We all know that cancer isn't caused by any one factor. Instead, a collection of influences -- genetics, environmental exposure, lifestyle factors like diet, exercise, BMI and stress and, frankly, serendipity -- create a perfect storm that can lead to the disease. And while there's not much you can do about the genes you inherit or the toxicants you've already been exposed to, there absolutely is something you can do about how you lead your life now. According to the latest research, genetic predisposition plays a role in only about 10 percent of breast cancers. Meanwhile, diet is a factor in an estimated 30 to 40 percent, according to the outreach organization breastcancer.org. And together, the elements of a healthful lifestyle can reduce cancer risk by as much as 38 percent.