Vast Study Pinpoints 4 Types of Breast Cancer

A sweeping, 348-author study has made giant leaps in scientists' understanding of breast cancer, with genetic analysis dividing the disease into four different types that call for different treatments. While it could take years, and perhaps dozens of clinical trials, before these therapies hit the mainstream, "this is the road map for how we might cure breast cancer in the future," one of the researchers tells the New York Times. In studying tumors in 825 patients, scientists made some significant findings.

One of the four types, known as basal-like cancer, actually looks less like other breast cancers and more like ovarian cancer—and routine ovarian cancer treatments might be the way forward. The majority of breast cancer cases fall into categories dubbed luminal A and luminal B. Those with luminal A respond well to hormonal treatments, while those with the latter type may need chemotherapy. Finally, there's HER-2 enriched breast cancer, which involves an extra gene copy and generally calls for a drug called Herceptin. But some patients with this type of cancer don't necessarily take well to Herceptin, calling for more clinical trials. Despite the long road ahead, "we are really getting at the roots of these cancers," says the study's lead author. The full study, published by Nature, is here. (More breast cancer stories.)