Gene Test May Improve BC Treatment

tousled1 · 09-07-2006, 05:37 AM

Gene Test May Improve Breast Cancer Treatment
70-gene 'signature' gives more accurate prognosis, study finds

WEDNESDAY, Sept. 6 (HealthDay News) -- A test that checks the expression of 70 genes associated with breast cancer can help doctors determine a patient's risk of cancer recurrence or death, an international study finds.

The study included 307 breast cancer patients assigned to high- and low-risk groups based on their scores from the 70-gene signature test and standard risk-assessment using a software program. The patients were followed for 13.6 years.

The gene-signature test was a more accurate predictor of cancer recurrence and death than the software, the researchers found. The study also concluded that the gene test included most of the prognostic information provided by traditional risk classifiers.

"These results indicate that the gene signature adds independent prognostic information," reported scientists at the Netherlands Cancer Institute in Amsterdam.

The findings were published in the Sept. 6 issue of the Journal of the National Cancer Institute.

The 70-gene signature test will be evaluated in a larger study of 6,000 women with node-negative early-stage breast cancer. The trial will assess whether the test can improve identification of women who can safely be spared adjuvant chemotherapy.

gdpawel · 09-07-2006, 04:55 PM

The genetic analysis of MammaPrint predicts which women will have a greater chance of breast cancer recurrence. The test looks at the expression of 70 genes linked to breast cancer with an accuracy level of 96.7% as determined by a study published in the New England Journal of Medicine. 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