I am disturbed by a recent study of advanced breast cancer among young women. Published in the Journal of the American Medical Association February 27, the study tracked breast cancer rates from 1976 to 2009. Over those 34 years, the incidence of metastatic breast cancer increased by 1.37 cases in 100,000 women. That is a very small number. Because breast cancer, especially metastatic breast cancer, is so rare among young women, this could be a statistical quirk. However in 1976 the incidence of advanced breast cancer was only 2.9. That means that the rate went up nearly 50%. When you look at it that way, these are pretty distressing numbers.
There was no similar increase among older women. The increase in young women was in estrogen dependent cancers, cancers whose growth is driven by estrogen. That catches my attention because our bodies have been facing an onslaught of estrogen mimicking chemicals in the environment. Those chemicals have been linked to a very, very wide range of health problems (obesity, miscarriage) and diseases (cancer, diabetes, allergies, etc). We know that environmental chemicals cause breast cancer. It is not far-fetched to wonder if there could be a connection between these widespread estrogen-dependent cancers in young women and increasing levels of man-made estrogen-like chemicals in our environment. Hopefully not.