • Age at first birth or pregnancy (mean of 25.1 for controls and 25.3 for cases)
  • Use of hormone replacement therapy
  • Height
  • Health insurance status
  • Frequency of pelvic exams and pap tests

Resulting Differences

Cases were more likely than controls to report:

  • A high socioeconomic status before the age of 21
  • Four or more mammograms in 1990-1994
  • Giving birth without breastfeeding
  • Being premenopausal
  • Never having used birth control pills
  • Having a lower highest body mass index
  • Beginning drinking after age 21
  • Drinking on average two or more drinks per day
  • Being raised in an organized religion

The similarities between cases and controls in this study and the high incidence of some breast cancer risk factors that were found in many areas, suggest that both groups are at a high risk for breast cancer. Specific findings, in combination with the results of other recent prospective studies, suggest that decreased alcohol consumption and increased breastfeeding after childbirth- modifiable risk factors in adults- might help to reduce breast cancer risk.

Marin Environmental Data Study (MEDS)

Authors: Barlow J, Flodmark A, Radtke J, Kianfar S, Yaghoubi S, Farren G, Patterson C, and Yarish T
Institutions: Marin Breast Cancer Watch
University of California, Berkeley
Funding: State of California Department of Health Services, Cancer Research Program though the Marin County Department of Health and Human Services

The purpose of the Marin Environmental Data Study was to set forth the foundation for a community-specific database by investigating community concerns about environmental problems that may relate to breast cancer in Marin, and subsequently identifying existing data sets that may be used to address these concerns.

This was achieved through eight clearly defined activities:

Solicit community input regarding possible current and historical environmental events and concerns that may relate to breast cancer in Marin.
Members of the community had opportunities to contribute their input or concerns about potential environmental causes of breast cancer through several different methods. These options included completing a short questionnaire on the Marin Breast Cancer Watch (MBCW) website, attending a workshop series conducted by MBCW or alternate freeform methods such as email or telephone. These avenues were publicized together using a diversity of strategies, including newspaper articles, televised public service announcements, and flyer distributions at community town meetings, corporations, libraries, and farmers’ markets.

Identify sources of selected other community environmental studies relating to breast cancer.
Significant reports about community-based studies that sought to examine environmental risk exposures and breast cancer in other high-incidence geographic locations were obtained, reviewed, and summarized. Two areas of focus were Massachusetts (The Newton Study and Cape Cod Study by the Silent Spring Institute) and Long Island, New York (The Long Island Breast Cancer Study Project).

Identify sources of environmental data for Marin County.

Sources of environmental data were sought for six categories of environmental risk factors/exposures:

  • Air Pollution
  • Electromagnetic Fields
  • Geology and Land Use (including animal waste management)
  • Pesticide Use
  • Toxic Sites, Hazardous Waste, and Leaking Underground Storage Tanks
  • Water Quality

Internet search engines were used to locate existing data sets related to the six environmental factors/exposures listed above. Emphasis was placed (where possible) on sources of data most relevant to breast cancer etiology. In addition, a study consultant conducted personal interviews with the general managers of Marin’s nine water districts.

Obtain documentation for selected data sets.

For each identified data set that was selected for MEDS inclusion, a brief protocol was provided that explains where and how the data set and its documentation may be obtained.

Provide a descriptive summary for each data set.

All data sets were summarized in a standard format that facilitates ease in understanding the data set’s subject matter and intended use.

The following data sets were selected for inclusion in MEDS:

  • ARIP- the USEPA’s Accidental Release Information Program Data base
  • CalPip- The California Department of Pesticide Regulation’s California Pesticide Information Portal
  • CAQ- California Air Quality data collected by the California Air Resources Board
  • CERCLIS- The USEPA’s Comprehensive Environmental Response, Compensation, and Liability Information System
  • GEIMS- The Geographic Environmental Information Management System of the California State Water Resources Control Board
  • PUSE- The State of California’s Pesticide Use Summaries Data base
  • STORET- The USEPA’s Storage and Retrieval Data base
  • SSURGO- The USDA’s Soil Survey Geographic Data base
  • WTB/ULS- The Wireless Telecommunications Bureau’s Universal Licensing System Data base

Prioritize data sets to be studied based on community input, literature review and knowledge of selected similar studies.
The data sets listed above were selected from among others that also included Marin environmental data. Prioritization was based on criteria shaped by community input, literature review, and knowledge of similar studies.

Train Marin Breast Cancer Watch personnel and targeted community members and organizations in the basic concepts and applications of Geographic Information Systems (GIS).
Marin Breast Cancer Watch sponsored a demonstration on the use of GIS, a sophisticated computerized data base tool that can be used to store, identify, analyze and understand patterns in environmental contamination, the spread of disease and other health and environmental issues. The following GIS map contains geographic data including elevation, slope, and soil erosion trends in relation to toxic sites of interest within Marin County.

By identifying data sets with Marin-specific environmental data, the MEDS pilot project facilitates the development of future research studies designed to investigate the extent environmental factors, including environmental exposures may be contributing to Marin County’s high rates of breast cancer.

Breast Cancer and Personal Environmental Risk Factors in Marin County – Pilot Study (PERFS)

Authors: Erdmann CA, Farren G, Baltzell K, Chew T, Clarkson C, Fleshman R, Leary C, Mizroch M, Orenstein F,
Russell ML, Souders-Mason V, Wrensch M
Institutions: Lawrence Berkeley National Laboratory
Marin Breast Cancer Watch
University of California, San Francisco
Funding: The Center for Disease Control through the Marin County Department of Health and Human Services

The goal of this community research collaboration was to develop methodologies and a questionnaire for a future population-based case-control study to investigate the role of selected environmental exposures in breast cancer development.

This pilot study focused on exposures that occurred during the ten-year period prior to a breast cancer diagnosis for cases and the last ten years for the control group, rather than historic exposures.

Exposure selection was based upon a combination of information derived from a comprehensive scientific literature review and levels of community concern.

Factors Selected for Detailed Study:

  • Alcohol use
  • Physical activity
  • Oral contraceptive use
  • Hormone replacement therapy use
  • Polycyclic aromatic hydrocarbons (PAH’s are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat.)
  • Light-at-night: an occupational risk factor associated with working the night shift

Community Input & Evaluation

Community members participated with academic researchers in all phases of the research. This included taking responsibility for extensive outreach and promotion for the first two methods of community input listed below. In addition to the distribution of approximately 4,000 flyers, community members promoted the invitation for community input by speaking on local radio and television broadcasts.

The intention was to:

  • Raise awareness about local breast cancer rates
  • Stimulate discussion among the community
  • Solicit information that could help guide the direction of current and future research

Community input was collected by:

  • Mail, email, telephone
  • Mapping workshops
  • An open-ended question included on the Adolescent Risk Factors Study (ARFS) that asked, “Do you have any ideas about what might cause breast cancer?”

Approximately, 336 unique concerns were expressed and compiled in a list of topics to be considered for current and future research. The research team organized these individual concerns into topical groupings as shown in Figure 1.

Most frequently mentioned concerns:

  • Pesticides (on hiking trails)
  • Water quality (chlorine, arsenic, asbestos in pipes, copper, degrading cement pipes)
  • Air contamination (Richmond oil refineries, vehicle emissions, Styrofoam factory in Corte Madera)
  • Hamilton Air Force Base

Although the majority of responses were in categories of environmental contamination, also mentioned were:

  • Stress
  • Personal care products
  • Diet
  • Medicines
  • Hormone replacement therapy
  • Genetics

There were many accomplishments during the course of the year and with the completion of this pilot study:

  • A questionnaire was developed
  • Nipple aspirate fluid (NAF) protocol was amended several times to improve successful collection within a field setting
  • Community mapping workshops were done with an enthusiastic community group
  • Community input was summarized
  • Interviews were conducted to pilot test the questionnaire
  • NAF specimens were analyzed
  • Articles were located and ideas shared
  • Hypotheses for future studies were developed

Breast Cancer Research

Abstract
Breast cancer incidence and mortality trends in an affluent population: Marin County, California, USA, 1990-1999.

Authors: Christina A Clarke, Sally L Glaser, Dee W West, Rochelle R Ereman, Christine A Erdmann, Janice M Barlow and Margaret R WrenschElevated rates of breast cancer in affluent Marin County, California, were first reported in the early 1990s. These rates have since been related to higher regional prevalence of known breast cancer risk factors, including low parity, education, and income. Close surveillance of Marin County breast cancer trends has nevertheless continued, in part because distinctive breast cancer patterns in well-defined populations may inform understanding of breast cancer etiology.

Breast cancer in Marin County.

Author: Alice S WhittemoreTwo 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 of such cancer “clusters,” and conclude with some thoughts about the future.

Evaluating local differences in breast cancer incidence rates: A census-based methodology (United States).

Authors: Angela Witt Prehn and Dee W. WestOBJECTIVES: We used readily accessible, existing data to assess whether or not geographic variation in breast cancer incidence rates in the San Francisco Bay Area was related to the unequal distribution of known breast cancer risk factors.

METHODS: Cancer registry and 1990 census block-group data were used to look at the associations between breast cancer incidence and known risk factors (including parity, urban/rural status, and socioeconomic indicators) in 25 California counties. Average annual age-adjusted invasive breast cancer incidence rates were calculated for the period 1988-1992, and adjusted morbidity ratios were computed.

RESULTS: While breast cancer incidence in Marin County was 9 percent higher than that of the other 24 counties combined (relative risk = 1.09, 95 percent confidence interval = 1.01-1.18), this increase appeared to be due to the unequal distribution of known risk factors. Block-groups that had a high level of any risk factor had higher incidence rates, regardless of geographic location. After multivariate adjustment, breast cancer incidence no longer differed between Marin and the other counties (adjusted morbidity ratio = 1.02).

CONCLUSIONS: The results suggest that the unequal distribution of known risk factors was responsible for Marin County’s high breast cancer incidence rate.

Geographic Excess of Estrogen Receptor-Positive Breast Cancer

Authors: Christopher C. Benz, Christina A Clarke, and Dan H. Moore IIElevated and more rapidly increasing breast cancer incidence rates have been described for Marin County, California (CA), a homogeneous, high socioeconomic status population for which yearly surveillance is facilitated by its status as a county. The present study evaluates the histology and hormonal phenotype of the excess breast cancer cases occurring in white, non-Hispanic women living in Marin County between 1992 and 2000 and compares them with patterns occurring in the rest of the San Francisco Bay Area (SFBA) and other urban parts of CA. Incidence data for invasive breast cancer histological subtypes and estrogen receptor (ER) and progesterone receptor (PR) status were obtained from the 1992-2000 Surveillance, Epidemiology, and End Results program. Expected numbers for Marin County were computed based on age-specific rates for five other SFBA counties. Incidence rates were age-adjusted to the 2000 United States standard. Marin County breast cancer diagnoses during 1992-2000 compared with other SFBA and other urban CA Surveillance, Epidemiology, and End Results county rates for white, non-Hispanic women consisted of a disproportionate increase in ER+/PR+ tumors. The observed absolute excess (versus expected) numbers of Marin County ER+/PR+ lobular and nonlobular (predominantly ductal) cases were similar; however, the relative increase appeared greatest for lobular breast cancer. The progressive increase in breast cancer incidence rates observed in Marin County over the past decade is occurring in women with high prevalence of risk factors predisposing toward excess development of ER+/PR+ breast cancer.

Increase in Breast Cancer Incidence in Middle-aged Women during the 1990s

Authors: Angela Witt Prehn, PhD; Christina Clarke, PhD; Barbara Topol, MS; Sally Glaser, PhD; and Dee West, PhDPURPOSE: The San Francisco Bay Area has a history of high breast cancer incidence rates relative to the rest of the United States. For Marin County, where Bay Area rates are highest and, moreover, have continued to increase over time, age- and tumor-specific incidence trends were compared with the rest of the region.

METHODS: The study included all white women diagnosed with invasive breast cancer in 1988 to 1997 in the five-county Bay Area (N = 19807). Annual age-specific incidence rates and estimated annual percent changes (EAPCs) were calculated for women ages less than 45, 45 to 64, and greater than or equal to age 65.

RESULTS: Women aged 45 to 64 from Marin County experienced a marked increase in breast cancer rates between 1991 and 1997 (EAPC = 8%, p = 0.02), regardless of disease stage or tumor histology. For the youngest and oldest women, no rate differences were observed by region or over time.

CONCLUSIONS: This regional difference in trend by age did not appear to be due to screening mammography or environmental exposures. Cohort exposures to breast cancer risk factors, such as oral contraceptive and/or hormone replacement therapy use, may have contributed to these rate increases. Although the reasons remain unclear, the finding may signal a rising risk of breast cancer in this demographic group.

Risk factors for breast cancer in a population with high incidence rates (Adolescent Risk Factor Study)

Authors: Margaret Wrensch, Terri Chew, Georgianna Farren, Janice Barlow, Flavia Belli, Christina Clarke, Christine A. Erdmann, Marion Lee, Michelle Moghadassi, Roni Peskin-Mentzer, Charles P. Quesenberry Jr., Virginia Souders-Mason, Linda Spence, Marisa Suzuki and Mary GouldBACKGROUND: This report examines generally recognized breast cancer risk factors and years of residence in Marin County, California, an area with high breast cancer incidence and mortality rates.

METHODS: Eligible women who were residents of Marin County diagnosed with breast cancer in 1997-99 and women without breast cancer obtained through random digit dialing, frequency-matched by cases’ age at diagnosis and ethnicity, participated in either full in-person or abbreviated telephone interviews.

RESULTS: In multivariate analyses, 285 cases were statistically significantly more likely than 286 controls to report being premenopausal, never to have used birth control pills, a lower highest lifetime body mass index, four or more mammograms in 1990-94, beginning drinking after the age of 21, on average drinking two or more drinks per day, the highest quartile of pack-years of cigarette smoking and having been raised in an organized religion. Cases and controls did not significantly differ with regard to having a first-degree relative with breast cancer, a history of benign breast biopsy, previous radiation treatment, age at menarche, parity, use of hormone replacement therapy, age of first living in Marin County, or total years lived in Marin County. Results for several factors differed for women aged under 50 years or 50 years and over.

CONCLUSIONS: Despite similar distributions of several known breast cancer risk factors, case-control differences in alcohol consumption suggest that risk in this high-risk population might be modifiable. Intensive study of this or other areas of similarly high incidence might reveal other important risk factors proximate to diagnosis.

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