Environment

The woman walked up to me, the bandana covering where her hair used to be, a brave smile on her face. She had just completed her initial treatments for a breast cancer diagnosis that came as a complete surprise. She was an otherwise healthy woman in her 40s who exercised, watched what she ate, and had no history of breast cancer in her family. The lump she discovered seemed to come from nowhere. "Why this diagnosis for someone like me?" she asked me. "I can't help but think that I've done something wrong. How could I have avoided this?"

I always feel a pang when women blame themselves for a disease whose origins we don't fully understand. There's some sense that if we had exercised more or eaten more organic food -- even been nicer people in our youth -- this might not have happened to us. That's hardly the case.

How breast cancer starts is still one of the most vexing questions facing science today. Unlike viruses or bacteria, which can be identified and isolated, cancer begins when otherwise normal cells suddenly "click on" in some people and begin a deadly trek through the body. How do these cells go from friend to foe, and how does an otherwise vigilant immune system allow them to grow and spread to bones and organs far away?

There are many theories, but none seems to fit into a neat mold. Certainly, there are genetic links to breast cancer that make vigilance necessary for the daughters and sons of cancer patients, or descendants of ethnic groups with higher numbers of genetic mutations linked to breast cancer (e.g., the BRCA1 and 2 mutations more prevalent in Ashkenazi Jews). We know that some racial groups, African American women, for example, are diagnosed with aggressive forms of breast cancer at higher rates than Caucasians, which is why we fund and urge more research into disparities in breast cancer.