ASCO Data Show Serum DNA Blood Tests Detect Cancers With High Sensitivity And Specificity
Growing body of data suggests Chronix’s serum DNA assays may represent a new approach to diagnostics and prognostics in cancer and other diseases
Chronix Biomedical today reported new data further demonstrating that its serum DNA blood tests have the potential to accurately detect early stage breast cancer and prostate cancer. Chronix’s proprietary technology identifies disease-specific genetic fingerprints based on circulating DNA fragments that are released into the bloodstream by damaged and dying (apoptotic) cells. In this new study of 575 individuals, Chronix’s proprietary assays detected and identified DNA fingerprints in the blood that indicated the presence of prostate cancer and breast cancer with 92% sensitivity and 100% specificity, significantly outperforming the published accuracy data for current diagnostic methods. The new study results were presented in an oral session today at the 2010 ASCO Annual Meeting in Chicago.
Breast cancer expert, Steven Narod, M.D., F.R.C.P.C., noted, “These new data, although early, provide further evidence that Chronix’s proprietary serum DNA assays may represent a new diagnostic and prognostic platform that can identify cancer earlier and more accurately than is currently possible. I am pleased to be working with Chronix to further validate these promising findings.” Dr. Narod is Director of the Familial Breast Cancer Research Unit at Women’s College Research Institute, an affiliate of the University of Toronto.
The tests use proprietary algorithms developed by Chronix researchers to detect, analyze and identify cancer-related fragments of circulating DNA that are released into the bloodstream by apoptotic cells. Chronix researchers consistently find that this apoptotic DNA in the serum is coming from a limited number of regions or “hotspots” on the genome specific to each cancer. According to the data presented today, DNA fragments from any one of the 29 breast cancer “hotspots” and 32 prostate cancer “hotspots” identified by Chronix researchers indicate that cancer is present.
“By focusing on these blood-borne genomic ‘hotspots,’ we can reliably detect the presence of cancer without having to first isolate or analyze the tumor cells,” said Howard Urnovitz, Ph.D., Chief Executive Officer of Chronix and a co-author of the study. “If verified by further studies, our Chronix blood-based assays would make it possible to diagnose cancer at its earliest stages, track progress as patients undergo treatment and possibly even optimize treatment using patients’ disease-specific genomic fingerprints.”
The testing involved 575 individuals: 178 with early stage breast cancer, 197 with invasive prostate cancer and 200 healthy controls. The Chronix assays detected breast cancer with a 92% sensitivity and 100% specificity. Although not directly comparable, for reference it is noteworthy that data from a large study of U.S. mammography screening programs reported an overall sensitivity of just 75%, and specificity of 92.3%, with lower figures for some populations such as younger women. The Chronix assays also detected invasive prostate cancer with a 92% sensitivity and 100% specificity. In contrast, the widely used PSA (prostate specific antigen) test has previously demonstrated 85% sensitivity and a specificity of just 25% to 35%. If the Chronix data are confirmed in larger studies, they have the potential to reduce the current rate of false positive and false negative results that contribute to poorer patient outcomes and higher health care costs.
Previous published studies have demonstrated that the Chronix approach can identify the presence or absence of active disease in multiple sclerosis patients and that it can accurately detect early stage breast cancer with high diagnostic sensitivity and specificity. Commercial applications for veterinary use are already in development in conjunction with the University of Calgary, including tests for the early detection of BSE, or mad cow disease.
Dr. Urnovitz added, “With these encouraging findings, we are launching a ‘For Investigative Use Only’ testing service that for the first time will enable cancer researchers to monitor the status of patients in their clinical trials with a high level of sensitivity and specificity, potentially accelerating clinical trials and increasing their chances for success.”
Patient data collected from this new service for clinical researchers along with additional planned clinical studies are expected to expand the database needed to obtain regulatory approval for the use of Chronix assays in ongoing cancer patient care.
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