Oncotype DX is a “companion diagnostic” for women with early stage breast cancer who might be treated with hormone therapy after surgery.  It examines 16 cancer-related genes (and 5 for control) that result in a “Recurrence Score” which indicates the probability of the cancer returning-and so, the possible need of and benefit from chemotherapy.  It is an expensive test that, while not FDA approved, generally is insurance reimbursable.  Its sales in 2010 reached $170m and with a compound annual growth rate is projected to hit $300m by 2015.   A seemingly infinite number of molecular pathways, if they can be discovered, hold similar potential for a diagnostic “gold rush.”            MORE