>>LOS ANGELES, June 2 (Reuters) - By analyzing old tumor samples, scientists have developed tests that can detect gene patterns that show how a cancer patient will respond to a drug or whether their cancer is likely to recur, according to research presented at a key cancer meeting this week.
"People have been saying that we won't reap benefits from the genomics revolution for another five or 10 years, but in fact there is a lot of excitement about this," said Randy Scott, chief executive of Genomic Health Inc., which developed the experimental tumor tissue test.
The company uses high-throughput analysis of stored tumor biopsies dating back to the 1980's to determine the molecular signature of cancers for which the patient's history is already known, Scott said.
Researchers at Cedars-Sinai Medical Center in Los Angeles used the molecular test to identify a panel of genes that correlated with tumor response to Iressa, a drug sold by AstraZeneca Plc (London:AZN.L - News), that shrinks tumors in about 10 percent of patients with advanced lung cancer.
The early findings, presented at a meeting of the American Society of Clinical Oncology in Chicago, may lead to a new way of selecting patients who will benefit from specific therapies based on the genomics of their tumor.
Iressa is part of a new category of cancer drugs that target the molecular switches turned on in cancer. It is designed to inhibit the epidermal growth factor receptor (EGFR) -- a key growth signaling pathway in cancer.
"Having a test that indicates whether a patient will or won't respond to a given therapy ... will ultimately enable us to offer our patients the most appropriate treatment," Dr. Ronald Natale, acting medical director at Cedars-Sinai cancer center, said in a statement.
Out of 39 patient tumors analyzed with the molecular test, the investigators found that seven patients responded to treatment with Iressa, which directly correlated with a distinct pattern of genes. They also identified a pattern of genes that correlated with the 32 patients who did not respond to the drug.
"This method of examining genes provides us with a basic road map of the genes involved in the EGFR pathway, so that we can see which genes are in the 'on' position and which are in the 'off' position," said Dr. David Agus, research director at Cedars-Sinai's prostate cancer center.
The test is also being used to foresee which patients with breast cancer who go into remission are at risk of having the cancer return.
"Until now, the only indications we have had of long-term prognosis in breast cancer were tumor size and the number of involved nodes," said Dr. Melody Cobleigh, an oncologist at Rush-Presbyterian-St. Luke's Medical Center in Chicago. "This technology will allow us to tailor a prognosis to an individual patient, using a small panel of genes selected from thousands of genes."
Based on encouraging results in breast cancer recurrence trials, Genomic Health has begun three large-scale clinical trials and expects those results within the next 12 months, Scott said. The company also plans to conduct similar large-scale trials looking at response to chemotherapy and EGFR inhibitor therapy.
Cheers, Tuck |
