Impact of Gene Expression Profiling Tests on Breast Cancer Outcomes

Book excerpt: Assesses the evidence that three marketed gene expression-based assays improve prognostic accuracy, treatment choice, and health outcomes in women diagnosed with early stage breast cancer. Three gene expression assays were evaluated; Oncotype DX¿, MammaPrint® and the Breast Cancer Profiling (BCP or H/I ratio) test, and for gene expression signatures underlying the assays. They sought evidence on: analytic performance of tests; clinical validity; clinical utility; harms; and impact on clinical decision making and health care costs. Conclusions: Oncotype DX is furthest along the validation pathway, with retrospective evidence that it predicts distant spread and chemotherapy benefit to a clinically relevant extent over standard predictors. Illus.