The genetic analysis of Oncotype DX predicts which women will have a greater chance of breast cancer recurrence. The test looks at 21 genes that influence the behavior of breast cancer cells. Until this test, it had been difficult to pinpoint which women would benefit most from chemotherapy, and those which wouldn’t.
This new gene expression profiling test enables the oncologist and breast cancer surgeon to more accurately determine who should be treated and who should not be treated with chemotherapy, but they cannot predict chemo response.
This laboratory test is a tool for the oncologist. The oncologist should take advantage of all the tools available to him/her to treat a patient. And since studies show that only 25-30% of patients do respond to chemotherapy that is available to them (and even less for "targeted" drugs), there should be due consideration to looking at the advantage of molecular and cellular assay tests to the resistance that has been found to chemotherapy drugs.
This test can enhance the ability to distinguish between "low" risk and "high" risk patients. Patients in the high-risk group, who would benefit from chemotherapy can then be pre-tested with a "functional" bio-marker (a cell-based assay using an EGFRx™ Anti-Tyrosine Kinase Profile) to see what treatments have the best opportunity of being successful, and offers a better chance of tumor response resulting in progression-free survival, while those in the lower-risk groups can be spared the unnecessary toxicity, particularly associated with ineffective treatment.
New anti-cancer drugs selectively "targets" cells within the body that have a specific molecular defect that is believed to cause dangerous cell behaviors such as uncontrolled proliferative growth and high metastatic potential, behaviors that are associated with aggressive cancer. The defect occurs within the interior of the cell in a region that is called the tyrosine kinase domain and it involves a complicated chemical process called EGFR signaling.
The drugs are called anti-EGFR drugs or tyrosine kinase inhibitors. When the drugs work, they can be highly beneficial, causing tumor shrinkage or promoting stable disease and extending survival. However, targeted therapy drugs like tyrosine kinase inhibitors only work for a small percentage of the patients who receive them. Further, the drugs are expensive and have been associated with toxic side effects. No molecular (gene-based) test has been proven to tell reliably who will benefit from anti-EGFR treatment.
The EGFRx™ Anti-Tyrosine Kinase Profile assay can prospectively report to a physician specifically which chemotherapy agent would benefit a high risk cancer patient by testing that patient's "live" cancer cells. Drug sensitivity profiles differ significantly among cancer patients even when diagnosed with the same cancer. Knowing the drug sensitivity profile of a specific cancer patient allows the treating oncologists to prescribe chemotherapy that will be the most effective against the tumor cells of that patient.
Every breast cancer patient should have her own unique chemotherapy trial based on consultation of pathogenic profiles and drug sensitivity testing data. Research and application of these tests are being encouraged by growing patient demands, scientific advances and medical ethics. These tests are not a luxury but an absolute necessity, and a powerful strategy that cannot be overlooked.
These new genetic and cellular-based tests have enormous implications for the short-term future of cancer research in general, and is one of the truly great cancer breakthroughs of our time.
http://weisenthalcancer.com/Patient%...RXPatients.htm
http://cancerfocus.org/forum/showthread.php?t=734