Many of you know that there are at least six different types of breast cancer, depending on whether the cancer is sensitive to estrogen and progesterone or whether it overexpresses HER2/neu. What's so promising is that we're beginning to understand that each type of breast cancer behaves differently and responds differently to the available therapies. In fact, we can now test certain ER-positive tumors, for example, to see if they are sensitive to hormones but not chemotherapy or if they are sensitive to chemotherapy but not hormone therapy. This type of test and targeted treatment can save women from unhelpful and potentially toxic therapies. 

One category of breast cancer, however, has been identified merely by the fact that it does not have a targeted therapy. This type is called 'triple negative' breast cancer (in other words, breast cancer that is estrogen receptor negative, progesterone receptor negative, and HER2/neu negative). When women are diagnosed with this kind of breast cancer they are made to feel like it's a terrible type and they're doomed. Yet, at the American Association of Cancer Researchers meeting in Denver, we had a whole session on this type of tumor that was really exciting.

First of all, Dan Hayes, clinical director of the breast oncology program at the University of Michigan Comprehensive Cancer Center, pointed out that just because we don't have a targeted therapy for triple negative breast cancer does not mean we do not have a good treatment. These tumors actually respond the best to chemotherapy and women so treated often do very well. In addition, it turns out that there are subcategories within the triple negative group, including basal-like tumors (more common in BRCA1/2 carriers, as well as African-Americans), claudin-low tumors (rare metaplastic breast cancer), and others. 

The most exciting news was that there are several treatments currently being studied that are specific to triple negatives, at least for the basal-like tumors. Some old drugs like Cisplatin may work in this subgroup, where they were not as good for breast cancer patients as a whole. Others are being newly developed, including PARP-2 inhibitors, which are given as a pill. In early studies, PARP-2 inhibitors are showing real promise in women with BRCA1/2 with either breast or ovarian cancer. 

Finally, in a separate session, my friend Thea Tlsty, professor of pathology at the University of California, San Francisco presented her data suggesting she may soon be able to determine which ductal carcinoma in situ (DCIS) has the potential to develop into these basal-like cancers. She also has data to suggest that Cox-2 inhibitors (aspirin, NSAIDs, and Celebrex) might have potential in preventing this from happening. So stay tuned as we work to figure out how best to test these findings with the Army of Women.

To those women who have panicked with a triple negative diagnosis, I say, 'Help is on the way!'