Gene Assays
Assays (tests) can help doctors learn more about your cancer in order to better tailor treatment to you. Several of these tests are being developed. The two below are in clinical trials today.
Oncotype DX
Research shows that the Oncotype DX™ 21-gene assay is effective in predicting the likelihood of disease recurrence within ten years and the magnitude of chemotherapy response in patients with node-negative, estrogen-receptor-positive, early-stage (I or II) breast cancer.
In the chemotherapy benefit study conducted by the National Surgical Adjuvant Breast and Bowel Project B-20, patients with a high risk of breast cancer recurrence, as determined by the Oncotype DX™ assay, derived a large benefit from chemotherapy. Those with a low risk of recurrence derived only a small (if any) benefit from chemotherapy. Those at high risk represented about 25% of patients with node-negative, estrogen-receptor-positive, early-stage breast cancer. Those at low risk represented about 50% of such patients.
The Oncotype DX test is included in the National Comprehensive Cancer Network (NCCN) Breast Cancer Treatment Guidelines, which outlines for physicians recommended methods of treatment and care.
MammaPrint
The MammaPrint® test measures the level of activity of 70 genes in a sample of surgically-removed breast cancer tissue. It produces a score that determines whether the patient is at low risk or high risk for spread of the cancer within the next five to ten years. Patients whose tissues are eligible for MammaPrint®
analysis must be younger than 61 years of age, have stage I or II invasive breast cancer that is estrogen-receptor positive or estrogen-receptor negative, and have negative lymph nodes.
MammaPrint® is performed on fresh tissue rather than formalin-fixed, paraffin-embedded tissue as is Oncotype DX.
