In November, a new study identified two large “areas of concern” in the Bay Area with breast cancer rates 10 to 20 percent higher than the state average. In 2008, the most recent year studied, the South Bay “area of concern” had 123 invasive breast cancer cases per 100,000 women, compared with a statewide rate of 95 cases.
The North Bay area of concern had 112 cases per 100,000 women.Researchers first became aware of the region’s high breast cancer rates in the early 1990s, particularly in Marin County.
Bay Area girls are starting to menstruate at a younger age, a national trend linked to increased breast cancer risk.It used to be that the average girl’s period began at age 17. Today, 12 or earlier is common.”It’s changed five years over a century,” Hiatt said. “That’s pretty remarkable.”One theory among researchers, Hiatt said, is the longer a woman is exposed to the surges in estrogen that occur during menstruation, the greater her breast cancer risk.That could explain why girls who start their periods earlier, women who go through menopause later, those who never have children and those who have their first child at an older age all have a higher risk.
To understand what is causing the region’s high breast cancer rates and to determine how women and girls can protect themselves — has fueled numerous studies in the Bay Area involving tens of thousands of women and girls. Researchers are looking at everything from genes — at least two have been identified that place women at higher risk — to environmental exposures and lifestyle factors such as diet, exercise and alcohol use.
Thoughts?
