Marin County Breast Cancer Study of Adolescent Risk Factors

Institution: Marin Breast Cancer Watch
Investigator(s): Georgianna Farren, M.D. - Margaret Wrensch, M.P.H., Ph.D. -
Award Cycle: 1999 (Cycle V) Grant #: 5BB-1200 Award: $246,800
Award Type: CRC Full Research Award
Research Priorities
Etiology and Prevention>Etiology: the role of environment and lifestyle

This is a collaboration with: 5BB-1201 -

Initial Award Abstract (1999)
The purpose of this study is to examine the potential relationships among established breast cancer risk factors and understudied or novel adolescent and pre-adolescent risk factors in Marin County, California. The study is a collaboration between Marin Breast Cancer Watch (MBCW) and the University of California, San Francisco. The long range goal of MBCW is to discover risk factors that ultimately may lead to a reduction of breast cancer incidence.

MBCW is a grass-roots, nonprofit, tax-exempt organization of approximately 350 members, established in 1995 because of community concern regarding the extremely high incidence (133.2 per 100,000 for the 1900-94 period) of breast cancer in Marin County. With the University of California, San Francisco, we conducted a BCRP-funded pilot study to determine the feasibility of conducting a large study with a traditional research partner and to assess the need for a larger study.

We reviewed the pertinent literature and developed a questionnaire and memory tools to overcome the difficult problems of recalling distant past life events. We also conducted focus groups and interviews with Marin County residents with and without breast cancer to evaluate and will pretest the memory tools and the questionnaire.

Guided by the results of the pilot study, we will conduct a large study in Marin County of relatively unexplored adolescent as well as known breast cancer risk factors. Our major question is: did adolescent and pre-adolescent experiences significantly differ between women with and without breast cancer in Marin County? Specific factors to be compared are: (1) physical development and changes; (2) adolescent stress, family and social connections; (3) detailed adolescent and contemporary socioeconomic factors; (4) passive and active smoking; (5) alcohol use; (6) residency and migration and (7) known breast cancer risk factors.

Few readily modifiable risk factors for breast cancer have yet been defined, despite studies showing that breast cancer risk is modifiable over a single lifetime. Adolescent factors have been understudied. This study will address two priority areas of breast cancer research, namely, breast cancer etiology, through greater attention to relatively unexplored adolescent and pre-adolescent factors, and prevention, through inclusion of some potentially modifiable behavioral and psychosocial factors.

Specifically, we will conduct in-person interviews with 300 women with breast cancer diagnosed between 7/1/97 and 6/30/99 in Marin County identified through the local cancer registry and 300 appropriately matched controls from the same population. We will evaluate four primary hypotheses about: (a) ages at menarche and breast development; (b) major life events before age 21; (c) adolescent and/or adult socioeconomic status; (d) age-adjusted lifetime years residing in Marin County. We also will evaluate associations of other adolescent social and lifestyle factors with breast cancer; write articles for scientific journals about our pilot and full study results; conduct community educational forums; and develop newsletter items and a website.

We expect that by increasing knowledge of breast cancer etiology, our studies ultimately will enhance possibilities for breast cancer prevention. Specific to the problem of high breast cancer rates in Marin County, finding no differences in cases and controls for total years of residence in Marin County might allay community concerns about Marin specific environmental exposures, while finding a difference might generate enthusiasm for additional explanatory studies. Bringing together community members and scientists in this successful collaboration may encourage other communities to take an active role in cancer research. Most importantly, information obtained may suggest learning tools and lifestyle changes in adolescence that can be incorporated into the lives of our daughters to prevent breast cancer.


Final Report (2002)
This project continues the collaboration between Marin Breast Cancer Watch (MBCW) and the University of California, San Francisco. The community of interest consists of Marin County women, a group known by cancer registry data to be at very high risk for breast cancer. We have completed data collection for a population-based case-control study of breast cancer in relation to relatively unexplored adolescent risk factors among women in Marin County.

We successfully conducted in-person interviews with 301 women diagnosed with breast cancer between 7/1/97 and 6/30/99 in Marin County identified through the local cancer registry and 305 appropriately matched controls from the same population. Approximately 19.5% of cases and 6.5% of controls contacted declined participation. Data entry and editing is complete and analyses are underway.

We have completed, or are in the process of completing several projects to disseminate the results of the research to date. Margaret Wrensch, Ph.D. joined Drs. Marion Kavanaugh-Lynch and Laura Esserman in a presentation to the UC Regents on January 10, 2001. Dr. Wrensch highlighted the community initiation of and involvement in this study of breast cancer in Marin County. An article by Spence and Peskin-Mentzer, describing how community initiated research projects succeed collaboratively is in progress. An article titled "Adolescent Exposures and Breast Cancer Risk: Focus groups to Assess the Utility of Memory Tools to Reduce Recall Bias" (Farren, Cabral-Evins, Lee, and Wrensch) regarding our pilot study has been submitted for publication. MBCW's website (http://www.breastcancerwatch.org) is updated regularly. Articles will continue to be submitted to appropriate journals for publication. We presented a poster at the 2002 CBCRP meeting.

Data analysis will continue even though the project has officially ended, and we will publish results as we have them. We are comparing cases and controls with respect to: (1) physical development and changes; (2) adolescent stress, family and social connections; (3) detailed adolescent and contemporary socioeconomic factors; (4) passive and active smoking; (5) alcohol use; (6) residency and migration and (7) standard breast cancer risk factors.

By increasing knowledge of breast cancer etiology, our studies may enhance possibilities for breast cancer prevention. Specific to the problem of high breast cancer rates in Marin County, finding no differences in cases and controls for total years of residence in Marin County might allay community concerns about Marin-specific environmental exposures, whereas finding differences may generate enthusiasm for additional studies.

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


Progress Report 1 (2000)
This project continues collaboration between Marin Breast Cancer Watch (MBCW) and the University of California, San Francisco. The community of interest consists of Marin County women, a group known by cancer registry data to be at very high risk for breast cancer. We are conducting a population based case control study of breast cancer in relation to relatively unexplored adolescent factors among women in Marin County.

We will conduct in person interviews with 300 women diagnosed between 7/1/97 and 6/30/99 in Marin County identified through the local cancer registry, and 300 appropriately matched controls from the same population. We will evaluate four primary hypothesis about: (a) ages at menarche and breast development; (b) major life events before age 21; (c) adolescent and/or adult socioeconomic status; and (d) age adjusted lifetime years residing in Marin County. We also will evaluate associations of other adolescent social and lifestyle factors with breast cancer; write articles for scientific journals about our pilot and full study results; conduct community educational forums; and develop newsletter items and a website.

As of April, 2000, we have completed approximately 71 interviews. So far, we have been informed by the Northern California Cancer Center of 298 breast cancer cases within our inclusion period. Out of 125 letters mailed to eligible cases, 17 (7 by mail) refused, 8 were deceased, and 1 was lost to follow up. Our refusal rate is approximately 14 %. In April we began recruiting controls through Random Digit Dialing (Survey Methods) and expect to receive 20 controls matched for age and ethnicity per month. We project an average of 29 interviews completed each month as as result of increased interview personnel effort. Interviews are averaging 7.2 total personnel hours per interview. An article titled "Adolescent Exposures and Breast Cancer Risk: Focus groups to Assess the Utility of Memory Tools to Reduce Recall Bias" (Farren, Cabral Evins, Lee, Wrensch) has been submitted for publication. Our new website (http://www.breastcancerwatch.org) is updated regularly. A weighted scale of severity of major life has been developed and will be given to both cases and controls during the interview. The questionnaire as the memory tools used in the interview have been refined and finalized. Data entry has started and will continue as interviews are completed. An article by Spence and Peskin-Mentzer, describing how community-initiated research projects succeed collaboratively is in progress.

Interviewing and data entry will continue during this upcoming year. Articles will continue to be submitted to appropriate journals for publication.

By increasing knowledge of breast cancer etiology, our studies may enhance possibilities for breast cancer prevention. Specific to the problem of high breast cancer rates in Marin County, finding no differences in cases and controls for total years of residence in Marin County might allay community concerns about Marin environmental exposures, whereas finding a difference might generate enthusiasm for additional studies.


Progress Report 2 (2001)
This project continues collaboration between Marin Breast Cancer Watch (MBCW) and the University of California, San Francisco. The community of interest consists of Marin County women, a group known by cancer registry data to be at very high risk for breast cancer. We propose a population-based case-control study of breast cancer in relation to relatively unexplored adolescent factors among women in Marin County.

We will conduct in-person interviews with 300 women with breast cancer diagnosed between 7/1/97 and 6/30/99 in Marin County identified through the local cancer registry and 300 appropriately matched controls from the same population. We will evaluate four primary hypothesis about (a) ages at menarche and breast development; (b) major life events before age 21; (c) adolescent and/or adult socioeconomic status; (d) age-adjusted lifetime years residing in Marin County. We also will evaluate associations of other adolescent social and lifestyle factors with breast cancer; write articles for scientific journals about our pilot and full study results; conduct community educational forums; and develop newsletter items and a website.

As of April, 2001, we have completed 235 interviews with women who have had breast cancer and 181 control women. Approximately 17% of cases have declined to participate and 5% of controls. We completed about 32 interviews each month with 1.7 FTE interviewer personnel effort. Interviews average about 8.5 total personnel hours per interview. An article titled "Adolescent Exposures and Breast Cancer Risk: Focus groups to Assess the Utility of Memory Tools to Reduce Recall Bias" Farren, Cabral-Evins, Lee, Wrensch regarding our pilot study has been submitted for publication. MBCW's website (http://www.breastcancerwatch.org) is updated regularly. Data entry is ongoing; 159 questionnaires have been completely entered and the remaining completed questionnaires are in the process of being edited, entered and cleaned. We have begun writing SAS programs for some preliminary data analysis. An article by Spence and Peskin-Mentzer, describing how community initiated research projects succeed collaboratively is in progress. Margaret Wrensch, Ph.D. joined Drs. Kavanaugh-Lynch and Esserman in a presentation to the UC Regents on January 10, 2001. Dr. Wrensch highlighted the community initiation of and involvement in this study of breast cancer in Marin County.

We will continue interviewing and entering the data as interviews are completed this upcoming year. Enrollment should be complete by the end of September 2001. Articles will continue to be submitted to appropriate journals for publication.

By increasing knowledge of breast cancer etiology, our studies may enhance possibilities for breast cancer prevention. Specific to the problem of high breast cancer rates in Marin County, finding no differences in cases and controls for total years of residence in Marin County might allay community concerns about Marin specific environmental exposures, whereas finding a difference might generate enthusiasm for additional studies.


Symposium Abstract (2003)
Background: This report examines generally recognized breast cancer risk factors and years of residence in Marin County, California, an area of unusually high breast cancer incidence and mortality.

Methods: Eligible women who were Marin county residents diagnosed with breast cancer in 1997-1999 and women without breast cancer obtained through random digit dialing frequency matched by cases’ age at diagnosis and ethnicity participated either in 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 use of birth control pills, lower highest lifetime body mass index, 4 or more mammograms in 1990-1994, beginning drinking after age 21, on average drinking 2 or more drinks per day, highest quartile of pack years of cigarette smoking and being raised in an organized religion. Cases and controls did not significantly differ with regard to having a first degree relative with breast cancer, history of benign breast biopsy, prior radiation treatment, age at menarche, parity, use of hormone replacement therapy, or age first or total years lived in Marin County. Results for several factors differed for women aged under 50 or 50 and over.

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

Risk factors for breast cancer in a population with high incidence rates.
Periodical:Breast Cancer Research
Index Medicus: Breast Cancer Res
Authors: Wrensch M, Chew T, Farren G, Barlow J, Belli F, Clarke C, Erdmann CA, Lee M, Moghadassi M,
Yr: 2003 Vol: 5 Nbr: 4 Abs: Pg:R88-102