18 January 2008
The US Agency for Healthcare Research and Quality (AHRQ) has released a new report sponsored by the Center for Disease Control (CDC) on the use of gene expression profiling of breast tumour samples as a guide to prognosis and treatment. The report, Impact of Gene Expression Profiling Tests on Breast Cancer Outcomes, looked at three commercially available gene expression assays in order to determine whether there was sufficient evidence to support their claims of improved prognostic accuracy, treatment choice and health outcomes in women with early-stage breast cancer.
The assays examined were Genomics Health’s Oncotype DX™, Agendia’s MammaPrint® and AviaraDX’s H/I™ test, and they were assessed for their analytic and clinical validity, clinical utility and impact on healthcare (including costs), and any associated harms. Relatively little evidence was identified for any of the assays, but the authors of the report found that the Oncotype DX did enhance standard prognostic indices “in a clinically meaningful manner” but evidence of clinical utility was not found for the other two tests. Assessments of the cost-effectiveness of the assays were inconclusive.
Overall, the conclusion was that further study was required to provide reliable evidence on the use of all three forms of test, although the Oncotype DX was “furthest along the validation pathway”. Of note, Food and Drugs Agency (FDA) guidance on applications for In Vitro Diagnostic Multivariate Index Asseys (IVDMIAs) such as the gene expression profiling kits requires evidence of analytical and clinical validity for the test (see previous news), but not of clinical utility.