Northern California Cancer Center Releases Breast Cancer Incidence and Mortality Rates in the Bay Area

Marin Breast Cancer Watch Statement in Response to the Rate Release

(San Rafael, September 15, 2023). Marin Breast Cancer Watch has carefully reviewed the long awaited analysis of the breast cancer incidence and mortality rates in Marin County and the Bay Area that the Northern California Cancer Center has worked so diligently to produce.

However, as we review this data, it is important to keep in mind the larger picture. Although there was a recent two-year decrease in the incidence rates of invasive breast cancer in Marin County, over time the rates have continued to increase. During the twelve-year period of 1988 to 2001, the rates of invasive breast cancer increased 12.4% in Marin County, nearly double the state wide average. During the same period of time, the rates of invasive breast cancer remained the same in San Francisco County.

As a community, we have always known that breast cancer incidence rates among white non-Hispanic women are higher in Marin County, but we have never had any information about incidence trends among women of other ethnic groups. This report confirms that the incidence rate for Hispanic women is also higher in Marin, more than anywhere else in Bay Area. This is particularly noteworthy because it is the first time our community has had any information on breast cancer trends among African-American, Hispanic or Asian/Pacific Islander women.

There is important information that is missing from this report because it is not collected or analyzed. For example, we still don't know what the relapse rates are for breast cancer in Marin County or the Bay Area. We also don't know the breast cancer survival trends. Marin Breast Cancer Watch in partnership with the Kaiser Permanente Division of Research, is beginning to investigate breast cancer relapse and survivorship.

This report not only highlights the elevated rates of breast cancer, but prostate and uterine cancer as well. Clearly we need more information on the possible connections and causes of these cancers- be they genetic, hormonal or environmental. Let us not grasp on to any one theory. For example, some believe that the use of hormone replacement therapy (HRT) explains the high rates of breast cancer in Marin County. Prostate cancer rates are comparable. How many men are taking HRT?

The work of the Bay Area Breast Cancer and the Environment Research Center is critically important to understanding the complex role environmental factors play in the development of breast cancer. Marin Breast Cancer Watch, UCSF Comprehensive Cancer Center, Kaiser Permanente Division of Research, county public health departments and breast cancer advocates are combining efforts in this unique bay area and national study.

Everyday we are reminded that breast cancer has a major impact on the lives of women and their families living in Marin and throughout the Bay Area. These new rates simply show that the geographical area of concern has widened to include San Francisco. In fact, breast cancer in the Bay Area is a much larger problem than previously reported. Which Bay Area County will be next? Even more than ever, we need to re-double our efforts to find out why this is happening. Marin Breast Cancer Watch firmly believes that the solution lies in forging new directions in community based research, education and advocacy.

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