National Breast Cancer Coalition

Truth #24


Women with breast cancer deserve evidence-based treatments that have been proven effective.

Evidence-based health care means using medical research--information about other patients that has been systematically collected and analyzed--to determine what is most likely to help an individual patient. Much of medical practice is handed down from generation to generation of clinicians, and is accepted as knowledge, but has not been shown to be both effective and safe by the most rigorous research. And because health care always comes with a possible mix of benefits and harms, it's important to understand what those benefits and risks are. The evidence of benefit and risk must be based on high-level studies upon which patients can rely. This nation has invested billions of dollars in research over the past decades in a search for answers in breast cancer. Those answers increase our knowledge, and that new knowledge often means the interventions or treatments we give women change.

One example that shows why evidence-based health care is so important was the introduction of high-dose chemotherapy with bone marrow or stem cell transplantation for the treatment of metastatic breast cancer in the mid-1980s and 1990s. Early research results from very small studies had indicated that patients with metastatic breast cancer who had undergone these treatments fared better than those given standard chemotherapy drugs. Eventually, even though there was no strong evidence it was effective, half the procedures were being performed in women with non-metastatic, but high-risk early breast cancer as well. More rigorous research studies later found that this new treatment was not more effective than the standard chemotherapy drugs, did not increase survival among women with metastatic or high-risk breast cancer, and in fact, had significant harms. Because the health care system (doctors, insurance companies, and patients) rushed to accept this new treatment without a strong evidence base to support its effectiveness and understand the risks, many women were harmed.