As I discussed in yesterday’s blog, not all women benefit from chemotherapy; tests like the Oncotype DX can be helpful, but may not be widely available across the country. In the meantime, here is the simple guide to the chemotherapy menu for those women who we know will likely benefit from chemotherapy.
1. Women whose breast cancers express the growth factor, Her 2: by and large, these women benefit from targeted therapy with Herceptin, a drug that blocks the Her 2 receptor. These women also benefit from chemotherapy, of the standard variety – which usually includes a taxane and anthracycline, but not always.
2. Women whose breast cancers express an estrogen receptor but not Her 2: these represent the majority of breast cancers in America. These women benefit from targeted hormonal therapy, like tamoxifen or aromatase inhibitors (Arimidex), that block the receptor and prevent the cancer cell from growing. Some of these women, especially those with large tumors or positive lymph nodes, will also benefit from standard varieties of chemotherapy – but the largest survival benefit comes from anti-hormonal therapy, and this is why yesterday’s blog discussed Oncotype DX and its use in distinguishing which of these patients will derive additional benefit from standard chemotherapy.
3. Women whose breast cancers express none of the receptors that are normally tested for; these women’s breast cancers are estrogen receptor negative, progesterone receptor negative and Her 2 negative. These are called “triple negative” cancers. These women benefit from chemotherapy only. However, researchers are hard at work looking at some of the other genes that are found in triple negative breast cancers so that targeted therapies for these tumors can be developed.
There is no crystal clear roadmap through the chemotherapy menu, but the three broad categories, and their specific treatments, are the generally accepted guide for medical oncologists who are treating women with breast cancer today.
Reference
Winer EP, The Evolving Role of Adjuvant Chemotherapy, Cancer Res 2009;(Suppl):(24) December 15, 2009, 484s