How a new breast cancer test that makes individual treatment decisions a reality

Widely hailed as the next frontier in medical advancement, the promise of personalized medicine is becoming a reality thanks to advances in understanding the molecular basis of diseases such as breast cancer. Scientists can now develop treatments that are tailored to individual genetic profiles, as well as tests that predict how a patient will respond to existing therapies. Today, some women with early-stage breast cancer and their doctors can make more informed treatment decisions with the Oncotype DX Breast Cancer Assay. The service provides quantitative gene information from a woman's individual tumor to generate a recurrence score between zero and 100 that indicates whether she has a high, moderate or low risk of the cancer returning after treatment. Oncotype DX is indicated for patients with node-negative, estrogen receptor-positive breast cancer who are likely to be treated with hormone therapy. About half of the 230,000 patients diagnosed with breast cancer in the United States each year fall into this category and are often offered chemotherapy, a widely used treatment with significant side effects. Clinical trials show that chemotherapy improves patient survival rates in only 4 out of 100 patients, yet thousands of women continue to choose this expensive and toxic treatment with only limited information about whether they might respond to it. A recent study showed that women with high recurrence scores were more likely to benefit from chemotherapy, while women with lower scores received only minimal benefit. Furthermore, only 25% of women were in the high-risk group compared to 50% in the low-risk group, suggesting that this common treatment is not suitable for every patient. Elizabeth Sloan of New York is one of many breast cancer patients who are unlikely to respond to chemotherapy. Elizabeth, an active mother of two young boys, was considering having another child when she was diagnosed at just 40 years old. She wanted to avoid chemotherapy with its disruptive, short-term side effects and potentially serious long-term consequences, but she also wanted to be absolutely sure it wouldn't help her. Working with her physician, Ruth Oratz, M.D., of NYU Medical Center, Elizabeth opted for the Oncotype DX test and was pleased to find that her recurrence score was low, indicating that she might not benefit significantly from chemotherapy. “No two women with breast cancer are the same. Oncotype DX provides information that goes beyond standard measures such as age, tumor size and tumor grade in determining the likelihood of disease recurrence,” says Dr. Oratz. “Oncotype DX has given Elizabeth and me more confidence and peace of mind in choosing the most appropriate treatment for her. For Susan Bakken of Denver, Colorado, Oncotype DX provided a different kind of peace of mind. Susan's recurrence score indicated that she was at high risk for cancer recurrence and would likely benefit significantly from chemotherapy—to her and her doctor's surprise. “Based on the other tests I had, my doctor said he wouldn't recommend chemotherapy otherwise. I was shocked when I found out my result, but I'm so glad I did it because I believe this test basically saved my life,” explained Susan. Elizabeth Sloan is also grateful for the information she received from Oncotype DX. "Not all cancers are the same, so why treat them all the same with something so toxic?" she said. "It's so remarkable that doctors can finally distinguish one person's cancer from another - I'm grateful." Oncotype DX is a simple test that can only be ordered by a doctor. It is performed on a small amount of breast tumor tissue taken during a standard lumpectomy, mastectomy or biopsy, meaning no further procedure is required.