Breast cancer cases are on the decline in Marin County and have hit a new low.
The trend is a significant change of direction for a county once known for having the highest breast cancer rates in California.
Alarming breast cancer rates in Marin County got Judi Shils' attention more than a decade ago. Shils and scores of volunteers set out to find what was making so many women sick.
"I started the Marin Cancer Project based on a board of supervisors meeting in 2002 and hearing our breast cancer rates had risen 60 percent in eight years," Shils said. "But we didn't have the money to figure out why."
In 2012, the county reported 130 cases of breast cancer per 100,000 women. The 2012 figures are 31 percent lower than the highest rate of 188 cases reported in 2001.
Researchers point to a women's health initiative publishing results that hormone therapy was dangerous, which prompted women to quit taking the treatment.
Once women stopped taking hormone therapy, researchers saw cancer rates drop rapidly in Marin County and in other parts of the country.
Shils is now advocating for a healthier environment and is still fighting to get the number of breast cancer cases in Marin County to zero.
With Marin County's number of breast cancer cases declining, researchers said San Mateo County now has the most cases of breast cancer in the Bay Area.