Very specifically, the last few years have enable us to understand one reason that breast cancer runs in some families (the BRCA genes), how specific genes within tumors influence the growth and survival of breast cancers, and how we can attack these potential targets. A particular area of excitement for me and my team has been the application of these scientific advances to the problems of risk and prevention. We are beginning to understand how some known risk factors, such as obesity, cause cancer-promoting signals that we may be able to interrupt. Here we might be treating the risk and abnormalities of normal, not cancer, cells to prevent the disease outright.

With regard to the use of drugs to treat and cure disease that may have spread beyond the breast (adjuvant therapy), we again have seen significant new developments, including increased numbers of safer and more effective hormone therapies, increased numbers of ever more effective agents that target HER2 (a protein receptor on the surface of breast cancers in about 20% of women), and clearer guidance on the optimal use of chemotherapy when it is indicated.

In this regard, a particularly important application of the new genetic tools we have developed is the use of a 21-gene test performed on an individual patient’s breast cancer that not only estimates prognosis but specifically guides the use of chemotherapy in addition to hormone therapy. This can sometimes mean that we recommend chemotherapy in situations where we previously did not, but more often it allows us to avoid chemotherapy where it will not be useful. As a consequence, our use of chemotherapy is diminishing somewhat but when we use it the impact is greater.

Rates of obesity are now projected to reach 65% of the U.S. population by 2030 and this is now identified as possibly responsible for up to 20% of the common cancers of adulthood. Caloric restriction and exercise are the two obvious steps that most adult women can take to lower their risks. In addition, there are two FDA-approved drugs (tamoxifen and raloxifene) that are known to reduce the risks of the most common kinds of breast cancer. These drugs have the “side effect” of treating or preventing osteoporosis and their use should be discussed with your physician.