As weâ€™ve learned more about breast cancer, weâ€™ve learned that not all breast cancers are the same. We are now aware that there are at least six types of breast cancer that we can differentiate based on whether the tumor is sensitive to estrogen and progesterone and whether it overexpresses Her2neu.
We also have begun to figure out that these different tumor types not only behave differently but that they respond differently to different therapies. In fact, we now have a test that we can offer to women who have ER-positive breast cancer to see whether their tumor is sensitive to hormone therapy but not chemotherapy or sensitive to chemotherapy and not hormone therapy. Using this test allows us to save women from unhelpful and potentially toxic treatments.
One of these categoriesâ€“triple negative breast cancer (estrogen receptor negative, progesterone receptor negative, and HER2- negative)â€”is distinguished merely by the fact that it does not have a targeted therapy (hormone therapy or Herceptin).
When women are diagnosed with this kind of breast cancer and learn the have no â€œtargeted therapyâ€ option, they often feel like they have worse diagnosis than others, and that they are doomed. At the American Association for Cancer Research meeting in Denver we had a whole session on this type of tumor that was really exciting and that reminded us that we have not done a great job of explaining to women what it means that they have a triple-negative tumor.
The first speaker, Dr. Dan Hayes, who is co-director of the Breast Care Center at the University of Michigan Health System, pointed out that just because we donâ€™t have a targeted therapy for triple-negative tumors does not mean we do not have a good treatment. It is these tumors that actually respond the best to chemotherapy, and women who receive chemotherapy 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 women who have a BRCA1 or BRCA1 mutation or who are African American), claudin low tumors (a rare, metaplastic breast cancer) and others.
We also learned that there are several treatments currently being studied that specifically target basal-like tumorsâ€”which is really exciting news! Some older drugs, like cisplatin, that we stopped using as often in women with breast cancer because they werenâ€™t as effective as newer drugs, may actually work really, really well in this subgroup. And there is a new family of drugs now in development, called Parp 2 inhibitors, which are given as a pill and, in early studies, show real promise in women who have breast or ovarian cancer and who have a BRCA 1 or BRCA2 mutation.
In a separate session, my friend Dr. Thea Tlsty, a pathologist at the University of California, San Francisco, presented data from her research that suggests that she may soon be able to determine which 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 be able to prevent this from happening! Stay tuned as we work to figure out how best to test these findings with the Army of Women.
So, if you have a triple negative diagnosis, donâ€™t panic. Help is on the way!