MARIN FACTS
Q. Does living in Marin increase my risk for breast cancer? Is risk associated with time spent in Marin?
A. One study in Marin found the odds of developing breast cancer were not higher for women who lived or worked here longer. The research showed that the risk of developing breast cancer did not increase with time spent in Marin (Wrensch M et al., Risk Factors for Breast Cancer in a Population with High Incidence Rates, 2003). This study did not provide evidence at the time to move forward with further residential research. However, these conclusions were based on one limited study, so a part of the Marin Women’s Study will examine these research questions again. Click here to view or download a pdf document containing a compilation of breast cancer research in Marin from 2001-2003.
Q. How do we compare to the rest of California? The U.S.?
A. The most updated invasive breast
cancer incidence rate in Marin (2005-2007) is 15% higher than all
other counties in California.
Q. Are the high rates simply due to increased screening in Marin?
A. No, four separate analyses showed that the use of mammography is only 0%-5% higher among women in Marin County than among women in California and the U.S. Higher screening accounts for approximately 0-2 cases per year.
Q. How do Marin’s mortality rates compare with mortality rates in other regions?
A. The breast cancer age-adjusted
mortality rates in Marin County (23.5 per 100,000 white, non-Hispanic
women) were not significantly different than California (24.4 per
100,000 white, non-Hispanic women). The good news is that in all
regions breast cancer mortality rates decreased between 1988 and
2001.
Q. How do breast cancer rates compare among different races and ethnicities in Marin?
A. Higher rates of invasive breast
cancer were observed for Hispanic women (131.8 per 100,000 women
adjusted for age) living in Marin, but were not observed for Asian/Pacific
Islander women when compared to California State rates.
Q. Does living in Marin increase my risk for breast cancer? Is risk associated with time spent in Marin?
A. No, research shows that the odds of developing breast cancer are not higher for women who have lived or worked here longer. The research shows that your risk of breast cancer does not increase with time spent in Marin. [link to Wrensch M et al., Risk Factors for Breast Cancer in a Population with High Incidence Rates]
Q. Are there concentrated areas of breast cancer in Marin?
A. When we mapped breast cancer incidence
in Marin among white women from 1988-1992, the high rates of breast
cancer were not concentrated in one area and did not vary widely
throughout Marin. We obtained our cases from the Cancer Prevention
Institute of California, and analyzed them by 1990 Census Tract.
There was no statistical difference in incidence among tracts. View
or download the map (a pdf document). A new map of the 1998-2002
case data will be available soon for analysis.
TOP OF PAGE
RISK FACTORS
Q. How do risk factors explain the disease?
A. Risk factors are characteristics that some people have that may make them more susceptible to a disease. The risk factors for breast cancer are not as clear-cut as they are for other diseases like heart disease or the flu.
Q. What are the traditional risk factors?
A. There is an association with many risk factors and breast cancer such as gender, age, diet, genetics, family history, age at menarche/menopause, age at first pregnancy, parity, breastfeeding, breast density, hormone replacement therapy, radiation, exercise, race and socioeconomic status. Click here for more detailed information on breast cancer risk factors.
Q. Do women in Marin have more risk factors for breast cancer?
A. There is a high prevalence of several known breast cancer risk factors in Marin. Compared to the average California population, women in Marin have more risk factors including higher socioeconomic status, later childbearing, fewer children, more frequent alcohol consumption, and higher levels of education. Based on this information, we would expect Marin County to have a somewhat higher breast cancer incidence rate than other geographic regions with fewer risk factors. The MWS is researching the impact of these established risk factors in Marin among women with breast cancer and among women without the disease.
Q. Do the known risk factors explain the high rate of breast cancer in Marin?
A. The results of the Traditional Risk Factor Study (TRIFS) suggest that approximately 50% of the breast cancer cases in Marin County are attributable to younger age at menarche (under 12 years old), delaying childbirth until after age 30, having no children, family history, older age at menopause (over 55 years old), and high postmenopausal body mass index. About 30% of the breast cancer cases in Marin are attributable to a later age (after age 29) at first child birth/nulliparity. Click here to view or download a pdf document containing a compilation of breast cancer research in Marin 2001-2003.
Q. Aren’t women healthier in Marin than the rest of California and U.S.?
A. More women in Marin report being physically active, eating fruits and vegetables, being at a recommended body weight, and breast-feeding than the rest of California and the U.S. These behaviors are all associated with being protective against breast cancer.
TOP OF PAGE
OUR STUDY
Q. What is the Marin Women’s Study investigating?
A. The Marin Women’s Study (MWS) is a research study that investigates how reproductive, lifestyle, demographic, and biologic factors affect breast cancer risk in Marin women.
Q. What is this study going to accomplish?
A. The MWS will further our understanding of previous breast cancer research in Marin by building upon our population-based data. We know that women in Marin have more of the established risk factors for breast cancer (alcohol consumption, use of hormone replacement therapy and higher socioeconomic status). However, we do not know if individuals getting breast cancer have the same risk factor profile. In short, we need to find out if the established risk factors are also higher among cases and then, examine how the risk factors relate to the disease in Marin.
The MWS will begin by investigating how alcohol consumption, use of hormone replacement therapy and higher socioeconomic status compare among women with and without breast cancer in Marin. This will allow us to take into account what we already know about established risk factors when we look at new risk factors such as breast density or environmental exposures. We will analyze blood and saliva for markers that are associated with breast cancer risk. The blood and saliva analysis will allow us to look at gene-environment interactions in the development of breast cancer. Most importantly, the MWS will create a data bank and set a precedent for future breast cancer research.
Q. How is the MWS moving beyond traditional risk factors? How is it different from other studies?
A. The MWS is moving beyond traditional risk factors by collecting information on stress, bovine leukemia virus, residence, preterm birth, and gene/environment interactions to name a few. In addition, this is the first prospective study in Marin County to collect individual level risk factor and biospecimen data.
TOP OF PAGE
ENVIRONMENT
Q. Could the environment be playing a role in the risk of the disease?
A. Many scientists believe that environmental risk factors such as exposures to everyday chemicals could be attributing to the disease worldwide. Much of the research and evidence linking breast cancer to a particular environmental factor is in its infancy and controversial at best. Since the disease is so complex and can take years to develop, it is difficult to isolate environmental exposures in humans. Often enough, we want to pinpoint one specific factor that caused our disease, but with most cancers, the cause is most likely due to a variety of lifetime factors that make some of us more susceptible to the disease. Nonetheless, environmental causes should not be ignored. With the Marin Women’s Study, we hope to bring more understanding to this puzzle and provide future researchers with biospecimens that can be analyzed using new tools as they are developed.
Q. Is there evidence that the environment in Marin is contributing to breast cancer risk?
A. Although there is no doubt environmental factors may play a role in the development of breast cancer, several studies have provided indirect evidence that the Marin County environment is not making a large contribution to elevated breast cancer rates. The Marin County Residence, School, and Workplace Study did not find sufficient evidence to conclude that years lived or worked in Marin were associated with an increased risk of developing breast cancer. A map of breast cancer rates by residence at time of diagnosis in Marin found that census tracts in Marin had similar rates of breast cancer, and that tracts with higher rates were not geographically related, nor related to the location of prior military bases or other areas of suspected environmental toxins. Extensive testing of the water supply in Marin has failed to reveal evidence of pesticides, estrogenic substances, or other known carcinogens.
Q. What is the Marin Women’s Study doing to address environmental concerns?
A. Our research goals with the MWS
are to discover how much traditional risk factors are contributing
to rates of disease and if other factors, such as environmental
exposures, help explain the rates of disease as well.
TOP OF PAGE
BIOSPECIMENS
Q. What is DNA and why is it important to cancer?
A. DNA is your hereditary information. It contains instructions for growth, development and replication. Replication of DNA occurs everyday, and sometimes the information is not copied accurately. When this information contains an error, our bodies have certain checkpoints that correct the errors. If an error gets past a number of checkpoints and the DNA continues to replicate, it may cause abnormal cell growth. If our body cannot get rid of these abnormal cells and the cells continue to replicate and grow, then we get cancer. Cancer is defined as abnormal and uncontrollable cell growth.
Q. Where will the biospecimens be stored?
A. Your saliva samples will not be
stored with any personal information on the vials. Instead, to
protect your privacy, the samples
will only be labeled with a barcode. After the saliva samples
are collected, they will be stored at the Buck Institute for the
Aging in locked freezers with restricted access.
Q.Who will have access to my samples?
A. Only select approved MWS research staff will be responsible for biospecimen data management. All of the staff working on the MWS are bound by signed confidentiality forms and have undergone training and certification on informed consent.
Q. What are you looking for in my saliva?
A. We want to test the saliva samples
for chemicals such as hormones. The importance of having a data
bank of these samples is that with emerging technology and advances
in science, we may be able to do more tests in the future than we
can do now. Having these samples creates the possibility of study
in many different areas of breast cancer research.
Q. Will I be able to get the results from my saliva
tests?
A. We are sorry, but due to confidentiality concerns, we will not give out individual results from the biospecimen tests.
TOP OF PAGE
PRIVACY/CONFIDENTIALITY
Q. I’m hesitant to give out personal information, let alone my private health data. How will my privacy be protected in this study?
A. Your privacy will be protected throughout the study and after it has ended. For the step-by-step process of where the data and samples will go and how they will be handled, visit our section on privacy and confidentiality. Also keep in mind that this study and breast cancer research in general would not be possible without your help, and the MWS will do everything possible to maintain the privacy of our valued participants.
TOP OF PAGE
PREVENTION
Q. How can I reduce my risk for breast cancer?
A. As far as we know, the best answer is to eat healthy and stay active. Be informed about choices you make. Since the risk factors for breast cancer do not adequately describe the majority of the cases, we do not fully know the best steps for prevention. Based on the current research in breast cancer and health in general we recommend the following:
- Eat a healthy, well-balanced diet with plenty of fruits and vegetables
- Be active every day
- Lose excess weight
- Don’t smoke
- Breast feed your baby
- Limit alcoholic drinks to less than one a day
- Reduce alcohol and increase folic acid intake for women on estrogen therapy
- Consult a healthcare practitioner about hormone replacement therapy
- Minimize ionizing radiation to the chest
- Protect yourself from unnecessary exposure to harmful chemicals
Early detection is not prevention, but being aware of your body and detecting cancer early can lead to healthier outcomes. We recommend all women participate in regular screening that includes breast self-exams, clinical breast exams, and annual mammograms for women aged 40 and over.
TOP OF PAGE
