Setting an Example
Genomic Health’s Oncotype DX® breast cancer assay is a prime example of a clinically relevant biomarker-based molecular diagnostic test. The 21-gene quantitative real-time PCR (RT-qPCR) assay produces a Recurrence Score® (RS) that guides patients and clinicians in the decision of whether to pursue treatment with adjuvant chemotherapy.
While many women with breast cancer will be offered chemotherapy, only a select group of estrogen receptor-positive (ER+), node-negative patients are likely to benefit from this toxic and debilitating therapy. As a result, some women who might benefit are undertreated, while many are overtreated.
Steve Shak, M.D., CMO at Genomic Health, reported that utilization of Oncotype DX is increasing, with more than 85,000 tests delivered since its launch in 2004, and the test is now reimbursed by Medicare and all major insurance payers. Dr. Shak emphasized the need for standardization in the molecular diagnostics arena, particularly in technology implementation, and the importance of quality control to ensure consistent and reliable results with biomarker-based diagnostics.
In a presentation entitled, “The BCR-ABL qRT-PCR Assay: Status of a Molecular Diagnostic that Is a Current Standard of Care,” J. Milburn Jessup, M.D., chief of the diagnostics evaluation branch, cancer diagnosis program at the National Cancer Institute, described how a qPCR assay to detect the BCR-ABL fusion gene—the cause of chronic myelogenous leukemia (CML), which accounts for 20% of leukemias—became the basis for a personalized medicine treatment paradigm with the drug imatinib (Gleevec), a targeted therapy that can reduce BCR-ABL by 3 logs from baseline and yield durable remissions.