About the Marin Women's Study

Two women have the same number of factors that are known to increase risk for breast cancer, yet one woman is diagnosed with breast cancer and the other is not.  Why?

Women can be sure their time will be well spent helping to better understand breast cancer in our community through participation in the Marin Women’s Study.

Larry Meredith, Ph.D., Former Director,
Marin County Department of
Health and Human Services.


The Marin County Department of Health and Human Services is conducting a breast cancer research project to better understand why breast cancer risk factors do not affect all women in the same way.

The occurrence of breast cancer in Marin County has been the subject of national and regional scientific interest, but here in Marin, the issue is personal for all of us. The Marin Women’s Study is the first breast cancer study in Marin County to look at individual risk factors linked to an analysis of biospecimens (saliva samples) and measures of breast health (breast density and breast cancer).

This study is a community effort in collaboration with the Marin Cancer Institute, University of California San Francisco, Buck Institute for Age Research, Kaiser Permanente San Rafael Medical Center, the Novato Community Hospital Kaiser Permanente Division of Research, Fred Hutchinson Cancer Research Center, Zero Breast Cancer, the Cancer Prevention Institute of California and many local community groups.


We hope to discover:

  • How risk factors vary by socioeconomic status and are associated with breast cancer risk
  • How alcohol use affects breast health
  • How women in Marin County are using complementary and alternative medicines (CAMS) for menopausal symptoms and how their use might relate to breast cancer risk
  • How early events in a young woman's life affect her chances of developing breast cancer
  • How tumor characteristics differ in women with different breast cancer risk factors
  • How adolescent risk factors, like teenage smoking, may affect breast health
  • Whether environmental agents like the heavy metal cadmium and bisphenol A (widely used in plastic water bottles, food containers and toys) can be measured in saliva, and if so, how levels may affect breast cancer risk
  • And much more…


Between late 2006 and early 2010, women were invited to fill out a questionnaire when they had a screening or a diagnostic mammogram. Women were also asked to donate a saliva sample, and to allow the MWS to link to the San Francisco Mammography Registry to obtain information on breast density and breast cancer. Analysis of these data will help us better understand the determinants of breast health and why breast cancer risk factors do not affect all women in the same way.

See the data collection process.