BETHESDA, Md. -- The Evaluation of Genomic Applications in Practice and Prevention group will release three new sets of recommendations later this year about gene expression profiling in breast cancer, genetic testing for lynch syndrome in colorectal cancer patients, and testing for UGT1A1 in colorectal cancer patients treated with irinotecan.
These three evaluations are currently in draft form, according to Alfred Berg, chair of the EGAPP Working Group, who spoke here yesterday at a conference sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases.
Of the three forthcoming recommendations, the one investigating gene expression profiling in breast cancer is the furthest along. "We found limited evidence of analytic validity, limited evidence of clinical validity. Of course no direct evidence, meaning controlled trials testing clinical outcomes or clinical utility. There are mixed estimates of cost-effectiveness," said Berg, who also chairs the University of Washington's Department of Family Medicine.
"Having said that, though, there is a very plausible positive balance with potential benefits versus potential harms," he added.
The recommendations for gene expression profiling in breast cancer will be released for peer review soon. The reports about genetic testing for lynch syndrome in colorectal cancer patients and testing for UGT1A1 in colorectal cancer patients treated with irinotecan are in earlier draft stages.
EGAPP's recommendations are part of a pilot project developed in 2004 by the National Office of Public Health Genomics at the Centers for Disease Control and Prevention. The project aims to evaluate genetic tests and other genomic applications currently in transition from research to clinical use.
As reported by GenomeWeb Daily News sister publication Pharmacogenomics Reporter, in January, EGAPP released its evaluation of cytochrome P450 testing with Roche's AmpliChip or other platforms to help doctors treating depression patients who are taking selective serotonin reuptake inhibitors.
Finding insufficient evidence to support routine CYP450 testing for SSRI-treated patients, EGAPP discouraged patients from beginning SSRI treatment based on such assays until the completion of further studies to confirm their clinical utility and validity. "In the absence of data that testing influences treatment or outcomes, there is a risk that the CYP450 test could increase costs without helping patients," the group found.
Prior to its assessment of SSRI genetic testing, AHRQ released its report on ovarian cancer detection and management, in which it evaluated tests for single gene products, genetic variations affecting risk of ovarian cancer, gene expression, and proteomics for CA-125 and BRCA1/2.
Although AHRQ found no evidence suggesting that genomic tests for ovarian cancer have adverse effects beyond those common to other ovarian cancer tests, which primarily include the risks of diagnosis for false-positive results and the risks of delayed or inappropriate treatment of false-negative results, "model simulations suggest that annual screening, even with a highly sensitive test, will not reduce ovarian cancer mortality by more than 50 percent."
According to Berg, the majority of the genomic technologies evaluated by EGAPP have been found lacking in evidence to support their clinical utility and validity. With these three recommendations, EGAPP will outline its investigational methodology, particularly its system for determining the clinical outcomes of these assays, "in great detail," he added.
More detailed coverage of this issue will provided in the upcoming issue of Pharmacogenomics Reporter.